Clinical study with sandblasted dental implants: a 17-year retrospective follow up.

Sandblasting is a standard procedure used for treating dental implant (DI) surfaces to enhance the osseointegration with known clinical success. This clinical study aimed to evaluate the long-term clinical outcomes of DIs with external hexagon connections and a surface sandblasted with calcium phosphate. Two hundred and seventy-five Mg-osseous™ (Mozo-Grau™) screw DIs were placed in 86 patients using a two-stage surgical technique and conventional loading protocol (at three months). Dental implants and prosthetic clinical findings were evaluated during a 17-year follow up. Four DIs were lost during the healing period, and 108 prostheses were placed over the 271 DIs left: 58 unitary implant-supported prosthesis (ISP), 31 partially ISP, 14 full-arch ISP, and five overdentures. Fourteen DIs were lost during the follow-up period. Clinical results indicated a DI survival rate of 93.50%. A total of 11.80% of DIs showed peri-implantitis as the primary biological complication. The mean (SD) marginal bone loss was 1.78 (0.40) mm, ranging from 0.90 to 2.80 mm. The most frequent complication was mechanical prosthodontic complications (24.40%). Sandblasted surface DIs inserted in both maxillary and mandibular areas produce favourable long-term (17-year follow up) outcomes and stable tissue conditions when a delayed loading protocol is followed.

Long-term clinical performance of short 6-mm implants supporting single crowns in the posterior region: A 10-year cohort study.

INTRODUCTION: Long-term clinical success of non-splinted, posterior, and short implants still is unclear. This prospective cohort study reports the 10-year follow-up of 6-mm implants supporting single crowns in the posterior region, and patient-reported outcomes. METHODS: Baseline sample comprised 20 patients treated with 46 screw-retained crowns supported by 6-mm implants with moderately rough implant surface. Participants were recalled for a 10-year clinical follow-up to assess survival rates, biologic and mechanic conditions, quality of life (OHIP-14), and treatment satisfaction. Data were collected with clinical-radiographic exams and analyzed using descriptive and inferential statistics. RESULTS: Fourteen patients with 35 implant-crown units were examined after 127.6 ± 11.8 months. For the entire cohort period, 7/46 implants were lost (survival estimate: 77.7% at 133 months), and mechanic complications occurred in 14/46 units (survival estimate: 66.4% at 116 months). In the Cox models, "maximum occlusal force" had a significant effect for implant loss (p = 0.038) and for prosthetic screw loosening (p = 0.038); "arch" and "bruxism" were not significant. Peri-implant bone loss was 0.4 ± 0.6 mm at 10 years. For peri-implant bone level, "crown-to-implant ratio" (p < 0.001) and "time" (p = 0.001) were significant. Bone levels differed from baseline to 12, 48, and 120 months. Satisfaction VAS was 94.0 ± 7.9 mm and OHIP-14 was 2.3 ± 2.2. CONCLUSION: Single screw-retained crowns supported by 6-mm implants have an acceptable long-term clinical performance, with stable peri-implant bone levels after 10 years of function.

Clinical and Radiographic Evaluation of OsseoSpeed EV Implants.

PURPOSE: To evaluate the survival rate (primary outcome) and the marginal bone loss (secondary outcome) of the OsseoSpeed EV Implants (Astra Tech Implant System, Dentsply Sirona Implants; hereinafter EV implants) used in a wide range of clinical scenarios and followed up to 8 years in a nonuniversity setting. MATERIALS AND METHODS: All EV implants consecutively placed from 2013 to 2021 in a private dental clinic were included, and medical and radiologic records were retrospectively investigated. Independent reviewers collected 11 data types as potential influencing variables and measured the mesial and distal marginal bone levels to the nearest 0.5 mm on available radiographs, either panoramic or periapical. Tables of descriptive statistics were made at implant and patient levels. Univariate and multiple Cox regression models were adjusted for clustering effects and determined the hazard ratio (HR) and odds ratio (OR) for each independent variable collected. RESULTS: The study sample consisted of 597 EV implants and 235 patients. During a mean follow-up of 42.1 ± 23 months (range: 10 to 94 months), 44 implants were lost (7.4%)-34 early (5.7%) and 10 late (1.7%)-in 38 patients (16.1%). The overall survival rate (SR) was 92.6% (CI: 90.5% to 94.7%), and the proportion of patients with all their implants surviving was 83.8% (CI: 79.1% to 88.5%). At the end of the study, the probability of survival of an implant that did not fail early was 98.2% (CI: 97.1% to 99.3%). Implant-level analysis identified two significant variables: implant diameter (HR 0.37, P = .009**) and immediate postextraction placement (HR 2.35, P = .025*). At the patient level, bruxism (OR = 3.29; P = .009**), history of periodontitis (OR = 2.18, P = .030*), and the number of implants placed (OR = 1.43; P = .001**) were found to be statistically significant. After removing dropouts and early failures from a sample of 528 implants, 412 (78%) had a marginal bone loss (MBL) ≤ 0 mm at the end of the observation time, and 106 surviving implants (22%) showed a mean MBL of 1.42 ± 1.08 mm (range: 0.25 to 6.75 mm). CONCLUSIONS: An overall medium-term SR of the EV implants was 92.6%. Four of five EV implants showed a mid-term MBL ≤ 0 mm, and 91.86% of implants completed the observation period with an MBL < 2 mm. Thus, the EV implant system was shown to be a valid alternative for routine use in a nonuniversity setting. Clinicians should remember that there is no 100% implant survival in everyday practice and that bruxism, periodontitis, narrow-diameter implants, and immediate placement are risk factors for a higher failure rate.

Analysis of risk factors for early crestal bone loss in osseointegrated, submerged implants prior to restoration.

BACKGROUND: Evidence on the etiology behind bone loss around submerged, prosthetically nonloaded implants is still limited. The long-term stability and success of implants with early crestal bone loss (ECBL), especially when placed as two-stage implants, is uncertain. Hence, the aim of this retrospective study is to analyze the potential patient-level, tooth- and implant-related factors for ECBL around osseointegrated, submerged implants, before restoration as compared with healthy implants with no bone loss. METHODS: Retrospective data were collected from patient electronic health records between 2015 and 2022. Control sites included healthy implants with no bone loss and test sites included implants with ECBL, both of which were submerged. Patient, tooth and implant level data were collected. ECBL was assessed using periapical radiographs obtained during implant placement and second-stage surgeries. Generalized estimating equation logistic regression models were used to account for multiple implants within patients. RESULTS: The total number of implants included in the study was 200 from 120 patients. Lack of supportive periodontal therapy (SPT) was shown to have nearly five-times higher risk of developing ECBL and was statistically significant (p < 0.05). Guided bone regeneration (GBR) procedures before implant placement had a protective effect with an odds ratio of 0.29 (p < 0.05). CONCLUSIONS: Lack of SPT was significantly associated with ECBL, while sites that received GBR procedures prior to implant placement were less likely to exhibit ECBL. Our results underscore the importance of periodontal treatment and SPT for peri-implant health, even when the implants are submerged and unrestored.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part II-Success and Survival Rate Analysis.

PURPOSE: To analyze the success and survival of splinted and nonsplinted implants. MATERIALS AND METHODS: A total of 423 patients (n = implants: 888) were included in the study. The success and survival of implants for 15 years were analyzed using a multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. RESULTS: The cumulative success rate was 34.2%: 33.2% in nonsplinted (NS) and 34.8% in splinted implants (SP). The cumulative survival rate was 92.9% (94.1%, NS; 92.3%, SP). Whether to splint was not related to the success and survival of implants. The smaller the implant diameter, the lower the survival rate. The crown length and implant length were significantly associated only with NS implants: The longer the crown length and the shorter the implant length, the greater the risk of implant failure. The emergence angle (EA) and the emergence profile (EP) had a significant effect on only the SP implants: EA3 showed a higher risk than EA1, and EP2 and EP3 had a higher risk of implant failure. CONCLUSION: Crown length and implant length affected only the nonsplinted implants: The higher the crown length and the shorter the implant length, the greater the risk of implant failure. A significant effect for emergence contour was found only in SP implants: the implants restored with prostheses with EA ≥ 30 degrees on both the mesial and distal sides, and convex EP on at least one side had higher risks of failure. Int J Oral Maxillofac Implants 2023;38:443-450. doi: 10.11607/jomi.10054.

Risk factors associated with loss of variable-thread tapered implants: A retrospective observational study of 1-5 years.

OBJECTIVES: This study aimed to evaluate the survival rate of variable-thread tapered implants (VTTIs) and identify risk factors for early/late implant loss. MATERIALS AND METHODS: From January 2016 to December 2019, patients who received VTTIs were included in this study. The cumulative survival rates (CSRs) at implant/patient levels were calculated by the life table method and presented via Kaplan-Meier survival curves. The relation between investigated variables and early/late implant loss was analyzed by the multivariate generalized estimating equation (GEE) regression model on the implant level. RESULTS: A total of 1528 patients with 2998 VTTIs were included. 95 implants from 76 patients were lost at the end of observation. At the implant level, the CSRs at 1, 3, and 5 years were 98.77%, 96.97%, and 95.39%, respectively, whereas they were 97.84%, 95.31%, and 92.96% at the patient level, respectively. The multivariate analysis revealed that non-submerged implant healing (OR = 4.63, p = .037) was associated with the early loss of VTTIs. Besides, male gender (OR = 2.48, p = .002), periodontitis (OR = 3.25, p = .007), implant length <10 mm (OR = 2.63, p = .028), and overdenture (OR = 9.30, p = .004) could significantly increase the risk of late implant loss. CONCLUSION: Variable-thread tapered implants could reach an acceptable survival rate in clinical practice. Non-submerged implant healing was associated with early implant loss; male gender, periodontitis, implant length <10 mm, and overdenture would significantly increase the risk of late implant loss.

Evaluation of Implant and Prosthesis Survival Rates Based on Crestal Bone Loss.

A dental implant mimics the tooth and restores its function. It has flourished as a replacement of missing natural teeth that has a success rate over 90% over the years. However, this root-form implant has also been associated with some complications after its application. Crestal bone loss, one of the biggest challenges in dental implant placement, occurs around the dental implant neck within a few months post-loading. The aim of this study was to determine survival rates and to measure crestal bone changes after placement of a single crown prosthesis. Data collection was done in a private dental university setting. Data from approximately 296 cases were retrieved after analyzing 86,000 case sheets. The following parameters were evaluated based on dental records: age, sex, implant placement area, implant diameter and length, and presence or absence of exudate. Crestal bone loss was assessed radiographically. Excel tabulation and SPSS version 23 were used for data analysis. Chi-square testing was done to correlate various parameters used in this study. Incipient crestal bone loss was commonly observed. It was seen that the association between crestal bone loss and exudate was statistically significant (Chi-square, p < 0.05). Within the limits of this study, incipient crestal bone loss was observed in most dental implants irrespective of bone density, implant length, implant diameter, and implant placement area.

Long-term performance of implants with moderately rough anodized surface supporting single-tooth restorations: A retrospective analysis with an up to 15-year follow-up.

OBJECTIVES: This retrospective study aimed to evaluate long-term clinical and radiologic performance of anodized surface implants supporting single implant restorations. MATERIALS AND METHODS: Patients who received at least one anodized surface implant for a single-tooth restoration between 2003 and 2004 in the Brånemark clinic (Göteborg, Sweden) were included in the study. The assessed outcomes included implant survival, biological and technical complications, as well as marginal bone levels (MBL) based on radiographs. Baseline data on patient demographics, implant placement, and surgery details were also collected. The cumulative survival rate (CSR) was calculated using the Kaplan-Meier survival analysis. RESULTS: The study included 97 patients with 129 implants. Mean patient age at the time of implant placement was 31.7 ± 16.4 years. All implants were placed in a two-stage approach with delayed loading. The last follow-up visit was on average 13.4 ± 4.8 years after implant insertion. Three implants failed, yielding the implant-level 15-year CSR of 97.4%. Majority of the implants had no biological (70.5%) nor technical (81.4%) complications. The mean MBL was -1.0 ± 0.7 mm (n = 101) at prosthetic placement and -1.8 ± 1.0 mm (n = 80) at the last follow-up, while the mean marginal bone loss (MBL) from prosthetic placement to last follow-up was 0.6 ± 1.1 mm (n = 65). CONCLUSIONS: Moderately rough anodized implants have shown favorable long-term outcomessingle-tooth indication, with high survival and a low rate of technical complications. Furthermore, long-term studies are needed to present longitudinal data on peri-implantitis.

Impact of machined versus structured implant shoulder designs on crestal bone level changes: a randomized, controlled, multicenter study.

PURPOSE: The collar region of an implant is its connection to the oral cavity. A balance between osseointegration on one hand and the absence of plaque accumulation on the other hand is necessary for successful implantation. It is yet to be determined which implant collar design, polished or rough, is best to stabilize the crestal bone level, avoiding peri-implantitis and subsequent risk of implant loss. The aim of this study was to investigate the influence of the architecture of the collar region on marginal bone and soft tissue response. METHODS: This prospective, randomized, clinically controlled multicenter study included 58 patients undergoing dental implant treatment using a pair of dental implants with either machined or rough-surfaced shoulder regions. Patients were clinically and radiologically examined for bone level height and signs of inflammation after 6, 12 and 24 months. RESULTS: No implant was lost within the 2 years of follow-up (100% survival rate). No significant differences on crestal bone loss (machined neck: 0.61 mm ± 0.28 mm, rough neck 0.58 mm ± 0.24 mm) and on soft tissue response (probing depth 3-6 mm with bleeding on probing 7.6% in machined-neck implants and in 8.3% in rough neck implants) were observed between implants with machined and roughened neck after 2 years. CONCLUSIONS: Machined and roughened neck implants achieved equally good results concerning peri-implant bone loss, the rate of peri-implantitis and implant survival rate/hard and soft tissue integration. None of the two collar designs showed a clear advantage in peri-implant reaction. Trial registration German Clinical Trials Register, DKRS00029033. Registered 09 May 2022-Retrospectively registered, http://www.dkrs.de.

Analysis of fractured dental implant body from five different implant systems: a long-term retrospective study.

The aim of this study was to perform an analysis of the incidence of implant body fracture and to identify possible risk factors. A long-term follow-up retrospective evaluation of 3477 patients who received 8588 implants from five implant systems was performed. Overall, 2810 patients who received 7502 implants, with an average follow-up of 6.9 years, were included in the analysis. The overall body fracture rate was 0.49% (37/7502), among which 32.4% (12/37) were implants with a reduced diameter. The estimated cumulative fracture rate was 1.24%. Fractures were observed in two patients with three Brånemark implants, 13 patients with 15 Nobel Replace implants, eight patients with eight Camlog implants, eight patients with 11 Ankylos implants, and none of the patients with Thommen implants. Most fractures occurred in the molar region (29/37) and in single implant-supported restorations (30/37). The results showed significant differences between splinted and unsplinted restorations (P = 0.005) and between regular and narrow diameter implants (P = 0.009). Within the limitations of this retrospective analysis, a narrow implant diameter is a potential risk factor for implant body fracture in the posterior region. Furthermore, unsplinted restorations appear to be associated with a higher rate of implant fracture.

Implications of considering peri-implant bone loss a disease, a narrative review.

BACKGROUND: Peri-implantitis has been suggested to cause significant increasing proportions of implant failure with increasing time. PURPOSE: To assess whether implant failure rates in long term studies are matching the supposed high prevalence of peri-implantitis. MATERIAL AND METHODS: This paper is written as a narrative review of the long-term clinical investigations available in the literature. RESULTS: Some implant systems have seen unacceptable marginal bone loss figures with time coupled to increased implant failure rates, resulting in the withdrawal of these systems. The reasons for such mishap are generally unknown, with the exception of one system failure that was found to be due to improper clinical handling. Modern, moderately rough implant systems have functioned excellently over 10-15 years of follow up with minor problems with marginal bone loss and implant failure rates within a few per cent. Machined implants have functioned adequately over 20-30 years of follow up. Implant failures occur predominantly during the first few years after implant placement. No significant increase of implant failures has been observed thereafter over 20-30 years of follow up. Over the years of our new millennium, scientific and technical advances have allowed the discovery of numerous molecular pathways and cellular interactions between the skeletal and immune system promoting the development of the interdisciplinary field called osteoimmunology. Nowadays, this knowledge has not only allowed the emergence of new etiologic paradigms for bone disease but also a new dynamic approach on the concept of osseointegration and MBL around oral implants, re-evaluating our older disease oriented outlook. This facilitates at the same time the emergence of translational applications with immunological perspectives, scientific approaches based on omics sciences, and the beginning of an era of personalized dental implant therapy to improve the prognosis of oral implant treatment. CONCLUSIONS: Oral implant systems have been found to function with very good clinical outcome over follow-up times of 20-30 years. Registered implant failures have occurred predominantly during the first few years after implantation, and there has been no significant increase in late failures due to peri-implantitis.

A prospective, multicentre study of 6-mm short implants in posterior alveolar bone supporting splinted crowns: A 5-year follow-up study.

AIM: To evaluate the clinical and radiographic outcomes of 6-mm short implants, placed in the posterior jaws and supporting splinted crowns, at 5 years after early loading. MATERIALS AND METHODS: Forty-five patients with 95 implants (diameter: 4 mm; length: 6 mm) were enrolled at three centres. Two to three implants were placed in either the maxillary or the mandibular posterior region in each patient and restored with screw-retained splinted crowns at 6 weeks later. Clinical and radiographic outcomes were evaluated at implant placement, at loading, and at 6, 12, 24, 36, and 60 months after loading. Biological and mechanical complications were recorded. Marginal changes in bone level in relation to clinical parameters were evaluated using a generalized linear mixed model. RESULTS: During the 5 years of follow-up, the mean change in the marginal bone level (MBL) was 0.04 ± 0.14 mm. Four implants in four patients were lost before loading, one implant in one patient was lost at the 5-year follow-up, and two patients were lost to follow-up. The survival and success rates were 88.4% (38/43) at the patient level. The incidence rates of peri-implant mucositis and peri-implantitis were 29.4% and 7.0%, respectively. The rate of technical complications was 14.0%. CONCLUSIONS: Over a 5-year period, 6-mm short implants supporting early loaded splinted crowns in maxillary or mandibular posterior regions showed stable MBLs and acceptable technical and biological complication rates.

Comparative analysis between extra-short implants (≤6 mm) and 6 mm-longer implants: a meta-analysis of randomized controlled trial.

The goal of this systematic study was to compare the survival rate (SR), marginal bone loss (MBL) and clinical complications between extra-short implants (≤6 mm) and 6-mm-longer implants in randomized clinical trials. A systematic electronic and manual search was performed using the PubMed, Web of Science, Scopus and DOAJ databases. A meta-analysis was conducted to compare the SR and MBL between both groups. We have selected 17 studies out of 1016 articles for qualitative and quantitative analysis. The data from 956 patients and 1779 implants were used with an overall mean clinical follow-up of 3.88 years ranging from 1 to 8 years. Overall, the SR of extra-short implants (93.12%) was lower than the observed in 6-mm-longer implants (95.98%); however, there was no statistical significance on these findings (P > 0.10). MBL analysis showed that extra-short implants and the 6-mm-longer group presented an average of -0.71 and -0.92 mm after 1-year respectively. Three years follow-up showed MBL of -0.42 mm (≤6 mm) and -0.43 mm (>6 mm); 5 years follow-up showed an MBL of -0.69 mm (≤6 mm) and -0.46 mm (>6 mm); and after 8 years of follow-up, it was found an MBL of -1.58 mm (≤6 mm) and -2.46 mm (>6 mm). Within the limitation of this study, the results indicated that SR of extra-short implants was similar to 6-mm-longer implants. In contrast, MBL and the presence of clinical complications were observed at a lessened rate on extra-short implants.

Marginal adaptation and fracture resistance of feldspathic and polymer-infiltrated ceramic network CAD/CAM endocrowns for maxillary premolars.

OBJECTIVE: The aim of this study was to evaluate the marginal adaptation and fracture resistance of feldspathic and Polymer-Infiltrated Ceramic Network (PICN) CAD/CAM endocrowns for maxillary premolars. MATERIALS AND METHODS: Twenty extracted human permanent maxillary premolars were randomly divided into two groups (n = 10); Group CEREC (GC), which was produced by feldspathic ceramic and the Group Enamic (GE), which was produced by PICN. All teeth were endodontically treated and decoronated horizontally at 2 mm above the cemento-enamel junction. Endocrown preparations were done with 4 mm depth into the pulp chamber. Endocrowns were manufactured using CAD/CAM from ceramic blocks. Following adhesive cementation, all specimens were subjected to thermocycling. Marginal adaptation evaluated under SEM at 200 × magnification. Each specimen was fixed in a universal testing machine and a compressive load was applied at 45° to long axis of the teeth until failure. Failure load was recorded and failure modes were evaluated. Statistical analyses were performed with SPSS 19.0 software and data were compared using Mann-Whitney U test. RESULTS: There were no significant differences in the marginal adaptation between two groups (P > 0.05). GE presented significantly higher fracture resistance when compared to GC (P < 0.05). Failure pattern was similar and characterized by the tooth-ceramic fracture on the force-applied side. CONCLUSIONS: CAD/CAM fabricated feldspathic ceramic and PICN endocrowns provide sufficient marginal adaptation, but the PICN endocrowns shows higher fracture resistance than the feldspathic ceramic endocrowns.

Long-Term Effectiveness of Extra-Short (≤ 6 mm) Dental Implants: A Systematic Review

PURPOSE: This systematic review evaluated the mean survival rate and marginal bone loss (MBL) of dental implants with ≤ 6 mm in length, across a time frame of 5 years. The overall prosthetic and biologic complications were evaluated, and their survival rates obtained. In addition, the complication rates of the splinted vs nonsplinted implants were assessed. MATERIALS AND METHODS: An electronic literature search in PubMed (MEDLINE) and EMBASE (OVID) and Cochrane were performed, in addition to a manual search through all periodontics and implantology-related journals, up to October 2017, to identify relevant articles. RESULTS: Out of 515 potentially eligible articles, 19 investigations assessing a total of 910 extra-short (≤ 6 mm) implants were included and further evaluated. After 5 years of follow-up, a mean survival rate of 94.1% (90% in the maxilla and 96% in the mandible) and a maximum bone loss of 0.53 mm were demonstrated. Additionally, a statistically significant difference in terms of bone loss was observed between tissue-level (0.12 mm) and bone-level implants (0.36 mm) at 12 months (P < .01), but not between internal and external abutment connections (P = .17). The most commonly reported prosthetic complication was screw loosening. Finally, splinted implants showed less overall prosthetic complications (RR = 3.32; 95% CI: 1.9 to 5.7), screw loosening (RR = 15.2; 95% CI: 5.92 to 39.31), and implant failure (RR = 1.96; 95% CI: 0.8 to 4.8) than nonsplinted implants. CONCLUSION: Extra-short implants are a viable treatment alternative in ridges exhibiting atrophy, demonstrating a satisfactory survival rate, as well as a low rate of prosthetic and biologic complications across a 5-year follow-up. Additionally, splinting extra-short implants is associated with fewer prosthetic complications and lower implant failure rate compared with nonsplinted implants.

Long-term biological complications of dental implants placed either in pristine or in augmented sites: A systematic review and meta-analysis.

AIM: To investigate and compare the prevalence of biological complications and failure of implants placed in pristine vs. augmented sites after a mean observation period of at least 10 years. MATERIALS AND METHODS: The focused question "In patients with osseointegrated dental implants, are there differences in biological complications and implant failure at implants placed in pristine vs. augmented sites?" was addressed using the Population, Exposure, Comparison and Outcome criteria. Electronic and manual searches supplemented by the screening of the grey literature were carried out. A case definition of peri-implant mucositis and peri-implantitis had to be specified. The binary random-effects method was chosen to conduct meta-analyses. Results are presented as Forest plots with weighted mean values and 95% confidence intervals (CI). The I2 statistic test was applied to quantify heterogeneity. The Newcastle-Ottawa Scale and the parameters provided in the Cochrane Center and CONSORT statement were used for quality assessment. The results are reported according to the PRISMA guidelines. RESULTS: No randomized clinical trial (RCT) comparing the outcomes of implants placed in pristine vs. augmented sites was identified. Five case-series studies, one case-control study, one cross-sectional study and one RCT were eligible for qualitative and quantitative analyses. No statistically significant differences (p > .05) were observed between implants placed in pristine vs. augmented sites for any outcome variables both at patient and at implant levels, respectively. High heterogeneity concerning patient sampling, case definitions of biological complications and eligibility criteria was observed. CONCLUSION: The studies included in the present systematic review did not directly address the focused questions. Hence, the outcomes of the meta-analysis should be interpreted with caution due to high variability with respect to study design.

Ten-year follow-up of dental implants used for immediate loading in the edentulous mandible: A prospective clinical study.

PURPOSE: The purpose of this study is to evaluate the 10-year outcome of 25 patients with immediate loading in the edentulous mandible. MATERIAL AND METHODS: Twenty-five patients were consecutively treated with 5 immediately loaded fluoride-modified implants in the edentulous mandible. Implant survival and bone loss were evaluated by an external researcher comparing digital periapical radiographs taken during recall visits with baseline (at implant insertion). Statistical descriptive analysis and nonparametric tests were performed using SPSS v23, multilevel analysis was performed by means of R version 3.1.0. to identify risk factors for bone loss. RESULTS: Twenty-one patients (8 males, 13 females, mean age 68.4, range 49-84) responded to the 10-year recall invitation. No implants were lost during follow-up, resulting in a 100% survival rate. After 10 years, bleeding on probing and plaque were present at 49.5% and 67.6% of the sites, respectively. The mean pocket probing depth was 3.77 mm (SD 0.73, range 3.0-6.83). Bone loss on implant level after 3, 12, 24, and 120 months was 0.16 mm (SD 0.33, range 0-1.75), 0.14 mm (SD 0.24, range 0-1.05), 0.17 mm (SD 0.27, range 0-1.5), and 0.49 mm (SD 1.08, range 0-7.8). Five implants were identified with or at risk for progressive bone loss. Forty-seven percent of the implants did not show any bone loss after 10 years in function and 87% lost less than 1 mm. Multilevel statistical analysis identified 2-year bone loss as a predictor for bone loss after 10 years of function. CONCLUSION: Immediate loading of 5 fluoride-modified dental implants with a fixed prosthetic rehabilitation is a predictable and reliable treatment in the edentulous mandible, based on a 100% implant survival and limited peri-implant bone loss. Implants used for immediate loading in the edentulous mandible who are showing early bone loss may be at higher risk to develop peri-implantitis.

Retention Load of Telescopic Crowns with Different Taper Angles between Cobalt-Chromium and Polyetheretherketone Made with Three Different Manufacturing Processes Examined by Pull-Off Test.

PURPOSE: To investigate the retention loads of differently fabricated secondary telescopic polyetheretherketone (PEEK) crowns on cobalt-chromium primary crowns with different tapers. MATERIALS AND METHODS: Cobalt-chromium primary crowns with 0°, 1°, and 2° tapers were constructed, milled, and sintered. Corresponding secondary crowns were fabricated by milling, pressing from pellets, and pressing from granules. For these nine test groups, the pull-off tests of each crown combination were performed 20 times, and the retention loads were measured (Zwick 1445, 50 mm/min). Data were analyzed using linear regression, covariance analysis, mixed models, Kruskal-Wallis, and Mann-Whitney U-test, together with the Benferroni-Holm correction. RESULTS: The mixed models covariance analysis reinforced stable retention load values (p = 0.162) for each single test sequence. There was no interaction between the groups and the separation cycles (p = 0.179). Milled secondary crowns with 0° showed the lowest mean retention load values compared to all tested groups (p = 0.003) followed by those pressed form pellets with 1°. Regarding the different tapers, no effect of manufacturing method on the results was observed within 1° and 2° groups (p = 0.540; p = 0.052); however, among the 0° groups, the milled ones showed significantly the lowest retention load values (p = 0.002). Among the manufacturing methods, both pressed groups showed no impact of taper on the retention load values (p > 0.324 and p > 0.123, respectively), whereas among the milled secondary crowns, the 0° taper showed significantly lower retention load values than the 1° and 2° taper (p < 0.002). CONCLUSION: Based on these results, telescopic crowns made of PEEK seem to show stable retention load values for each test sequence; however, data with thermo-mechanical aging are still required. In addition, further developments in CAD/CAM manufacturing of PEEK materials for telescopic crowns are warranted, especially for 0°.

Effect of Preparation Designs on the Prognosis of Porcelain Laminate Veneers: A Systematic Review and Meta-Analysis.

OBJECTIVE: To investigate the association between preparation designs and prognosis of porcelain laminate veneers (PLVs). METHODS: Electronic and manual literature searches were performed in Medline, Embase, CENTRAL, and Scopus databases for randomized controlled trials and retrospective and prospective cohort studies comparing any two of three preparation designs. The quality of the included studies was assessed using the Newcastle-Ottawa scale. Pooled hazard ratios and risk ratios were used to evaluate the difference between two preparation designs. Subgroup analyses, sensitivity analysis, and evaluation of publication bias were performed if possible. RESULTS: Of 415 screened articles, 10 studies with moderate to high quality were included in the meta-analysis. Comparison of preparations with incisal coverage to preparations without coverage revealed a significant result based on time-to-event data (hazard ratio=1.81, 95% confidence interval [CI]=1.18-2.78, I2=12.5%), but the result was insignificant based on dichotomous data (risk ratio=1.04, 95% CI=0.59-1.83, I2=42.3%). The other comparisons between any two of overlap, butt-joint, and window types revealed no statistically significant difference. Subgroup analyses regarding the porcelain materials, location of prosthesis, and tooth vitality could account for only part of the heterogeneity. No evidence of publication bias was observed. CONCLUSIONS: Within the limitation of the present study, it can be concluded that preparation design with incisal coverage for PLVs exhibits an increased failure risk compared to those without incisal coverage. The failure risk of the overlap type may be higher than the butt-joint type but must be validated in further studies.