A systematic review of the survival and complication rates of implant-supported fixed dental prostheses (FDPs) after a mean observation period of at least 5 years

Transalveolar sinus floor lift without bone grafting in atrophic maxilla: A meta-analysis

We performed a meta-analysis aimed to assess the clinical results after transalveolar sinus floor lift without bone grafting in the atrophic maxilla. A systematic electronic literature search was conducted in PubMed, Embase and The Cochrane Library, followed by a manual search. Two reviewers independently extracted study data and conducted quality assessments. Ten non-controlled studies including 1484 implants and eight controlled studies (5 RCTs and 3 prospective studies) including 817 implants (451 implants in the non-graft group) were enrolled in this study. The survival rate of implants via the graft-free method was 98% (95%CI 96% to 100%). There was no significant difference in the survival rate between the non-graft group and the graft group (RR: 1.02; p = 0.18). No statistically significant difference in marginal bone loss was detected between the groups at 12 months (0.57, p = 0.07) or 36 months (0.05, p = 0.61). The endo-sinus bone gain in the non-graft group was significantly lower than in the graft group at 12 months (−1.10, p = 0.0001) and 36 months (−0.74, p = 0.02). Hence, the available evidence suggests that predictable results could be acquired through transalveolar sinus floor lift without bone grafting, while there may be a trend toward more endo-sinus bone gain with bone grafts.

Report of a human autopsy case in maxillary sinuses augmented using a synthetic bone substitute: Micro-computed tomographic and histologic observations

OBJECTIVE

This study of a human autopsy case aimed to characterize the histologic and micro-computed tomographic results of maxillary sinus augmentation using a synthetic bone substitute and simultaneous implant placement at 6 years.

MATERIAL AND METHODS

This report is based on the whole-body donation of a 62-year-old male patient who died due to bladder cancer. Implants had been placed in conjunction with sinus augmentation using a mixture of biphasic calcium phosphate and autogenous bone into both maxillary sinuses 6 years prior to the body donation. The maxillary sinus areas containing implants were gently removed from the cadaver and scanned using high-resolution micro-computed tomography. Samples were sectioned, prepared for undecalcified histologic slides and stained with haematoxylin-eosin.

RESULTS

The augmented volume was observed up to the apex of the implants, which were successfully osseointegrated. Cross-sectional micro-computed tomographic views revealed that the bone-substitute particles were embedded in radiopaque-mineralized tissues showing a trabecular pattern around the implants. The histologic analysis revealed mature lamellar bone surrounding the remaining bone-substitute particles as well as well-organized bone marrow spaces in the augment bone area and around the dental implants.

CONCLUSION

This human autopsy study histologically confirmed the presence of successful bone formation and long-term volume stability after sinus augmentation using biphasic calcium phosphate and simultaneous implant placement.

Influence of subcrestal implant placement compared with equicrestal position on the peri-implant hard and soft tissues around platform-switched implants: a systematic review and meta-analysis

AIM

The aim of this article is to systematically review the effect of subcrestal implant placement compared with equicrestal position on hard and soft tissues around dental implants with platform switch.

MATERIAL AND METHODS

A manual and electronic search (National Library of Medicine and Cochrane Central Register of Controlled Trials) was performed for animal and human studies published up to December 2016. Primary outcome variable was marginal bone level (MBL) and secondary outcomes were crestal bone level (CBL), soft tissue dimensions (barrier epithelium, connective tissue, and peri-implant mucosa), and changes in the position of soft tissue margin. For primary and secondary outcomes, data reporting mean values and standard deviations of each study were extracted and weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 14 publications were included (7 human studies and 7 animal investigations). The results from the meta-analyses have shown that subcrestal implants, when compared with implants placed in an equicrestal position, exhibited less MBL changes (human studies: WMD = - 0.18 mm; 95% CI = - 1.31 to 0.95; P = 0.75; animal studies: WMD = - 0.45 mm; 95% CI = - 0.66 to - 0.24; P < 0.001). Furthermore, the CBL was located at a more coronal position in subcrestal implants with respect to the implant shoulder (WMD = - 1.09 mm; 95% CI = - 1.43 to - 0.75; P < 0.001). The dimensions of the peri-implant mucosa seem to be affected by the positioning of the microgap and were greater at implants placed in a subcrestal position than those inserted equicrestally (WMD = 0.60 mm; 95% CI = 0.26 to 0.95; P < 0.001). While the length of the barrier epithelium was significantly greater in implants placed in a subcrestal position (WMD = 0.39 mm; 95% CI = 0.19 to 0.58; P < 0.001), no statistical significant differences were observed between equicrestal and subcrestal implant positioning for the connective tissue length (WMD = 0.17 mm; 95% CI = - 0.03 to 0.36; P = 0.10).

CONCLUSION

This systematic review suggests that PS implants placed in a subcrestal position have less MBL changes when compared with implants placed equicrestally. Furthermore, the location of the microgap seems to have an influence on the dimensions of peri-implant soft tissues. Clinical relevance When compared with PS placed in an equicrestal position, subcrestal implant positioning demonstrated less peri-implant bone remodeling.

Dentists' Most Common Practices when Selecting an Implant System

PURPOSE

To report a comprehensive description of dental implant system selection practices among dentists practicing implantology worldwide.

MATERIALS AND METHODS

An online questionnaire was designed and sent to members of 15 dental implant organizations. The survey questions addressed: dental implant system selection criteria, implant design variables, dentists' perspective to implant quality stamps, and dentists' satisfaction with their implant system(s). Responses were compiled and analyzed to determine correlation of responses using the chi-squared test (level of significance α ≤ 0.05).

RESULTS

Out of 4264 invitations sent, a total of 2001 (response rate = 46.9%) dentists participated in the survey. Approximately half of survey respondents (48.7%) were general dentists. More than two-thirds of the survey respondents (72.5%) were performing both the surgical and prosthetic implant phases. Implant-abutment connections were the most important dental implant system selection criterion (84.7%), followed by scientific evidence available on the implant system (82.8%), and simplicity of prosthetic steps (81.4%). Patient preferences (19.8%) were rated as the least important aspect. Sandblasted large gritted acid etched implant surfaces (SLA) were the most commonly used implant surfaces (75.8%); fluoride coated surfaces were the least commonly used (15.4%).

CONCLUSION

According to the results of this survey, most survey respondents practiced both surgical and prosthetic phases of dental implantology. The majority of survey respondents agreed on the importance of implant-abutment connections, scientific evidence available on implant systems, and simplicity of prosthetic steps when selecting implant systems.

A systematic review and meta-analysis of 3-unit fixed dental prostheses: Are the results of 2 abutment implants comparable to the results of 2 abutment teeth?

The purpose of the systematic review and meta-analysis was to compare the performance of 3-unit bridges on teeth with 3-unit bridges on implants, evaluating survival of the bridges, survival of the teeth or implants, condition of the hard and soft tissues surrounding the supports, complications and patient-reported outcome measures (PROM) after a mean observation period of at least 1 year. A literature search was conducted using a combination of the search terms: fixed partial denture and fixed dental prostheses (FDPs). An electronic search for data published until January 2017 was undertaken using the MEDLINE, EMBASE and Cochrane Library databases. Eligibility criteria included clinical human studies, either randomised or not, interventional or observational, which evaluated the results of 3-unit FDPs on either 2 implants or 2 abutment teeth. The search identified 1686 unique references. After applying eligibility criteria, 66 articles were included in the analysis. A total of 1973 3-unit FDPs were supported by teeth, and 765 were implant-supported. No significant differences were found either in the survival of the supporting abutments (P = .52; 99% vs 98.7% survival per year) or in the survival of the prostheses (P = .34; 96.4% vs 97.4% survival per year). Both treatments show an almost equally low complication rate, but there is a low level of reporting of hard and soft tissue conditions and PROM. It is concluded that implant-supported 3-unit FDPs seem to be a reliable treatment with survival rates not significantly different from the results of teeth-supported 3-unit FDPs.

Antimicrobial Effects of Three Different Treatment Modalities on Dental Implant Surfaces

Resolution of peri-implant inflammation and re-osseointegration of peri-implantitis affected dental implants seem to be dependent on bacterial decontamination. The aims of the study were to evaluate the antimicrobial effects of 3 different instrumentations on a micro-textured dental implant surface contaminated with an avirulent or a virulent Porphyromonas gingivalis strain and to determine alterations to the implant surface following instrumentation. Forty-five dental implants (Straumann SLA) were allocated to 3 treatment groups: Er:YAG laser, chitosan brush, and titanium curette (10 implants each) and a positive (10 implants) and a negative (5 implants) control. Each treatment group and the positive control were split into subgroups of 5 implants subsequently contaminated with either the avirulent or virulent P. gingivalis strain. The antimicrobial effect of instrumentation was evaluated using checkerboard DNA-DNA hybridization. Implant surface alterations were determined using a light interferometer. Instrumentation significantly reduced the number of attached P. gingivalis ( P < .001) with no significant differences among groups ( P = .310). A significant overall higher median score was found for virulent compared with avirulent P. gingivalis strains ( P = .007); the Er:YAG laser uniquely effective removing both bacterial strains. The titanium curette significantly altered the implant surface micro-texture. Neither the Er:YAG laser nor the chitosan brush significantly altered the implant surface. The 3 instrumentations appear to have a similar potential to remove P. gingivalis. The titanium curette significantly altered the microstructure of the implant surface.

Maxillary Sinus Floor Augmentation: a Review of Selected Treatment Modalities

Objectives

The objective of the present study is to present the current best evidence for enhancement of the vertical alveolar bone height and oral rehabilitation of the atrophic posterior maxilla with dental implants and propose some evidence-based treatment guidelines.

Material and Methods

A comprehensive review of the English literature including MEDLINE (PubMed), Embase and Cochrane Library search was conducted assessing the final implant treatment outcome after oral rehabilitation of the atrophic posterior maxilla with dental implants. No year of publication restriction was applied. The clinical, radiological and histomorphometric outcome as well as complications are presented after maxillary sinus floor augmentation applying the lateral window technique with a graft material, maxillary sinus membrane elevation without a graft material and osteotome-mediated sinus floor elevation with or without the use of a graft material.

Results

High implant survival rate and new bone formation was reported with the three treatment modalities. Perforation of the Schneiderian membrane was the most common complication, but the final implant treatment outcome was not influenced by a Schneiderian membrane perforation.

Conclusions

The different surgical techniques for enhancement of the vertical alveolar bone height in the posterior part of the maxilla revealed high implant survival with a low incidence of complications. However, the indication for the various surgical techniques is not strictly equivalent and the treatment choice should be based on a careful evaluation of the individual case. Moreover, further high evidence-based and well reported long-term studies are needed before one treatment modality might be considered superior to another.

Effects of Bacterial Contamination on Dental Implants During Surgery: A Systematic Review

INTRODUCTION

Contamination during surgery negatively influences the prognosis of orthopaedic implants; however, it has not been proven whether contamination influences the success of dental implant treatment. The aim of the systematic review was to investigate if there exists evidence in the literature whether contamination of dental implants during surgery affects osseointegration and clinical success.

MATERIALS AND METHODS

Four data bases were used for the literature search. Primary studies and reviews regarding both clinical and preclinical research were eligible. Rating of the summarized quality of the evidence was performed.

RESULTS

Five preclinical studies were included. Because of the estimated high risk of bias in all included studies and extensive differences in study design between the included studies, meta-analysis was not performed and no reliable aggregated data could be extracted.

CONCLUSIONS

It is suggested that the scientific evidence with regard to the current topic is insufficient. Further controlled studies are warranted.

Full mouth rehabilitation with retrievable metal-ceramic implant-supported fixed prostheses for a young patient with atrophic jaws: a clinical report

Treatment of atrophic edentulous jaws with implant‐supported fixed prostheses is one of the most complicated challenges in dentistry. This clinical report describes the prosthesis which consists of screw retained frameworks with individual cement retained crowns which combines the advantages of the screw retained restoration with the advantage of cement retained.

Retrospective cohort study of rough-surface titanium implants with at least 25 years' function

Background

The longitudinal clinical outcomes over decades contribute to know potential factors leading to implant failure or complications and help in the decision of treatment alternatives.

Methods

The cases of all patients who received dental implants treated with titanium plasma-sprayed surfaces and whose prostheses were set in the period 1984–1990 at seven private practices were retrospectively analyzed. The cumulative survival rate, the cumulative incidence of peri-implantitis, and the complication-free prosthesis rate were calculated with Kaplan-Meier survival curves, and the factors’ influence on implant survival rate and the incidence of peri-implantitis were determined by a single factor in univariate analyses and multivariate analyses.

Results

A total of 223 implants and 106 prostheses were applied to 92 patients, and approx. 62% of the implants and patients dropped out over the 25 years following their treatment. The cumulative survival rates of the implants at 10, 15, and 25 years were 97.4, 95.4, and 89.8%, respectively. A significant difference was observed in the implant position. The cumulative incidences of peri-implantitis at 10, 15, and 25 years were 15.3, 21.0, and 27.9%, respectively. Significant differences were observed in the gender, implant type, and width of keratinized mucosa around the implant. The cumulative survival rates of mechanical complication-free prostheses at 10, 15, and 25 years were 74.9, 68.8, and 56.4%, respectively. The difference in the type of prosthesis resulted in significant differences.

Conclusions

The high rate of dropout during follow-up indicates the difficulty of determining long-term (> 25 years) prognoses. The gender, location, and width of keratinized mucosa affected the development of peri-implantitis, resulting in late failures. Implant-supported overdentures were frequently repaired. Tooth implant-supported prostheses are not recommended for long-term survival.

Prevalence and risk indicators of peri-implantitis in Korean patients with a history of periodontal disease: a cross-sectional study

Purpose

The aim of this study was to analyze the prevalence and risk indicators of peri-implantitis in Korean patients with history of periodontal disease.

Methods

A total of 444 patients with 1,485 implants were selected from patients who had been treated at the Department of Periodontology, Chonbuk National University Dental Hospital between July 2014 and June 2015. A group with a history of peri-implantitis (HP) (370 patients with 1,189 implants) and a group with a current peri-implantitis (CP) (318 patients with 1,004 implants) were created based on the radiographic and clinical assessments of implants. The prevalence of peri-implantitis was calculated at both the patient and implant levels. The influence of risk variables on the occurrence of peri-implantitis was analyzed using generalized estimating equations analysis.

Results

The prevalence of peri-implantitis in the HP and CP groups ranged from 6.7% to 19.7%. The cumulative peri-implantitis rate in the HP group estimated with the Kaplan-Meier method was higher than that in the CP group over the follow-up period. Among the patient-related risk variables, supportive periodontal therapy (SPT) was the only significant risk indicator for the occurrence of peri-implantitis in both groups. In the analysis of implant-related variables, implants supporting fixed dental prosthesis (FDP) and implants with subjective discomfort were associated with a higher prevalence of peri-implantitis than single implants and implants without subjective discomfort in the HP group. The presence of subjective discomfort was the only significant implant-related variable predictive of peri-implantitis in the CP group.

Conclusions

Within the limitations of this study, the prevalence of peri-implantitis in Korean patients with a history of periodontal disease was similar to that reported in other population samples. Regular SPT was important for preventing peri-implantitis. Single implants were found to be less susceptible to peri-implantitis than those supporting FDP. Patients' subjective discomfort was found to be a strong risk indicator for peri-implantitis.

The Emergency Dental Appointment: Restorative Emergencies Part 2 - Dental Implant Related Problems

This is the second paper in a two-part series discussing the management of common restorative dental emergencies. The first paper focussed upon problems relating to conventional fixed and removable restorations, and this paper discusses the management of common dental implant related emergencies. With dental implant treatment becoming an increasingly popular method of replacing missing teeth, it is very likely that dentists working in general practice will routinely come across patients who have previously undergone this form of treatment, even if they themselves are not directly involved in placing or restoring dental implants. This paper is aimed at general dental practitioners (GDPs) who have some experience in managing dental implants, and those who want to gain further insight into how such situations may be managed.

Failure torque of ceramic neck titanium implant

STATEMENT OF PROBLEM

Dental implants are typically made of titanium. However, with the current systems on the market, the implant neck often shows through the gingival tissues as a black or dark gray line and/or as a grayish discoloration of the peri-implant soft tissue.

PURPOSE

The purpose of this in vitro study was to test a new implant design. The key component of this design is the ceramic shell that covers the polished collar of the tissue-level titanium implant and masks its dark color to mimic natural dentition. The main purpose was to determine the maximum torque for fracturing the ceramic shell and compare it with clinical implant insertion torque value.

MATERIAL AND METHODS

Type 4 commercially pure titanium endosseous implants of 3 different diameters (3.3, 4.1, and 4.8 mm) were used. Porcelain was applied in 0.5-mm thickness to the polished collar of each implant. An axial-torsional universal testing machine was used to twist the implants until failure. The data (n=10) were statistically analyzed by ANOVA and the Tukey honest significant difference test (α=.05). The maximum torque for each diameter group was also compared with the optimum clinical implant insertion torque value of 35 Ncm (control) using a 1-sample t test.

RESULTS

None of the tested groups had a fractured ceramic shell. Instead, the implant carriers fractured at the maximum torque levels. Therefore, the fracture of the implant carriers was selected as the maximum (failure) torque value. A statistical difference was found for the failure torque between the 3.3-mm diameter and the other 2 diameters (P<.001) although no statistical differences were found between the 4.1-mm and 4.8-mm diameters (P=.106). A statistically significant difference was found between the failure torque of any one of the tested groups and the clinical insertion torque (P<.001).

CONCLUSIONS

The ceramic shells did not fracture. Instead, the implant carriers fractured at certain torque levels. These levels were sufficiently higher than the clinical torque values.

Position paper for the evaluation and management of oral status in patients with valvular disease: Groupe de Travail Valvulopathies de la Société Française de Cardiologie, Société Française de Chirurgie Orale, Société Française de Parodontologie et d'Implantologie Orale, Société Française d'Endodontie et Société de Pathologie Infectieuse de Langue Française

Oral health is of particular importance in patients with heart valve diseases because of the risk of infective endocarditis. Recommendations for antibiotic prophylaxis before dental procedures have been restricted, but the modalities of oral evaluation and dental care are not detailed in guidelines. Therefore, a multidisciplinary working group reviewed the literature to propose detailed approaches for the evaluation and management of buccodental status in patients with valvular disease. Simple questions asked by a non-dental specialist may draw attention to buccodental diseases. Besides clinical examination, recent imaging techniques are highly sensitive for the detection of inflammatory bone destruction directly related to oral or dental infection foci. The management of buccodental disease before cardiac valvular surgery should be adapted to the timing of the intervention. Simple therapeutic principles can be applied even before urgent intervention. Restorative dentistry and endodontic and periodontal therapy can be performed before elective valvular intervention and during the follow-up of patients at high risk of endocarditis. The detection and treatment of buccodental foci of infection should follow specific rules in patients who present with acute endocarditis. Implant placement is no longer contraindicated in patients at intermediate risk of endocarditis, and can also be performed in selected high-risk patients. The decision for implant placement should follow an analysis of general and local factors increasing the risk of implant failure. The surgical and prosthetic procedures should be performed in optimal safety conditions. It is therefore now possible to safely decrease the number of contraindicated dental procedures in patients at risk of endocarditis.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection: a Systematic Review and Meta-Analysis

OBJECTIVES

The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection.

MATERIAL AND METHODS

A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied.

RESULTS

The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone loss around implants with a scalloped implant-abutment connection.

CONCLUSIONS

A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must be rejected. However, further long-term randomized controlled trials assessing implant treatment outcome with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of implants with a scalloped implant-abutment connection on preservation of the peri-implant marginal bone level.

Micromorphological differences of the implant-abutment junction and in vitro load testing for three different titanium abutments on Straumann tissue level implants

BACKGROUND

The aim of this study was to investigate the micromorphological differences among three commercially available titanium abutments on Straumann implants. Furthermore, the possible impact of functional loading on the micromorphology and potential complications was investigated with the use of in vitro testing.

MATERIAL AND METHODS

Three groups of Titanium abutments (A: Straumann Variobase n = 5, B: EBI best Duo n = 5, and C: Implant Direct n = 5) were torqued on Straumann RN implants, as according to each of the manufacturer's instructions. The implant-abutment units were scanned with Micro-CT. Three units of each group were directly sliced in the microtome and photographed under different magnifications (10×-500×) through a Scanning Electron Microscope. Six units (two from each group) were restored with cement-retained crowns, subjected to 2000,000 load cycles with loads between 30 and 300 N at 2 Hz, examined through Micro-CT and finally sliced and photographed as described above. The micromorphology of each unit was studied, and the total length of tight contact (<3 μm) was calculated between the implant, abutment and screw contact areas.

RESULTS

Major morphological differences were identified between the three units, as well as differences in the extent of tight contact in all areas examined. Despite the morphological differences, the 2M cycles of loading via in vitro test did not result in any noticeable complications although some changes in the micromorphology were observed.

CONCLUSION

The examined implant-abutment units presented with major morphological differences. Two million cycles of in vitro loading did not appear to affect the stability of the units despite the micromorphological changes. These results need to be interpreted however under the limitations of the small sample size and the specific set-up of the in vitro testing.

Cement- and Screw-Retained Implant-Supported Restorations Showed Comparable Marginal Bone Loss and Implant Survival Rate

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Evaluation of cement-retained versus screw-retained implant-supported restorations for marginal bone loss: A systematic review and meta-analysis. Lemos CAA, de Souza Batista VE, de Faria Almeida DA, Júnior JFS, Verri FR, Pellizzer EP. J Prosthet Dent 2016; 115(4):419-27.

SOURCE OF FUNDING

São Paulo Research Foundation (FAPESP), grant 2014/02490-8.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data.

Success Rate of Two-Piece Zirconia Implants: A Retrospective Statistical Analysis

PURPOSE

About 10 years ago, one-piece zirconia implants were introduced to dentistry. The aim of the study was to evaluate the clinical success of two-piece zirconia implants regarding osseointegration using the manufacturers' warranty data.

MATERIALS AND METHODS

Over a period of 4 years (2010-2014), the data of warranty replacements of 15,255 sold Zeramex implants were evaluated retrospectively and blinded.

RESULTS

Three hundred forty-seven (2.2%) nonosseointegrated implants were sent back. Zeramex T showed an average success rate of 96.7%, whereas Zeralock implants exhibited an average success rate of 98.5%. Furthermore, Zeramex Plus implants exhibit an average success rate of 99.4% within the investigated period. Assuming, that 2% of the failed implants were unreturned, the above-mentioned values show no changes. Assuming 5% (10%) of unreturned nonosseointegrated implants, the average success rate of Zeramex T decreases from 96.7% to 96.6% (96.4%) and of Zeralock from 98.5% to 98.4% (98.4%), respectively. The success rate of Zeramex Plus implants remains unchanged at 99.4%.

CONCLUSION

The results of this study imply that two-piece zirconia implants show competitive success rates, improved from >96.7% to >98.5% over three product generations.

Treatment concepts for the posterior maxilla and mandible: short implants versus long implants in augmented bone

The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician.

What do sales data tell us about implant survival?

Objective

The aim of this study was to evaluate the influence of implant diameter, length and shape on a surrogate parameter of implant survival; i.e. the implant return rate in a big data analysis.

Materials and methods

A retrospective study was conducted and the factors influencing the success rates of 69,377 sold implants over a seven-year period were evaluated. The osseointegration program of a reseller provides reliable data of a single country. Implant loss rates were investigated using logistic regression models and regressed by implant type, diameter, and length.

Results

The return rate of 69,377 sold implants was 2.78% and comparable to implant loss rates in previous published prospective studies as its surrogate parameter. A total of 80% of implant returns had occurred within 157 days, and an additional 15% within 750.25 days. Diameters of 3.8 to 5.0mm showed the lowest return rates with its bottom in the 4.3mm implant whilst 6.0mm implants had significantly higher return rates. In comparison to the most sold implant length (13mm) shorter implants showed significantly higher early return rates.

Conclusions

The study provides evidence that in cases of standard indications and sufficient bone, the use of screw typed dental implants with 3.8 or 4.3 diameter and 11 or 13 mm length shows the lowest implant return rates. Other implants may be selected only in specific indications.

The role of IL-1 gene polymorphisms (IL1A, IL1B, and IL1RN) as a risk factor in unsuccessful implants retaining overdentures

PURPOSE

Implant-supported overdentures are an alternative predictable rehabilitation method that has a high impact on improving the patient's quality of life. However, some biological complications may interfere with the maintenance and survival of these overdenture implants. The goal of this article was to assess the factors that affect peri-implant success, through a hypothetical prediction model for biological complications of implant overdentures.

METHODS

A retrospective observational, prevalence study was conducted in 58 edentulous Caucasian patients rehabilitated with implant overdentures. A total of 229 implants were included in the study. Anamnestic, clinical, and implant-related parameters were collected and recorded in a single database. "Patient" was chosen as the unit of analysis, and a complete screening protocol was established. The data analytical study included assessing the odds ratio, concerning the presence or absence of a particular risk factor, by using binary logistic regression modeling. Probability values (p values) inferior to 0.05 were considered as representing statistically significant evidence.

RESULTS

The performed prediction model included the following variables: mean probing depth, metal exposure, IL1B_allele2, maxillary edentulousness, and Fusobacterium nucleatum. The F. nucleatum showed significant association with the outcome. Introducing a negative coefficient appeared to prevent complications or even boost the biological defense when associated with other factors.

CONCLUSIONS

The prediction model developed in this study could serve as a basis for further improved models that would assist clinicians in the daily diagnosis and treatment planning practice of oral rehabilitation with implant overdentures.

Influence of misfit on the occurrence of veneering porcelain fractures (chipping) in implant-supported metal-ceramic fixed dental prostheses: an in vitro pilot trial

OBJECTIVE

Technical complications such as veneer fractures are more common in implant-supported than tooth-supported restorations. The underlying causes have not been fully identified. The aim of this study was to evaluate whether misfit between the restoration and the implant may affect the risk of veneer fractures.

MATERIALS AND METHODS

Twenty standardized five-unit implant-supported metal-ceramic fixed dental prostheses (FDP)s were manufactured and fixed in acrylic blocks. The test group consisted of ten FDPs fixed with a 150-μm misfit at the distal abutment. The remaining ten FDPs were fixed without misfit and acted as a control group. All FDPS underwent cyclic loading for a total of 100,000 cycles at 30-300 N. The FDPs were checked for cracks or chip-off fractures regularly. After cyclic load, the retorque value of all abutment screws was checked.

RESULTS

Cracks within the veneering porcelain were noted in nine FDPs in the test group and one FDP in the control group. This difference was statistically significant (P < 0.001). Fractures of the veneering porcelain occurred in three FDPs in the test group. No fractures occurred in the control group. This difference was not statistically significant. There were no significant differences in retorque values neither between the groups nor between different abutment positions in the FDPs.

CONCLUSIONS

Within the limitations of this in vitro pilot trial, it is suggested that misfit between a restoration and the supporting implant may increase the risk of cracking and/or chipping of the veneering porcelain for metal-ceramic FDPs.

A multicenter randomized controlled clinical trial using a new resorbable non-cross-linked collagen membrane for guided bone regeneration at dehisced single implant sites: interim results of a bone augmentation procedure

Objective

To compare clinical performance of a new resorbable non‐cross‐linked collagen membrane, creos xenoprotect (CXP), with a reference membrane (BG) for guided bone regeneration at dehisced implant sites.

Materials and methods

This randomized controlled clinical trial enrolled patients with expected dehiscence defects following implant placement to restore single teeth in the maxillary and mandibular esthetic zone and premolar area. Implants were placed using a two‐stage surgical protocol with delayed loading. Bone augmentation material placed at the implant surface was immobilized with CXP or BG membrane. Soft tissue health was followed during the healing period, and the defect size was measured at reentry and 6 months after implant placement.

Results

Of the 49 included patients, 24 were treated with CXP and 25 with BG. Patient characteristics did not differ between the two arms. In the CXP arm, the defect height at implant insertion was (mean ± SD) 5.1 ± 2.1 mm (n = 24) and reduced at reentry by 81% to 1.0 ± 1.3 mm (n = 23). In the BG arm, the defect height at implant insertion was 4.9 ± 1.9 mm (n = 25) and reduced at reentry by 62% to 1.7 ± 2.1 mm (n = 24). Assuming a margin of non‐inferiority of 1 mm, CXP was non‐inferior to BG. Membrane exposure rate was highest at week 3 in both arms, reaching 16.7% for BG and 8.7% for CXP.

Conclusions

The new resorbable non‐cross‐linked collagen membrane facilitates bone gain to support implant placement in expected dehiscence defects. The observed trend toward higher mean bone gain and lower exposure rate with CXP compared to BG should be further investigated.

The Esthetic Effect of Veneered Zirconia Abutments for Single-Tooth Implant Reconstructions: A Randomized Controlled Clinical Trial

PURPOSE

The purposes of this study were to test whether or not veneering of the submucosal part of zirconia abutments can positively influence the esthetic outcome compared with nonveneered zirconia abutments; to evaluate the influence of the mucosal thickness on the esthetic outcomes of the veneered and nonveneered abutments; and to evaluate the thickness of the peri-implant mucosa compared with the thickness of the gingiva of contralateral tooth sites.

MATERIALS AND METHODS

Forty-four single-tooth implants in 44 patients were randomly restored with either cemented (CR) or screw-retained (SR) reconstructions based on white zirconia abutments (CR-W, SR-W) or pink-veneered zirconia abutments (CR-P, SR-P). Esthetic outcome measurements were performed based on a spectrophotometric evaluation of the peri-implant mucosal color. In addition, the thickness of the mucosa was measured. A two-way analysis of variance was conducted to test the effect of veneering (pink vs white) and mucosa thickness (<2 mm vs ≥2 mm) on the calculated color difference ΔE for pooled data of CR and SR reconstructions (p < .05).

RESULTS

Analyses grouping the sites according to veneering of the abutments and mucosal thickness demonstrated less discoloration for sites with a veneered abutment irrespective of the mucosal thickness: ΔE 4.50 ± 1.93 (<2 mm) and ΔE 6.88 ± 2.45 (≥2 mm); CR-P, SR-P) compared with sites without veneering ΔE 9.72 ± 3.82 (<2 mm; CR-W, SR-W) and ΔE 8.31 ± 2.98 (≥2 mm). The differences between veneered and nonveneered abutments were significant (p = .032).

CONCLUSIONS

Veneering of zirconia abutments with pink veneering ceramic positively influenced the peri-implant mucosal color.

Dental implant treatment in a young woman after marginal mandibulectomy for treatment of mandibular gingival carcinoma: a case report

Dental implants play an important role in postoperative rehabilitation after surgical treatment of oral cancer through the provision of prosthetic tooth replacement. Two major implant prosthesis designs are available: fixed implant-supported prostheses and implant-supported overdentures. We herein report a case of a 16-year-old female patient who underwent alveolar ridge resection for treatment of mandibular gingival carcinoma. Following surgery, oral rehabilitation was attempted using an implant-supported overdenture on a gold bar retainer splinting four implants. However, the patient was not satisfied with this prosthesis because of mucosal pain and discomfort, and she gradually ceased its use. Consequently, contact with the opposing teeth caused wear of the prosthetic screws. We elected to replace the implant-supported overdenture with an implant-fixed prosthesis approximately 16 years after insertion of the overdenture to prevent further wear of the prosthetic screws. The patient was highly satisfied with the improved stability of the implant-fixed prosthesis. This case report indicates that the clinician must occasionally re-evaluate and sometimes alter the direction of treatment, even after definitive therapy has been completed.

Effect of prosthetic restoration on implant survival and success

PURPOSE

The objective of this work was to evaluate the effect of prosthetic restoration on the survival of implants and on the incidence of implant-related complications.

MATERIAL AND METHODS

From a prospectively documented clinical study, 1569 implants placed in 630 patients (mean age 59.56 years) were evaluated. Selection criteria were a conventional loading protocol, prosthetic restoration with at least one follow-up, and a minimum observation period of 9 months. Implants that failed before prosthetic restoration were excluded. The sample included 1345 tissue-level implants and 104 bone-level implants (Straumann), and 120 Replace implants (Nobel Biocare). The observation period ranged between 9 months and 11 years after prosthetic restoration (mean 4.0 years; SD 2.5). The implants were restored with single crowns (n = 557), fixed dental prostheses (n = 594), or removable dental prostheses (RDP) (n = 418). In the RDP group, 356 implants were restored with telescoping crowns, 22 with bar units 24 with bar joints, and 16 with locator attachments. The incidence of implant-related complications and failures was analyzed by use of Kaplan-Meier survival curves. Cox regression analysis was used to identify possible risk factors.

RESULTS

Twenty-seven failures (1.8%; loosened or removed implants) were observed after prosthetic restoration; the incidence of failure was 3% for implants placed in males and 1% for implants placed in females. Other factors had no effect on the incidence of failure. Peri-implantitis (n = 29) and marginal bone loss >2 mm without acute inflammation (n = 6) also resulted in a 4% incidence of severe implant-related complications (62 of 1569; success 96%). Cox regression analysis revealed combined tooth-implant-supported restorations as a significant risk-reducing factor for severe implant-related complications (hazard ratio, HR = 0.34; P = 0.04). There was, furthermore, a tendency toward a greater incidence of complications for implants restored with RDPs than for single crowns (P = 0.08). Other factors, for example location (anterior/posterior, maxilla/mandible), age, sex, or implant placement combined with bone augmentation, had no significant effect on the incidence of implant-related complications (P values ranging between 0.16 and 0.94).

CONCLUSIONS

The type of support has a small but significant effect on implant prognosis. For detailed analysis of the effects of loading by different types of prosthetic restoration, larger sample sizes are required.

Intricate Assessment and Evaluation of Effect of Bruxism on Long-term Survival and Failure of Dental Implants: A Comparative Study

INTRODUCTION

Dental implants are one of the common lines of treatment used for the treatment of missing tooth. Various risk factors are responsible for the failure of the dental implants and occurrence of postoperative complications. Bruxism is one such factor responsible for the failure of the dental implants. The actual relation between bruxism and dental implants is a subject of long-term controversy. Hence, we carried out this retrospective analysis to assess the complications occurring in dental implants in patients with and without bruxism.

MATERIALS AND METHODS

The present study included 1100 patients which were treated for rehabilitation by dental implant procedure at 21 dental offices of Ghaziabad (India) from 2004 to 2014. Analyzing the clinical records of the patients along with assessing the photographs of the patients was done for confirming the diagnosis of bruxism. Clinical re-evaluation of the patients, who came back for follow-up, was done to confirm the diagnosis of bruxism. Systemic questionnaires as used by previous workers were used to evaluate the patients about the self-conscience of the condition. Estimation of the mechanical complications was done only in those cases which occurred on the surfaces of the restoration of the dental implants. All the results were analyzed by Statistical Package for Social Sciences (SPSS) software. Student's t-test and Pearson's chi-square test were used to evaluate the level of significance.

RESULTS

In both bruxer and non-bruxers, maximum number of dental implants was placed in anterior maxillary region. Significant difference was obtained while comparing the two groups for dimensions of the dental implants used. On comparing the total implant failed cases between bruxers and non-bruxers group, statistically significant result was obtained. Statistically significant difference was obtained while comparing the two study groups based on the health parameters, namely hypertension, diabetes, and smoking habit.

CONCLUSION

Success of dental implant is significantly affected by bruxism. Special attention is required in such patients while doing treatment planning.

CLINICAL SIGNIFICANCE

For the long-term clinical success and survival of dental implants in patients, special emphasis should be given on the patient's deleterious oral habits, such as bruxism as in long run, they influence the stability of dental implants.

Nanometer-grooved topography stimulates trabecular bone regeneration around a concave implant in a rat femoral medulla model

In the present study, a method was developed to reproduce two nanogrooved patterns (groove width/ridge width/depth: 150/150/50 nm and 200/800/70 nm) into cylindrical epoxy resin implants, which were subsequently coated with 20 nm of titanium. Also, implants with a conventional surface roughness (R_q=1.6 μm) were produced. After cytocompatibility analysis of the produced surfaces, implants were installed into the femoral condyle of rats for 4 and 8 weeks. The histomorphometrical analysis of bone volume in a 100 μm wide zone close to the implant surface showed that only for the 200/800 grooves the amount of bone increased significantly between 4 and 8 weeks of implantation. In addition, at the late time point only implants with the 200/800 pattern revealed a significantly higher bone volume compared to the rough controls. In conclusion, the 200/800 grooved pattern can positively influence bone volume adjacent to the implant surface, and should be evaluated and optimized in further (pre-)clinical studies.