Implant placement in the esthetic area: criteria for positioning single and multiple implants

Accuracy of Anterior Immediate Versus Delayed Implant Placement With an Autonomous Robotic System: A Retrospective Study

OBJECTIVE

This study aimed to compare the accuracy of an autonomous robotic system for anterior immediate and delayed implant placement.

METHODS

This retrospective study included patients who underwent anterior dental implant surgery from September 2022 to March 2025 using an autonomous robotic system. Osteotomies performed with the autonomous robotic system in this study were modified by using precision and side-cutting drills, along with repeated lifting of drills to minimize deviations. Linear and angular deviations in two- and three-dimensional space were assessed by matching preoperative planning with postoperative cone beam computed tomography. Postoperative pain and surgical satisfaction were recorded using a 100-mm visual analog scale. The Shapiro-Wilk test, Student's t-test, Mann-Whitney U-test, Pearson's Chi-Square test, and Fisher's exact test were used, and p < 0.05 was considered statistically significant.

RESULTS

This retrospective study included 53 patients (65 implants) who underwent anterior dental implant surgery with the autonomous robotic system (immediate implant placement group: 19 patients, 21 implants; delayed implant placement group: 34 patients, 44 implants). Comparison of deviations in immediate and delayed implantation using the autonomous robotic system showed a mean (± SD) coronal deviation of 0.57 ± 0.19 mm versus 0.49 ± 0.20 mm (p = 0.129), a mean apical deviation of 0.57 ± 0.19 mm versus 0.52 ± 0.21 mm (p = 0.373), and a mean angular deviation of 0.53° ± 0.18° versus 0.61° ± 0.28° (p = 0.742). Postoperative pain and surgical satisfaction were not significantly different between the two groups (p > 0.05).

CONCLUSIONS

The autonomous robotic system demonstrated high and comparable accuracy in both anterior immediate and delayed implantation, with overall patient satisfaction. This could reduce the technical sensitivity of anterior immediate implant placement, enhance precision, and broaden the clinical applications of the autonomous robotic system.

Implant-Supported Cantilever Fixed Dental Prosthesis in the Anterior Region: Effect of Implant Type and Aging In Vitro

OBJECTIVES

To investigate if the fracture load of implant-supported cantilever fixed dental prostheses (ICFDPs) in the anterior region is affected by the implant type and the aging protocol.

MATERIALS AND METHODS

Sixty ICFDPs were prepared using multilayer monolithic zirconia for restoring bone-level (BL) and tissue-level (TL) titanium-zirconium implants. Fracture load was measured at baseline (no aging) or after aging in a chewing simulator loading the implant crown or the cantilever in a 30° angle (n = 10 per group). A two-way ANOVA was applied (α = 0.05) for the effects of implant type and aging protocol.

RESULTS

Implant type (p < 0.001) and aging (p < 0.001) had a significant effect on fracture load values. Baseline specimens of both BL (665 ± 62 N) and TL (554 ± 23 N) had significantly higher mean fracture load values than those of aged specimens(BL implant crown 545 ± 46 N, BL cantilever 563 ± 45 N, TL implant crown 455 ± 32 N, TL cantilever 476 ± 24 N) (p < 0.001). The loading position during aging did not affect fracture load values for BL (p = 0.980) nor TL (p = 0.749). BL implants failed by cement fracture and abutment deformation, while for TL the transmucosal part of the implant deformed.

CONCLUSIONS

The fracture load values of anterior ICFDPs decrease with aging in a chewing simulator. BL implants are preferable over TL implants for anterior ICFDPs as higher fracture load values were achieved, and no implant deformation occurred.

Evaluation of the Pink Esthetic Score for Single Implants in the Esthetic Zone Using Intraoral Scanning Data: A Proof-of-Concept Study

OBJECTIVES

To evaluate the feasibility of esthetic assessments based on intraoral scanning data using pink and white esthetic scores (PES/WES).

MATERIALS AND METHODS

Thirty samples with both intraoral photographs and scanning data were collected and rated by two observers with excellent consistency independently. PES includes seven variables, and WES includes five. The maximum scores were 14 and 10, respectively.

RESULTS

The mean PES/WES was 10.60 ± 1.69 and 8.50 ± 1.28 for photographs and 10.97 ± 1.69 and 8.40 ± 1.25 for scanning data. No significant difference was observed between the two sample types. The alveolar process variable had significantly higher scores, while the soft-tissue color variable had significantly lower scores based on intraoral photographs compared to scanning.

CONCLUSIONS

Intraoral scanning could be a method for the esthetic evaluation of single implant-supported restorations using PES/WES. The use of three-dimensional imaging enables the precise assessment of esthetic outcomes, paving the way for improvements in the digital workflow of implant dentistry. However, the limitations of color and texture reproducibility should be noted.

CLINICAL SIGNIFICANCE

Intraoral scanning data can be used for esthetic evaluation, and reliable results could be achieved with the application of scanning.

Retrospective study on the clinical and radiographic outcomes of 2.8 mm diameter implants supporting fixed prostheses up to 11 years

OBJECTIVES

This study aimed to report the clinical and radiographic results of 2.8 mm two-piece narrow diameter implant (NDI) supporting fixed restorations.

MATERIALS AND METHODS

Clinical and radiographic data of 54 NDIs in 32 patients were retrospectively assessed after 2 to 11 (mean 8.17) years of follow-up. Clinical and radiographic measurements were taken. Survival rate, implant and prosthesis failure, pink aesthetic scores (PES), white aesthetic scores (WES), bleeding on probing (BOP), probing depth (PD), marginal bone loss (MBL), and mechanical and biological complications were evaluated.

RESULTS

An implant failed during the follow-up period, resulting in a cumulative survival rate of 98.15% at the implant level and 96.88% in the patient. The total mean values of PES and WES for 2.8 mm NDIs were 7.09 ± 1.15 (range: 3.33-9.00) and 7.42 ± 1.03 (range: 3.67-9.33). The prevalence of sites with positive BOP was 38.14 ± 29.77%. The mean PD value was 2.46 ± 0.62 mm. The average MBL was 1.15 ± 0.74 mm (range: 0.25-4.03 mm). No implant or abutment fracture was detected. A veneer chipping was present in one patient, and a loose crown appeared in another patient. Two implants (3.7%) and two patients (6.3%) were diagnosed with peri-implantitis.

CONCLUSION

Within the limitation of the study, the results indicate that the use of two-piece 2.8 mm NDI for the fixed prosthetic rehabilitation of edentulous regions with reduced interdental and/or buccal-lingual width is viable.

Clinical and radiographic evaluation of implant-supported single-unit crowns with cantilever extensions: A systematic review and meta-analysis

PURPOSE

The purpose of this systematic review and meta-analysis was to analyze the clinical and radiographic outcomes of patients rehabilitated using a single implant supporting a crown with a cantilever extension or two implants supporting two single crowns.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 guidelines, a systematic review of relevant literature published from 2000 was conducted in the Cochrane Library, Scopus, and MEDLINE databases. Moreover, a manual search was performed. A meta-analysis of the resulting data was carried out. Peri-implant marginal bone level, probing pocket depth, prevalence of technical and mechanical complications, implant survival rate, and prosthesis survival rate were assessed.

RESULTS

The meta-analysis showed a non-statistically significant change in the peri-implant marginal bone level and probing pocket depth in the cantilever group and revealed a non-significant prevalence of technical complications, showing a 27% rate in the cantilever group. The analysis of the prosthesis survival rate in the cantilever group showed a mean survival rate of 99% while the comparison of the implant survival between the two groups revealed an odds ratio of 0.50.

CONCLUSIONS

The use of a single implant supporting a crown with a cantilever extension does not result in lower implant survival rate if compared with two implants supporting two single crowns. Moreover, a high prosthesis survival rate was observed in the cantilever group even if the high prevalence of complications should be carefully considered by the clinician.

Impact of labially inclined implant axes on immediate implant placement and provisionalization in anterior maxilla: A prospective cohort study

OBJECTIVES

To investigate whether a labially inclined implant axis compromises the clinical outcomes of immediate implant placement and provisionalization (IIPP) in the anterior maxilla.

MATERIALS AND METHODS

Patients with unsalvageable central or lateral maxillary incisors were enrolled. IIPP with simultaneous connective tissue graft (CTG) was performed in all participants. In the control group, the alveolar ridge had a long axis aligned with the tooth, which ensured that the immediate implant was aimed at the incisor edge or the cingulum of future restoration. The test group had a large angle between the axes of the ridge and tooth. To avoid bone fenestration, the implants were placed labially inclined and emerged from the labial side of future restoration. Intra-oral scanning and cone-beam computed tomography were performed to record soft and hard tissue profiles at baseline and 1 year later. Soft tissue stability, bone remodeling, and pink esthetic score (PES) were evaluated and compared between two groups.

RESULTS

Thirty-nine participants (19 tests and 20 controls) completed the study. At 1-year post-surgery, the mid-facial gingival margin migrations were 0.85 ± 0.37 mm (test) and 0.81 ± 0.33 mm (control), without significant differences. No differences were identified in buccal profile alteration, linear ridge reduction, buccal bone thickness, or PES scores. The test group demonstrated thinner buccal soft tissue at the crestal level than the control group.

CONCLUSIONS

When large tooth-ridge angulation presented, labially inclined implant, avoiding buccal ridge fenestration in IIPP with CTG, did not compromise the clinical outcome in short term.

Accuracy of robotic-assisted surgery for immediate implant placement in posterior teeth: a retrospective case series

BACKGROUND

Robotic computer-assisted implant surgery (r-CAIS) is a revolutionary innovation in oral implantation; however, the clinical feasibility of r-CAIS for immediate implant placement (IIP) in posterior teeth has not been verified. Thus, this study aimed to evaluate the accuracy of r-CAIS for IIP in posterior tooth regions.

METHODS

Patients with posterior teeth to be extracted and indicated to undergo r-CAIS were evaluated. The patients had positioning markers installed in the oral cavity and underwent cone-beam computed tomography (CBCT). Subsequently, minimally invasive tooth extractions were performed, and an individualised surgical plan was generated in the robotic software. After marker registration, implantation surgery was performed by the robotic arm under the supervision and assistance of the surgeons. Finally, the deviations between the planned and placed implants were evaluated based on preoperative and postoperative CBCT data.

RESULTS

A total of 12 patients were evaluated. No adverse events occurred during the surgery. The mean global coronal, global apical, and angular deviations were 0.46 ± 0.15 mm (95%CI:0.36 to 0.56 mm), 0.46 ± 0.14 mm (95%CI:0.37 to 0.54 mm), and 1.05 ± 0.55° (0.69 to 1.40°), respectively.

CONCLUSIONS

Under the limited conditions of this study, the r-CAIS exhibited high accuracy in posterior teeth IIP surgery. Further multicentre randomised controlled studies are required to confirm the feasibility of this technology.

Advancements in dental implantology: The alveolar ridge split technique for enhanced osseointegration

The alveolar ridge split (ARS) technique is a pivotal advancement in dental implantology, addressing the limitation of insufficient bone width for implant placement. This review traces the historical development of ARS from its initial conceptualization to current practices and future directions. Emphasizing the technique's development, indications, procedural overview, and osteotomy variations, we highlight its minimally invasive nature, which reduces patient morbidity and treatment time. This article reviews various osteotomy methods within ARS, examining their applications, benefits, and limitations. Furthermore, it discusses the technique's role in expanding treatment options for patients with compromised alveolar structures, underpinned by a high implant survival rate and the potential for immediate implant placement. We also cover the necessity of meticulous surgical technique, the importance of patient-specific factors, and the promising future of ARS facilitated by advancements in biomaterials and regenerative medicine. In summary, this review provides a comprehensive overview of ARS, offering valuable insights for dental professionals and informing future clinical practices and research in implantology.

Comparative Study between Two Adjacent Implants Supported Crowns and One Implant Supported Cantilever Fixed Dental Prosthesis: An In Vivo Study

AIM

To assess hard as well as soft peri-implant tissues within cases having two lost adjacent anterior teeth treated through placing either two implants with two separate crowns or only an implant along with a crown with a cantilever, and evaluating the effect of polyetheretherketone (PEEK) restoration on cantilever design up to 18 months after functional loading.

MATERIALS AND METHODS

Twenty-seven participants (15 males and 12 females; mean age, 38.6 years; range 20-50 years) with missing two adjacent anterior teeth were treated with implant system (Flotecno implant system, Italy). In the first group (implant-implant metal ceramic group), we treated nine participants utilizing two adjacent implants with two separate single metal ceramic crowns. In the second group (implant-cantilever metal ceramic group), we treated nine participants by placing single implant with cantilever metal ceramic fixed dental prosthesis (FDP). In the third group (implant-cantilever PEEK group), we treated nine cases utilizing single implant with a cantilever PEEK FDP framework. Clinical and radiographic examinations were recorded. Marginal bone level, implant stability, and prosthetic complications were assessed during an 18-month follow-up period.

RESULTS

Marginal bone loss (MBL) exhibited similar measurements among all groups. The clinical outcomes did not address significant variance among all groups as regards implant stability within the period of follow-up. We also observed minor prosthetic complications. Participants were very satisfied within all groups.

CONCLUSION

Based on the limitations of our research, utilizing cantilever extensions has no influence on MBL as well as implant stability.

CLINICAL SIGNIFICANCE

Mean marginal bone level exhibited a significant rise from baseline to 18 months for all groups, however, still within the clinically accepted range. Regarding implant stability, no significant variance was observed among all groups for 18 months. The cantilever FDP design facilitated prosthesis fabrication among those having laterals of narrow diameters. Further research is required to investigate such a particular concern due to a limited sample size in our research. How to cite this article: Hussain MR, Shrif MM, Othman HI, et al. Comparative Study between Two Adjacent Implants Supported Crowns and One Implant Supported Cantilever Fixed Dental Prosthesis: An In Vivo Study. J Contemp Dent Pract 2024;25(10):983-991.

Incidence of straight and angulated screw channel following immediate implant placement in esthetic zone: A simulated cone-beam computed tomography study

STATEMENT OF PROBLEM

The demand for immediate implant placement (IIP) in the esthetic zone is rapidly increasing. Despite the treatment's benefits, the sagittal root position often dictates implant angulation, commonly necessitating the use of cement-retained restorations. This study investigates the impact of angulated screw channel on IIP in the esthetic zone.

PURPOSE

The purpose of this cone-beam computed tomography (CBCT) study was to determine the probability of IIP in the esthetic zone, using four different implant angulations.

MATERIALS AND METHODS

A retrospective review of CBCT images was conducted and accessed on 9 June 2021. The midsagittal images of maxillary anterior teeth were input into an implant planning software (Implant Studio®). Bone Level X Straumann® implant (BLX 3.5, 3.75, 4.0, 4.5, 5.0 mm) and Bone Level Tapered implant (BLT 2.9, 3.3 mm) were selected for 3D implant planning of IIP in the esthetic zone. The frequency distribution and probability of IIP were recorded and compared among all maxillary anterior teeth.

RESULTS

CBCT images from 720 teeth (120 patient) were evaluated, revealing an overall probability of IIP in the esthetic zone is 76.11% (548/720). Different implant restoration type was evaluated in this study, with the following results; straight screw-retained prosthesis at 3.47% (19/548), cement-retained prosthesis at 14.59% (80/548) and angle screw-retained prosthesis at 85.40% (468/548).

CONCLUSION

IIP with traditional straight screw-retained prosthesis demonstrated the lowest probability. Nevertheless, the use of angulated screw channels enhances the probability of achieving straight screw-retained prostheses.

CLINICAL IMPLICATIONS

The angulated screw channel is essential for increasing the probability of screw-retained prosthesis in IIP in the esthetic zone. However, limitation in screw angle correction still necessitate the use of cement-retained prostheses for numbers of patients undergoing IIP.

Automatic planning of maxillary anterior dental implant based on prosthetically guided and pose evaluation indicator

PURPOSE

Preoperative planning of maxillary anterior dental implant is a prerequisite to ensuring that the implant achieves the proper three-dimensional (3D) pose, which is essential for its long-term stability. However, the current planning process is labor-intensive and subjective, relying heavily on the surgeon's experience. Consequently, this paper proposes an automatic method for computing the optimal pose of the dental implant.

METHODS

The method adopts the principle of prosthetically guided dental implant placement. Initially, the prosthesis coordinate system is established to determine the implant candidate orientations. Subsequently, virtual slices of the maxilla in the buccal-palatal direction are generated according to the prosthesis position. By extracting feature points from the virtual slices, the implant candidate starting points are acquired. Then, a candidate pose set is obtained by combining these candidate starting points and orientations. Finally, a pose evaluation indicator is introduced to determine the optimal implant pose from this set.

RESULTS

Twenty-two cases were utilized to validate the method. The results show that the method could determine an ideal pose for the dental implant, with the average minimum distance between the implant and the left tooth root, the right tooth root, the palatal side, and the buccal side being 2.57 ± 0.53 mm, 2.59 ± 0.65 mm, 0.74 ± 0.19 mm, 1.83 ± 0.16 mm, respectively. The planning time was less than 9 s.

CONCLUSION

Unlike manual planning, the proposed method can efficiently and accurately complete maxillary anterior dental implant planning, providing a theoretical analysis of the success rate of the implant. Thus, it has great potential for future clinical application.

Mechanical performance of patient-specific prefabricated temporary shell versus laboratory-fabricated CAD/CAM provisional implant-supported single-tooth restorations: A laboratory study

OBJECTIVE

To evaluate the mechanical performance of patient-specific prefabricated temporary shell versus laboratory-fabricated CAD/CAM provisional restorations on titanium temporary abutments, with and without thermo-mechanical ageing.

MATERIALS AND METHODS

Implants with a conical connection were divided into four groups (n = 24) and restored with temporary shell or laboratory-fabricated central or lateral incisor PMMA restorations that were relined or bonded on titanium temporary abutments. The diameter of the central and lateral incisor groups' implants was regular (ϕ 4.3 mm) or narrow (ϕ 3.5 mm), respectively. Half of each group's specimens were subjected to ageing, simultaneous thermocycling (5-55°C) and chewing simulation (120,000 cycles, 50 N, 1.7 Hz) resulting in eight groups in total (n = 12). The aged specimens were evaluated with optical microscopy, and survival and complication rates were determined according to modified USPHS criteria. The non-aged specimens and those that had survived ageing were loaded until failure, whereupon bending moments were calculated.

RESULTS

Survival rates after ageing were 100% for all groups. Apart from wear facets (ϕ 2-3 mm) on the palatal restoration surface, no complications were observed. The mean fracture load and bending moments ranged between 597.6-847.1 N and 433.3-550.6 Ncm, respectively, with no significant differences between the eight groups (p = .25; p = .20).

CONCLUSIONS

As patient-specific temporary shell central and lateral incisor provisional implant-supported restorations are mechanically stable enough to withstand clinical bite forces, even after thermo-mechanical ageing, they may serve as an alternative to laboratory-fabricated provisional restorations.

Clinical and radiographic outcomes of implant-supported fixed prostheses with cantilever extension in anterior mandible: A retrospective study

OBJECTIVES

The objective of this study is to analyze the clinical and radiographic outcomes of implant-supported fixed protheses with cantilever extensions (ISFPCs) in the partially edentulous anterior mandible.

MATERIALS AND METHODS

Patients who received anterior mandible implant restoration between January 2016 and December 2021 were included. Patients with two, three, or four continuous missing teeth receiving adjacent implant supported single-unit crowns (ISSCs), ISFPCs, implant-supported fixed protheses without cantilever extensions (ISFPNs) were divided into groups: ISSC+ISSC, ISFPC, ISSC+ISFPC, three-unit ISFPN, ISFPC+ISFPC, or four-unit ISFPN, respectively. We recorded and evaluated survival rates, mechanical and biological complications, peri-implant marginal bone loss (MBL), esthetic outcomes, and patient perceptions. Statistical analysis was performed using linear mixed models (LMM).

RESULTS

The study included 87 patients and 152 implants. No implant loss occurred during an average follow-up of 3.48 ± 1.85 years (range: 1-7 years). According to LMM models, prosthetic type had a statistically significant impact on MBL during follow-up periods, in favor of the ISFPC and ISFPC+ISFPC groups (0.16 ± 0.48 mm vs. 0.51 ± 0.49 mm, p = .034; 0.22 ± 0.49 mm vs. 0.60 ± 0.62 mm, p = .043, respectively). Mechanical and biological complications were relatively low and comparable. The four-unit ISFPC group had higher subjective esthetic scores compared with the ISSC+ISSC group (98.6 vs. 83.8, p < .05), and patients in the ISFPC+ISFPC group expressed greater satisfaction with cleanability than the ISFPN group (98.8 vs. 80.6).

CONCLUSION

ISFPCs offer a highly predictable treatment option in the anterior mandible, characterized by high survival rates, and comparable complication rates, peri-implant bone stability and esthetics to adjacent ISSCs or ISFPNs.

Inter- and intraindividual variability in virtual single-tooth implant positioning

OBJECTIVES

The purpose of this prospective study was to determine the inter- and intraindividual variability in virtual single-tooth implant positioning based on the level of expertise, specialty, total time spent, and the use of a prosthetic tooth setup.

MATERIALS AND METHODS

Virtual implant planning was performed on matched pre- and post-extraction intraoral scans (IOS), and cone-beam computed tomography scans of 15 patients. Twelve individual examiners, involving six novices and experts from oral surgery and prosthodontics positioned the implants, first based on anatomical landmarks utilizing only the post-extraction, and second with the use of the pre-extraction IOS as a setup. The time for implant positioning was recorded. After 1 month, all virtual plannings were performed again. The individual implant positions were superimposed to obtain 3D deviations using a software algorithm.

RESULTS

An interindividual variability with mean angular, crestal, and apical positional deviations of 3.8 ± 1.94°, 1.11 ± 0.55, and 1.54 ± 0.66 mm, respectively, was found. When assessing intraindividual variability, deviations of 3.28 ± 1.99°, 0.78 ± 0.46, and 1.12 ± 0.61 mm, respectively, were observed. Implants planned by experts exhibited statistically lower deviations compared to those planned by novices. Longer planning times resulted in lower deviations in the experts' group but not in the novices. Oral surgeons demonstrated lower crestal, but not angular and apical deviations than prosthodontists. The use of a setup only led to minor adjustments.

CONCLUSIONS

Substantial inter- and intraindividual variability exists during implant positioning utilizing specialized software planning. The level of expertise and the time invested influenced the deviations of the implant position during the planning sequence.

Accuracy analysis of robotic-assisted immediate implant placement: A retrospective case series

OBJECTIVES

This study aimed to investigate the accuracy of a robotic computer-assisted implant surgery (r-CAIS) for immediate implant placement.

METHODS

Patients requiring immediate implant placement in the maxillary anterior region were enrolled for r-CAIS. Before surgery, the patients underwent a cone beam computed tomography (CBCT) scan with a positioning marker. Virtual implant placement position and drilling sequences were planned. Following spatial registration and calibration, the implants were placed with the robotic system under supervision. A postoperative CBCT was taken to control the actual implant positions. The DICOM data of the virtually planned and the actually placed implant were superimposed and registered through the accuracy verification software of the robotic system. The accuracy was calculated automatically. The deviation at the mesial-distal, labial-palatal, and apico-coronal directions were recorded.

RESULTS

Fifteen patients with 20 implants were included. No adverse surgical events or postoperative complications were reported. The global platform, apex, and angular deviation were 0.75 ± 0.20 mm (95 % CI: 0.65 to 0.84 mm), 0.70 ± 0.27 mm (95 % CI: 0.57 to 0.82 mm), and 1.17 ± 0.73° (95 % CI: 0.83 to 1.51°), respectively. Moreover, the vertical platform and apex deviation were 0.50 ± 0.31 mm, (95 % CI: 0.35 to 0.64 mm) and 0.48 ± 0.32 mm, (95 % CI: 0.33 to 0.63 mm), respectively. All the placed implant positions were further labial and apical than the planned ones, respectively.

CONCLUSIONS

High accuracy of immediate implant placement was achieved with the robotic system.

CLINICAL SIGNIFICANCE

Our study provided evidence to support the potential of the robotic system in implant placement, even in challenging scenarios.

Failure Rate of Dental Implants in the Esthetic Zone: A Systematic Review and Meta-Analysis

The present systematic review and meta-analysis has systematically reviewed and analyzed dental implant failure for the implants placed in the esthetic zone. An electronic database search was performed in PubMed and ScienceDirect, including a manual search through the references using appropriate keywords and the PICO (population, intervention, control, and outcomes) format for the inclusion criteria. A total of 11 relevant articles were included. The quality of the randomized controlled trial (RCT) studies was assessed using the Cochrane Risk of Bias tool while the quality of non-randomized studies was assessed using the Newcastle Ottawa scale. Of the 11 articles included, 5 were RCTs, and 6 were non-randomized. The overall failure rate was found to be 2% (95% CI; 0.00-0.03%). The percentage marginal bone loss was estimated to be 1% (95% CI; 0.00 - 0.02%) and the mean and proportion pink esthetic scores were approximately 11.75 (0.43%) with 2% mid-facial soft tissue recession and the mesial and distal papillary recession was 0.02% and 0.01%, respectively. Based on this systematic review and meta-analysis, the rate of dental implant failure for implant placement in the esthetic zone was minimal. In addition, 1% proportional marginal bone loss and moderately high esthetic scores were found.

Accuracy of the novel digital non-cross-arch surgical guides with integration of tooth undercut retention and screw-bone support for implant placement in mandibular free-end

BACKGROUND

Large cross-arch free-end surgical guides can obscure the visual field, compromising surgical accuracy due to insufficient stability at the free-end. This in vitro study aims to evaluate the accuracy of novel digital non-cross-arch surgical guides designed for implant placement at the mandibular free-end, incorporating tooth undercut retention and screw-bone support.

MATERIALS AND METHODS

A mandibular dental model lacking left molars was utilized to fabricate unilateral (cross-arch) tooth-supported surgical guides (GT I, n = 20). Subsequently, two additional types of surgical guides were fabricated: GT II (covering two teeth, n = 20) and GT III (covering three teeth, n = 20). These novel surgical guides were designed to utilize the undercut of the supporting teeth for retention and enhance stability with screw-bone support at the guide's free-end. Furthermore, 60 identical guiding blocks were assembled on the three types of surgical guides to facilitate the implants' insertion. On a phantom head, 120 implant replicas were placed at the Federal Dentaire Internationale (FDI) teeth positions #36 and #37 on the dental model, employing a combination of surgical guides and guiding blocks. To assess accuracy, planned and placed implant positions were compared using intraoral optical scanning. Discrepancies in angulation and linear deviations, including the coronal/apical 3D deviations, lateral deviation as well as depth deviation, were measured. Statistical analysis was performed using two-way ANOVA and Bonferroni test (α = 0.05).

RESULTS

GT I exhibited significantly largest discrepancies, including angular and linear deviations at the crest and apex at every implant site. Especially in depth, at implant site #36, the mean deviation value of GT I (0.27 ± 0.13 mm) was twice as large as GT III (0.13 ± 0.07 mm), and almost twice as large as GT II (0.14 ± 0.08 mm). However, at implant site #37, this deviation increased to almost a five-fold relationship between GT I (0.63 ± 0.12 mm) and II (0.14 ± 0.09 mm), as well as between GT I and III (0.13 ± 0.09 mm). No significant discrepancies existed between the novel surgical guides at either implant site #36 or #37.

CONCLUSION

This study provides a practical protocol for enhancing accuracy of implant placement and reducing the size of free-end surgical guides used at mandibular molar sites.

Oral health-related quality of life in implant-supported rehabilitations: a prospective single-center observational cohort study

BACKGROUND

Oral Health-Related Quality of Life (OHRQoL) is a comprehensive concept covering daily comfort, self-esteem, and satisfaction with oral health, including functional, psychological, and social aspects, as well as pain experiences. Despite abundant research on OHRQoL related to oral diseases and hygiene, there is limited data on how patients perceive changes after implant-prosthetic rehabilitation. This study aimed to evaluate OHRQoL and aesthetic perception using OHIP-14 and VAS scales respectively, before (baseline-TB), during (provisional prostheses-TP), and after (definitive prostheses-TD) implant-prosthetic rehabilitation. It also explored the impact of biological sex, substitution numbers, and aesthetic interventions on OHRQoL and VAS scores, along with changes in OHIP-14 domains.

METHODS

A longitudinal prospective single-center observational cohort study was conducted with patients requiring implant-prosthetic rehabilitation. Quality of life relating to dental implants was assessed through the Italian version of Oral Health Impact Profile-14 (IOHIP-14), which has a summary score from 14 to 70. Patients' perceived aesthetic was analyzed through a VAS scale from 0 to 100. Generalized Linear Mixed Effect Models, Linear Mixed Effect Models, and Friedman test analyzed patient responses.

RESULTS

99 patients (35 males, 64 females) aged 61-74, receiving various prosthetic interventions, were enrolled. Both provisional and definitive prosthetic interventions significantly decreased the odds of a worse quality of life compared to baseline, with odds ratios of 0.04 and 0.01 respectively. VAS scores increased significantly after both interventions, with estimated increases of 30.44 and 51.97 points respectively. Patient-level variability was notable, with an Intraclass Correlation Coefficient (ICC) of 0.43. While biological sex, substitution numbers, and aesthetic interventions didn't significantly affect VAS scores, OHRQoL domains showed significant changes post-intervention.

CONCLUSIONS

These findings support the effectiveness of implant-prosthetic interventions in improving the quality of life and perceived aesthetics of patients undergoing oral rehabilitation. They have important implications for clinical practice, highlighting the importance of individualized treatment approaches to optimize patient outcomes and satisfaction in oral health care.

The Effect of Connective Tissue Graft Compared to Concentrated Growth Factor Graft on Buccal Peri-Implant Gingival Thickness: A 12-month Randomized Controlled Clinical Trial

BACKGROUND

Attached gingival phenotype has a crucial impact on the implant's durability and its future success.

PURPOSE

This study aims to measure and compare buccal peri-implant gingival thickness following grafting with connective tissue graft (CTG) and the concentrated growth factor (CGF) graft.

STUDY DESIGN, SETTING, SAMPLE

This is a split-mouth designed randomized controlled clinical study in which a total of 20 aged 18 to 55 have bilateral missing teeth in the maxillary premolar region with less than 2 mm of healthy peri-implant gingival thickness. Patients were excluded if they were smokers, had poor oral hygiene, had uncontrolled widespread periodontal disease, or had a history of radiation treatment. The same surgical protocol was followed for each study participant, where an independent blinded medical practitioner assigned the first stage side to be treated with CTG, while the second stage side with CGF 2 weeks later.

EXPOSURE VARIABLE

The primary exposure variable of this study was the gingival grafting technique; CTG or CGF.

OUTCOME VARIABLE

The primary outcome variable was the buccal peri-implant gingival thickness. Gingival thickness was measured at six different times; immediately before the procedure (T0), after 30 days (T1), after 45 days (T2), after 3 months (T3), after 6 months (T4), and after 12 months (T5).

COVARIATES

The covariates were age, sex general health, and periodontal status.

ANALYSIS

The statistical analysis; repeated measures analysis of variance test was used to compare the gingival thickness between the studied follow-up times within each group. The level of significance was set at ≤ 0.05.

RESULTS

The sample was composed of 40 treatment sites of 20 patients. The mean age of the sample was 32 years and 45% were male. The mean gingival thickness value of the CTG group was 1.62 mm with a (standard deviation = 0.18) compared to 1.28 mm for the CGF group with (standard deviation = 0.20) and an overall P value (0.001) at T5.

CONCLUSIONS AND RELEVANCE

CTG showed to have better gingival thickness than CGF in managing peri-implant buccal gingival thickness deficiency.

The three-dimensional stability and accuracy of 3D printing surgical templates: An In Vitro study

OBJECTIVE

To evaluate the three-dimensional (3D) stability and accuracy of additively manufactured surgical templates fabricated using two different 3D printers and materials.

MATERIALS AND METHODS

Forty surgical templates were designed and printed using two different 3D printers: the resin group (n = 20) used a digital light processing (DLP) 3D printer with photopolymer resin, and the metal group (n = 20) employed a selective laser melting (SLM) 3D printer with titanium alloy. All surgical templates were scanned immediately after production and re-digitalized after one month of storage. Similarly, the implant simulations were performed twice. Three-dimensional congruency between the original design and the manufactured surgical templates was quantified using the root mean square (RMS), and the definitive and planned implant positions were determined and compared.

RESULTS

At the postproduction stage, the metal templates exhibited higher accuracy than the resin templates (p < 0.001), and these differences persisted after one month of storage (p < 0.001). The resin templates demonstrated a significant decrease in three-dimensional stability after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). No significant differences in implant accuracy were found between the two groups. However, the resin templates showed a significant increase in apical and angular deviations after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05).

CONCLUSION

Printed metal templates showed higher fabrication accuracy than printed resin templates. The three-dimensional stability and implant accuracy of printed metal templates remained unaffected by one month of storage.

CLINICAL SIGNIFICANCE

With superior three-dimensional stability and acceptable implant accuracy, printed metal templates can be considered a viable alternative technique for guided surgery.

A biologically oriented preparation technique (BOPT) for immediate posterior implant placement, immediate provisionalization, and definitive implant crown fabrication: A complete digital workflow

OBJECTIVE

Immediate implants and immediate alveolar sealing have been a widely utilized treatment with high predictability and biological advantages. The improvement in technology has made it possible to simplify clinical processes. The aim of the present report was to describe the complete digital workflow of the Biologically oriented preparation technique for immediate posterior implant, immediate provisionalization and fabrication of definitive implant crowns.

CLINICAL CONSIDERATIONS

The surgical process and prosthetic management to preserve the gingival contours of the extracted natural tooth during immediate implant placement and provisionalization are described. Additionally, during the same clinical intervention, the definitive intraoral digital implant scans for capturing the implant position, peri-implant tissue contours, adjacent and antagonist dentition, and profile emergence of the interim implant crown are captured for the fabrication of the definitive crown.

CONCLUSIONS

Based on the technique described, the immediate implant placement and provisionalization in the posterior area provides biological and clinical advantages, reducing the number of abutment-implant disconnections and the number of clinical appointments, as well as increases patient comfort.

CLINICAL SIGNIFICANCE

The present article describes a technique for an immediate implant placement and provisionalization in the posterior region for maintaining the gingival architecture of the extracted tooth. During the same appointment, the implant position, peri-implant tissue contours, and adjacent and antagonist dentition, and profile emergence of the interim implant crown are captured by using an intraoral scanner and used for the fabrication of the definitive crown. This technique aims to reduce the number of abutment-implant disconnections and clinical appointments.

Accuracy and patient-centered results of marker-based and marker-free registrations for dynamic computer-assisted implant surgery: A randomized controlled trial

OBJECTIVES

To compare implant placement accuracy and patient-centered results between the dynamic computer-assisted implant surgeries (d-CAISs) using marker-based and marker-free registration methods.

MATERIALS AND METHODS

A double-armed, single-blinded randomized controlled trial was conducted, in which 34 patients requiring single implant placement at the esthetic zone were randomly assigned to the marker-based (n = 17) or marker-free (n = 17) groups. The marker-based registration was performed using a splint containing radiopaque markers, while the marker-free registration used natural teeth. The primary outcome assessed implant positioning accuracy via angular and linear deviations between preoperative and postoperative implant positions in CBCT. Patients were also surveyed about the intraoperative experience and oral health impact profile (OHIP).

RESULTS

The global linear deviations at the implant platform (0.82 ± 0.28 and 0.85 ± 0.41 mm) and apex (1.28 ± 0.34 and 0.85 (IQR: 0.64-1.50) mm) for the marker-based and marker-free groups respectively showed no significant difference. However, the angular deviation of the marker-free group (2.77 ± 0.92° ) was significantly lower than the marker-based group (4.28 ± 1.58° ). There was no significant difference in the mean postoperative OHIP scores between the two groups (p = .758), with scores of 2.74 ± 1.21 for marker-based and 2.93 ± 2.18 for marker-free groups, indicating mild oral health-related impairment in both. Notably, patients in the marker-free group showed significantly higher satisfaction (p = .031) with the treatment procedures.

CONCLUSIONS

D-CAIS with a marker-free registration method for single implantation in the anterior maxilla has advantages in improving implant placement accuracy and patients' satisfaction, without generating a significant increase in clinical time and expenses.

Comparison between platelet rich fibrin as space filling material versus xenograft and alloplastic bone grafting materials in immediate implant placement: a randomized clinical trial

BACKGROUND

This study aimed to compare the efficacy of different gap filling materials in immediate implant in anterior and premolar regions of maxilla.

MATERIALS AND METHODS

Thirty-six implants were inserted in patients seeking for replacement of non-restorable maxillary anterior and premolar teeth (esthetic zone) by immediate implant. Patients were randomly distributed into three equal groups, twelve implants in each group. Group 1 received Platelet Rich Fibrin (PRF) into the jumping distance, Group 2 received Xenograft into the jumping distance and Group 3 received Alloplastic bone grafting material into the jumping distance. Implant stability by measuring the changes in Resonance Frequency Analysis (RFA), peri-implant pocket depth, marginal bone loss and changes in buccal bone thickness were evaluated during follow up periods. All the clinical and radiographic data were subjected to statistical analysis by One Way ANOVA test and the Post Hoc Tukey test.

RESULTS

This study involved 19 female patients and 17 male patients who received 36 dental implants. There was no significant difference between the study groups regarding implant stability, peri-implant pocket depth and palatal bone loss, while there was a significant difference between PRF Group (Group 1) and the other Groups regarding buccal bone loss and changes in buccal bone thickness.

CONCLUSION

PRF can be used as a gap filling material in conjunction with immediate implant placement, but other bone grafting materials give superior result regarding buccal bone loss and changes in buccal bone thickness.

TRIAL REGISTRATION

The study was listed on www.

CLINICALTRIALS

gov with registration number (NCT05878392) on 26/05/2023. The Institutional Review Board (IRB) of the Faculty of Dentistry, Mansoura University, Mansoura, Egypt, approved the current study in compliance with the seventh revision of the Helsinki Declaration in 2013 (A0103023OS).

The natural CAD/CAM anterior implant single tooth restoration: A novel digital workflow

OBJECTIVE

To report a novel digital workflow to replace an anterior maxillary tooth lost due to trauma with an implant multilayer restoration by using the patient's extracted tooth as a final crown restoration using computer-aided design/computer-aided manufacturing (CAD/CAM) technology.

CLINICAL CONSIDERATIONS

Instead of using the patient's natural tooth as an immediate provisional restoration to achieve predictable results in terms of esthetics and soft tissue structure, a novel digital strategy was performed to obtain a natural final crown restoration by using the patient's tooth associated with a lithium disilicate customized implant abutment.

CONCLUSIONS

The perspective of using this strategic approach for implant restorative dental treatments in patients with traumatic root fractures in the anterior region has great potential as it helps to maintain the emergence profile of the natural dentition and esthetics.

CLINICAL SIGNIFICANCE

Optimal esthetic outcomes are challenging in implant dentistry regarding soft tissue structure and morphology factors. Using natural teeth from surgery to deliver the final restoration might be beneficial when an anterior tooth is lost due to trauma.

Multidisciplinary approach involving strategic implant placement before orthodontic (SIMBO) treatment for generalized stage IV grade C periodontitis: A case report with 10-year follow-up

OBJECTIVE

The aim of this case report was to demonstrate the long-term effects of a multidisciplinary approach involving periodontal reconstructive surgery and strategic implant placement before orthodontic (SIMBO) treatment in a patient with severe periodontitis (e.g., stage IV/grade C).

CLINICAL CONSIDERATIONS

The patient presented with severe periodontitis and pathologic tooth migration (PTM) without stable occlusion or occlusal support. After performing cause-related therapy, periodontal regenerative surgery, pre-orthodontic posterior implant placement, and orthodontic treatment involving anterior implant placement with papilla reconstruction, the patient achieved full-mouth rehabilitation and improvement of dental and smile esthetics. The clinical and radiographic results obtained were maintained over a 10-year period.

CONCLUSION

Within the limits of this as a single case, multidisciplinary treatment involving the SIMBO approach appeared to allow long-term improvement of periodontal condition, stability of the dental arches and occlusion, and esthetics in a patient with severe periodontitis, PTM and posterior bite collapse. Future studies with more subjects are needed to evaluate and validate this approach.

CLINICAL SIGNIFICANCE

When addressing periodontal disease, SIMBO approach-based multidisciplinary treatment appears safe and effective as a clinical protocol for establishing esthetic and functional rehabilitation in generalized stage IV/grade C periodontitis.

Clinical effect of Nobel Biocare angulated screw channel crown compared with cement crown in the aesthetic area: A retrospective cohort study with a mean 32 months follow-up (range 12 to 70 months)

OBJECTIVE

The objective of this study is to compare the clinical efficacy of angulated screw channel abutment applied in the anterior area with regular cemented crowns.

MATERIALS AND METHODS

Forty-eight patients were included and divided into two groups: the angulated screw channel group (ASC) and regular cemented group (RC) in this retrospective cohort study. The evaluation criteria included implant/restoration survival rate, keratinized mucosa width (KMW), bleeding on probing rate (BOP%), probing depth (PD), pink aesthetic score (PES), mechanical/biological complications, emergence angle (EA), the site of implant axis penetrate (SA), marginal bone loss (MBL), and buccal bone thickness (BBT) at 0 mm, 1 mm, 3 mm, 5 mm below the implant shoulder were evaluated in immediate postoperative (T0) and follow-up period (T1).

RESULTS

This retrospective cohort study included a total of 48 patients, with a mean 32 months follow-up period range from 12 months to 70 months. The study did not find any cases of implant failure or restoration failure. EA was significantly wider in the RC group than ASC group (RC: 33.53° ± 8.36° vs ASC: 27.43° ± 8.08°, p = 0.016*). While the BOP% was statistically significant higher in the RC group than ASC group (RC: 28.35% ± 22.92% vs ASC: 13.18% ± 20.00%, p = 0.027*). No significant differences were observed in the other measurements of comparison.

CONCLUSION

Within the limitations of the study, angulated screw channel (Nobel Biocare) crowns might allow the implant axis aim at incisal edge to reduce the emergence angle in the anterior area and benefit the soft-tissue during the 12-70 months follow-up period.

Surface demineralized freeze-dried bone allograft followed by reimplantation in a failed mandibular dental implant

The removal of a failed implant with high torque causes significant damage to the surrounding tissue, compromising bone regeneration and subsequent osseointegration in the defect area. Here, we report a case of carrier screw fracture followed by immediate implant removal, bone grafting and delayed reimplantation. A dental implant with a fractured central carrier screw was removed using the bur-forceps technique. The resulting three-wall bone defect was filled with granular surface demineralized freeze-dried bone allograft (SD-FDBA). Cone-beam computerized tomography was performed at 1 week, 6 months and 15 months postoperatively and standardized for quantitative evaluation. The alveolar bone width and height at 15 months post-surgery were about 91% of the original values, with a slightly lower bone density, calculated using the gray value ratio. The graft site was reopened and was found to be completely healed with dense and vascularized bone along with some residual bone graft. Reimplantation followed by restoration was performed 8 months later. The quality of regenerated bone following SD-FDBA grafting was adequate for osseointegration and long-term implant success. The excellent osteogenic properties of SD-FDBA are attributed to its human origin, cortical bone-like structure, partly demineralized surfaces and bone morphogenetic protein-2-containing nature. Further investigation with more cases and longer follow-up was required to confirm the final clinical effect.

Simultaneous or staged lateral ridge augmentation: A clinical guideline on the decision-making process

Lateral ridge augmentation is a standard surgical procedure that can be performed prior to (staged) or simultaneously with implant placement. The decision between a simultaneous or staged approach involves considering multiple variables. This paper proposed a decision-making process that serves as a guideline for choosing the best treatment choice based on the available evidence and the author's clinical experience.

Digital workflow for image-guided immediate implant placement by using the socket-shield technique and custom abutment in the esthetic area

Marginal bone loss around immediately placed implants may compromise esthetic outcomes in the anterior maxilla. The relatively recent socket-shield technique of partial extraction therapy has been described as being useful to maintain the structure of peri-implant tissues. The present technique report introduced a digital workflow to perform image-guided implant placement after partial extraction therapy. In this technique, digital 3-dimensional images are used to plan and orient the flapless surgical procedure and to digitally design a custom abutment based on the natural emergence profile as segmented from the tooth to be extracted.

Estimating the occurrence of labial bone perforation and implantation into the maxillary sinus maxillary premolars based on the morphology of maxillary premolars: A clinical study

STATEMENT OF PROBLEM

Previous studies have classified the sagittal root position of the maxillary anterior teeth and measured buccal plate thickness to aid treatment planning. A thin labial wall and buccal concavity may cause buccal perforation, dehiscence, or both in maxillary premolars. However, data on the restoration-driven principle to classify the maxillary premolar region are lacking.

PURPOSE

The purpose of this clinical study was to investigate the occurrence of labial bone perforation and implantation into the maxillary sinus between various tooth-alveolar classifications with respect to the crown axis in maxillary premolars.

MATERIAL AND METHODS

Cone beam computed tomography images of 399 participants (1596 teeth) were analyzed to determine the probability of labial bone perforation and implantation into the maxillary sinus when associated with variables that included tooth position and tooth-alveolar classification.

RESULTS

The morphology in the maxillary premolars was classified as straight, oblique, or boot-shaped. The first premolars were 62.3% straight, 37.0% oblique, and 0.8% boot-shaped, and labial bone perforation occurred in 4.2% (21 of 497) of the straight, 54.2% (160 of 295) of the oblique, and 83.3% (5 of 6) of the boot-shaped first premolars when the virtual implant was 3.5×10 mm. When the virtual tapered implant was 4.3×10 mm, labial bone perforation occurred in 8.5% (42 of 497) of the straight, 68.5% (202 of 295) of the oblique, and 83.3% (5 of 6) of the boot-shaped first premolars. The second premolars were 92.4% straight, 7.5% oblique, and 0.1% boot-shaped, and labial bone perforation occurred in 0.5% (4 of 737) of the straight, 33.3% (20 of 60) of the oblique, and 0% (0 of 1) of the boot-shaped, respectively, when the virtual tapered implant was 3.5×10 mm; and labial bone perforation occurred in 1.3% (10/737) of the straight, 53.3% (32/60) of the oblique, and 100% (1/1) of the boot-shaped second premolars when the virtual tapered implant was 4.3×10 mm.

CONCLUSIONS

When an implant is placed in the long axis of a maxillary premolar, the tooth position and tooth-alveolar classification should be considered when assessing the risk of labial bone perforation. Attention should be paid to the implant direction, diameter, and length in the oblique and boot-shaped maxillary premolars.

Is Laser Therapy an Adjuvant in the Treatment of Peri-Implant Mucositis? A Randomized Clinical Trial

(1) Background: Early diagnosis and treatment of peri-implant mucositis may reduce inflammatory markers and halt the progression of the condition to peri-implantitis. Adjunctive laser treatment may have therapeutic benefits that are not yet well known. The aim of this study was to determine the advantages and limitations of laser therapy as an adjuvant in the treatment of peri-implant mucositis. (2) Methods: A total of 42 patients with at least 2 implants situated in different hemiarches were included in this study and divided into two groups: G1 (received laser therapy) and G2 (no laser therapy). Periodontal health status indices were recorded at the initial moment (T0), and all patients underwent non-surgical debridement therapy accompanied by oral hygiene training. In patients from group G1, one implant site received adjuvant laser therapy (subgroup IL), and the other one did not receive active laser light (IC). The plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) values recorded after 3 months (T1) and 6 months (T2) were analyzed and compared with those at T0. (3) Results: PI values considerably reduced at moment T1 and T2 for both G1 and G2 (p = 0.0031). PPD was also reduced, but the difference between the groups and the three recording moments was not statistically significant. Statistically significant differences were found when comparing the BOP values between G1 IL and G1 IC for T0/T1 (p = 0.0182) and T1/T2 (p < 0.0001), but there was no significant difference between G2 and G1 IL or G1 IC. (4) Conclusions: Laser therapy as an adjunct to conventional treatment of peri-implant mucositis leads to a statistically significant reduction in bleeding on probing at 3-month and 6-month re-evaluations. Moreover, it leads to an evident reduction in probing depth but with no statistical significance. These results should be interpreted with caution, and more in-depth research should be performed to create a complete laser therapy protocol for peri-implant mucositis.

Three-dimensionally printed implant surgical guide-related experience, knowledge, attitude, and professional behaviors among 2028 dentists in China: A cross-sectional study

STATEMENT OF PROBLEM

Research on the current place of 3-dimensionally printed implant surgical guides (3D-ISGs) among practicing dentists worldwide is lacking, with little research focused on dentists' experience, knowledge, attitude, or professional behavior related to 3D-ISG or on the main obstacle to adoption.

PURPOSE

The purpose of this cross-sectional study was to identify the adoption of 3D-ISG in dental practice in China and to determine factors that influence its further application and dentists' attitudes and willingness.

MATERIAL AND METHODS

Semistructured questionnaires were sent to a sample of Chinese dentists composed of users and nonusers of 3D-ISG. The questionnaires were displayed and distributed through a professional online survey system (http://www.wjx.cn) and a social media platform (WeChat). The responses were analyzed with multivariable generalized equations, and the effect of various demographic variables was determined, including dentist experience, academic degree, and type of practice (public or private).

RESULTS

A total of 2028 valid questionnaires were collected. In dental practice, 39.3% of the respondents used 3D-ISG. Respondents with a PhD (62.4%) used the 3D-ISG more than twice as frequently as respondents with a junior college degree or below (31.8%). The majority of the members of implantology departments (81.7%) applied 3D-ISG, but doctors in other departments used it at a rate of less than half. The 3D-ISG was most frequently used in the maxillary anterior area (78.4%), followed by the edentulous maxilla and mandible (61.0% and 60.5%, respectively). The main barriers were high initial cost, complex and time-consuming digital design, and lack of expertise in the proper use of 3D-ISG.

CONCLUSIONS

Most dentists did not use 3D-ISG in dental practice. The 3D-ISG application rate was significantly associated with sex, academic degree, years of dental practice, department, monthly income, and type of healthcare facility. To improve the popularity of 3D-ISG, particularly among dentists without advanced degrees, it would be important to optimize the digital design software program and provide sufficient training.

Computer-Guided Osteotomy with Simultaneous Implant Placement and Immediately Loaded Full-Arch Fixed Restoration: A Case Report

Aim: This case report aims to illustrate a clinical protocol that allows for the rehabilitation of patients requiring extensive osteotomy, simultaneous implant placement, and full-arch, screwed-in prosthetics in one session. This protocol allows for the improvement of the aesthetics and functionality of the fixed implant-supported prosthesis through the preoperative planning of all surgical procedures, including osteotomy, and of the prosthesis through the application of 3D-printing technology for the creation of surgical templates and prostheses. Methods: This case report concerns a 72-year-old patient, ASA1, who, following diagnosis, the establishment of a treatment plan, and the provision of informed consent, opted for an immediate, full-arch rehabilitation of the lower arch. The digital planning stage started with the correct positioning of the fixtures. The proper bone levels were found and used to guide the creation of the provisional screwed-in prothesis. Two templates with the same supports (landmarks/pins) were then 3D-printed: a positioning template, including a slit to assist the surgeon during the osteotomy, and a surgery template to assist the surgeon during the implants’ positioning. A screwed-in prosthesis encased in resin C&B MFH (NEXTDENT®, Soesterberg, The Netherlands) was delivered. Minimal occlusal adjustments were performed. Results: In a single clinical session, through careful planning and the pre-operative 3D printing of a prosthesis, a temporary implant-supported prosthetic rehabilitation was possible in a case that required an extended osteotomy. Clinically, the correspondence between the virtual design phase and the final realization was consistent. At a functional level, the provisional prosthesis required minimal occlusal adjustments and the DVO values obtained in the immediate post-operative period were found to be comparable to those of the virtual design. By planning the final position of the bone and the implants in advance, it was possible to deliver a full-arch prothesis with proper implant emergence, occlusal vertical dimensions, and occlusal relationship. Conclusion: This fully digital protocol allows the clinician to preview and plan the osteotomy and implant surgery as well as the delivery of the temporary, immediately loaded, complete, fixed prosthesis in patients who are candidates for post-extraction surgery with the need for severe osteotomy.

Fixation Pins Increase the Accuracy of Implant Surgery in Free-End Models: An In Vitro Study

PURPOSE

Implant surgical guides, in combination with implant planning software, have been designed for accurate surgery, especially in partial edentulism. The purpose of this study was to examine the effect of fixation pins of surgical guides on the accuracy of static computer-assisted implant surgeries in a maxillary free-end situation.

MATERIALS AND METHODS

This in vitro study was conducted to compare surgical guides using various fixation pin protocols in implant surgery. A patient dental model with missing teeth from maxillary right first premolar to third molar was used as the study model… Implant placement was planned at maxillary right first premolar, right first molar, and right second molar; Straumann full guide templates were designed and fabricated using the coDiagnostiX software. The experiment involved surgical guides with no fixation pins (NF), buccal unilateral fixation pin (BF), palatal unilateral fixation pin (PF), and bilateral fixation pins on the buccal and palatal sides (BPF), based on the position and number of fixation pins. The deviation between the actual and planned positions was used to evaluate implant accuracy. The fixation pin protocols were the primary predictive variables. Angular, 3D platform, and 3D apex deviations were the primary outcome variables. Statistical analysis was performed using the one-way analysis of variance and Tukey's test (α = 0.05).

RESULTS

NF generated the maximum angular deviation (3.65 ± 1.39°), 3D platform deviation (1.58 ± 0.55 mm), and 3D apex deviation (2.18 ± 0.79 mm), whereas BPF produced the minimum angular deviation (1.88 ± 0.86°), 3D platform deviation (1.09 ± 0.51 mm), and 3D apex deviation (1.53 ± 0.45 mm). A statistically significant difference between NF and BPF in the angular deviation, 3D platform, and apex deviation (P < .0001, P = .009, and P = .002, respectively) was identified. The unilateral fixation pin exerted a significant effect only on the angular accuracy (BF, P = .0018; PF, P = .0001).

CONCLUSION

In a maxillary free-end situation, templates with a fixation pin generate better implant accuracy than those without it. A bilateral fixation pin protocol may produce less deviation than those without fixation pins. The implant accuracy does not appear to be affected by the position of the unilateral fixation pin.

Prevention of peri-implant disease in edentulous patients with fixed implant rehabilitations

OBJECTIVES

To provide an overview about the current approaches to prevent peri-implant diseases in edentulous patients with complete-arch implant-supported prostheses, and to review the clinical applications of the latest digital technologies for implant prosthodontics.

METHODS

A review of the guidelines to prevent peri-implant diseases in patient's receiving complete-arch implant-supported prostheses including facially driven treatment planning procedures using either conventional or digital methods, computer-aided implant planning procedures, and prosthodontic design variables including the optimal number and distribution of dental implants, implant to abutment connection type, implant or abutment level design, screw- or cement-retained alternatives, prostheses contours, and material selection is provided. Furthermore, an outline of the current therapeutic management approaches to address peri-implant diseases is reviewed.

CONCLUSIONS

Clinicians should understand and know different planning and design-related variables that can affect biological and mechanical complication rates of complete-arch implant-supported prostheses. Maintenance protocols are fundamental for minimizing biological and mechanical complications.

Implant prosthodontic design as a predisposing or precipitating factor for peri-implant disease: A review

Over the past decade, emerging evidence indicates a strong relationship between prosthetic design and peri-implant tissue health. The objective of this narrative review was to evaluate the evidence for the corresponding implant prosthodontic design factors on the risk to peri-implant tissue health. One of the most important factors to achieve an acceptable implant restorative design is the ideal implant position. Malpositioned implants often result in a restorative emergence profile at the implant-abutment junction that can restrict the access for patients to perform adequate oral hygiene. Inadequate cleansability and poor oral hygiene has been reported as a precipitating factors to induce the peri-implant mucositis and peri-implantitis and are influenced by restorative contours. The implant-abutment connection, restorative material selection and restoration design are also reported in the literature as having the potential to influence peri-implant sort tissue health.

Immediate vs. Delayed Placement of Immediately Provisionalized Self-Tapping Implants: A Non-Randomized Controlled Clinical Trial with 1 Year of Follow-Up

This study aimed to examine the clinical and esthetic outcomes of immediately provisionalized self-tapping implants placed in extraction sockets or healed edentulous ridges one year after treatment. Sixty patients in need of a single implant-supported restoration were treated with self-tapping implants (Straumann BLX) and immediate provisionalization. The implant stability quotient (ISQ) and insertion torque were recorded intraoperatively. After one year in function, the implant and prosthesis survival rate, pink esthetic score (PES), white esthetic score (WES), and marginal bone levels (MBL) were assessed. Sixty patients received 60 self-tapping implants. A total of 37 implants were placed in extraction sockets and 23 in edentulous ridges, and then all implants were immediately provisionalized. All implants achieved a high implant stability with a mean insertion torque and ISQ value of 58.1 ± 14.1 Ncm and 73.6 ± 8.1 Ncm, respectively. No significant differences were found between healed vs. post-extractive sockets (p = 0.716 and p = 0.875), or between flap vs. flapless approaches (p = 0.862 and p = 0.228) with regards to the insertion torque and ISQ value. Nonetheless, higher insertion torque values and ISQs were recorded for mandibular implants (maxilla vs. mandible, insertion torque: 55.30 + 11.25 Ncm vs. 62.41 + 17.01 Ncm, p = 0.057; ISQ: 72.05 + 8.27 vs. 76.08 + 7.37, p = 0.058). One implant did not osseointegrate, resulting in an implant survival rate of 98.3%. All implants achieved PES and WES scores higher than 12 at the 1-year follow-up. The clinical use of newly designed self-tapping implants with immediate temporization was safe and predictable. The implants achieved a good primary stability, high implant survival rate, and favorable radiographic and esthetic outcomes, regardless of the immediate or delayed placement protocols.

Comparison of Sub-epithelial Connective Tissue Graft and Platelet Rich Fibrin in Peri-implant Soft Tissue Augmentation: A Randomized Clinical Split-mouth Study

Aims and Background:

Gingival phenotype has a crucial impact on the peri-implant marginal bone stability. The aim of this clinical trial is to assess and compare the efficacy of the sub-epithelial connective tissue graft (SCTG) and platelet-rich fibrin (PRF) in improving the peri-implant soft tissue phenotype and enhancing esthetic outcomes.

Materials and Methods:

The present study was a split-mouth randomized controlled clinical trial. A total of ten patients who had bilateral missing teeth in the maxillary esthetic zone with a thin gingival phenotype were included in this study. For each study participant, one randomly selected site was treated with SCTG, while the other was treated with PRF membrane during dental implant placement. Treatment outcomes included the assessment of the facial gingival thickness using cone-beam computed tomography (CBCT) at the baseline (T0) and 6 months postoperatively (T1), and the Pink esthetic score (PES) at T1 and 3 months later after prosthesis placement (T2).

Results and Discussion:

Both treatment options resulted in a significant increase in gingival tissue thickness at T1 compared with T0, and in PES at T2 compared with T1 (p ˂ 0.05).

Conclusion:

PRF is an effective alternative to SCTG in augmenting peri-implant soft tissue phenotype and improving esthetic outcomes. This would help overcome the complications associated with harvesting the SCTG and increasing patients’ satisfaction.

Clinical Trial Registration ID: ISRCTN11961919.

Ultrasound insonation angle and scanning imaging modes for imaging dental implant structures: A benchtop study

INTRODUCTION

High frequency ultrasound has shown as a promising imaging modality to evaluate peri-implant tissues. It is not known if the ultrasound imaging settings might influence ultrasound's ability to differentiate implant structures. The aim of this benchtop study was to evaluate the dependence of ultrasound on imaging angles and modes to measure implant geometry-related parameters.

METHODS

A clinical ultrasound scanner (ZS3, Mindray) with an intraoral probe (L30-8) offering combinations of harmonic and compound imaging modes was employed for imaging 16 abutments and 4 implants. The samples were mounted to a micro-positioning system in a water tank, which allowed a range of -30 to 30-degree imaging angles in 5-degree increment between the probe and samples. The abutment angle, implant thread pitch and depth were measured on ultrasound, compared to the reference readings. The errors were computed as a function of the image angles and modes. All samples were replicated 3 times for 3 image modes and 11 image angles, thus resulting in 2,340 images.

RESULTS

The mean errors of ultrasound to estimate 16 abutment angles, compared to the reference values, were between -1.8 to 2.7 degrees. The root mean squared error (RMSE) ranged from 1.5 to 4.6 degrees. Ultrasound significantly overestimated the thread pitch by 26.1 μm to 36.2 μm. The error in thread depth measurements were in a range of -50.5 μm to 39.6 μm, respectively. The RMSE of thread pitch and depth of the tested 4 implants was in a range of 34.7 to 56.9 μm and 51.0 to 101.8 μm, respectively. In most samples, these errors were independent of the image angle and modes.

CONCLUSIONS

Within the limitations of this study, high-frequency ultrasound was feasible in imaging abutments and implant fixtures independent of scanning angle within ±30° of normal incidence and for compounding and non-compounding-based imaging modes.

Addition of Synthetic Biomaterials to Deproteinized Bovine Bone Mineral (DBBM) for Bone Augmentation-A Preclinical In Vivo Study

(1) Aim: To investigate the effect of synthetic bone substitutes, α-tricalcium phosphate (α-TCP) or bi-layered biphasic calcium-phosphate (BBCP) combined with deproteinized bovine bone mineral (DBBM), on bone formation. (2) Methods: Thirty critical size defects were randomly treated with the following five different treatment modalities: (1) negative control (NC, empty), (2) DBBM, (3) α-TCP + DBBM (1:1), (4) BBCP 3%HA/97%α-TCP + DBBM (1:1), and (5) BBCP 6%HA/94%α-TCP + DBBM (1:1). The samples, at four weeks post-surgery, were investigated by micro-CT and histological analysis. (3) Results: A similar level of new bone formation was demonstrated in the DBBM with α-TCP bone substitute groups when compared to the negative control by histomorphometry. DBBM alone showed significantly lower new bone area than the negative control (p = 0.0252). In contrast to DBBM, the micro-CT analysis revealed resorption of the α-TCP + DBBM, BBCP 3%HA/97%α-TCP + DBBM and BBCP 6%HA/94%α-TCP + DBBM, as evidenced by a decrease of material density (p = 0.0083, p = 0.0050 and p = 0.0191, respectively), without changing their volume. (4) Conclusions: New bone formation was evident in all defects augmented with biomaterials, proving the osteoconductive properties of the tested material combinations. There was little impact of the HA coating degree on α-TCP in bone augmentation potential and material resorption for four weeks when mixed with DBBM.

Reconstruction of dental roots for implant planning purposes: a feasibility study

Purpose

Modern virtual implant planning is a time-consuming procedure, requiring a careful assessment of prosthetic and anatomical factors within a three-dimensional dataset. In order to facilitate the planning process and provide additional information, this study examines a statistical shape model (SSM) to compute the course of dental roots based on a surface scan.

Material and methods

Plaster models of orthognathic patients were scanned and superimposed with three-dimensional data of a cone-beam computer tomography (CBCT). Based on the open-source software “R”, including the packages Morpho, mesheR, Rvcg and RvtkStatismo, an SSM was generated to estimate the tooth axes. The accuracy of the calculated tooth axes was determined using a leave-one-out cross-validation. The deviation of tooth axis prediction in terms of angle or horizontal shift is described with mean and standard deviation. The planning dataset of an implant surgery patient was additionally analyzed using the SSM.

Results

71 datasets were included in this study. The mean angle between the estimated tooth-axis and the actual tooth-axis was 7.5 ± 4.3° in the upper jaw and 6.7 ± 3.8° in the lower jaw. The horizontal deviation between the tooth axis and estimated axis was 1.3 ± 0.8 mm close to the cementoenamel junction, and 0.7 ± 0.5 mm in the apical third of the root. Results for models with one missing tooth did not differ significantly. In the clinical dataset, the SSM could give a reasonable aid for implant positioning.

Conclusions

With the presented SSM, the approximate course of dental roots can be predicted based on a surface scan. There was no difference in predicting the tooth axis of existent or missing teeth. In clinical context, the estimation of tooth axes of missing teeth could serve as a reference for implant positioning. However, a higher number of training data must be achieved to obtain increasing accuracy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-022-02716-x.

The influence of thin as compared to thick peri-implant soft tissues on aesthetic outcomes: A systematic review and meta-analysis

Objectives

In systematically healthy patients with an implant‐supported fixed restoration (P), what is the influence of thin (E) as compared to thick (C) peri‐implant soft tissues on aesthetic outcomes (O)?

Methods

Following an a priori protocol, a literature search of six databases was conducted up to August 2020 to identify prospective/retrospective clinical studies on healthy patients with an implant‐supported fixed reconstruction. Measurement of the buccal soft tissue thickness and an aesthetic outcome was a prerequisite, and sites presenting with a buccal soft tissue thickness of <2 mm or shimmering of a periodontal probe were categorized as a thin phenotype. After study selection, data extraction, and risk of bias assessment, random‐effects meta‐analysis of Mean Differences (MD) or Odds Ratios (OR) with their corresponding 95% Confidence Intervals (CI) were conducted, followed by sensitivity analyses and assessment of the quality of evidence.

Results

Thirty‐four unique studies reporting on 1508 patients with 1606 sites were included (9 randomized controlled trials, one controlled trial, 10 prospective cohort studies, 8 cross‐sectional studies, and 6 retrospective cohort studies). The mean difference of the pink aesthetic score (PES) after the follow‐up was not significantly different between thin (<2.0 mm) or thick soft tissues (≥2.0 mm) or phenotypes (12 studies; MD = 0.15; [95% CI = −0.24, 0.53]; p = .46). PES changes during the follow‐up, however, were significantly in favour of thick soft tissues (≥2.0 mm) or phenotypes (p = .05). An increased mean mucosal thickness was associated with an increased papilla index (5 studies; MD = 0.5; [95% CI = 0.1, 0.3]; p = .002) and an increase in papilla presence (5 studies; OR = 1.6; [95% CI = 1.0, 2.3]; p = .03). Thin soft tissues were associated with more recession, −0.62 mm (4 studies; [95% CI = −1.06, −0.18]; p = .006). Patient‐reported outcome measures (patient satisfaction) were in favour of thick soft tissues −2.33 (6 studies; [95% CI = −4.70, 0.04]; p = .05). However, the quality of evidence was very low in all instances due to the inclusion of non‐randomized studies, high risk of bias and residual confounding.

Conclusion

Within the limitations of the present study (weak study designs and various soft tissue measurements or time‐points), it can be concluded that increased soft tissue thickness at implant sites was associated with more favourable aesthetic outcomes.

The long-term impact of alveolar ridge preservation with xenograft bone mineral on peri-implant health after 5 years in function: A retrospective cohort study of 108 patients assessed clinically and radiologically

Objectives

When teeth are lost, dental implants contribute to improved oral function and quality of life. Limitations in dental implant placement arising from poor bone anatomy may be circumvented via alveolar ridge preservation (ARP). The aim is to evaluate the long‐term impact of ARP on peri‐implant health and the relationship with common risk indicators such as smoking and history of periodontitis.

Materials and Methods

One hundred and eight patients were enrolled in this retrospective cohort study with 308 implants. Of these, ∼41% were placed in bone sites that had previously received ARP with deproteinized bovine bone mineral xenograft. Association between baseline variables: ARP, age, gender, number of implants per patient, anatomical site, smoking, and previous history of grade III/IV periodontitis, and outcome variables: mucositis, peri‐implantitis, implant loss, full‐mouth plaque score (FMPS), full‐mouth bleeding score, and marginal bone loss (MBL) was evaluated using both univariate and multivariate models.

Results

After 5 years, the overall survival rate was 93.7%. The occurrence of peri‐implantitis was 21.3% and the extent of MBL was ~2.2 mm. Both peri‐implantitis occurrence and MBL were comparable between ARP⁺ and ARP⁻. Smoking is associated with higher FMPS and MBL.

Conclusions

The findings indicate that peri‐implant health can be maintained around dental implants for up to 5 years in ARP⁺ sites using Bio‐Oss®. Smoking is a major risk indicator for peri‐implantitis, whereas the association between history of periodontitis and the risk of peri‐implantitis, based on this specific, well‐maintained cohort and the specific implants used, remains inconclusive.

Soft Tissue Management on Pontic and Implant Sites Before Implants Insertion

Complex implant therapy can include methods requiring several phases of treatment, and they are usually referred to as one-stage and two-stage approaches. The reasons for the staged approach include the extraction of non-restorable teeth. Such a treatment approach may offer a fixed provisional prosthesis during implant osseointegration that enables the patient to avoid removable prostheses. However, this case aims to demonstrate how to manage the soft tissue in the pontic region prior to immediate implant placement.

A 45- years old female patient presented with non-restorable teeth from the maxillary right lateral incisor to the left lateral incisor were removed, followed by socket preservation and fixed provisional restoration from right maxillary canine to left canine. Soft tissue was contoured to achieve ovate shape by first with a tooth-supported provisional restoration from the maxillary left canine to the right canine and then by re-shaping with carbide and diamond burs; after the tissue obtained the desired architecture, implants were inserted on sites of the maxillary right lateral incisor and left central lateral incisor without immediate loading, but the same provisional fixed restoration maintained the previously contour tissue. Once implant osseointegration was achieved, screw-retained provisional restoration was placed, followed by the definitive fixed implant restoration. Because the soft tissue was previously contoured, the screw-retained implant provisional restorations maintained the tissue architecture.

These initial contouring procedures provided a more predictable outcome for the final tissue contour after implants were inserted. The final re-shaping with the implant screw-retained provisional restorations was minimum, and prostheses followed the previously provided tissue architecture. Before the endosteal implants are inserted, soft-tissue contouring prior to implant placement may provide a more predictable outcome of the final tissue architecture for pontic and implant areas. The patient and clinician can evaluate the success and limitations of tissue contouring prior to implant placement. It may also shorten the time required for tissue contouring with provisional implant restorations.

Accuracy of DICOM-DICOM vs. DICOM-STL Protocols in Computer-Guided Surgery: A Human Clinical Study

Guided implant surgery can enhance implant placement positioning, increasing predictability and decreasing postoperative complications., To date, the best protocol to be used for template realization is still unknown. Thus, the aim herein was to clinically compare the accuracy of two different protocols. A total of 48 implants were divided into Group A (24 implants), in which a stereolithographic template was realized using the digital imaging and communications in medicine (DICOM) data arrived from cone beam computer tomographies (CBCTs) (patients and prothesis alone), and Group B (24 implant), in which a standard intraoral stent with a standardized extraoral support was used for patients’ intraoral impressions and CBCT. The preimplant virtual planning and postsurgery CBCT images of both groups were superimposed, and differences were registered in terms of average deviations at the platform (a) and implant apex (b), mean depth change (c), and angular deviation (d). The results demonstrated that there were no statistically significant differences between groups (p = 0.76) for the parameters measured. However, statistically significant differences (p < 0.05) were found between maxillary and mandible implant surgery, as the latter showed greater accuracy. Additional studies are necessary to further reduce discrepancies between planning and surgical procedures.

An esthetic evaluation of different abutment materials in the anterior Maxilla: A randomized controlled clinical trial using a crossover design

PURPOSE

To assess the effect of implant abutment material and soft tissue thickness on the peri-implant soft tissue color using spectrophotometry and to evaluate gingival esthetics and patient satisfaction with three different abutments.

MATERIALS AND METHODS

Twenty-five patients with a missing maxillary tooth in the esthetic area received an endosseous implant using a two-stage protocol. Grey titanium, pink anodized titanium, and hybrid zirconia custom abutments were fabricated for each participant and inserted for one week with a cross-over design in a randomized manner. Color measurements were made using a spectrophotometer comparing midfacial peri-implant soft tissue and marginal gingiva of the contralateral tooth. CIE Lab color scale was employed following the formula: ΔE = [(∆L)² +(∆a)² +(∆b)² ] ^½ . PES scores were recorded, and patient satisfaction questionnaires were completed at each abutment change visit and at 1-year follow-up. Statistical analysis was performed using Friedman's test and the Wilcoxon signed-rank test with Bonferroni correction as well as the Mann-Whitney U test (α = 0.05).

RESULTS

Abutment material type significantly affected the ΔΕ values of the peri-implant mucosa when compared to the contralateral teeth. At baseline, the highest ΔΕ means ± standard deviation (SD) values were obtained with grey titanium (11.25 ±2.98), followed by pink anodized titanium (9.90 ±2.51), and zirconia abutments (6.46 ±1.43). Differences were statistically significant irrespective of soft tissue thickness. The highest PES values were obtained with zirconia abutments (10.88 ±0.88), followed by pink anodized titanium (10.12 ±1.13) and the lowest with grey titanium (9.68 ±1.41). PES differences were significant only for the thin soft tissue group. Regarding patient satisfaction, VAS scores for the pink anodized and zirconia hybrid abutment groups were higher than the grey titanium group for each question.

CONCLUSION

The color difference between soft tissues around teeth and implants was significant in all groups regardless of tissue thickness. The hybrid zirconia abutments resulted in the least color difference, followed by pink anodized and grey titanium. Significantly different PES values were recorded only for the thin tissue group. There was no significant difference in patient satisfaction between zirconia and pink anodized abutments at the 1-year follow up. Pink anodized abutments represent a good esthetic alternative to zirconia hybrid abutments especially in mechanically challenging situations. This article is protected by copyright. All rights reserved.

Dimensional Changes in the Alveolus after a Combination of Immediate Postextraction Implant and Connective Grafting and/or Socket Shield Technique

Immediate implant placement protocols after dental extraction have enabled a reduction in surgical phases. This procedure has increased patient satisfaction and similar survival rates to late implant placement procedures. However, placing an implant immediately after dental extraction does not counteract the physiological remodeling of alveolar bone. For this reason, additional surgical techniques have been developed, such as the placement of a connective tissue graft (CTG) or the socket shield technique (SST). Dimensional changes in the peri-implant tissues were observed after placement of immediate implants following the extraction and CTG and/or SST. A total of 26 surgical interventions were carried out in which dimensional change variables of peri-implant tissues were analyzed. The preoperative state and immediate postoperative situation were compared with the situation after one year. Measurements were taken at 3, 5, and 7 mm from the gingival margin and analyzed in this CBCT radiological study (Planmeca Promax 3D). The implant platform was used as a reference point for the measurement of changes in alveolar crest height. One year after performing either of the two techniques (CTG and/or SST), a significant increase in the gingiva thickness and vestibular cortex occurred at 5 mm (0.65 ± 1.16 mm) and 7 mm (0.95 ± 1.45 mm) from the gingival margin. Additionally, an increase in thickness of palatal bone was registered at 3 mm (0.48 ± 0.90 mm). The graft placement group showed an increase in thickness of peri-implant tissue in the vestibular area after one year, although CTG and SST groups were clinically similar. The implementation of SST revealed promising results regarding the buccal thickness of hard and soft tissues after one year. A significant increase in vestibular cortical bone thickness, as well as the overall mucosa thickness and buccal bone at 3 mm from the gingival margin, was observed. A significant reduction in the distance from the bone crest to the platform was detected in both techniques. Both techniques (CTG and SST) are appropriate to provide sufficient volume to peri-implant tissues in the vestibular area of anterior maxillary implants. Some limitations were detected, such as the lack of an aesthetic analysis or small sample size, so results should be interpreted with caution. Future studies are necessary to further evaluate the long-term predictability of these techniques.

Associations among the anterior maxillary dental arch form, alveolar bone thickness, and the sagittal root position of the maxillary central incisors in relation to immediate implant placement: A cone-beam computed tomography analysis

Purpose

This study evaluated the associations of the dental arch form, age-sex groups, and sagittal root position (SRP) with alveolar bone thickness of the maxillary central incisors using cone-beam computed tomography (CBCT) images.

Materials and Methods

CBCT images of 280 patients were categorized based on the dental arch form and age-sex groups. From these patients, 560 sagittal CBCT images of the maxillary central incisors were examined to measure the labial and palatal bone thickness at the apex level and the palatal bone at the mid-root level, according to the SRP classification. The chi-square test, Kruskal-Wallis test, and multiple linear regression were used for statistical analyses.

Results

Significant differences were found in alveolar bone thickness depending on the arch form and SRP at the apex level. The square dental arch form and class I SRP showed the highest bone thickness at both levels of the palatal aspect. The taper dental arch form and class II SRP presented the highest bone thickness at the apex level of the labial aspect. No association was found between the dental arch form and SRP. Elderly women showed a significant association with thinner alveolar bone. Age-sex group, the dental arch form, and SRP had significant associations with alveolar bone thickness at the apex level.

Conclusion

The patient’s age-sex group, dental arch form, and SRP were associated with alveolar bone thickness around the maxillary central incisors with varying magnitudes. Therefore, clinicians should take these factors into account when planning immediate implant placement.

Accuracy and primary stability of tapered or straight implants placed into fresh extraction socket using dynamic navigation: a randomized controlled clinical trial

OBJECTIVES

To compare the accuracy and primary stability of tapered and straight implants undergoing immediate implant placement with dynamic navigation.

MATERIALS AND METHODS

Patients with compromised anterior teeth in maxilla were recruited and allocated randomly into (1) tapered implant group (TI group) and (2) straight implant group (SI group). Implants were inserted into fresh sockets with dynamic navigation. Three-dimensional platform deviation, apex deviation, angular deviation, insertion torque value (ITV) and implant stability quotient (ISQ) were recorded.

RESULTS

Twenty patients with 20 implants were included. The overall platform, apex, and angular deviation were 0.87 ± 0.35 mm, 0.81 ± 0.34 mm, and 2.40 ± 1.31°, respectively. The accuracy was 0.86 ± 0.26 mm, 0.76 ± 0.33 mm, and 2.49 ± 1.54° for TI, and 0.89 ± 0.44 mm, 0.88 ± 0.36 mm, and 2.31 ± 1.01° for SI, with no significant difference (p = 0.85, 0.45, 0.76). Sagittal root position classification (SRP) class I may obtain greater error in numerical values in straight implants (0.97 ± 0.47 mm vs. 0.6 ± 0.16 mm, 0.92 ± 0.36 mm vs. 0.73 ± 0.36 mm, 2.48 ± 1.19° vs. 1.71 ± 0.14°). The overall ISQ was 60.74. ISQ was 60.48 for TI and 60.96 for SI, with no significant difference. Acceptable ITV (> 15 Ncm) was achieved in most of the included patients (SI 7/10, TI 9/10).

CONCLUSIONS

High accuracy and primary stability of immediate implant placement could be achieved both in tapered and straight implants with dynamic navigation systems.

CLINICAL RELEVANCE

Tapered and straight implants did not reach a consensus on which was better in immediate implant regarding to accuracy and primary stability. Our study demonstrated implant macrodesign did not affect accuracy and primary stability in immediate implant using dynamic navigation.

The influence of crown coverage on the accuracy of static guided implant surgery in partially edentulous models: An in vitro study

OBJECTIVE

To evaluate the influence of crown coverage of surgical guides on the accuracy of static computer-assisted implant surgeries (sCAISs) in different partially edentulous situations.

METHODS

Acrylic models with five types of partially edentulous situations were fabricated in this study. In coDiagnostiX software (Dental Wings, Montreal, Canada), surgical templates were designed and fabricated with reduced crown coverage (RCC), standard crown coverage (SCC) and extended crown coverage (ECC). Then, fully guided implant placement into the acrylic models was performed by dental surgeons with more than 10 years of experience. In total, 120 models and 120 guides were manufactured, and 168 bone-level Straumann replica implants (4.1 × 10 mm, Institut Straumann AG, Basel, Switzerland) were inserted. Postoperative implant positions were scanned (Trios 3, 3 shape, Copenhagen, Denmark) and compared with the preplanned virtual positions via coDiagnostiX (Dental Wings, Montreal, Canada). The angular, coronal and apical deviations were measured and analyzed to evaluate the accuracy of implant insertion. Statistical analysis was performed using one-way ANOVA and Tukey's test.

RESULTS

For single tooth missing situations, the RCC group was similar to the SCC group and ECC group in anterior sites. In premolar or molar sites, the SCC and ECC groups had no statistically significant difference (p > .05), while the RCC group had more coronal and apical deviation (p < .05). For multiple teeth missing situations, there was no difference among the RCC, SCC and ECC groups (p > .05). No difference was found among the five edentulous situations with different CCs (p > .05).

CONCLUSION

The CC of templates can significantly affect the accuracy of guided surgeries when implants are inserted in a single gap at posterior sites. Templates with CC extended to the undercut line may be an optimal choice for static guided surgeries.

CLINICAL SIGNIFICANCE

The accuracy of static guided implant surgery can be influenced by the CC of templates, and proper CC with the guide covering extending to the undercut line may contribute to improved accuracy. CC should be taken into consideration when designing surgical templates.