Background: Very long-term follow-up of oral implants is seldom reported in the literature. Purpose: To assess oral implant failure rates and marginal bone loss (MBL) of patients followed up for a minimum of 20 years. Materials and Methods: Implants placed in patients followed up for 20+ years were included. Descriptive statistics, survival analyses, generalized estimating equations were performed. Three-hundred implants were randomly selected for MBL. Results: 1,045 implants (227 patients) were included. Implant location, irradiation, and bruxism affected the implant survival rate. Thirty-five percent of the failures occurred within the first year after implantation, and another 26.8% in the second/third year. There was a cumulative survival rate of 87.8% after 36 years of follow-up. In the last radiological follow up, 35 implants (11.7%) had bone gain, and 35 implants (11.7%) presented at least 3 mm of MBL. Twenty-six out of 86 failed implants with available radiograms presented severe MBL in the last radiological register before implant failure. Conclusions: Most of the implant failures occurred at the first few years after implantation, regardless of a very long follow up. MBL can be insignificant in long-term observations, but it may, nevertheless, be the cause of secondary failure of oral implants in some cases.

Background: Implant fractures are rare but offer a challenging clinical situation. Purpose: To determine the prevalence of implant fracture and the possible risk factors predisposing an implant to a higher fracture risk. Materials and Methods: This retrospective study is based on 2670 patients consecutively treated with implant-supported prostheses. Anatomical-, patient-, and implant-related factors were collected. Descriptive statistics and survival analyses were performed. Generalized estimating equations (GEE) evaluated the effect of explanatory variables on implant fracture. Results: Forty-four implants (out of 10 099; 0.44%) fractured. The mean ± standard deviation time for fracture to occur was 95.1 ± 58.5 months (min-max, 3.8-294.7). Half of the occurrences of fracture happened between 2 and 8 years after implantation. Five factors had a statistically significant influence on the fracture of implants (increase/decrease in fracture probability): use of higher grades of titanium (decrease 72.9%), bruxism (increase 1819.5%), direct adjacency to cantilever (increase 247.6%), every 1 mm increase in implant length (increase 22.3%), every 1 mm increase in implant diameter (decrease 96.9%). Conclusions: It is suggested that 5 factors could influence the incidence of implant fractures: grade of titanium, implant diameter and length, cantilever, bruxism.

OBJECTIVE: To assess the outcomes of implant-supported full-arch fixed dental prostheses (ISFAFDPs) and the supporting implants.

MATERIAL AND METHODS: This retrospective study included patients treated with ISFAFDPs at one specialist clinic. Implant/prosthesis failure and complications were the outcomes analyzed. Survival analysis methods were used.

RESULTS: A total of 709 patients with 869 ISFAFDPs (4,797 implants) were included, with a mean ± SD follow-up of 10.7 ± 7.2 years. A total of 353 implants and 62 prostheses failed. Estimated cumulative survival rates were as follows: 93.3% (95% CI 91.3, 95.3) after 10 years and 87.1% (95% CI 83.4, 90.8) after 20 years. Implants installed in bruxers, smokers, and maxilla had a lower survival than implants installed in non-bruxers, non-smokers, and mandible, respectively. A total of 415 ISFAFDPs (47.8%) presented technical complications, of which 67 (7.7%) presented only occurrences of loss/fracture of implant access hole sealing. Bruxism was a factor to exert a higher risk of screw loosening (HR 3.302; also in younger patients), screw fracture (HR 4.956), ceramic chipping/fracture (HR 5.685), and loss/fracture of acrylic teeth (HR 2.125; this last complication with higher risk also in men, in maxillae, and when the opposing jaw presented natural dentition or fixed prostheses). Patients with bruxism had a statistically significant higher risk of prosthesis failure than non-bruxers (HR 3.276).

CONCLUSIONS: ISFAFDPs presented good long-term prognosis. Failure of several supporting implants was the main reason for failure. The results of the present study strongly suggest that bruxism is an important contributor to implant and prosthesis failure, as well as to an increased prevalence of technical complications in ISFAFDPs.

The aim of this study was to compare the clinical outcomes of implant-supported overdentures (ODs) with either bar-clip or ball attachments. The implant, prosthesis failure, and technical complications were the outcomes analyzed in this retrospective clinical study conducted in a specialty clinic. Seventy-five patients with 242 implants supported by 76 ODs (36 maxillary, 40 mandibular) were included in the study and followed up for 88.8 ± 82.9 months (mean ± standard deviation). Bar-clip and ball attachments were used in 78.9% and 21.1% of the cases, respectively. Forty-three implant failures (17.8%) in 17 prostheses (17/76; 22.4%) were observed in this study. The average period of implant failure was 43.3 ± 41.0 months, and most of them were maxillary turned implants. The bar-clip system demonstrated more complications in the attachment parts compared to the ball attachment system. Poor retention of the prosthesis was similar between the two systems. Loss of implants resulted in the failure of 10 ODs in this study. ODs opposed by natural dentition or fixed prostheses presented with more complications. The Cox proportional hazards model did not show a significant effect on prosthesis failure for any of the factors. These findings indicated that patients with ODs need constant maintenance follow-ups to address the technical complications and perform prosthodontic maintenance regardless of the attachment system used.

BACKGROUND: The oral rehabilitation with fixed restorations supported by the combination of teeth and dental implants has been advocated in some cases.

PURPOSE: To assess the clinical outcomes of these prostheses. Fixed restorations supported by the combination of teeth and dental implants.

MATERIALS AND METHODS: This retrospective study included all patients treated with combined tooth-implant-supported fixed dental prostheses (FDPs) at one specialist clinic. Abutment/prosthesis failure and technical complications were the outcomes analyzed.

RESULTS: A total of 85 patients with 96 prostheses were included, with a mean follow-up of 10.5 years. Twenty prostheses failed. The estimated cumulative survival rate was 90.7%, 84.8%, 69.9%, and 66.2% at 5, 10, 15, and 20 years, respectively. The failure of tooth and/or implant abutments in key positions affected the survival of the prostheses. There were seven reasons for prostheses failure, with the loss of abutments exerting a significant influence. Bruxism was possibly associated with failures. Prostheses with cantilevers did not show a statistically significant higher failure rate. No group had a general higher prevalence of technical complications in comparison to the other groups.

CONCLUSIONS: Although combined tooth-implant-supported FDPs are an alternative treatment option, this study has found that across 20 years of service nearly 35% the prostheses may fail.

BACKGROUND: Implant-supported fixed partial dentures (ISFPDs) are one of the most common options to rehabilitate partially edentulous patients.

PURPOSE: To assess the clinical outcomes of ISFPDs.

METHODS: This retrospective study included all patients treated with ISFPDs with 2 to 6 prosthetic units at one specialist clinic. Implant/prosthesis failure and technical complications were the outcomes analyzed.

RESULTS: Six hundred and forty-two patients with 876 ISFPDs (2241 implants) were included, followed up for 108.0 ± 76.2 months. Eighty-eight prostheses and 112 implants (26 before, 86 after prosthesis installation) failed. The estimated CSR of ISFPDs at 30 years was 72.7%. Smokers presented lower implant survival than nonsmokers. Two hundred and ninety-nine ISFPDs (33.2%) presented technical complications. Bruxism was a factor to exert a higher risk of screw and implant fracture, and ceramic chipping. ISFPDs with cantilever presented higher risk of failure, and screw loosening/fracture. Prostheses supported by implants with internal abutment connection or with two pontics had higher risk of presenting ceramic chipping. Extension of the prosthesis did not seem to exert influence on prosthesis failure/complications.

CONCLUSIONS: ISFPDs presented good long-term prognosis. Implant failure was the main reason for ISFPD failure. The results suggest that bruxism and the presence of cantilever may contribute to the increased rate of mechanical complications and prosthesis failure.

Objective: To retrospectively assess the clinical outcomes of implant‐supported single crowns and the supporting implants. Material and Methods: This retrospective study included all patients treated with implant‐supported single crowns at one specialist clinic. Implant and prosthesis failure, and mechanical/technical complications (ceramic fracture/chipping; crown loss of retention/mobility; crown failure/fracture; loosening/loss/fracture of prosthetic screw; implant failure/fracture) were the outcomes analyzed. Any condition/situation that led to the removal/replacement of crowns was considered prosthesis failure. Results: 438 patients with 567 crowns were included. Mean±SD follow‐up of 183.4±69.3 months. 37 implants (6.5%) and 54 crowns (9.5%) failed. If only technical problems were considered, the crown failure rate decreased to 4.1% (23/567). Most common reasons for crown failure: esthetic issue (n=12), crown constantly mobile (n=9), change to another type of prosthesis together with other implants (n=8), crown fracture (n=7), crown in infraposition in comparison to adjacent teeth (n=7). The odds of crown failure were shown to be statistically significantly higher for the following factors: younger patients, maxillary crowns, and screw‐retained crowns. Loose prosthetic screw was much more prevalent in screw‐retained than in cemented crowns. Ceramic fracture/chipping was more prevalent in screw‐retained crowns, maxillae, females. Crown fracture was more prevalent in ceramic crowns, screw‐retained crowns, maxillae, posterior region, females. However, these differences were statistically significant only for crown fractures in females. Conclusions: The odds of crown failure were significant for some factors, but one must keep in mind that non‐technical complications are as common as technical ones as reasons for the replacement of implant‐supported single crowns.

The purpose of the present study was to assess the clinical outcome of dental implants in a series of patients with Sjögren’s syndrome (SS), as well as review of the literature. The study consisted of two parts: report of a case series and a systematic review. Results of the clinical series: 19 patients received 107 implants, followed for a mean of 125 months. Two patients lost 3 implants (failure rate 2.80%, 3/107). At the last follow-up, there was a mean±SD marginal bone loss (MBL) of -2.190±1.384 mm. Estimation of 4.39 mm of MBL after 30 years. Results of the review: 19 studies, including the present clinical series, with 712 implants in 186 patients (failure rate 4.11%, 29/705; failed at a mean time of 12.9±31.7 months), followed up for a mean of 72.5 months. The probability of failure was 2.8% (95% CI 1.6%, 4.1%). Primary SS had lower implant failure rate (2.54%, 3/118) than secondary SS patients (6.52%, 12/184). As a conclusion, dental implants should be considered by dentists as a viable treatment option in patients with SS, as the failure rate is fairly low. The SS patients may, however, present a higher MBL around implants than in the general population.

Objectives: Retrospectively evaluate the survival, radiographic and peri-implant outcome of single turned Brånemark™ implants after at least 16 years. Materials and methods: From 134 patients (C-group), 101 could be contacted concerning implant survival and 50 (59 remaining implants) were clinically examined (I-group). Marginal bone level was radiographically measured from the implant–abutment junction at baseline (=within 6 months after abutment connection) and 1–4, 5–8 and 16–22 years post-operatively. Probing depth, gingival and plaque index were measured. Marginal bone-level changes were analyzed using Friedman's and Wilcoxon's signed ranks tests. Spearman's correlations between radiographic and clinical parameters were calculated. Results: In the C-group, 13 out of 166 implants in 11 out of 134 patients failed (CSR=91.5%). In the I-group (28 males–22 females; mean age 23.9 years at baseline; range 14–57), the mean follow-up was 18.4 years (range 16–22). The mean bone level was 1.7±0.88 mm (range −0.8 to 5) after 16–22 years. Changes in the mean marginal bone level were statistically significant between baseline and the second measuring interval (1–4 years). Thereafter, no significant differences could be demonstrated. The mean interproximal probing depth, gingival and plaque indices were 3.9±1.27 mm, 1.2±0.81 and 0.2±0.48, respectively. Probing depth was moderately correlated with gingival inflammation (r=0.6; P<0.001) but not with bone level (P>0.05). 81.4% of the implants had a bone level ≤2nd thread and 91.5% had a probing depth ≤5 mm. 76.3% had both bone level ≤2nd thread and probing depth ≤5 mm. Conclusions and clinical implications: The single turned Brånemark™ implant is a predictable solution with high clinical survival and success rates. In general, a steady-state bone level can be expected over decades, with minimal signs of peri-implant disease. A minority (5%), however, presents with progressive bone loss.

Purpose Long term studies on single implants are scarce and merely focus on clinical response parameters, complications and bone remodelling. The objective of this retrospective case series was to assess alterations in soft tissue levels and aesthetics over a 16–22 year period in periodontally-healthy patients. Material and methods Patients who had received a single turned implant in the anterior maxilla/mandible at the Dental Specialist Clinic in Malmö between 1987 and 1993 were invited for a re-examination on the basis of a number of inclusion criteria. Both neighbouring teeth had to be present at re-examination and baseline clinical photographs (within the first year of function) had to be available for soft tissue evaluation. These photographs were superimposed onto final clinical photographs to assess longitudinal soft tissue alterations. Results Twenty-one patients (nine females; mean age 23, range 16–41) treated with 24 single implants met the criteria for soft tissue evaluation. Peri-implant soft tissue levels (papillae, midfacial level) remained stable over a 16–22 year observation period (p ≥ 0.372). However, neighbouring teeth demonstrated midfacial recession and eruption pointing to a major distortion with the implant crown (> 1 mm) in 5/24 (21%) and 10/24 (42%) of the cases, respectively. Baseline aesthetics was considered poor (mean Pink Esthetic Score 7.42, mean White Esthetic Score 5.43), yet a significant time effect could not be demonstrated (p ≥ 0.552). Implant and tooth bone loss was low (mean 0.6 mm and 0.4 mm, respectively) over a 16–22 year period. Conclusions This limited case series demonstrated stable peri-implant soft tissue levels and aesthetics in the long term following single implant treatment in periodontally-healthy patients. However, midfacial recession and eruption may be expected at neighbouring teeth.

Background Single implants were introduced in the 1980s, but long-term follow-up is scarce. Purpose The study aims to retrospectively investigate the prosthetic survival and complication rates of single implants in periodontally healthy patients after 16-22 years, and to evaluate the influence of different prosthetic procedures Materials and Methods Patients with a single implant were recalled for clinical examination. Prosthetic procedures included single-tooth (ST) and CeraOne (CO) abutments supporting a porcelain-fused-to-metal (PFM), all-ceramic (CER), or gold-acrylic (ACR) crown. Prosthetic survival, success, and occurrence of biological, technical, and aesthetic complications were obtained. Procedures were compared by log-rank tests Results Fifty patients attended the examination. All implants were functional; however, 15% of abutments and 27% of crowns had been renewed. Replacements (1/4) were related to technical issues whereas the main cause was aesthetics. The abutment cumulative survival rate (CSR) differed significantly between ST-PFM (74%), ST-ACR (0%), and CO reconstructions (97%). The crown CSR was significantly lower for ST-ACR crowns (0%) compared with ST-PFM (68%) and CO (81%). Thirty-nine percent of implants remained complication free throughout the mean 18.5 years. Complications (1/3) required component replacement, and 53% occurred within 5 years after surgery Conclusion Prosthetic survival rates of single implants are encouraging after 16 to 22 years. However, 66% of the patients encountered at least one complication during follow-up.

Background: Survival rates in implant dentistry today are high, although late failures do occur for many reasons, including peri-implant infections. The primary objective of this study is to investigate microbiota around single turned implants after 16 to 22 years. Secondary objectives are to compare teeth and implants and to correlate microbiologic, radiographic, and clinical parameters. Methods: A total of 46 patients with single implants were invited for a clinical examination. Clinical datawere collected from implants and contralateral natural teeth. Radiographic bone level was measured around implants. Microbiologic samples were taken from implants, contralateral teeth, and the deepest pocket per quadrant. Samples were analyzed with DNA-DNA hybridization including 40 species. Statistical analysis was performed using Wilcoxon signed-rank tests, McNemar tests, and Spearman correlation coefficients with a 0.05 significance level. Results: Mean follow-up was 18.5 years (range 16 to 22 years). Tannerella forsythia (1.5 x 10(5)) and Veillonella parvula (1.02 x 10(5)) showed the highest concentrations around implants and teeth, respectively. Porphyromonas gingivalis, Prevotella intermedia, and T. forsythia were significantly more present around implants than teeth. Mean counts were significantly higher around implants than teeth for Parvimonas micra, P. gingivalis, P. intermedia, T. forsythia, and Treponema denticola. Total DNA count was correlated to interproximal bleeding index (r = 0.409) and interproximal probing depth (r = 0.307). No correlations were present with plaque index or radiographic bone level. Conclusions: In the present study, bacterial counts around single implants in periodontally healthy patients are rather low. Although pathogenic bacteria are present, some in higher numbers around implants than teeth (five of 40), the majority of implants present with healthy peri-implant tissues without progressive bone loss.

The aim of this prospective randomized clinical study was to compare the clinical treatment outcome for single dental implants submitted to either immediate loading (IL) or delayed loading (DL) after 5 years of follow-up. Fifty patients with a missing maxillary tooth (15-25) were randomly allocated to either the IL or DL. The treatment procedures included implant installation in healed sites, temporary screw-retained crown and replacement with a permanent single implant crown. The two groups were evaluated with regard to implant survival, marginal bone level, papillae index, pink and white esthetic score (PES, WES). At the 5-year follow-up the implant survival rate was 100% and 95.8% for IL and DL, respectively. Implant success rate was 91.7% and 83.3% for IL and DL, respectively. The mean +/- SD marginal bone loss for IL and DL was -0.50 +/- 0.73 mm and -0.54 +/- 0.65 mm, respectively. (p = 0.782). Statistically significant less marginal bone loss was found non-smokers (p = 0.021). No statistically significant differences were found for IL and DL concerning papillae index PES and WES after 5 years. This study suggests that implant-supported single crowns in the maxillary aesthetic zone can present similar results with respect to either IL or DL after 5 years.

Purpose: To compare clinical and esthetic outcomes between immediately loaded single implants placed with and without a fully guided surgical procedure. Materials and Methods: Patients with a missing maxillary tooth (second premolar to second premolar) were considered for inclusion in this 1-year prospective nonrandomized study. Exclusion criteria were general health contraindications for oral surgery besides the need for bone grafting or ridge augmentation. One group received digital implant planning, fully guided surgery, and immediate loading (DIL). The other group received freehand surgery and immediate loading (IL). Outcome measures were implant survival, marginal bone loss, soft tissue changes, papilla index, pink and white esthetic scores (PES and WES, respectively), and patient-reported outcome measures (PROMs). Results: Two of 21 implants failed in the DIL group soon after placement, resulting in a 1-year implant survival rate of 90.5%, while no implants failed in the IL group. Significantly higher papilla index scores and lower soft tissue changes were found for the DIL group compared to the IL group. No differences were found after 1 year regarding marginal bone loss, PES, WES, or PROMs. Conclusion: Within the limitations of this study, immediate loading in combination with fully guided surgery might negatively affect implant survival. Immediate loading, fully guided surgery, and a digital workflow appear to have a positive effect on early soft tissue adaptation.

Purpose: To investigate the risk factors related to failure of removable partial dentures (RPDs) and to compare the survival of RPDs when abutment teeth have good vs reduced bone support. Materials and Methods: In this longitudinal patient record-based cohort study with a mean follow-up of 44.9 months, Cox regression models were used to evaluate the associations between clinical covariates and abutment tooth failure, as well as prosthesis failure. Results: A total of 142 patients and 172 RPDs were included. Of the 172 prostheses, 64 (nearly 40%) failed after a mean time of about 4 years. Loss of abutment teeth was the main reason leading to RPD failure, followed closely by poor fit and adaptation. No factor was shown to be statistically significant at the prosthesis level. Women (Hazard Ratio [HR] = 0.542), endodontic treatment (HR = 3.460), presence of post and core (HR = 0.302), presence of a prosthetic crown (HR = 3.403), and abutment tooth type (in relation to incisor: canine HR = 0.196, premolar HR = 0.449) were the risk factors statistically significantly associated with the loss of abutment teeth. The pre-prosthesis amount of bone support of the teeth did not affect their prognosis as abutments for RPDs. Conclusion: RPD treatment modality presented a high failure rate after a mean follow-up of 4 years. Vital abutment teeth had a better survival rate than the ones treated endodontically (whether restored with or without a post and core); nevertheless, the amount of bone support did not affect their survival.