German O. Gallucci

Success Criteria in Implant Dentistry: A Systematic Review

The purpose of this study was to examine the most frequently used criteria to define treatment success in implant dentistry. An electronic MEDLINE/PubMED search was conducted to identify randomized controlled trials and prospective studies reporting on outcomes of implant dentistry. Only studies conducted with roughened surface implants and at least five-year follow-up were included. Data were analyzed for success at the implant level, peri-implant soft tissue, prosthetics, and patient satisfaction. Most frequently reported criteria for success at the implant level were mobility, pain, radiolucency, and peri-implant bone loss (> 1.5 mm), and for success at the peri-implant soft-tissue level, suppuration, and bleeding. The criteria for success at the prosthetic level were the occurrence of technical complications/prosthetic maintenance, adequate function, and esthetics during the five-year period. The criteria at patient satisfaction level were discomfort and paresthesia, satisfaction with appearance, and ability to chew/taste. Success in implant dentistry should ideally evaluate a long-term primary outcome of an implant-prosthetic complex as a whole.

Descriptive analysis of implant and prosthodontic survival rates with fixed implant-supported rehabilitations in the edentulous maxilla.

BACKGROUND This descriptive study reviewed the 1- to 15-year survival rates of fixed implant rehabilitations in the edentulous maxilla. METHODS An electronic search was conducted, and cohort studies with 1- to 15-year follow-ups were identified by two independent reviewers. The implant and prosthodontic survival rates were reviewed at 1-, 3-, 5-, 10-, and 15-year endpoints. Descriptive analysis includes surface characteristics, bone-augmentation procedure, prosthetic design, and implant number and distribution along the edentulous maxilla. RESULTS Thirty-three studies, including 1,320 patients and 8,376 implants, were selected for analysis. The overall calculated implant survival rates ranged from 94% (1 year) to 87.7% (15 years). The implant survival rates for rough-surface implants ranged from 97% (1 year) to 98% (15 years); machined implants showed survival rates of 92% to 87.7%; respectively. Implants placed in native bone had greater survival rates than those placed in augmented bone. The prosthodontic survival rate ranged from 98.2% at 1 year to 92.1% at the 10-year endpoint, and it was only influenced by the implant number and distribution. CONCLUSIONS Implants with rough surfaces showed a statistically higher survival rate than machined implants at all intervals. Implants placed in augmented bone had a statistically lower survival rate, except for rough-surface implants, for which no statistical difference between augmented and non-augmented bone survival rates was found. Machined implants showed a stable survival rate only when placed in native bone. When machined implants were placed in augmented bone, the survival rate decreased significantly at each study endpoint. The prosthetic design, veneering material, and the number of prostheses per arch had no influence on the prosthodontic survival rate. Implant number and distribution along the edentulous maxilla seemed to influence the prosthodontic survival rate.

Dimensions of buccal bone and mucosa at immediately placed implants after 7 years: a clinical and cone beam computed tomography study

OBJECTIVE The objective of this study was to evaluate the dimensions of buccal bone and soft tissue at immediately placed implants over a 7-year period. MATERIAL AND METHODS Twenty-four patients, that participated in a clinical prospective study and received implants immediately placed into extraction socket, were enrolled for this study. Residual bone defects were grafted with xenogenic bone substitute and covered by means of collagen membrane. Baseline examination included measurements of full-mouth plaque and bleeding scores, width of keratinized mucosa, and dimensions of residual bone defects at the buccal aspect. Seven years after implant placement, full-mouth plaque score, full-mouth bleeding score, width of keratinized mucosa, and probing pocket depth were assessed and cone beam computed tomography images acquired. Dimensions of buccal bone and soft tissue were evaluated on the cross-sectional cone beam computed tomography reconstructions. Differences between two time-points were tested using the two-sided t-test. Correlation analysis was used to investigate the influence of baseline bone defect dimensions on the bone dimensions measured at the 7-year follow-up. RESULTS AND CONCLUSIONS Fourteen patients attended the follow-up examination. In five implants almost no buccal bone was detected, whereas in the remaining nine implants the buccal bone was found covering the rough implant surface. No correlation was found between initial bone defects and bone dimensions at the follow-up examination. The sites without radiographically detectable buccal bone at the 7-year control presented with 1 mm more apical mucosal level in comparison to implants with intact buccal bone.

Five‐year results of fixed implant‐supported rehabilitations with distal cantilevers for the edentulous mandible

OBJECTIVES The purpose of this study was to evaluate the survival rate, success rate and primary complications associated with mandibular fixed implant-supported rehabilitations with distal cantilevers over 5 years of function. MATERIAL AND METHODS In this prospective multi-center trial, 45 fully edentulous patients were treated with implant-supported mandibular hybrid prostheses with distal extension cantilevers. Data were collected at numerous time points, including but not limited to: implant placement, abutment placement, final prosthesis delivery, 3 months and 5 years post-loading. Biological, implant and prosthetic parameters defining survival and success were evaluated for each implant including: sulcus bleeding ndex (SBI) at four sites per implant, width of facial and lingual keratinized gingiva (mm), peri-implant mucosal level (mid-facial from the top of the implant collar, measured in mm), modified plaque index (MPI) at four sites per implant, mobility and peri-implant radiolucency. Survival was defined as implants or prostheses that did not need to be replaced. Success rate was defined as meeting well-established criteria that were chosen to indicate healthy peri-implant mucosa osseointegration, prostheses success and complications. RESULTS A total of 237 implants in 45 completely edentulous patients were included in the study. In each patient, four to six implants were placed to support hybrid prostheses with distal cantilevers. Cantilevers ranged in length from 6 to 21 mm, with an average length of 15.6 mm. The ages of the patients ranged from 34 to 78 with a mean age of 59.5 years. The survival rate of implants was 100% (237/237) and for prostheses 95.5% (43/45). The overall treatment success rate was calculated as 86.7% (39/45). Of the six patients that have not met the criteria for success, two patients required replacement of the entire prosthesis and four patients presented >four complications events. CONCLUSION Fixed implant-supported rehabilitation with distal cantilever resulted in a reliable treatment modality over the 5-year observation period. Although biological parameters of MPI, SBI, keratinized tissue and peri-implant mucosal levels showed statistically significant differences over time, the mean values for each patient remained within the normal limits of oral health. Complications were categorized as biological or technical. The majority of complications were technical complications (54/79) and of these most involved fracture of the acrylic teeth and base (20/54). While the survival rate was 100% for implants and 95.5% for prostheses, the application of strict criteria for treatment success resulted in an overall treatment success rate of 86.7%.

Consensus Statements and Clinical Recommendations for Implant Loading Protocols

No abstract available.

Accuracy of implant impressions for partially and completely edentulous patients: a systematic review

PURPOSE To compare the accuracy of digital and conventional impression techniques for partially and completely edentulous patients and to determine the effect of different variables on the accuracy outcomes. MATERIALS AND METHODS An electronic and manual search was conducted to identify studies reporting on the accuracy of implant impressions. Pooled data were descriptively analyzed. Factors affecting the accuracy were identified, and their impact on accuracy outcomes was assessed. RESULTS The 76 studies that fulfilled the inclusion criteria featured 4 clinical studies and 72 in vitro studies. Studies were grouped according to edentulism; 41 reported on completely edentulous and 35 on partially edentulous patients. For completely edentulous patients, most in vitro studies and all three clinical studies demonstrated better accuracy with the splinted vs the nonsplinted technique (15 studies, splint; 1, nonsplint; 9, no difference). One clinical study and half of the in vitro studies reported better accuracy with the open-tray vs the closed-tray technique (10 studies, open-tray; 1, closed-tray; 10, no difference). For partially edentulous patients, one clinical study and most in vitro studies showed better accuracy with the splinted vs the nonsplinted technique (8 studies, splint; 2, nonsplint; 3, no difference). The majority of in vitro studies showed better accuracy with the open-tray vs the closed-tray technique (10 studies, open-tray; 1, closed-tray; 7, no difference), but the only clinical study reported no difference. CONCLUSION The splinted impression technique is more accurate for both partially and completely edentulous patients. The open-tray technique is more accurate than the closed-tray for completely edentulous patients, but for partially edentulous patients there seems to be no difference. The impression material (polyether or polyvinylsiloxane) has no effect on the accuracy. The implant angulation affects the accuracy of implant impressions, while there are insufficient studies for the effect of implant connection type. Further accuracy studies are needed regarding digital implant impressions.

Bioengineered Periodontal Tissue Formed on Titanium Dental Implants

The ability to use autologous dental progenitor cells (DPCs) to form organized periodontal tissues on titanium implants would be a significant improvement over current implant therapies. Based on prior experimental results, we hypothesized that rat periodontal ligament (PDL)-derived DPCs can be used to bioengineer PDL tissues on titanium implants in a novel, in vivo rat maxillary molar implant model. Analyses of recovered implants revealed organized PDL tissues surrounding titanium implant surfaces in PDL-cell-seeded, and not in unseeded control, implants. Rat PDL DPCs also exhibited differentiative potential characteristic of stem cells. These proof-of-principle findings suggest that PDL DPCs can organize periodontal tissues in the jaw, at the site of previously lost teeth, indicating that this method holds potential as an alternative approach to osseointegrated dental implants. Further refinement of this approach will facilitate the development of clinically relevant methods for autologous PDL regeneration on titanium implants in humans.

Digital versus conventional implant impressions for edentulous patients: accuracy outcomes

PURPOSE To compare the accuracy of digital and conventional impression techniques for completely edentulous patients and to determine the effect of different variables on the accuracy outcomes. MATERIALS AND METHODS A stone cast of an edentulous mandible with five implants was fabricated to serve as master cast (control) for both implant- and abutment-level impressions. Digital impressions (n = 10) were taken with an intraoral optical scanner (TRIOS, 3shape, Denmark) after connecting polymer scan bodies. For the conventional polyether impressions of the master cast, a splinted and a non-splinted technique were used for implant-level and abutment-level impressions (4 cast groups, n = 10 each). Master casts and conventional impression casts were digitized with an extraoral high-resolution scanner (IScan D103i, Imetric, Courgenay, Switzerland) to obtain digital volumes. Standard tessellation language (STL) datasets from the five groups of digital and conventional impressions were superimposed with the STL dataset from the master cast to assess the 3D (global) deviations. To compare the master cast with digital and conventional impressions at the implant level, analysis of variance (ANOVA) and Scheffes post hoc test was used, while Wilcoxons rank-sum test was used for testing the difference between abutment-level conventional impressions. RESULTS Significant 3D deviations (P < 0.001) were found between Group II (non-splinted, implant level) and control. No significant differences were found between Groups I (splinted, implant level), III (digital, implant level), IV (splinted, abutment level), and V (non-splinted, abutment level) compared with the control. Implant angulation up to 15° did not affect the 3D accuracy of implant impressions (P > 0.001). CONCLUSION Digital implant impressions are as accurate as conventional implant impressions. The splinted, implant-level impression technique is more accurate than the non-splinted one for completely edentulous patients, whereas there was no difference in the accuracy at the abutment level. The implant angulation up to 15° did not affect the accuracy of implant impressions.

Implant and Prosthodontic Survival Rates with Implant Fixed Complete Dental Prostheses in the Edentulous Mandible after at Least 5 Years: A Systematic Review

BACKGROUND The treatment of mandibular edentulism with implant fixed complete dental prostheses (IFCDPs) is a routinely used treatment option. PURPOSE The study aims to report the implant and prosthodontic survival rates associated with IFCDPs for the edentulous mandible after an observation period of a minimum 5 years. MATERIALS AND METHODS An electronic MEDLINE/PubMED search was conducted to identify randomized controlled clinical trials and prospective studies with IFCDPs for the edentulous mandible. Clinical studies with at least 5-year follow-up were selected. Pooled data were statistically analyzed and cumulative implant- and prosthesis survival rates were calculated by meta-analysis, regression, and chi-square statistics. Implant-related and prosthesis-related factors were identified and their impact on survival rates was assessed. RESULTS Seventeen prospective studies, including 501 patients and 2,827 implants, were selected for meta-analysis. The majority of the implants (88.5% of all placed implants) had been placed in the interforaminal area. Cumulative implant survival rates for rough surface ranged from 98.42% (95% confidence interval [CI]: 97.98-98.86) (5 years) to 96.86% (95% CI: 96.00-97.73) (10 years); smooth surface implant survival rates ranged from 98.93% (95% CI: 98.38-99.49) (5 years) to 97.88% (95% CI: 96.78-98.98) (10 years). The prosthodontic survival rates for 1-piece IFCDPs ranged from 98.61% (95% CI: 97.80-99.43) (5 years) to 97.25% (95% CI: 95.66-98.86) (10 years). CONCLUSION Treatment with mandibular IFCDPs yields high implant and prosthodontic survival rates (more than 96% after 10 years). Rough surface implants exhibited cumulative survival rates similar to the smooth surface ones (p > .05) in the edentulous mandible. The number of supporting implants and the antero-posterior implant distribution had no influence (p > .05) on the implant survival rate. The prosthetic design and veneering material, the retention type, and the loading protocol (delayed, early, and immediate) had no influence (p > .05) on the prosthodontic survival rates.

Accuracy of digital versus conventional implant impressions

OBJECTIVE The accuracy of digital impressions greatly influences their clinical viability in implant restorations. The aim of this study was to compare the accuracy of gypsum models acquired from the conventional implant impression to digitally milled models created from direct digitalization by three-dimensional analysis. MATERIALS AND METHODS Thirty gypsum and 30 digitally milled models, impressed directly from a reference model, were prepared. The models and reference model were scanned by a laboratory scanner, and 30 surface tessellation language datasets from each group were imported to an inspection software program. The datasets were aligned to the reference dataset by a repeated best-fit algorithm, and 10 specified contact locations of interest were measured in mean volumetric deviations. The areas were pooled by cusps, fossae, interproximal contacts, horizontal and vertical axes of implant position and angulation. The pooled areas were statistically analysed by comparing each group to the reference model to investigate the mean volumetric deviations accounting for accuracy and standard deviations for precision. RESULTS Milled models from digital impressions had comparable accuracy to gypsum models from conventional impressions. However, differences in fossae and vertical displacement of the implant position from the gypsum and digitally milled models compared to the reference model exhibited statistical significance (P < 0.001, P = 0.020, respectively). CONCLUSION Milled models from digital impression are comparable to gypsum models from conventional impression.