Clinical and radiographic performance of late placed and early loaded dental implants with a conditioned hydrophilic surface in posterior mandible sites: A prospective case series with an 8.5- to 9.5-year follow-up.

OBJECTIVE: To assess the clinical outcomes by means of implant and prosthetic survival of late placed and early loaded implants with a hydrophilic, moderately rough surface for partially edentulous patients after a follow-up of 8.5 to 9.5 years. MATERIALS AND METHODS: A prospective case series study involving 15 patients with single, late placed and early loaded implants in the posterior mandible was performed. Clinical and radiographical parameters, including biological and technical complications and patient satisfaction, were assessed. RESULTS: From an initial sample of 15 patients, 12 were included. A total of 16 implants were observed. After a mean follow-up of 9 years and 7 months (SD ± 3.8 months), implant success and survival rate were 100%. The prosthetic survival rate was 100%, and the prosthetic success rate was 93.8% since a major chipping was observed. No biological complications were observed, and the mean modified plaque index was 0.03 (SD ± 0.09) with a mean probing pocket depth of 2.95 mm (SD ± 0.09). A mean marginal bone level (MBL) of 0.04 mm (SD ± 0.88) and a mean VAS of 9.42 (SD ± 0.90) for patient satisfaction were recorded. CONCLUSION: Late placed and early loaded implants with a moderately rough endosseal surface are a reliable option for rehabilitating partially edentulous patients. An implant survival rate of 100% and a prosthodontic success rate of 93.8% were observed. Patient satisfaction scores were high and peri-implant hard and soft tissues remained healthy. The study findings should be carefully interpreted because of the small sample.

A multicenter randomized controlled clinical pilot study of buccally micro-veneered lithium-disilicate and zirconia crowns supported by titanium base abutments: 1-year outcomes.

OBJECTIVES: To investigate survival rates, technical and biologic outcomes of buccally micro-veneered all-ceramic single implant crowns. MATERIAL AND METHODS: Sixty subjects randomly received immediately or early placed implants. Crowns out of lithium-disilicate (n = 30) and zirconia-ceramic (n = 30) were bonded to titanium-base-abutments. Restorations were inspected at baseline (BL) and during follow-up visits (6, 12 months). Technical and biologic parameters were recorded. Data were analysed descriptively. Differences between groups were tested with Student's t-test. Paired T-test was used when comparing data from the same implant or tooth over time. Linear model repeated measures were used to test differences between materials over time. Differences in counts were evaluated using Pearson Chi-square test. The level of significance was at p < .05. RESULTS: After a mean observation time of 13.2 ± 2.4 months, 54 restorations were re-examined. The implant survival rate was 98.3%, and the restoration survival rate was 100%. One early implant failure occurred. Two minor chippings occurred in lithium-disilicate restorations. No chippings or fractures occurred in any zirconia restorations at 1 year (0%). The technical complication rate was 3.7%, with 7.7% complications among the lithium-disilicate restorations and no differences between the two materials (p = .558). At 1-year follow-up, mean Bleeding on Probing (BOP) was higher at implants (0.27 ± 0.3) than adjacent teeth (0.17 ± 0.18) (p = .046) with no differences between materials (p = .36). Differences in pocket probing depth (PPD) between implants and adjacent teeth were significant (p < .01). Jemt Index improved significantly from BL to 1-y-follow-up (p < .001). CONCLUSIONS: Preliminary results were good, suggesting that the ceramic type does not impact technical and biologic parameters.

Influence of the Titanium Base Abutment Design on Monolithic Zirconia Multiple-Unit Implant Fixed Dental Prostheses: A Laboratory Study.

PURPOSE: This in vitro study evaluated technical outcomes of monolithic zirconia implant-supported fixed dental prostheses (iFDPs) supported by different designs of titanium base abutments after aging and static load testing. MATERIALS AND METHODS: Sixty three-unit monolithic zirconia (yttrium oxide partially stabilized tetragonal zirconia polycrystals; Y-TZP)iFDPs were produced and divided into four groups: group A-conical titanium base abutments for the prosthesis; group B-cylindrical titanium base abutments for the crown; group C-conical titanium base abutment for the prosthesis and cylindrical titanium base abutment for the crown; group D-cylindrical titanium base abutments for the prosthesis. The samples were subjected to an aging protocol and to continuous static loading until failure and analyzed visually and with specific software. The technical outcomes comprised the occurrence of debonding, screw loosening, deformation and fracture, abutment deformation and fracture, implant deformation and fracture, zirconia chipping and fracture, and bending moments. The Pearson chi-squared test (χ2) and Fischer exact test were used to compare the outcomes. The Kolmogorov-Smirnov test was used to evaluate data distribution of the bending moments. Analysis of variance (ANOVA) was used for the analysis of parametric data distribution, and the Kruskal-Wallis test was used for nonparametric data distribution. RESULTS: After aging, a higher percentage of debonding (P = .042) and micromovement (P = .034) was recorded in group C (P = .042). The conical titanium base abutments had a higher debonding (P = .049) and a higher macromovement rate (P = .05). The static load test showed higher bending moments in group D (P = .001) and lower bending moments in group A (P = .001). Debonding was highest in group C (P = .001) and lowest in group A (P = .002). Complete loss of retention rate was highest in group C (P = .001). The conical titanium base abutment had the highest debonding rate (P = .001) and complete loss of retention (P = .001). The micromovement rate was the highest for cylindrical titanium base abutments for the crown (P = .001). The lowest screw loosening, zirconia chipping, and fracture rate (P = .001) and the highest screw deformation (P = .004) were recorded in group A. The screw deformation rate was lowest in the cylindrical titanium base abutments for the crown (P = .008). CONCLUSION: The mixed titanium base abutment design comprising one conical and one cylindrical abutment in Y-TZP iFDPs led to the highest debonding rate. The cylindrical titanium base abutment for the prosthesis provided a lower percentage of debonding and the highest load resistance.

Clinical performance of implant crowns with customized zirconia abutments: A prospective cohort study with a 4.5- to 8.8-year follow-up.

OBJECTIVE: To assess the clinical and esthetic outcomes and patient satisfaction of screw-retained one-piece implant crowns fabricated with zirconia abutments after a 4.5- to 8.8-year follow-up. MATERIAL AND METHODS: Thirty-two patients (12 women and 20 men), who received 40 implant single crowns in anterior and premolar sites, were included in this prospective study. All restorations were based on ceramic hand-veneered customized CAD/CAM zirconia abutments. The follow-up consisted of clinical and radiological examinations. The pink esthetic score-white esthetic score (PES-WES) was used to evaluate the esthetic outcome. Patients' satisfaction was assessed via visual analog scale (VAS). RESULTS: Implant and prosthetic survival rates were 100% and 97.5%, respectively. Mean marginal bone loss was -0.17 mm (SD 1.16 mm). Probing depth was ≤4 mm in 98.7% and 5 mm in 1.3% of the sites; 8.3% of them were bleeding on probing positive. No technical or biological complications were observed except for one abutment fracture. The mean PES-WES scores were 7.0 and 7.1, respectively. VAS scores (10-point) of 9.41 for function and 9.26 for esthetics showed high patient satisfaction. CONCLUSION: After a mean observation period of 6 years and 7 months, screw-retained implant crowns based on veneered customized CAD/CAM zirconia abutments with conical connection showed very good clinical performance and may be recommended for the replacement of missing anterior and premolar teeth. (ClinicalTrials.gov # NCT04370314).

Early Loading of Titanium Dental Implants with an Intraoperatively Conditioned Hydrophilic Implant Surface: 3-Year Results of a Prospective Case Series Study.

PURPOSE: The hydrophilic implant surface (INICELL) is a chemical alteration of a sandblasted and thermally acid-etched surface that should lead to long-term osseointegration. This study investigated 3-year results after early loading of implants with a hydrophilic, moderately rough surface in occlusal contact. MATERIALS AND METHODS: This prospective case series study was conducted in subjects with partially edentulous mandibles. Implants were placed on day 21 and loaded with a provisional reconstruction after at least 21 days of healing (baseline, day 0) if their implant stability quotient (ISQ) was ≥ 70 (mean of three measurements) and were replaced by definitive porcelain-fused-to-metal prostheses at the 6-month follow-up visit. Follow-up examinations were planned 1, 3, 6, 12, and 36 months after baseline. RESULTS: A total of 20 implants were placed in 15 patients (mean age: 51 years, range: 32 to 67 years). After 36 months, all implants were osseointegrated, and no suppuration was recorded. Small changes of bone level were observed between 3 months and 36 months. At 36 months, the median values of the 20 implants were 0.25 (range: 0 to 0.5, SD: 0.17), 0.25 (range: 0 to 1, SD: 0.27), and 4 (range: 2 to 7.25, SD: 1.17) for the mean modified Plaque Index (mPI), mean modified Sulcus Bleeding Index (mSBI), and mean probing pocket depth, respectively. The pairwise analysis between 3 and 36 months showed an improvement in the mean mPI (P = .0126) and mean mSBI (P = .0059). After 36 months, all patients (n = 15) were fully satisfied with a mean of 9.43 (range: 8 to 10, SD: 0.678) at the visual analog scale. CONCLUSION: Early functional loading of implants with a hydrophilic, moderately rough outer surface in occlusal contact 21 days after healing appears to be a safe and feasible treatment option when placed in the posterior mandible of partially edentulous patients.

Reliability of Interproximal Bone Height Measurements in Bone- and Tissue-Level Implants: A Methodological Study for Improved Calibration Purposes.

PURPOSE: To evaluate the interobserver and intraobserver agreement between prosthodontists when measuring interproximal peri-implant bone levels from digital periapical radiographs and to introduce a radiographic quality index for periapical imaging assessment. MATERIALS AND METHODS: Periapical radiographs of 122 single implants in the anterior and posterior regions with two categories of imaging quality (ie, optimal and suboptimal) were assessed. Six prosthodontists were asked to linearly measure the distance from the first bone-to-implant contact to the implant platform/shoulder (DIB) using an image processing program (ImageJ 1.48u4, NIH). The procedure was repeated after 3 to 4 weeks. Interobserver and intraobserver agreements were evaluated by intraclass correlation coefficient and kappa. A radiographic quality index developed for periapical imaging assessment has been introduced in this study. Each implant was classified into two categories according to the implant type and the quality of the radiographic image. RESULTS: There were significant interobserver differences (P < .001). Most of the discrepancies between repeated measures were below 0.5 mm (range: 0.37 [SD ± 0.76] to 0.55 [SD ± 0.68]). The interobserver and intraobserver agreements on the bone-level values were "fair to moderate" regardless of the implant type and radiographic quality. With optimal image quality in tissue-level images, "substantial agreement" could be achieved. There was no significant effect of the implant level type (P = .973). CONCLUSION: Image quality, as well as the interpreter, influenced the measurements' reproducibility by prosthodontists. Bone height assessments at bone-level implants seem to be slightly more variable compared with tissue-level assessments; however, there were no significant differences. Specific guidelines on how to estimate DIB for calibration purposes in the case of suboptimal radiographic image quality and how to obtain optimal images need to be developed. The radiographic quality index for periapical imaging assessment is expected to be adopted in future studies.

Clinical performance and patient satisfaction obtained with tooth-supported ceramic crowns and fixed partial dentures.

STATEMENT OF PROBLEM: Studies reporting survival rates along with patient-centered outcomes are necessary to select the appropriate restorative material for crowns and fixed partial dentures (FPDs). However, studies that report the survival and complication rates of lithium disilicate crowns and the performance of zirconia FPDs compared with metal-ceramic FPDs are lacking. PURPOSE: The purpose of this clinical study was to assess the failure and complication incidence of tooth-supported ceramic crowns and FPDs in function for at least 5 years. Groups included were pressed lithium disilicate crowns (CP), veneered pressed lithium disilicate crowns (CV), and computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate crowns (CC). Veneered zirconia-based FPDs (FPDC) were compared with metal-ceramic FPDs (FPDM). Outcomes were survival and failure, success and complications, periodontal conditions, and patient satisfaction assessed at 2 examinations (at baseline ≥1 year after delivery and at the follow-up examination ≥5 years of function). MATERIAL AND METHODS: Eighty-two participants with 158 restorations (CP=39, CV=16, CC=20, FPDM=30, FPDC=53) were examined (2.38 ±0.96 years after delivery) to form the baseline data. For the prospective follow-up examination, 70 participants with 141 restorations (CP=39, CV=15, CC=16, FPDM=28, FPDC=43) were examined 4.08 ±0.36 years later. RESULTS: At the follow-up, restorations were in function for a mean of 6.44 ±1.14 years. Survival rates for crowns were 97.1% (CP=97.4%, CV=100%, and CC=93.8%) and 98.6% for FPDs (FPDM=96.4%, FPDC=100%). Among the 68 crowns, 1 technical and 4 biological complications were recorded. FPDs had more biological and technical complications than crowns (15/149 abutment teeth and 11/71 restorations). Technical complications were seen in 9.3% of zirconia FPDs compared with 25% for metal-ceramic FPDs. Complications were commonly observed at the baseline examination (crowns: 12/75 biological and 1/75 technical; FPDs: 40/174 abutment teeth with biological and 8/83 FPDs with technical complications). The periodontal conditions improved significantly after baseline. The patients reported a high level of satisfaction with the esthetics and function of the crowns and FPDs. CONCLUSIONS: Survival rate for ceramic crowns and FPDs was 97.9% after a mean observation time of 6.44 ±1.14 years. Biological complications were more commonly observed than technical complications, and complications were more common in FPDs than in crowns. The complication rate was similar for zirconia FPDs and metal-ceramic FPDs. Adherence to strict maintenance measures may have reduced the risk of biological complications.

Explantation of an Osseointegrated Titanium Implant Using Laser-Induced Thermo-necrosis: A Case Report.

Explantation of fully or partially osseointegrated titanium implants is a complex procedure for myriad reasons and often results in major bone loss and pronounced defects of the hard and soft tissues. This may require more elaborate surgical interventions in cases of re-implantation. In this patient case, an osseointegrated titanium implant with some visible bone loss, missing attached mucosa at the buccal aspect, and a nonideal three-dimensional (3D) position had to be explanted. For this, the implant's inner connection was heated using a CO2 laser, which resulted in localized laser-induced thermo-necrosis at the bone-to-implant contact. One week following laser application, explantation could be performed easily with a torque slightly more than 35 Ncm. No complications occurred during the healing period. The result was a very easily performed explantation while preserving a maximum of the surrounding bony structure. Healing was uneventful, and no further visible bone loss could be observed during the healing time.

Performance and marginal bone level alteration around immediately loaded narrow-diameter implants. A prospective clinical study: Results after 1 year.

OBJECTIVE: The aim of the present prospective clinical study was to assess the survival rate and the radiologic crestal bone level alteration around four interforaminal immediately loaded narrow-diameter implants (NDIs) in the edentulous mandible. METHOD AND MATERIALS: A total of 20 participants received each 4 NDIs (MDI, 3M Espe; diameter 1.8 mm, length 13 or 15 mm) in the edentulous mandible. Immediate loading was performed if insertion torque was 35 Ncm or higher. The implants were loaded the same day by converting the existing full denture into an implant overdenture. Follow-up visits were performed five times (baseline to 52 weeks). Standardized radiographs were taken at baseline and 12, 26, and 52 weeks post-loading. Clinical parameters (Plaque Index, probing depth, bleeding on probing) were assessed. The nonparametric ANOVA test was used to assess crestal bone level changes. RESULTS: In all 20 patients the healing of the total 80 implants was uneventful and no implant was lost. Sixty-eight (85%) implants were loaded immediately. All clinical parameters showed healthy, stable, and well-maintained peri-implant soft tissue conditions. The mean (± standard deviation) radiographic bone loss after 1 year was 0.78 (± 0.64) mm. CONCLUSION: According to the 1-year results of this prospective clinical study, NDIs seem to be a reliable alternative to support prostheses in edentulous patients with a reduced horizontal mandibular bone volume.

Clinical Performance of One-Piece, Screw-Retained Implant Crowns Based on Hand-Veneered CAD/CAM Zirconia Abutments After a Mean Follow-up Period of 2.3 Years.

PURPOSE: The aim of this study was to evaluate the clinical performance of one-piece, screw-retained implant crowns based on hand-veneered computer-aided design/computer-aided manufacture (CAD/CAM) zirconium dioxide abutments with a crossfit connection at least 1 year after insertion of the crown. MATERIALS AND METHODS: Consecutive patients who had received at least one Straumann bone level implant and one-piece, screw-retained implant crowns fabricated with CARES zirconium dioxide abutments were reexamined. Patient satisfaction, occlusal and peri-implant parameters, mechanical and biologic complications, radiologic parameters, and esthetics were recorded. RESULTS: A total of 50 implant crowns in the anterior and premolar region were examined in 41 patients. The follow-up period of the definitive reconstructions ranged from 1.1 to 3.8 years. No technical and no biologic complications had occurred. At the reexamination, 100% of the implants and reconstructions were in situ. Radiographic evaluation revealed a mean distance from the implant shoulder to the first visible bone-to-implant contact of 0.06 mm at the follow-up examination. CONCLUSION: Screw-retained crowns based on veneered CAD/CAM zirconium dioxide abutments with a crossfit connection seem to be a promising way to replace missing teeth in the anterior and premolar region. In the short term, neither failures of components nor complications were noted, and the clinical and radiographic data revealed stable hard and soft tissue conditions.