Immediate loading vs. early/conventional loading of immediately placed implants in partially edentulous patients from the patients' perspective: A systematic review

Immediate implant placement with immediate or delayed provisionalization in the maxillary aesthetic zone: A 10-year randomized trial

AIM

To compare the marginal bone level of immediately placed implants, with either immediate or delayed provisionalization (IP or DP), in the maxillary aesthetic zone after 10 years of function.

MATERIALS AND METHODS

Participants with a failing tooth in the maxillary aesthetic zone were randomly assigned to immediate implant placement with either IP (n = 20) or DP (n = 20) after primary wound closure with a free gingival graft. The final restoration was placed 3 months after provisionalization. The primary outcome was change in marginal bone level. In addition, implant survival, restoration survival and success, peri-implant tissue health, mucosa levels, aesthetic indices, buccal bone thickness and patient satisfaction were evaluated.

RESULTS

After 10 years, the mean mesial and distal changes in marginal bone level were -0.47 ± 0.45 mm and -0.49 ± 0.52 mm in the IP group and -0.58 ± 0.76 mm and -0.41 ± 0.72 mm in the DP group (p = .61; p = .71). The survival rate was 100% for the implants; for the restorations, it was 88.9% in the IP group and 87.5% in the DP group. Restoration success, according to modified USPHS criteria, was 77.8% in the IP group and 75.0% in the DP group. The prevalence of peri-implant mucositis was 38.9% and 35.7% and of peri-implantitis 0.0% and 6.3%, respectively, in the IP group and DP group (p = 1.0; p = .40). The Pink Esthetic Score and White Esthetic Score was 15.28 ± 2.32 in the IP group and 14.64 ± 2.74 in the DP group, both clinically acceptable (p = .48). The buccal bone thickness was lower in the DP group. Patient satisfaction was similar in both groups (p = .75).

CONCLUSIONS

The mean marginal bone level changes after immediate implant placement with IP were similar to those after immediate placement with DP.

CLINICAL TRIAL REGISTRATION

Registered in the National Trial Register (NL9340).

Primary stability and osseointegration comparing a novel tapered design tissue-level implant with a parallel design tissue-level implant. An experimental in vivo study

OBJECTIVES

The aim of the present study was to compare a novel tapered, double-threaded self-tapping tissue-Level design implant (TLC) to a well-established parallel walled tissue-level (TL) implant in terms of primary and secondary stability over time.

MATERIALS AND METHODS

Test TLC (n = 10/per timepoint) and control TL (n = 10/per timepoint) implants were placed in the mandible of minipigs and left for submerged healing for 3, 6, and 12 weeks. Maximum insertion torque and implant stability quotient (ISQ) were measured for each implant at placement. Osseointegration and cortical bone maintenance were histologically evaluated by measuring total bone-to-implant contact (BIC) and first bone-to-implant contact (fBIC).

RESULTS

A significantly higher maximum insertion torque was measured for the test implant TLC compared to the control TL implant (57.83 ± 24.73 Ncm and 22.62 ± 23.16 Ncm, respectively; p < .001). The mean ISQ values were comparable between the two implant types (75.00 ± 6.70 for TL compared to 75.40 ± 3.20 for TLC, p = .988). BIC was comparable between both implant types at each of the evaluated time points. The fBIC was found to be significantly more coronal at 12 weeks for the TLC implant compared to the TL implant (0.31 ± 0.83 mm for TLC compared to -0.22 ± 0.85 for TL, p = .027).

CONCLUSION

The novel tapered tissue level design implant showed improved primary stability and an overall improved crestal bone height maintenance compared to the parallel walled design at 12 weeks.

Immediate versus delayed implant placement of novel fully tapered tissue-level implants - A retrospective multicenter clinical study

OBJECTIVES

To compare the clinical and radiological outcomes of novel fully tapered tissue-level implants in immediate implant placement (type 1) versus late implant placement (type 4) for the first time.

MATERIALS AND METHODS

For this clinical study, 318 fully tapered tissue-level implants in 65 patients were inserted immediately (n = 68 implants) or late (n = 250 implants) in two different centers. Implant survival and success rates and marginal bone levels were analyzed.

RESULTS

After a mean follow-up of 12.0 ± 5 months, implant survival rates were 97.8% for all implants. No statistically significant difference in implant survival rates between type 1 and type 4 could be detected (98.5% vs 97.6%, HR 0.70, 95%-CI 0.084-5.81). Neither for implant length (HR 0.53, 95%-CI 0.055-5.08) nor for implant width (HR 0.27, CI 0.028-2.55), a significant influence on implant survival could be detected. Type of used biomaterial for filling the gap and immediate loading showed no effect on implant survival. Mean marginal bone loss was 0.02 ± 0.05 mm for type 1 and 0.04 ± 0.1 for type 4.

CONCLUSIONS

Within the limitations of this retrospective study and the short follow-up, the results demonstrated comparable high survival and success rates and stable marginal bone levels for type 1 and type 4 placement of this novel tissue-level implant (no clinical trial registration as retrospective study design).

Single immediate implant placement in the maxillary aesthetic zone with and without connective tissue grafting: Results of a 5-year randomized controlled trial

AIM

To assess the 5-year effects of grafting connective tissue while undertaking single immediate implant placement and provisionalization at the mid-buccal mucosa level (MBML). Secondary outcomes were buccal bone wall thickness (BBT), marginal bone level (MBL) and patient satisfaction.

MATERIALS AND METHODS

Sixty patients with a single failing tooth in the maxillary anterior region were provided with an immediately placed and provisionalized implant. At implant placement, the patients randomly received either a connective tissue graft from the maxillary tuberosity (n = 30, test group) or no graft (n = 30, control group). The alveolar socket classification was mainly Type 2A. Data were collected before removing the failing tooth (T0 ), and at 1 (T1 ), 12 (T12 ) and 60 (T60 ) months after final crown placement. The primary outcome was the change in MBML compared with the pre-operative situation. Additionally, the change in BBT, MBL, aesthetics (using the Pink Aesthetic Score-White Aesthetic Score), soft-tissue peri-implant parameters and patient satisfaction were assessed.

RESULTS

At the 5-year follow-up, 27 patients could be analysed from each group. In each group, one implant was lost during the osseointegration period, within 3 months of placement, resulting in an implant survival rate of 96.7% in both groups. MBML change at T60 was -0.6 (-1.1 to -0.1) mm in the control group and 0.1 (-0.4 to 0.5) mm in the test group (p = .008). BBT and MBL, aesthetics, soft-tissue peri-implant parameters and patient satisfaction showed stable results and satisfied patients, without clinically relevant differences between the groups.

CONCLUSIONS

This 5-year follow-up study shows that grafting connective tissue when replacing a single failing tooth with immediately placed and provisionalized implant results in favourable peri-implant tissues and fewer MBML changes.

Effects of immediate loading directionality on the mechanical sensing protein PIEZO1 expression and early-stage healing process of peri-implant bone

BACKGROUND

The reduced treatment time of dental implants with immediate loading protocol is an appealing solution for dentists and patients. However, there remains a significant risk of early peri-implant bone response following the placement of immediately loaded implants, and limited information is available regarding loading directions and the associated in vivo characteristics of peri-implant bone during the early stages. This study aimed to investigate the effects of immediate loading directionality on the expression of mechanical sensing protein PIEZO1 and the healing process of peri-implant bone in the early stage.

METHODS

Thirty-two implants were inserted into the goat iliac crest models with 10 N static lateral immediate loading applied, followed by histological, histomorphological, immunohistochemical, X-ray microscopy and energy dispersive X-ray spectroscopy evaluations conducted after 10 days.

RESULTS

From evaluations at the cellular, tissue, and organ levels, it was observed that the expression of mechanical sensing protein PIEZO1 in peri-implant bone was significantly higher in the compressive side compared to the tensile side. This finding coincided with trends observed in interfacial bone extracellular matrix (ECM) contact percentage, bone mass, and new bone formation.

CONCLUSIONS

This study provides a novel insight into the immediate loading directionality as a potential influence factor for dental implant treatments by demonstrating differential effects on the mechanical sensing protein PIEZO1 expression and related early-stage healing processes of peri-implant bone. Immediate loading directions serve as potential therapeutic influence factors for peri-implant bone during its early healing stage.

Oral health-related quality of life (OHRQoL) and implant therapy: A prospective multicenter study of preoperative, intermediate, and posttreatment assessment

The purpose of this multicenter continuation study was to use high patient numbers in order to generate reliable statements regarding the association between different implant indications and OHRQoL. Patients with various types of indication for dental implants, ranging from single tooth loss to edentulous jaws, were included. Quality of life relating to dental implants was assessed through the oral health impact profile (OHIP-G-21), which has a summary score from 0 to 20 in healthy patients. In total, 16 253 patients from 29 centers (European Centers for Dental Implantology (ECDI)) were involved in the study between 2009 and 2021.8251 patients (50.7%) completed the questionnaire after implant insertion, and 4996 patients (30.7%) after prosthodontic treatment. The average age was 54 years (range 18-88 years). Posterior single-tooth gap (28.5%) and free-end gap (27.8%) were the most frequent indications. The preoperative OHIP-G-21 score for all patients was 32.81 (SD 11.92), while the score during the healing period was 30.00 (SD 10.72), and after completion of treatment 27.24 (SD 9.26) (p < 0.001). The most significant improvements in OHIP-G-21 scores were in the indication of edentulous jaw (phase 1, 41.81 (SD 15.53); phase 2, 35.39 (SD 14.22); phase 3, 29.60 (SD 10.12) (p < 0.001). The study revealed significant improvements in the most frequently reported problems (chewing, serious concerns, appearance) (p < 0.001). Insertion of dental implants and prosthodontic rehabilitation led to an improved OHRQoL for patients with all indications for dental implants. Special attention should be paid to patients with edentulous jaw, since in comparison with other indications it had the greatest impact on improving OHRQoL. The psychological dissatisfaction scale of the OHIP-G-21 represented the most important factors for patients, and these scores were substantially influenced by implant therapy. Thus, treating physicians should increase their focus on these factors, in order to avoid dissatisfaction and increase the likelihood of complete implant therapy success.

Selection criteria for immediate implant placement and immediate loading for single tooth replacement in the maxillary esthetic zone: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to review available evidence for Type 1A (immediate implant placement and immediate loading) of single tooth replacement in the maxillary esthetic zone.

MATERIALS AND METHODS

An electronic search was conducted utilizing the databases of MEDLINE, Embase, and Cochrane to identify publications reporting on the outcomes of Type 1A for single tooth replacement in the maxillary esthetic zone. The success and survival rates of the included articles were reported, which were further categorized according to the clinical criteria reported in Type 1A. Mean survival rates were univariately compared between risk groups and additionally between studies published before and since 2012 using bias-corrected and study size-weighed bootstrap tests. A study time-correcting meta-analysis was then performed to obtain an overall effect for the study pool.

RESULTS

A total of 3118 publications were identified in the search, with a total of 68 articles included. A mean number of implants per study were 37.2 and mean follow-up was 2.8 years. All the included studies utilizing Type 1A report highly selective inclusion and exclusion criteria. Univariate risk group comparison determined that studies before 2012 report a significantly lower mean survival rate (difference of -1.9 percentage points [PP], 95% CI: [-0.3, -4.0], p = .02), facial gap dimension had an impact on survival rates (+3.1 PP [0.2, 5.3] for width >2 mm, p = .04), as well as presence of endodontic infection (+2.6 PP [0.9, 5.1], p = .004).

CONCLUSIONS

Type 1A has a high survival rate in studies reporting strict patient and site selection criteria. Further research is required to assess esthetic and functional success with Type 1A treatments.

A fully digital protocol to provide a fixed interim complete denture for immediate loading for a completely edentulous patient: A dental technique

Complete arch immediate-loading implant-supported prostheses can represent a major challenge for the patient and the dental team. Obtaining stable references and an accurate occlusal record after implant placement to provide an interim prosthesis is a difficult task and can deviate from the initial treatment plan. The described technique presents a fully digital protocol to provide an immediate complete arch implant-supported fixed interim prosthesis for edentulous patients by making postoperative cone beam computed tomography and intraoral digital scans that correlate with the previous plan.

Patient-reported outcomes in patients with severe maxillary bone atrophy restored with zygomatic implant-supported complete dental prostheses: a systematic review

Introduction and Objective: Zygomatic implants (ZI) offer a good and predictable alternative to reconstructive procedures of atrophic maxillae. The main objetive of this systematic review was to assess the effect of rehabilitation with zygomatic implants on patient's quality of life (QLP) using Patient Reported Outcomes Measures (PROMs).Materials and Methods: This review followed PRISMA guidelines. An automated electronic search was conducted in four databases supplemented by a manual search for relevant articles published until the end of January 2021. The Cochrane Collaboration Risk of Bias tool and the Newcastle-Ottawa Quality Assessment Scale were used to assess the quality of evidence in the studies reviewed.Results: General findings of this systematic review showed substantial increases in Oral health-related quality of life (OHRQoL) among patients restored with ZI and high scores in terms of general satisfaction, especially in chewing ability and esthetics. An overall survival rate of ZI was 98.3% after a mean follow-up time of 46.5 months was observed. Occurrence of 13.1% biological complications and 1.8% technical complications were reported.Conclusions: Patients rehabilitated with zygomatic implant-supported complete dental prostheses showed substantial improvements in OHRQoL and general satisfaction with the treatment received.

Immediate implant placement vs. early implant treatment in the esthetic area. A 1-year randomized clinical trial

OBJECTIVES

To assess the impact of implant placement and temporization timing on esthetic outcomes of single maxillary anterior implants with intact bone walls and interproximal bone.

MATERIALS AND METHODS

Test group patients received an immediate implant with immediate provisional restoration and socket preservation, while patients in the control group received an early implant placement with guided bone regeneration and delayed loading. Patients were followed for 1 year after final prosthetic and pink esthetic score (PES), mid-buccal mucosal level (MBML), crestal bone changes (CBC), and peri-implant soft tissue parameters, and patient chair time was recorded.

RESULTS

Fifty patients received the intended treatment (25 test and 25 control). No implants failed. PES after 1 year was 12.8 ± 1.19 for the test group and 12.5 ± 1.36 for the control group (p = .362). MBML difference between baseline (after final crown delivery) and the 1-year follow-up was gain of 0.2 ± 1.02 mm for the test group (p = .047) and no change in the control group. CBC after 1 year were 0.1 mm ± 0.21 mm (mesial) and 0.2 mm ± 0.22 mm (distal) for the test group and 0.2 mm ± 0.25 mm (mesial) and 0.3 mm ± 0.19 mm (distal) for the control group, p = .540 (mesial) and p = .462 (distal). Test group required half the chair time (127 ± 13 min) when compared to the control group (259 ± 15 min, p < .001).

CONCLUSIONS

Within the limits of this trial, both treatment protocols resulted in excellent esthetic outcomes with PES >12 after 1-year follow-up.

Success Rates and Complications Associated with Single Immediate Implants: A Systematic Review

This study examined the success rates of single immediate implants and their associated biological, hardware and aesthetic complications. Using a developed search strategy, randomized controlled trials (RCTs) on single-unit immediate implants with at least six human participants, a minimum follow-up time of 12 months and published between January 1999 and January 2021 were identified. Data was extracted independently using pre-designed data extraction forms. Information on success rates and associated biological, hardware and aesthetic complications were obtained and assessed. Out of 191 potentially eligible studies, 26 RCTs assessing 1270 patients with a total of 1326 single implants were included and further evaluated. In this review, success rate was reported to be 96.7–100% over a total of 9 studies. However, there was a lack of consensus on a universal success criterion between authors emphasizing the need for agreement. The average follow up was 29 months and most reported complications were aesthetic (63 cases, 4.7%), whilst there were relatively fewer biological, (20 cases, 1.5%), and hardware complications (24 cases, 1.8%). Success rate is an uncommon clinical outcome with 9 out of 26 of the selected RCTs reporting it. In these studies, single immediate implants showed a high success rate with low numbers of biological and hardware complications, and high patient satisfaction with aesthetics were reported in the short-term follow-up of one year.

Peri-implant bone preservation of a novel, self-cutting, and fully tapered implant in the healed crestal ridge of minipigs: submerged vs. transgingival healing

OBJECTIVES

The aim of this study was to assess the influence of transgingival compared with submerged healing on peri-implant bone maintenance around a novel, fully tapered implant in a healed crestal ridge in minipigs.

MATERIALS AND METHODS

In each of 12 minipigs, two implants (Straumann® BLX, Roxolid® SLActive®, Ø 3.75 × 8 mm) were placed. Implants were either left for submerged or for transgingival healing for 12 weeks. Measurements performed were bone-to-implant contact (BIC), first bone-to-implant contact (fBIC), bone area to total area (BATA), perpendicular bone crest to implant shoulder (pCIS), bone height change from placement, and bone overgrowth (for submerged implants).

RESULTS

No significant differences were found between transgingival and submerged healing in any of the measured parameters, except for BATA on the buccal aspect in which significantly more bone formation was found for the transgingival healing group. For both groups, there was a gain in crestal bone height during the 12-week healing period.

CONCLUSIONS

Loaded compared with unloaded implants displayed comparable levels of osseointegration and equivalent marginal bone levels. This qualifies the implant placement protocol with respect to the osteotomy dimensions and subcrestal placement protocol for immediate loading.

CLINICAL RELEVANCE

The here presented results related to osseointegration and crestal bone maintenance after submerged or transgingival healing have demonstrated a high level of consistency in the used in vivo translational model. The obtained results support the translation of the novel implant type in conjunction with the developed surgical workflow and placement protocol into further clinical investigation and use.

Implant Survival in Immediately Loaded Full-Arch Rehabilitations Following an Anatomical Classification System-A Retrospective Study in 1200 Edentulous Jaws

This retrospective study analyzed implant survival of immediate implant-supported fixed complete denture (IFCD) treatment options (TOs) based on the level of alveolar atrophy (CC). Records of 882 patients receiving a total of 6042 implants at one private referral clinic between 2004 and 2020 were considered. The mean follow-up period was 3.8 ± 2.7 years. Cumulative implant survival rates (CSRs) were analyzed as a function of CCs and TOs according to Mantel-Haenszel and Mantel-Cox. Hazard risk ratios for implant loss were compared using Cox regression. Confounding factors were identified using mixed Cox regression models. The 2- and 5-year CSRs were 98.2% and 97.9%, respectively. Maxillary 2- and 5-year CSRs were lower (97.7% and 97.3%) compared to mandibular CSRs (99.8% and 98.6%) (p = 0.030 and 0.0020, respectively). The CC did not influence CSRs of IFCDs in the mandible (p = 0.1483 and 0.3014, respectively) but only in the maxilla (p = 0.0147 and 0.0111), where CSRs decreased with increasing atrophy. TOs did not statistically differ in terms of survival rate for a given level of alveolar atrophy. The adaption of IFCD treatments to the level of atrophy and patient-specific risk factors can result in high CSRs, even at different levels of bone atrophy.

Immediate loading protocols increase the risk of failure of implants placed by fully guided surgery in partially edentulous jaws: A randomized clinical trial

AIM

To compare the 1-year outcomes of immediate loading (IL) and delayed loading (DL) protocols for implants placed by fully guided surgery in partially edentulous jaws.

MATERIALS AND METHODS

This study included 72 patients who received implant surgery with either IL (93 implants, 36 patients) or DL (94 implants, 26 patients). A prefabricated provisional prosthesis was delivered immediately for the IL group (86 implants, 32 patients) with the exception of 4 subjects in whom an initial torque of >20 Ncm and an implant stability quotient of >65 were not achieved, while all DL-group implants were loaded after 3 months. The 1-year implant survival rate estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and the marginal bone loss (MBL) estimated by cone-beam computed tomography were statistically evaluated (p < 0.05).

RESULTS

The survival rate in the DL group was 100% at both patient and implant levels. With only 26 subjects with 78 implants surviving in the IL group, the survival rates were 69.4% and 83.4% at the patient and implant levels, respectively, in the ITT analysis, and 78.1% and 90.2% in the PP analysis. All intergroup differences in survival rates were statistically significant (p < 0.01). MBL was less than 0.1 mm in both groups (p > 0.05).

CONCLUSIONS

IL for implants placed by fully guided surgery in the partially edentulous jaws increased the probability of failure compared to 3-month DL. Regardless of when loading occurred, marginal bone levels remained stable.

Does immediate loading of a single implant in the healed anterior maxillary ridge improve the aesthetic outcome compared to conventional loading?

Background

Immediate loading is an attractive option for avoiding secondary surgery. However, it is unclear whether it provides a better aesthetic outcome compared to conventional loading with implants placed in healed ridges.

Aims

To compare the aesthetic outcomes of immediately and conventionally loaded single implants in healed anterior maxillary ridges.

Methodology

A systematic review using PICO was conducted. EMBASE, MEDLINE and DoSS databases were searched. The Cochrane Risk of Bias tool for Randomised Controlled Trials and the Effective Public Health Practice Project tool for other study designs were used for quality appraisal. A narrative synthesis was undertaken.

Results

A total of 622 articles were identified. After screening, a total of five papers were included. Results indicated no statistically significant difference in pink or white aesthetic scores between the immediate and conventional loading groups at 1- and 5-year review and the Papilla Index at the 1-year review.

Conclusion

Within the limitations of this review, immediate loading of single implants provides a comparable aesthetic outcome to conventional loading in healed ridges of the anterior maxillary.

Comparison of sandblasted and acid-etched surface implants and new hydrophilic surface implants in the posterior maxilla using a 3-month early-loading protocol: a randomized controlled trial

Objectives

In this prospective randomized controlled trial, we measured the primary and secondary stability of two surface-treated implants placed in the posterior maxilla, applied 3-month loading protocols, and compared and analyzed the short-term outcomes of the implants.

Patients and Methods From June 2018 to June 2019, patients with a residual bone height of 4 mm in the posterior maxilla were enrolled and randomly divided into two groups to place SA implants (Osstem Implants, Korea) in Group A and NH implants (Hiossen, USA) in Group B. Finally, 14 implants placed in 13 patients in Group A and 17 implants placed in 14 patients in Group B were analyzed. The measured primary and secondary stability of each implant was represented by implant stability quotient (ISQ), and treatment outcomes were evaluated.

Results

Group A consisted of patients with an average age of 62.2 years (range, 48-80 years), and Group B consisted of patients with an average age of 58.1 years (range, 35-82 years). Primary stability was 73.86±6.40 and 71.24±5.32 in Groups A and B, respectively (P=0.222). Secondary stability was 79.07±5.21 in Group A and 78.29±4.74 in Group B (P=0.667). A steep increase in ISQ during the healing period was observed in Group B, though it was not significant (P=0.265). The mean follow-up period was 378.5±164.6 days in Group A and 385.3±167.9 days in Group B. All implants in each group met the success criteria, and the success rate was 100%.

Conclusion

Two surface-treated implants placed in the posterior maxilla with greater than 4 mm alveolar bone height exhibited successful one-year treatment outcomes if a primary stability of 65 or higher ISQ was obtained and a 3-month early loading protocol was applied.

Understanding the Lived Experience of North American Dental Patients With a Single-Tooth Implant in the Upper Front Region of the Mouth: Protocol for a Qualitative Study

BACKGROUND

Assessment of the subjective experiences of individuals with maxillary anterior (ie, the upper front region of the mouth) single-tooth implants is limited mainly to quantitative measurements of satisfaction with appearance. Interestingly, there is unexplained variability in the relationship between satisfaction and appearance.

OBJECTIVE

This qualitative study protocol aims to explore and better understand the satisfaction with appearance and function in a Canadian population with maxillary anterior single-tooth implants treated at a postgraduate university clinic. Thus, we aim to obtain diversity among participants relating to the identification of esthetically pleasing and displeasing cases from a clinician perspective.

METHODS

A qualitative research design using interpretative phenomenology analysis (IPA) will provide an adaptable inductive research approach. The participants will be recruited, and consent documents, photographs, digital intraoral scans, and self-administered questionnaire responses will be obtained from them. The transcribed verbatim data from audio-recorded, in-depth, semistructured, one-to-one interviews of the participants will be managed, coded, and analyzed thematically with computer-assisted qualitative data analysis software. The IPA will consider the COnsolidated criteria for REporting Qualitative (COREQ) guidelines when applicable.

RESULTS

For the qualitative interview, we plan to include at least eight patients to conduct up to 1.5 hours of open-ended interviews with each participant aided by an interview guide. Ethical approval was granted by the University of British Columbia Behavioral Research Ethics Board (H19-00107) in May 2019. Two American dental foundations funded this study.

CONCLUSIONS

The analysis in this study will elucidate the aspects (including their value) that influence participant satisfaction at different dental implant treatment stages. This will be the first qualitative study on this group of the population to explore and obtain a better understanding of their satisfaction with appearance and function, as well as any other patient-reported outcome measures that could be identified.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/25767.

A novel fully tapered, self-cutting tissue-level implant: non-inferiority study in minipigs

Objectives

To assess the osseointegration and crestal bone level maintenance of a novel fully tapered self-cutting tissue-level implant for immediate placement (test) compared to a clinically established tissue-level implant (control) in moderate bone quality.

Materials and methods

Test and control implants were compared in 3 groups, i.e., small-, medium-, and large-diameter implants in an edentulous mandibular minipig model with moderate bone quality after 12 weeks of healing. Histometrically derived bone-to-implant contact (BIC) and first bone-to-implant contact (fBIC) were subjected to statistical non-inferiority testing. Maximum insertion torque values in artificial bone were assessed for comparison.

Results

BIC values for the tests and control implants for all 3 diameters were comparable and non-inferior: small diameter (61.30 ± 10.63% vs. 54.46 ± 18.31%) (p=0.99), medium diameter (60.91 ± 14.42 vs. 54.68 ± 9.16) (p=0.55), and large diameter (45.60 ± 14.67 vs. 52.52 ± 14.76) (p=0.31). fBIC values for test implants were higher and non-inferior compared to control implants in all three groups. Test implants further showed distinctly higher maximum insertion torque values compared to control implants.

Conclusion

The investigated novel tissue-level implant is able to achieve high levels of primary and secondary implant stability under simultaneous preservation of crestal bone levels. This qualifies the studied implant as an attractive candidate for immediate placement in bone of limited quality.

Clinical relevance

This pilot pre-clinical study investigated a novel tissue-level implant for immediate placement. With the aim of translating the studied prototype into clinical application pre-clinical models, procedures and controls have been chosen with the aim of reflecting its future clinical indication and use.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-03912-w.

Immediate single-tooth implant placement with simultaneous bone augmentation versus delayed implant placement after alveolar ridge preservation in bony defect sites in the esthetic region: A 5-year randomized controlled trial

BACKGROUND

It is unclear if an intact buccal bony plate is a prerequisite for immediate implant placement in post-extraction sockets. The aim of this 5-year randomized controlled trial was therefore comparison of peri-implant soft and hard tissue parameters, esthetic ratings, and patient-reported satisfaction of immediate implant placement in post-extraction sockets with buccal bony defects of ≥ 5 mm in the esthetic zone, with delayed implant placement after ridge preservation.

METHODS

Patients presenting a failing tooth in the esthetic region and a buccal bony defect of ≥ 5 mm after extraction were randomly assigned to immediate (Immediate group, n = 20) or delayed (Delayed group, n = 20) implant placement. Second-stage surgery and placement of a provisional restoration occurred 3 months after implant placement in both groups, followed by definitive restorations 3 months thereafter. The follow-up was 5 years. Marginal bone level (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded.

RESULTS

Mean marginal bone level change was -0.71 ± 0.35 mm and -0.54 ± 0.41 mm in respectively the Immediate group and the Delayed group after 5 years (P = 0.202). This difference, and in other variables, was not significant.

CONCLUSIONS

Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in post-extraction sockets with buccal bony defects of ≥ 5 mm, were comparable to those following delayed implant placement after ridge preservation in the esthetic zone.

PRIMARY STABILITY IN VARIOUS-LEVELS IMPACTED IMPLANTS: AN EX-VIVO STUDY

The aim of this study was to examine the primary stabilization of different vertically impacted bone implants. Implant stability was measured by resonance frequency analysis. Forty-five dental implants were used and divided into three groups. Group 1 was placed 4 mm (1/3 impacted), Group 2 was placed 8 mm (2/3 impacted), and Group 3 was placed 12 mm (fully impacted). Implant stability quotient values were measured on the longitudinal and transversal axis by two independent researchers. The fully-impacted group showed the significantly highest value among the groups (p < 0.05). There were statistically varying implant-stability quotient values between researchers. None of the 1/3 impacted implants' value reached a 70 implant-stability quotient value.

Immediate placement of single implants with or without immediate provisionalization in the maxillary aesthetic region: A 5-year comparative study

Aim

To compare marginal bone level changes around immediately placed and immediately provisionalized implants with immediately placed and delayed provisionalized implants in the aesthetic region after five years of function.

Materials and Methods

Forty patients with a failing tooth in the maxillary anterior region were randomly assigned immediate implant placement with immediate (Group A: n = 20) or delayed (Group B: n = 20) provisionalization. Definitive crown placement occurred three months after provisionalization. The primary outcomes were changes in marginal bone level. In addition, survival rates, buccal bone thickness, soft peri‐implant tissues, aesthetics and patient‐reported outcomes were assessed.

Results

After 5 years, the mean mesial and distal marginal bone level changes were 0.71 ± 0.68 mm and 0.71 ± 0.71 mm, respectively, in group A and 0.49 ± 0.52 mm and 0.54 ± 0.64 mm, respectively, in group B; the difference between the groups was not significant (p = .305 and p = .477, respectively). Implant and restoration survivals were 100%. No clinically relevant differences in buccal bone thickness or in mid‐facial peri‐implant mucosal level, aesthetic and patient outcomes were observed.

Conclusions

The mean marginal bone level changes following immediate implant placement and provisionalization were comparable with immediate implant placement and delayed provisionalization. (www.isrctn.com: ISRCTN57251089 and www.trialregister.nl: NL8255).

Effect of implant rehabilitation on oral health-related quality of life with three different implant strategies

Design Non-randomised controlled trial.Case selection Patients requiring dental implants were recruited from a private dental surgery in Spain. According to the clinical diagnosis and patient preference, patients were assigned to one of the following three treatment protocols: the conventional treatment (CGCL), in which implants were inserted after flap elevation without guiding templates; the guided surgery/conventional loading group (GSCL); and the guided surgery/immediate loading group (GSIL).Data analysis An oral examination and a questionnaire-based interview were carried out at baseline and three months after the delivery of the definitive prosthetic rehabilitation. Two complementary indicators, Oral Impacts on Daily Performances (OIDP) and Oral Satisfaction Scale (OSS) were used to assess the changes in oral health-related quality of life (OHQoL). Paired t-tests were used to compare the within-subject change scores. ANOVA tests were used to compare quantitative variables between groups. Chi-square tests were used to compare the distribution of data between groups. Effect size was used to assess the relative responsiveness of different health indicators and to compare the amount of change resulting from different treatment protocols. A forward stepwise logistic regression analysis was performed to predict the risk of having impact after treatment.Results A total of 104 patients were recruited: CGCL (n = 40), GSCL (n = 35) and GSIL (n = 29). At baseline, the OHQoL was significantly greater among those assigned to CGCL (2.4 ± 1.3) than those assigned to GSCL (3.3 ± 1.3), which were both greater than those patients assigned to GSIL (4.6 ± 2.0). After implant therapy, the oral wellbeing was significantly better than at baseline, and patient satisfaction was greater when the implants were loaded immediately (8.7 ± 1.1) than if the prosthetic rehabilitation was delayed (8.3 ± 1.1). In the GSIL group, the effect size of the OIDP exceeded the threshold value of 0.8 for all of the OIDP domains and for the total OIDP score and patient satisfaction.Conclusions A global improvement in the OHQoL scores and patient satisfaction was observed after implant therapy, but the change was marked greater in the GSIL group.

Supraeruption as a consideration for implant restoration

Purpose

The aim of this study was to compare the prevalence, amount, and rate of supraeruption of the maxillary second molar according to sex, age, and history of periodontitis.

Methods

Data were collected retrospectively from the charts and panoramic radiographs of 65 patients who were scheduled to undergo implant placement at the site of the mandibular second molar. The amount of supraeruption of the maxillary second molar and the alveolar bone level of the neighboring teeth were measured on digital panoramic radiographs. The prevalence was evaluated in each group, and univariate and multivariate logistic regression analyses were used to identify factors influencing the prevalence of supraeruption. The amount and the rate of supraeruption were compared between pairs of groups using the Mann-Whitney U test. For all tests, P values <0.05 were considered to indicate statistical significance.

Results

Supraeruption occurred in 78% of the patients. The prevalence of supraeruption was affected by sex, age, and history of periodontitis. The mean amount of supraeruption was 0.91 mm and the mean rate of supraeruption was 0.14 mm/month. The amount and the rate of supraeruption showed no significant differences according to sex, age, or the distance from the cementoenamel junction to the alveolar bone crest (P>0.05).

Conclusions

These results show that the amount of supraeruption on the maxillary second molar was similar to the thickness of the enamel on the occlusal surface. When a single implant is scheduled to be placed on the mandibular second molar, supraeruption of the antagonist should be considered.

Relevant Design Aspects to Improve the Stability of Titanium Dental Implants

Post-extractional implants and immediate loading protocols are becoming much more frequent in everyday clinical practice. Given the existing literature about tapered implants, the objective of this paper was to understand whether implant shape had a direct influence on the results of the insertion torque (IT) and implant stability quotient (ISQ). Seven tapered implant prototypes were developed and distributed into three groups and compared with a control cylindrical implant-VEGA by Klockner Implant System. The implants were inserted into bovine bone type III according to Lekholm and Zarb Classification. The sample size was n = 30 for the three groups. Final IT was measured with a torquemeter, and the ISQ was measured with Penguin Resonance Frequency Analysis (RFA). Modifications done to the Prototype I did not reveal higher values of the ISQ and IT when compared to VEGA. In the second group, when comparing the five prototypes (II-VI) with VEGA, it was seen that the values of the ISQ and IT were not always higher, but there were two values of the ISQ that were statistically significantly higher with the 4.0 mm diameter Prototypes II (76.3 ± 6.1) and IV (78 ± 3.7). Prototype VII was the one with higher and significant values of the ISQ and IT. In both diameters and in both variables, all differences were statistically significant enough to achieve the higher values of primary stability values (IT and ISQ). Given the limitations of this study, it can be concluded that when there is an increase of the diameter of the implant and body taper, there is an increase of the ISQ and IT, showing that the diameter of the implant is an important criteria to obtain higher values of primary stability.

Immediate versus early non-occlusal loading of dental implants placed flapless in partially edentulous patients: A 10-year randomized clinical trial

AIM

To compare immediate versus early non-occlusal loading of dental implants placed flapless in a 10-year, parallel group, randomized clinical trial.

MATERIALS AND METHODS

Patients were randomized to receive implants for fixed partial dentures. The immediate group was represented by immediate non-occlusal implant loading, whereas the early group was represented by early non-occlusal implant loading. The outcome variables were implant failure, complications, subjective satisfaction and radiographic bone level at implant sites 10 years after loading.

RESULTS

Sixty patients were randomized: 30 to the immediately loaded group and 30 to the early loaded group. Three patients dropped out in the immediate group, and three patients dropped out in the early group. One implant failure occurred in the early group (p = 1.0). Three complications occurred in the immediate group and four in the early group (RR = 0.75, 95% CI 0.19 to 3.04, p = 1.0). The difference in bone level was 0.1 mm (95% CI -0.2 to 0.5, p = .3752) favouring the early group. Difference in subjective functional satisfaction was 0.2 (95% CI -0.2 to 0.7; p = .3271). Difference in subjective aesthetic satisfaction was 0.0 (95% CI -0.4 to 0.4; p = .9656).

CONCLUSION

At 10-year follow-up, no differences between implants loaded immediately and early were detected in this randomized clinical trial.

Immediate implant placement in molar extraction sites: a 1-year prospective case series pilot study

Background

There is a growing tendency to place single tooth implants immediately after extracting a failing tooth in the posterior region. The aim of this prospective case series pilot study was to evaluate immediate implant placement in molar post-extraction sites during a 1-year follow-up period.

Materials and methods

Fifteen consecutive patients with a single failing molar in the maxilla or mandible, and presenting enough bone to expect primary implant stability and an implant site free of infection, were included. The implants, with a large thread depth and sharp thread edges, were placed in each patient according to a two-staged surgical procedure. Three months later, a full contour screw-retained zirconia restoration with an angulated screw channel abutment was provided. Clinical and radiographic examinations were performed 1 month and 12 months after placing the restoration. In addition, the patients’ satisfaction with the restoration was scored after 12 months.

Results

Four out of 15 of the mobile implants had to be removed before the 1-year evaluation. The implant and restoration survival rates were 73.3% at the 1-year evaluation (n = 15). The mean marginal bone loss, from loading to the 12-month follow-up, was 0.17 mm (n = 11). The mean plaque, calculus, peri-implant mucosa, bleeding, and pocket probing depth scores were low, depicting healthy peri-implant conditions. The patients were very satisfied.

Conclusion

It was demonstrated, within the limitations of this study, that immediate placement of regular diameter implants in molar post-extraction sites in the maxilla and mandible resulted in a high implant failure rate during a 1-year follow-up period.

Trial registration

Netherlands Trial Register, NL8117. Registered 24 October 2019 - Retrospectively registered, https://www.trialregister.nl/trial/8117.

Standard vs customized healing abutments with simultaneous bone grafting for tissue changes around immediate implants. 1-year outcomes from a randomized clinical trial

BACKGROUND

Immediate implants have shown risks of esthetic complications. The hypothesis was that a customized healing abutment could improve the peri-implant tissue healing.

PURPOSE

To evaluate and compare the soft and hard tissue healing around immediate implants that received bone grafting and a customized vs a standard healing abutment.

MATERIALS AND METHODS

Patients, who required tooth extraction and who received an immediate implant (with an alloplastic graft material) were randomly assigned to a customized or a standard healing abutment group. Clinical and radiographic examinations were taken at baseline, at 4 and 12 months.

RESULTS

Twenty-five patients out of 61 were excluded from the study because unsuitable for immediate implantation. In total, 36 patients were randomized in the two groups. There were 17 females and 19 males (age range 23-77). No prosthetic or implant failure was registered during the study period. The Papilla Index was significantly higher in the customized than in the standard group at 4 and 12 months (P = .0002). The bone loss at mesial sites was significantly higher in the control than in the test group (P = .0014).

CONCLUSION

The customized healing abutment group showed the most favorable outcomes (in terms of PI and MBL) in case of immediate implant that received a peri-implant bone grafting procedure.

Implant insertion torque value in immediate loading: A retrospective study

BACKGROUND

The aim of this study is to verify if the Insertion Torque Value (ITV) of 32 Ncm for immediate loading protocol (ILP), as indicated by literature, is still, with the advance in implant research, a real significant cut-off for long-term implant survival.

MATERIAL AND METHODS

In this retrospective study, data from 224 patients that during three years of clinical practice, were submitted to the insertion of 322 implants with immediate loading protocol, have been recorded, pooled and analyzed. Data were organized based on Insertion Torque Value (ITV): > 32 Ncm (CG) and < 32 Ncm (LTG) and two different groups of equal sample size, 161 implants each, were distinguished. Crestal bone reabsorption, and the implant failure rate were evaluated after 2-years of follow-up.

RESULTS

The bone reabsorption in LTG (0.49 ± 0.11 mm ) was significantly greater than CG (0.22 ± 0.04 mm), p<0.001. However, the survival rate after 2-years of follow-up was quite high and similar for both groups: 96.89% for LTG and 97.52% for CG and no statistically significant differences have been found among the two groups for the implant failure rate (p=0.455).The Odds Ratio (OR) of implant failure was of 1.258 (95% CI 0.332, 4.772), but results were not statistical significant, p=0.740.

CONCLUSIONS

The present study showed that although implants with ITV> 32 Ncm are still characterized by a lower crestal bone resorption, there are no statistically significant differences among the two groups for what concerning the failure rate during the 2 years of follow-up and OR. These results permit us to suppose that the cut-off of ITV >32 Ncm for immediate loading implants, could be reduced to inferior values. However further studies are necessary to indicate precise clinical guidelines.