Immediate Loading of Fixed Complete Denture Prosthesis Supported by 4-8 Implants Placed Using Guided Surgery: A 5-Year Prospective Study on 66 Patients with 356 Implants

Treatment alternatives for the rehabilitation of the posterior edentulous maxilla

Rehabilitation of the edentulous maxilla with implant-supported fixed dental prostheses can represent a significant clinical challenge due to limited bone availability and surgical access, among other factors. This review addresses several treatment options to replace missing teeth in posterior maxillary segments, namely the placement of standard implants in conjunction with maxillary sinus floor augmentation, short implants, tilted implants, and distal cantilever extensions. Pertinent technical information and a concise summary of relevant evidence on the reported outcomes of these different therapeutic approaches are presented, along with a set of clinical guidelines to facilitate decision-making processes and optimize the outcomes of therapy.

Clinical Outcome of Immediate Loading UV-Photofunctionalized Implants in Patients with Completely Edentulous Mandible, Placed with Guided Surgery

Objectives

The purpose of this study was to evaluate clinical results of immediate loading UV-photofunctionalized dental implants placed using guided surgery in patients with completely edentulous mandible.

Material and Methods

In this study, 58 fully edentulous patients were treated with immediate loading implant-supported mandibular prostheses. All patients underwent a thorough clinical examination according to the generally accepted scheme; qualitative and quantitative parameters of the jaw bones patients were diagnosed with cone beam computerized tomography (CBCT). Surgical templates modeled in the 3 Shape software were made from biocompatible polymeric materials and provided with depth-calibrated drill sleeves for preparing osteotomies using a 3D printer (Stratasys). Before short implant placement, ultraviolet functionalization of implant surfaces was performed by UV Activator YWJ-QSY001 (Foshan, Wenjian Medikal Enstriman) in the device for 20 s. After flapless surgery, implant sockets were prepared with guided surgery and implants were placed through the sleeves of the surgical template tightening torque of 35-45 Ncm. An implant-supported temporary prosthesis made of acrylic resin was installed 6 h after implantation. Final dental prosthetics was performed 2 months after implant placement.The patients had 128 short (length 5-6 mm, diameters 4,5-5 mm) and 256 implants with length greater than 10 mm in bone segments with sufficient bone parameters. The following parameters were assessed: implant success, prosthetics survival and changes in peri-implant marginal bone loss (MBL).

Results

During a clinical examination, no serious biological or prosthetic complications have been reported. The esthetic result evaluated from patients was excellent. The mean ISQ of short implants was 69.2 ± 8 for primary stability at implant placement and 73.6 ± 4 ISQ after 3 months. The mean of implants with length greater than 10 mm was 71,2ISQ at implant placement, respectively, and 75,6 ISQ after 3 months. After 3 months of prosthetic loading for short implants marginal bone loss (MBL) 0.74 mm, after 1 year of MBL 11.21 mm, after 5 years of MBL 1,37 mm, for implants with length greater than 10 mm after 3 months of MBL 0.72 mm, after 1 year of MBL 1.19 mm and after 5 years of MBL 1.35. There was no statistically significant difference in clinical indices between short and standard implants. After 5 years of follow-up, stable levels of bone tissue around the implants and healthy tissues around the implants were recorded, and postoperative occlusal function was favorable. The success rates of the short implants in maxilla were 95.5%, and the success rates of the short implants in mandible were 98.7%. The success rates of the implants with length greater than 10 mm in maxilla were 97.8%, and the success rates of the implants with length greater than 10 mm in mandible were 98.8%.

Conclusion

Computer-guided implant surgery and immediate loading of UV-photofunctionalized implants in patients with completely edentulous mandible are a predictable and effective method with a minimum rehabilitation period.

Digitally prefabricated versus conventionally fabricated implant-supported full-arch provisional prosthesis: a retrospective cohort study

Background

To evaluate and compare the clinical outcomes of digitally prefabricated and conventionally fabricated implant-supported full-arch provisional prostheses.

Methods

In this retrospective study, a total of 39 patients (22 males and 17 females) who underwent implant-supported full-arch rehabilitation using the All-on-4 concept with an immediate loading protocol were included: 20 patients treated with digitally prefabricated provisional prostheses were assigned into Group A, and 19 patients treated with conventionally fabricated provisional prostheses were assigned into Group B. Implant/provisional prosthesis survival rates and complications were reviewed. Marginal bone loss (MBL) was investigated by CBCT. Surgical time, restorative time, and total operative time were analyzed. Postoperative pain and swelling were evaluated with the visual analog scale (VAS). The oral health impact profile (OHIP) questionnaire was administered before and after surgery.

Results

The implant/provisional prosthesis survival rate was 100%, and complications appeared with low frequency in both groups, while the mean MBL was 0.30 ± 0.29 mm in Group A and 0.31 ± 0.41 mm in Group B after 3~ 6 months (P > 0.05). The average restorative time in Group A (116.16 ± 16.61 min) was significantly shorter than that in Group B (242.11 ± 30.14 min) (P < 0.05). Patients in Group A showed lower pain/swelling VAS scores after surgery than Group B (P < 0.05). Low OHIP scores with high satisfaction with the overall effects were shown in both groups.

Conclusion

Prefabricated prostheses reduced the prosthetic time and postoperative discomfort in patients whose immediate rehabilitation was based on the All-on-4 concept. This prefabrication technology may be a predictable alternative to improve the short-term clinical outcome of implant-supported full-arch provisional rehabilitation.

Screw-Retained Surgical Guide for Implant Placement in Terminal Dentition Patients With Existing Implants

For patients with existing implants in need of additional implant placement, the use of the existing implants for guide fixation seems to be a logical alternative. Current options for the fabrication of surgical guides involve creating surgical guides that are mucosa-borne and/or retained by fixation pins. Since these existing techniques involve inherent inaccuracies, the fabrication of surgical guides that are screw-retained at the implant- or abutment-level would eliminate the introduction of those same fundamental inaccuracies. The purpose of the present technical report is to illustrate a step-by-step digitally planned guided implant placement protocol for terminal dentition patients with salvageable existing implants requiring full-arch implant rehabilitation. The advantages of this protocol include enhancing the accuracy of guided implant placement with screw-retention vs the traditional mucosa- or fixation pin support. Thus, this simplifies the transition from failing teeth to implants by ensuring that fixed provisionalization serves both functional and esthetic requirements. This protocol can also predictably reduce chairside time and adjustments at the surgical implant placement appointment. This article is protected by copyright. All rights reserved.

Immediate Maxillary Full-Arch Rehabilitation of Periodontal Patients with Terminal Dentition Using Tilted Implants and Bone Augmentation: A 5-Year Retrospective Cohort Study

Background: All-on-four protocols with tilted implants in the maxilla are used to rehabilitate the terminal dentition of the severe generalized periodontitis patients. Data on long-term biological complications are scarce. Methods: Eighty-four axial and forty-six tilted immediate implants have been placed in the extraction sockets of 23 patients according to a four–six implants protocol combined with ridge augmentation. Within 72 h, a provisional prosthesis was cemented to the implants; after 6 months, a cemented ceramic–metallic prosthesis was delivered. The patients were followed for up to 5 years. Results: The 5-year survival rate of the straight and tilted implants was 100% and 97.8, and the prosthetic one was 100%. Marginal bone loss (MBL) of the straight implants was 0.42 ± 0.67 and 0.59 ±1.01 mm on the mesial and distal sides; for the tilted, it was 0.37 ± 0.68 and 0.34 ±0.62 mm, and the differences were not statistically significant. Implant position, smoking, keratinized mucosal width, and cantilever did not affect MBL. Peri-implant mucositis involved 29.4% and 22.2% of the straight and tilted implants, respectively; peri-implantitis involved 5.8% and 4.4% of the straight and tilted implants, respectively, without statistical significance. Conclusions: This immediate loading protocol’s 5-year survival and success rates were high. No difference between the straight and tilted implants was found regarding survival, success rates, and MBL.

Digital Workflow in Implant Treatment Planning For Terminal Dentition Patients

Treatment planning for the transition of patients from terminal dentition to full-arch implant rehabilitation poses challenges. Such challenges pertain to achieving the new orientation of the occlusal and esthetic plane as well as the change of vertical dimension of occlusion (VDO), while the fixed provisionalization using a digital workflow, still tends to be considered complex and hard to perform. This article illustrates step-by-step the utilization of a digital workflow protocol in the treatment planning for rehabilitation of terminal dentition patients, simplifying the smile design and ensuring that fixed provisionalization serves both the functional and esthetic requirements. This protocol includes facially-driven, three-dimensional (3D) digital smile design and chairside mock-up restoration workflows that enable prosthetically-driven assessment prior to implant treatment planning and 3D printing of surgical templates, which can predictably reduce chairside time and adjustments at the surgical and fixed provisionalization appointment. This article is protected by copyright. All rights reserved.

Five-Year Prospective Study on Implant Failure and Marginal Bone Remodeling Expected Using Bone Level Implants with Sandblasted/Acid-Etched Surface and Conical Connection

OBJECTIVE

 The purpose of the present prospective, case-series study was to report implant survival rate and marginal bone remodeling expected 5 years after loading using dental implants placed in daily practice.

MATERIALS AND METHODS

 This research was designed as an open-cohort, prospective, case-series evaluation. Any partially or completely edentulous patient, scheduled to receive at least one bone level implant, was considered eligible for this study. Primary outcome measurements were: implant and prosthetic cumulative survival rate and any complications experienced up to the 5-year follow-up. Secondary outcome measures were: thickness of gingival biotype, implant insertion torque, implant stability quotient, and marginal bone loss (MBL).

RESULTS

 Ninety consecutive patients (34 males and 56 females, aged between 24 and 81 years old [mean: 53.2 ± 15.4]) with 243 inserted implants were followed for at least 5 years after loading (mean: 65.4 ± 3.1 months; range from 60 to 72). At the 1-year follow-up, no drop-outs were recorded, but 17 patients (18.9%) with 18 restorations (12.6%) delivered on 34 implants (14%) were lost at the 5-year examination. At the 5-year follow-up examination, six implants lost osseointegration (97.5%). In the same period, four prostheses failed (97.2%). Five complications were reported in five different patients (prosthetic success rate was 96.5%, at patient level). Five years after loading, the mean MBL was 0.41 ± 0.30 mm. The difference from the 1-year data was 0.04 ± 0.19 mm. A statistically significant higher MBL was found for smokers, and patients with thin gingival biotype. The mean implant insertion torque was 42.9 ± 4.8 Ncm (range from 15 to 45 Ncm). Two-hundred and three implants (83.5%) were inserted with an insertion torque ≥35 and ≤45 Ncm.

CONCLUSIONS

 High implant survival and success rate could be expected with stable marginal bone remodeling up to 5 years after loading. Smoking and thin tissue biotype were the most important variabilities associated with higher MBL. Further research studies are needed to confirm these results.

Accuracy of static digital surgical guides for dental implants based on the guide system: A systematic review

In the present study, we tried to review the current literature, focusing on the effect of different guide systems on the accuracy of the digital surgical guides. A search in PubMed's database, without any date restriction, was performed using keywords based on the PICO question. 54 of the 2378 articles' were chosen for full-text assessment. Articles were screened using predetermined inclusion and exclusion criteria. 21 articles were included in the qualitative assessment. Descriptive analysis was performed for numeric parameters using mean ± standard deviation. Six types of guide systems were used in the included articles. The commonest guide system was SimPlant (45.64%) followed by NobleGuide (23.00%). The pooled mean angle deviation, global coronal deviation, and global apical deviation were 3.43 mm (95% CI = 2.96, 3.90), 1.16 mm (95% CI = 0.98, 1.24) and 1.35 mm (95% CI = 1.11, 1.59), respectively. The maximum mean(SD) of angle deviation, global coronal deviation, and global apical deviation happened in Stent Cad 4.1(1.86) degrees, NobleGuide 1.86(0.56) mm, and OnDemend3d 1.56(1.48) mm, respectively. Although a final statement could not be made on which system is better, it is certain that the software affects the deviation and could be as important as the implant itself. CLINICAL SIGNIFICANCE: The choice of guide systems used for the production of static guide systems which was studied in this article could affect the accuracy of the implant placement procedure.

Analysis of the sagittal root angle and its correlation with hard and soft tissue indices in anterior teeth for immediate implant evaluation: a retrospective study

BACKGROUND

To assess the root angle characteristics of maxillary incisors, and to analyze the relationship between the root angle and other implant-related anatomical indices to use the sagittal root angle as an index for immediate implant evaluation and design.

METHODS

A random sample consisting of 400 cone-beam computed tomography (CBCT) images and 65 maxillary plaster models were selected for the present study. CBCT and stereolithography (STL) scan images were imported as DICOM files into coDiagnostiX software for matching the hard and soft tissue. The angle between the long axis of the anterior tooth and the corresponding alveolar bone and implant-related hard and soft tissue indices were measured in the sagittal section. Descriptive statistics, frequency analysis, multi-level comparisons, and correlation analyses were performed.

RESULTS

The average sagittal root angles were 15° at the central incisor and 19° at the lateral incisor. The root angle in males was significantly larger than that in females, and increased with age. The largest angle, 22.35°, was found in the lateral incisors of the oldest (> 50 years old) male group. The root angle was found to correlate with coronal buccal bone thickness, coronal palatal bone thickness, apical buccal bone thickness, palatal bone thickness, and the below apex bone thickness.

CONCLUSIONS

The sagittal root angle could reflect the distribution of other implant-related anatomical indices, which may provide additional reference for the evaluation of immediate implant placement.

Tissue Recession around a Dental Implant in Anterior Maxilla: How to Manage Soft Tissue When Things Go Wrong?

Dental implants represent the gold standard for the treatment of single edentulism, even in anterior areas. Today, the basic criteria for implant success has changed from mobility, pain, radiolucency, and peri-implant bone loss (>1.5 mm) to prosthetic level success, aesthetics, soft tissue parameters, as well as patient satisfaction. This case report documents a combination of surgical and prosthetic procedures for the treatment of gingival recessions in the anterior maxilla, appearing after tooth extraction, socket preservation, and staged guided implant placement. Prosthetic management of the temporary restoration, orthodontic treatment, and a connective tissue graft were performed. The decision-making process and step-by-step execution of the treatments are presented to describe the entire clinical and surgical management of the reported case. Finally, good aesthetic outcomes, patient satisfaction, and recovery of the soft tissue recession were observed with the combination of these techniques.

Digitally Designed and Milled Verification Jigs Generated from Photogrammetry Data Acquisition: A Clinical Report

The objective of the present report is to illustrate a proof-of-concept protocol for CAD/CAM fabrication of milled verification jigs during full-arch implant rehabilitation using photogrammetry for data acquisition. The present report aims to bridge the gap between analog and digital workflows by introducing a CAD/CAM technique to intraorally verify digitally acquired information without the use of the technique-sensitive and labor-intensive conventional resin verification jig. One patient was treated with a digital prosthodontic protocol where a digitally designed CAD/CAM milled verification jig (generated from intraoral digital scans) was used to confirm implant 3D positioning prior to the fabrication of double full-arch monolithic definitive zirconia prostheses. The procedures are presented step-by-step after clinical and radiographic observation.

1-Year Evaluation of OT Bridge Abutments for Immediately Loaded Maxillary Fixed Restorations: A Multicenter Study

Objective  Preliminary data on survival and success rates of immediately loaded, maxillary, screw-retained, implant-supported, fixed restorations delivered on narrow and low-profile OT Equator abutments (OT Bridge, Rhein’83) were evaluated.

Materials and Methods  This retrospective study evaluated data collected from patients rehabilitated with OT Bridge prosthetic concept between November 2017 and February 2019 in six different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index.

Results  A total of 76 implants were inserted in 14 patients. Patients were followed for a mean period of 15.8 months (range = 12–24). All the patients receive OT Equator (Rhein'83) as intermediate abutments. One year after loading, one implant failed (1.3%). None of the prosthesis failed. One prosthetic complication was experienced in one patient. Three out of 76 implants were connected to the prosthetic framework using only the Seeger system, without screw. Difference in OHIP values was statistically significant (71.9 ± 8.5; p = 0.000). One year after loading, MBL was 0.21 ± 0.11 mm and p- value was 0.000. One year after loading, 8.7% of the examined implant sites present positive bleeding on probing, while 6.4% of the implant sites presented plaque.

Conclusion  The OT Equator abutments (Rhein'83) showed successful results when used to support maxillary fixed dental prosthesis delivered on four to six implants. High implant and prosthetic survival rates, very low complications, high patient satisfaction, and good biological parameters, including only 0.2 mm of bone remodeling were experienced one year after function. Further studies are needed to confirm these preliminary results.

Implant Placement Following Crestal Sinus Lift with Sequential Drills and Osteotomes: Five Years after Final Loading Results from a Retrospective Study

The aim of this retrospective study was to clinically evaluate the five-year outcomes of implants placed following a combined approach to the sinus, consisting of sequential drills and osteotomes. Medical records of patients with implants placed in combination with crestal sinus lift using sequential drills and osteotomes, with a residual alveolar bone crest between 4 to 8 mm, and a follow-up of at least five years after final loading, were evaluated. Outcomes were implant and prosthetic survival and success rates, any complication, and marginal bone loss. Data from 96 patients (53 women and 43 men; mean age 54.7 years; range 23-79 years) were collected. A total of 105 single implants were analyzed. After five years of function, two implants were lost and two prostheses failed. No major biological or prosthetic complications occurred. At the five-year examination, the marginal bone loss was 1.24 ± 0.28 mm. Within the limitations of this retrospective study it can be concluded that implants placed following a combined approach to the sinus consisting of sequential drills and osteotomes seem to be a viable option for the treatment of posterior atrophic edentulous maxilla.

Three-Year Retrospective Comparative Study between Implants with Same Body-Design but Different Crest Module Configurations

Crest module can be defined as the portion of a two-piece implant designed to retain the prosthetic components and to allows the maintenance of the peri-implant tissues in the transition zone.

AIM

To evaluate the three-year after loading clinical and radiographic data, collected from patients that received a prosthetic rehabilitation on conical connection implants with partial machined collar (PMC; CC Group) and same body-designed implants, with flat-to-flat connection and groovy neck design (FC Group).

MATERIALS AND METHODS

A retrospective chart review of previously collected data, including documents, radiographs, and pictures of patients who received at least one implant-supported restoration on NobelReplace CC PMC or NobelReplace Tapered Groovy implants was performed. Patients with at least three years of follow-up after final loading were considered for this study. Outcomes measures were implant and prosthesis failures, any biological or technical complications, marginal bone loss.

RESULTS

Eight-two patients (44 women, 38 men; average age 55.6) with 152 implants were selected and divided in two groups with 77 (CC group) and 75 (FC group), respectively. Three years after final loading, one implant in CC group failed (98.7% survival rate), while no implants failed in FC group (100% survival rate). One restoration failed in CC group (98.7% survival rate) with no restoration failing in the FC one (100% survival rate). Differences were not statistically significant (p = 1.0). Three years after final loading, mean marginal bone loss was 0.22 ± 0.06 mm (95% CI 0.2-0.24) in CC group and 0.62 ± 0.30 mm (95% CI 0.52-0.72) in FC group. The difference was statistically significant (0.40 ± 0.13 mm; 95% CI 0.3-0.5; p = 0.003).

CONCLUSION

with the limitation of this retrospective comparative study, implants with conical connection and partial machined collar seem to achieve a trend of superior outcomes if compared with implants with flat connection and groovy collar design.

A One-Year, Multicenter, Retrospective Evaluation of Narrow and Low-Profile Abutments Used to Rehabilitate Complete Edentulous Lower Arches: The OT Bridge Concept

Purpose: To evaluate preliminary data on survival and success rates of immediately loaded, screw-retained, restorations delivered on lower arches using narrow and low-profile OT Equator abutments. Methods: This retrospective study analyzed data of patients rehabilitated with OT Bridge (fixed prosthetic system built on OT Equator) prosthetic concept from November 2017 to February 2019 in five different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. Results: A total of 60 implants were inserted in 12 patients. Patients were followed for a mean period of 15.8 months (range 12–24). All the patients received OT Equator as intermediate abutments. Four out of 60 implants were connected to the prosthetic framework using only the Seeger system, without a screw. One year after loading, three implants failed (implant survival rate of 95.0%) in two patients. No prosthesis failed and no major biological and technical complications were experienced. One year after initial loading, the marginal bone level was 0.32 ± 0.2 mm. The OHIP before treatment was 87.7 ± 6.0. One year after treatment, OHIP was 23.6 ± 1.2. The difference was statistically significant (64.1 ± 7.2; p = 0.0000). One year after loading, 8.9% of the examined implant sites present positive bleeding on probing, while 5.8% of the implant sites presented plaque. Conclusions: The OT Equator abutments showed successful results when used to support mandible fixed dental prosthesis delivered on 4–6 implants. Whole prosthetic survival and success rates, high patient satisfaction, and good biological parameters were experienced one year after function. Further prospective studies are needed to confirm these preliminary results.

FEM Analysis Applied to OT Bridge Abutment with Seeger Retention System

OBJECTIVE

 The purpose of this investigation is to highlight the technical components of a new kind of screw-retained dental implant prosthesis. The hypothesis is whether the OT Bridge (Rhein 83 S.R.L.; Bologna, Italy) system could be applied without secondary screw in the "all-on-four" retention system, thanks to the presence of an internal seeger.

MATERIALS AND METHODS

 By using engineering device such as finite element method (FEM) and von Mises investigation, it has been studied how the fixed prosthodontics for full-arch retention can be influenced by the presence of the screw for stabilizing it.

RESULTS

 In a dental implant, one model with four different configurations of the full-arch prosthesis retainer and the seeger has been investigated and then examined in contrast with or without the passant screw for locking the system. The experiments of this virtual study highlighted different features and mechanical behaviors of prosthodontic attachments.

CONCLUSION

 The first two configurations, respectively those in which there are four and three connection screws, are safe and predictable. Therefore, the presence of the seeger significantly improves the stability and the retention of the whole prosthesis.

Customized 3D-Printed Titanium Mesh Developed to Regenerate a Complex Bone Defect in the Aesthetic Zone: A Case Report Approached with a Fully Digital Workflow

Alveolar-ridge augmentation, anterior aesthetics, and digital technologies are probably the most popular topics in the dental-implant field. The aim of this report is to present a clinical case of severe atrophy of the anterior maxilla in a younger female patient, treated with a titanium membrane customized with computer-aided design/computer-aided manufacturing (CAD/CAM), simultaneous guided implant placement, and a fully digital workflow. A young female patient with a history of maxillary trauma was treated and followed-up for 1 year after implant placement. A narrow implant was inserted in a prosthetically driven position with the aid of computer-guided surgery. In the same surgical section, a customized implantable titanium mesh was applied. The scaffold was designed according to the contralateral maxillary outline in order to recreate a favorable maxillary bone volume. Finally, highly aesthetic, CAD/CAM, metal-free restorations were delivered using novel digital technologies.

Errors in Implant Positioning Due to Lack of Planning: A Clinical Case Report of New Prosthetic Materials and Solutions

The achievement of the optimal implant position is a critical consideration in implant surgery, as it can facilitate the ideal prosthesis design and allow adequate oral hygiene maintenance. The switch from bone-driven to prosthetic-driven implant placement, through a comprehensive diagnosis and adequate treatment plan, is a prerequisite for long-term successful implant-based therapy. The aim of the present case report is to describe a step-by-step prosthetic retreatment of a patient with primary treatment failure due to incorrect dental implant placement. Although dental implants achieve high survival rates, the success of implant prosthetic therapy significantly relies on an appropriate implant position. Malpositioned implants can cause damage to vital structures, like nerves or vessels. Moreover, improper implant positioning can result in esthetic, biological, and technical complications and can, in extreme situations, render the desired prosthetic rehabilitation impossible to achieve.

Five-year survival rates for implants placed using digitally-designed static surgical guides: a systematic review

Digitally-designed static surgical guides provide an acceptable level of accuracy and predictability for the placement of dental implants. However, to our knowledge, few published studies have compared the long-term survival of implants placed in this way with those placed using other methods. A systematic search of electronic databases using a population, intervention, comparison, and outcome (PICO) framework was conducted of Medline and EMBASE, as well as grey literature and hand searches, to obtain all relevant work pertaining to the survival of dental implants placed by guided surgery. The studies were required to have at least 10 patients with a follow up of at least five years. A total of 621 titles were screened. Four studies met the inclusion criteria for quantitative analysis, and they all reported the exclusive use of Nobel Biocare implants and the NobelGuide system (Nobel Biocare Services). Cumulative survival rates ranged from 94.5% to 100% over five years. The survival rates of implants placed using digitally-designed static surgical guides are comparable to the estimated overall survival rate (95.6% over five years), despite the complex nature of the treatments done with guided surgery. Clinicians who do these operations should, however, have the experience and ability to revert to conventional freehand techniques if complications arise.

A Systematic Review of Survival Rates of Osseointegrated Implants in Fully and Partially Edentulous Patients Following Immediate Loading

Background: The aim of this systematic review was to evaluate the survival rates of immediately loaded implants after at least five years. Besides implant failure, the amount of marginal bone loss around implants and the complication type were assessed. Methods: The electronic search was undertaken on Medline, Scopus, and Cochrane Central Register of Controlled Trials using key terms such as: “immediate loading”, “immediate function”, “immediate restoration”, “immediate temporization”, “dental implants”, “fully edentulous patients”, “partially edentulous patients”. The search terms were combined using the Boolean operators AND, OR. The last electronic search was performed on 15 February 2018. Two authors independently screened the studies, extracted the data, and assessed the risk-of bias. The main outcomes recorded for each study were: implant and prosthesis success and survival, marginal bone level change, incidence and type of complications. Kaplan–Meier analysis was used to estimate cumulative survival rates. Results: Thirty-four prospective studies with at least five-year follow-up, published between 2007 and 2017 were included. A total of 5349 immediately loaded implants in 1738 patients were analyzed. The mean follow-up was 72.4 months (median 60 months, 95% confidence intervals (CI): 64.53, 80.25 months, range 60 to 147 months). The mean weighted implant survival was 97.4% (median 98.15%, 95% CI: 96.29%, 98.54%, range 83.80% to 100%). Cumulative survival rate of implants placed in the mandible was significantly higher than for the maxilla (p < 0.01). No significant difference in failure rate was found among the types of prosthesis employed (p = 0.27). The mean peri-implant bone level change at the end of the follow-up in each study ranged from 0.3 to 1.7 mm. Conclusion: Immediate loading of implants appears to have long-term predictability and success rate under well-defined circumstances.

Computer-Aided Design/Computer-Aided Manufacturing Milling of Allogeneic Blocks Following Three-Dimensional Maxillofacial Graft Planning

Despite the advent of stereolithography in craniofacial surgery for creating surgical guides and custom synthetic scaffolds, little is known about the feasibility of computer-aided design/computer-aided manufacturing (CAD/CAM) milling of freeze-dried allogeneic bone blocks following previously designed volumetric graft plans. The aim of this technical report is to present a methodology for CAD/CAM milling to achieve the volume and shape of allogeneic bone blocks as estimated by using a virtual planning software. To perform the current methodology, an ex vivo simulation was performed. The milled allogeneic block presented satisfactory dimensional accuracy as compared with the respective three-dimensional virtual model.

Computer-assisted, template-guided immediate implant placement and loading in the mandible: a case report

BACKGROUND

Computer-assisted implant planning has become an important diagnostic and therapeutic tool in modern dentistry. This case report emphasizes the possibilities in modern implantology combining virtual implant planning, guided surgery with tooth and implant supported templates, immediate implant placement and loading.

CASE PRESENTATION

A straight forward approach was followed for the mandible presenting with hopeless lower incisors. Diagnosis, decision making and treatment approach were based on clinical findings and detailed virtual three-dimensional implant planning. Extractions of the hopeless mandibular incisors, immediate and guided implant placement of six standard implants, and immediate loading with a provisional fixed dental prosthesis (FDP) were performed fulfilling patient's functional and esthetic demands. The final computer assisted design / computer assisted manufacturing (CAD/CAM) FDP with a titanium framework and composite veneering was delivered after 6 months. At the 1-year recall the FDP was free of technical complications. Stable bony conditions and a healthy peri-implant mucosa could be observed.

CONCLUSIONS

Computer assisted implantology including three-dimensional virtual implant planning, guided surgery, and CAD/CAM fabrication of provisional and final reconstructions allowed for a concise treatment workflow with predictable esthetic and functional outcomes in this mandibular full-arch case. The combination of immediate implant placement and immediate loading was considerably more complex and required a high level of organization between implantologist, technician and patient. After the usage of a first tooth-supported surgical template with subsequent extraction of the supporting teeth, a second surgical template stabilized on the previously inserted implants helped to transfer the planned implant position in the extraction sites with a guided approach.

Accuracy of Computer-Assisted Template-Based Implant Placement Using Two Different Surgical Templates Designed with or without Metallic Sleeves: A Randomized Controlled Trial

Purpose: To compare virtual planning accuracy of novel computer-assisted, template-based implant placement techniques, which make use of CAD/CAM stereolithographic surgical templates with or without metallic sleeves. Furthermore, to compare open versus closed sleeves for templates without metallic sleeves. Materials and methods: Any partially edentulous patients requiring at least one implant to be placed according to a computer-assisted template-based protocol were enrolled. Patients were randomized according to a parallel group design into two arms: Surgical template with or without metallic sleeves. Three deviation parameters (angular, horizontal, vertical) were defined to evaluate the discrepancy between the planned and placed implant positions. Results: No implants failed, and no complications were experienced. Forty-one implants were placed using surgical templates with metallic sleeves while 49 implants were placed with a surgical template without metallic sleeves. Of these, 16 implants were placed through open sleeves and 33 through closed sleeves. There was a statistically significant difference in angle (p = 0.0212) and in the vertical plan (p = 0.0073) with lower values for implants placed with a surgical template without metallic sleeves. In the test group, close sleeves were more accurate compared with open sleeves in angle (p = 0.0268) and in horizontal plan (p = 0.0477). Conclusion: With the limitations of the present study, surgical templates without metallic sleeves were more accurate in the vertical plan and angle compared to the conventional template with metallic sleeves. Open sleeves should be used with caution in the molar region only in case of reduced interarch space. Further research is needed to confirm these preliminary results.

Optimal number of implants for complete-arch implant-supported prostheses with a follow-up of at least 5 years: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Consensus is lacking regarding the optimal number of implants for supporting complete-arch prostheses with good survival rates and lower prosthetic complications and marginal bone loss.

PURPOSE

The purpose of this systematic review was to evaluate the influence of the number of implants used for complete-arch prostheses with at least 5 years of follow-up.

MATERIAL AND METHODS

A search was performed in the PubMed/MEDLINE, Scopus, and Cochrane Library databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria and was registered in The International Prospective Register of Systematic Reviews (CRD42016048468). The following was the population, intervention, comparison, outcome (PICO) question: Does the number of implants influence the longevity of complete-arch prostheses?

RESULTS

Nineteen studies including 1006 patients with a mean age of 61.44 years were selected for evaluation. The number of implants per jaw ranged between 2 and 9 in the maxilla, mandible, or both jaws. For implant survival rate in complete-arch prostheses with fewer than 5 implants per jaw, the pooled weighted event rate was 1.4% (I²=25.26%; P=.211) and 4.2% (I²=81.35%; P<.001) for complete arches with more than 4 implants per jaw. For the prosthesis survival rate, the pooled weighted event rate for a complete-arch with fewer than 5 implants per jaw was 1.5% (I²=0%; P=.677) and 9% (I²=17.33%; P=.304) for complete arches with more than 4 implants per jaw. For prosthesis complications for complete arches with fewer than 5 implants per jaw, the pooled weighted event rate was 19.9% (I²=93.5%; P<.001) and 24.5% (I²=88.89; P<.001) for complete arches with more than 4 implants per jaw. The mean marginal bone loss for complete arches with fewer than 5 implants per jaw was 1.22 ±0.49 mm (I²=99.46; P<.001) and 1.46 ±0.46 mm (I²=99.6; P <.001) for more than 4 implants per jaw.

CONCLUSIONS

The current systematic review indicated no relationship of the number of implants used to support a complete-arch prosthesis with implant survival rate, prosthesis survival rate, prosthesis complications, or marginal bone loss in studies with follow-up periods of between 5 and 15 years.

Double Guided Surgery in All-on-4® Concept: When Ostectomy Is Needed

Background

The rehabilitation of edentulous jaws with guided and flapless surgery applied to the All-on-4 concepts is a predictable treatment with a high implant and prosthetic survival rates, but there are several contraindications for this technique like when bone reduction is needed due to a high smile line in the maxilla or when there is an irregular or thin bone crest.

Purpose

To report a technique with double guided surgery for bone reduction and implant placement with the All-on-4 concept.

Materials and Methods

7 patients were included in the study. Guided implant planning was performed using CBCT, and the virtual templates were created with three dedicated software. Custom surgical templates were made for the ostectomy and for implants positioning.

Results

28 implants were placed using a double bone-supported surgical guide. The mean angular errors between the preoperative-planned implant and the postoperative-placed implant were 2.155° ± 2.03°; the mean distance errors between the planned and the placed implants were 0.763 mm ± 0.55 mm on the shoulder implant and 0.570 mm ± 0.40 mm on the apex implant.

Conclusions

The results of our study indicate that this treatment is predictable with an excellent survival rate allowing excellent results even when bone reduction is mandatory.

The Ball Welding Bar: A New Solution for the Immediate Loading of Screw-Retained, Mandibular Fixed Full Arch Prostheses

Purpose

To present a new intraoral welding technique, which can be used to manufacture screw-retained, mandibular fixed full-arch prostheses.

Methods

Over a 4-year period, all patients with complete mandibular edentulism or irreparably compromised mandibular dentition, who will restore the masticatory function with a fixed mandibular prosthesis, were considered for inclusion in this study. The “Ball Welding Bar” (BWB) technique is characterised by smooth prosthetic cylinders, interconnected by means of titanium bars which are adjustable in terms of distance from ball terminals and are inserted in the rotating rings of the cylinders. All the components are welded and self-posing.

Results

Forty-two patients (18 males; 24 females; mean age 64.2 ± 6.7 years) were enrolled and 210 fixtures were inserted to support 42 mandibular screw-retained, fixed full-arch prostheses. After two years of loading, 2 fixtures were lost, for an implant survival rate of 97.7%. Five implants suffered from peri-implant mucositis and 3 implants for peri-implantitis. Three of the prostheses (3/42) required repair for fracture (7.1%): the prosthetic success was 92.9%.

Conclusions

The BWB technique seems to represent a reliable technique for the fabrication of screw-retained mandibular fixed full-arch prostheses. This study was registered in the ISRCTN register with number ISRCTN71229338.