Comparison of marginal bone loss between internal- and external-connection dental implants in posterior areas without periodontal or peri-implant disease

Impact of splinting implant-supported crowns on the performance of adjacent posterior implants: A systematic review and meta-analysis

STATEMENT OF PROBLEM

While rehabilitation with implant-supported crowns in the posterior region is widely practiced, guidance on clinical considerations when choosing between splinted or nonsplinted implant-supported crowns is limited.

PURPOSE

The purpose of this systematic review with meta-analysis was to assess whether adjacent implants with internal connections in the posterior region should be treated with splinted or nonsplinted crowns.

MATERIAL AND METHODS

The systematic review was registered on the prospective register of systematic reviews (PROSPERO) under the code, CRD42021248525. Two authors searched 4 electronic databases (PubMed, Cochrane Library, Scopus, and Web of Science) independently for articles published up to December 2023. Additionally, a hand search was conducted in the nonpeer-reviewed literature and the reference lists of included articles. Only clinical studies comparing splinted and nonsplinted hexagonal or conical internal connection adjacent implants in the posterior region were considered. A single-arm meta-analysis was conducted using RevMan. Risk of bias and quality were assessed using the Cochrane Collaboration's Tool for Assessing Risk and the Newcastle-Ottawa scale.

RESULTS

Qualitative synthesis included 17 studies, and quantitative synthesis involved 13 studies. A total of 2085 implants (1244 splinted and 841 nonsplinted) were inserted in 1027 participants, with observation times ranging from 5 months to 16 years. Thirteen studies related the type of crown retention (cemented or screw-retained). Only 2 studies related annual bone loss results considering the type of crown retention, but whether they were splinted or nonsplinted crowns and significant differences were not specified. The meta-analysis revealed no statistical differences between splinted and nonsplinted implants for biological complications (P=.95, I2=0%). However, the nonsplinted implants exhibited significantly more mechanical complications than the splinted implants (P<.001, I2=1%, RR 0.37; 95% IC [0.26-0.54]). The studies included demonstrated a low risk of bias and were of good quality.

CONCLUSIONS

Splinting was not found to affect the incidence of biological complications in posterior adjacent implants. However, more mechanical complications occurred in nonsplinted crowns than splinted ones.

Impact of the Habit of Alcohol Consumption on the Success of the Implants: A Retrospective Study

Introduction

A recent study has demonstrated that social factors have an impact on the condition of dental implants. The present investigation investigated how varied alcohol intake quantities might alter the condition of dental implants and related peri-implant inflammation.

Materials and Methods

This retrospective research was piloted in a tertiary care center, and implants inserted between 2010 and 2022 were evaluated through a retrospective cohort analysis. Within 3 months following implant implantation, information on alcohol intake was gathered from the health maintenance records and employed as the predictor variable. The implant results as well as peri-implantitis were examined at follow-up visits. Using the logistic regression model, the Wald test analysis analyzed the statistical consequences of each parameter. The findings were translated using an odds ratio that was determined with a 95% confidence level. The data were generated and analyzed using descriptive statistics, with statistical significance defined as P < 0.05.

Results

At the time of implant placement, the enrolled patients were 59 ± 11.3 years old on average. The median time before peri-implantitis occurred was 31.3 ± 22.2 months. Within the first 2 years following implant implantation, the majority of people experienced peri-implantitis. The incidence of peri-implantitis was the lowest among light and moderate alcoholics (11.5%) and the highest among heavy alcoholics (46.2%). Moderate alcohol use was associated with a 79.1% decrease in peri-implantitis when compared to not drinking (P = 0.0365), whereas light alcohol consumption was connected to a 51.3% decrease (P = 0.026). The incidence of peri-implantitis among heavy drinkers was significantly significant (P = 0.0001).

Conclusion

According to the findings of the current retrospective cohort analysis, drinking alcohol at mild-to-moderate levels is connected to a reduction in the incidence rate of peri-implantitis compared to heavy drinkers. In contrast, high alcohol consumption was found to be associated with an increase in the prevalence of peri-implantitis among the participants who had dental implants.

Evaluation of a platform-switched Morse taper connection for all-on-four or six treatment in edentulous or terminal dentition treatment: A retrospective study with 1-8 years of follow-up

BACKGROUND

The survival rate, marginal bone loss and soft tissue health of the Ankylos implants and the balanced base abutments in all-on-four or six implant restoration of edentulous or terminal dentition patients has not been reported in the clinical research.

PURPOSE

This retrospective study aimed to evaluate the Ankylos implants and the balanced base abutments in all-on-four or six implant restoration of edentulous or terminal dentition patients after 1-8 years of follow-up.

MATERIALS AND METHODS

A retrospective study was conducted based on the medical records of 33 patients who received all-on-four or six treatments from April 2014 to May 2020. Four radiographic examinations [immediate postoperative (T0), definitive restorations (T1), 1-3 years after prosthetic restorations (T2), and more than 3 years after prosthetic restorations (T3)] were obtained to evaluate vertical bone height (VBH). We also calculated the survival rate and examined the condition of soft tissue with this implant system in edentulous or terminal dentition patients. Three-level linear model analyses were used to explore potential risk factors for VBH changes on the mesial and distal sides. The generalized linear model was used to analyze the influencing factors of BOP and plaque.

RESULTS

A total of 218 implants were included in this study. The cumulative survival rate of the implants was 97.25% before the definitive prosthesis, 96.33% within 3 years of follow-up and 95.32% after more than 3 years of follow-up. The mean ± standard deviation (SD) bone losses of the VBH were 0.27 ± 0.05 mm (T1-T3) on the mesial side and 0.49 ± 0.06 mm (T1-T3) on the distal side. During 1-8 years of follow-up, the height and angle of the abutment (p < 0.001), the mandible implant site (p < 0.001), the length of the implant (p = 0.014 < 0.05) and age (p = 0.029 < 0.05) showed statistically significant effects on vertical mesial bone height (VMBH) and vertical distal bone height (VDBH). The risk of BOP among participants who brushed three times a day was lower than those who brushed less than three times. The plaque risk of short abutment height was higher than the long abutment.

CONCLUSION

The current study showed that the Ankylos implants with the balanced base abutments in all-on-four or six implants treatment is a viable and predictable option with a high survival rate and low marginal bone loss in edentulous or terminal dentition patients. VBH around the implants was strongly associated with the mandible implant site, abutment height and angle, the length of the implant and age. Moreover, teeth-brushing times and abutment height significantly affect soft tissue health.

Marginal Bone Level and Clinical Parameter Analysis Comparing External Hexagon and Morse Taper Implants: A Systematic Review and Meta-Analysis

The goal of this systematic review was to verify the marginal bone loss (MBL) and other clinical parameters comparing external hexagon (EH) and Morse taper (MT) implants when they were evaluated within the same study. The focused question was, "For patients (P) treated with external connection (I) or Morse taper (C) dental implants, were there differences in the marginal bone crest maintenance after at least three months in occlusal function (O)"? As for the inclusion criteria that were considered, they included clinical studies in English that compared the MBL in implants with EH and MT, with follow-up of at least three months, that were published between 2011 and 2022; as for the exclusion criteria, they included publications investigating only one type of connection that analyzed other variables and did not report results for the MBL, reports based on questionnaires, interviews, and case reports/series, systematic reviews, or studies involving patients with a significant health problem (ASA Physical Status 3 and above). The PubMed/MEDLINE, Embase, and Web of Science databases were screened, and all of the data obtained were registered in a spreadsheet (Excel^®). The Jadad scale was used to assess the quality of the studies. A total of 110 articles were initially identified; 11 were considered for full-text reading. Then, six articles (four RCTs and two prospective studies) met the eligibility criteria and were included in this study. A total of 185 patients (mean age of 59.71) were observed, and the follow-up ranged from 3 months to 36 months. A total of 541 implants were registered (267 EH and 274 MT). The survival rate ranged between 96% and 100% (the average was 97.82%). The MBL was compared among all periods studied; therefore, the common assessment period was the 12-month follow-up, presenting greater MBL for EH than for MT (p < 0.001). A mean MBL of 0.60 mm (95% CI 0.43-0.78) was found after the same period. BoP was reported in 5 studies and plaque index was reported in 4 (2 with more than 30%). Deep PD was observed in three studies. High heterogeneity was observed (I₂ = 85.06%). Thus, within the limitation of this review, it was possible to conclude that there is higher bone loss in EH than in MT implants when evaluating and comparing this variable within the same study. However, the results must be carefully interpreted because of this review's limited number of clinical studies, the short assessment period, and the high heterogeneity found.

Marginal Bone Loss Compared in Internal and External Implant Connections: Retrospective Clinical Study at 6-Years Follow-Up

The aim of this study was to assess and compare the marginal bone loss between two different categories of implants (Winsix, Biosafin, Ancona, Italy) having the same diameter and belonging to the Torque Type^® (TT^®) line, in the internal hexagon version (TTi, Group A) and in the external hexagon configuration (TTx, Group B). Patients with one or more straight implants (insertion parallel to the occlusal plane) in the molar and premolar regions in association with tooth extraction at least 4 months prior to implant insertion, who have a fixture diameter of 3.8 mm, who followed up for at least 6 years, and whose radiographic records were available were enrolled in this study. Depending on implant connections (externally or internally), the sample was divided into groups A and B. For externally connected implants (66), the marginal resorption was 1.1 ± 0.17 mm. The subgroup of single and bridge implants showed no statistically significant differences with a marginal bone resorption of 1.07 ± 0.15 mm and 1.1 ± 0.17 mm, respectively. Internally connected implants (69) showed an overall marginal resorption of 0.91 ± 0.17 mm, while the subgroup of single and bridge implants showed resorption of 0.90 ± 0.19 mm and 0.90 ± 0.17 mm, respectively, with no statistically significant differences. According to the obtained results, internally connected implants showed less marginal bone resorption than externally connected implants.

Marginal Bone Loss around Implants with Internal Hexagonal and Internal Conical Connections: A 12-Month Randomized Pilot Study

The aim of this study was to analyze the differences in terms of the marginal bone level (MBL) around implants with either an internal conical or an internal hexagonal implant–prosthesis connection. A randomized clinical trial included patients in need of a single implant-supported restoration. The implant–prosthesis connection was either internal conical or internal hexagonal while maintaining the same type of implant macro- and microarchitecture. Clinical and radiographical variables were registered up to 12 months of follow-up, including MBL. A total of 30 patients were included in the study. The main outcome variable, MBL 12 months after prosthesis delivery, was statistically different in both groups: −0.25 (0.12) vs. −0.70 (0.43) (conical vs. hexagonal; p = 0.033). Differences were also observed at the 3- and 6-month follow-up visits as well as for the MBL change from prosthesis delivery to the 12-month follow-up (−0.15 (0.13) vs. −0.56 (0.44); conical vs. hexagonal; p = 0.023). Correlations between MBL around the implants and radiographic measurements on the adjacent teeth, buccal bone to implant, tissue thickness or keratinized tissue were not significant neither globally nor when analyzed independently by group. In view of such results, it can be concluded that single-unit restorations with internal hexagonal-connection implants induce higher marginal bone loss after 12 months of follow-up from prosthesis delivery than internal conical-connection implants.

Survival Rates of Splinted and Nonsplinted Prostheses Supported by Short Dental Implants (≤8.5 mm): A Systematic Review and Meta-Analysis

PURPOSE

To evaluate and compare the implant survival rates, marginal bone loss, and mechanical complications of prostheses supported by splinted and nonsplinted short implants (≤8.5 mm).

MATERIAL AND METHODS

Electronic database (MEDLINE, CENTRAL, Web of Science, and EMBASE) and manual searches up to May 2021 were conducted to identify studies comparing splinted and nonsplinted short implants (≤8.5 mm). The primary outcome was implant survival rate. Secondary outcomes were marginal bone loss and mechanical complications. The quality of included studies and risk-of-bias were assessed according to the Newcastle-Ottawa Scale. A random-effects model was used to analyze the data.

RESULTS

Twelve studies fulfilled the inclusion criteria and featured 1506 short implants (596 nonsplinted and 910 splinted) with a follow-up time ranging from 1 to 16 years. Quantitative analysis found no statistically significant differences between splinted and nonsplinted short implants (≤8.5 mm) for survival rate (RR = 0.98; 95% CI 0.96, 1.01; p = 0.26)) and marginal bone loss (SMD = -0.08; 95% CI - 0.23, 0.07; p = 0.28). Veneer chipping, abutment screw breakage, screw loosening, and loss of retention were reported in the selected studies as common complications. However, no statistically significant difference was found between splinted and nonsplinted short implants (RR = 0.56; 95% CI 0.20, 1.54; p = 0.26).

CONCLUSIONS

Within the limitations of the present meta-analysis, it might be concluded that splinted short implants (≤8.5 mm) do not present superior performance in survival rate, marginal bone maintenance and prevention of mechanical complications compared with single-unit prostheses.

Are proton pump inhibitors associated with implant failure and peri-implantitis?

OBJECTIVE

Proton pump inhibitors (PPIs) may be linked to implant failure by affecting bone metabolism and osseointegration. This study evaluated how PPIs influence long-term implant failure and peri-implantitis in PPI users and nonusers.

STUDY DESIGN

This was a retrospective cohort study of patients treated at the Philadelphia Veterans Affairs Medical Center between 2006 and 2013. The primary predictor variable was PPI use. Outcome variables were long-term implant failure and the presence of peri-implantitis. Data gathered included demographic characteristics, medical comorbidities, implant location, and dimensions. Multivariate regression models measured independent factor associations. The final study cohort contained 933 implants placed in 284 patients. A total of 323 (32.6%) implants were placed in patients with ongoing PPI use. PPI users were less likely to smoke (22.1% vs 31.9%; P < .01) and use illicit drugs (5.0% vs 9.7%; P = .01) and more likely to have undergone prior bone grafting (18.3% vs 12.9%; P = .03).

RESULTS

PPI use lost significance after controlling for confounding factors and was not an independent predictor of implant failure (odds ratio [OR], 0.801; 95% confidence interval [CI], 0.56-1.15; P = .24) or peri-implantitis (OR, 0.801; 95% CI, 0.56-1.15; P = .24).

CONCLUSIONS

Our study found no independent associations between PPI use and implant failure or peri-implantitis. Contrary to published literature, PPIs may not influence implant health.

An evaluation of peri-implant marginal bone loss according to implant type, surgical technique and prosthetic rehabilitation: a retrospective multicentre and cross-sectional cohort study

To evaluate implant loss (IL) and marginal bone loss (MBL); follow-up period of up to 10 years after prosthetic loading. Retrospective multi-centre cross-sectional cohort study. Double analysis: (1) all the implants (n = 456) were analysed; (2) to allow for possible cluster error, one implant per patient (n = 143) was selected randomly. Statistical analysis: Spearman's correlation coefficient; Kruskal-Wallis (post-hoc U-Mann-Whitney); Chi-square (post-hoc Haberman). (1) Analysing all the implants (456): IL was observed in patients with past periodontitis (6 vs. 2.2%, p < 0.05), short implants (12 vs. 2.8%, p < 0.001) and when using regenerative surgery (11.3 vs. 2.9%, p < 0.001); greater MBL was observed among smokers (0.39 ± 0.52 vs. 0.2 ± 0.29, p < 0.01), maxillary implants (0.28 ± 0.37 vs. 0.1 ± 0.17, p < 0.0001), anterior region implants (0.32 ± 0.36 vs. 0.21 ± 0.33, p < 0.001), external connection implants (0.2 ± 0.29 vs. 0.63 ± 0.59, p < 0.0001), and 2-3 years after loading (p < 0.0001). (2) analysing the cluster (143): IL was observed in smokers (18.8 vs. 3.5%, p < 0.05), splinted fixed crowns (12.9%, p < 0.01), short implants (22.2 vs. 4.0%, p < 0.01) and when using regenerative surgery (19.2 vs. 3.4%, p < 0.01); greater MBL was observed in maxillary implants (0.25 ± 0.35 vs. 0.11 ± 0.18, p < 0.05), in the anterior region (p < 0.05), in the first 3 years (p < 0.01), in external connection implants (0.72 ± 0.71 vs. 0.19 ± 0.26, p < 0.01) and in short implants (0.38 ± 0.31 vs. 0.2 ± 0.32, p < 0.05). There is greater risk in smokers, patients with past periodontal disease, external connection implants, the use of short implants and when regenerative techniques are used. To prevent MBL and IL, implantologists should be very meticulous in indicating implants in patients affected by these host factors.

Hygiene Recall in Diabetic and Nondiabetic Patients: A Periodic Prognostic Factor in the Protection Against Peri-Implantitis?

PURPOSE

Diabetes mellitus is associated with an increased risk of poor outcomes with dental implant placement. This study aims to identify if frequency of hygiene visits is a protective factor for the development of peri-implantitis in diabetic patients.

METHODS

A retrospective cohort design was conducted on patients presenting for dental implant placement at the Philadelphia Veterans Affairs (VA) Medical Center from 2006 to 2012. The primary predictor variable was hygiene frequency, recorded as either infrequent, annual (7-12 month recall), or biannual (≤6-month recall). The number of months between implant placement and the presence of peri-implantitis was the primary outcome (time-to-peri-implantitis) variable, which was assessed on a subject level and adjusted for clustered, correlated multiple implants on the same subject. Additional variables were greater than or equal to 60 years of age, male gender, smokers, short implant length, diabetes, uncontrolled diabetes, and removable prostheses. Descriptive, univariate, and Cox proportional hazards regression statistics were computed to measure associations with peri-implantitis with P ≤ .05 used to define statistical significance.

RESULTS

The study sample was composed of 286 patients. In total, 748 implants were placed. Subjects greater than or equal to 60 years of age were 2 times more likely to develop peri-implantitis (hazards ratio (HR) = 2.015, 95% Cl (0.985-4.119), P = .0549). Subjects receiving implant-supported removable prostheses were 2.3 times more likely to develop peri-implantitis (HR = 2.315, 95% CI (1.006-5.327), P = .0485). With each hygiene visit, patients' risk of developing peri-implantitis decreased 20% (HR = 0.805, 95% Cl (0.394-1.647), P = .5528). In addition, diabetic patients were 49% more likely to develop peri-implantitis (HR = 1.491, 95% CI (0.758-2.936), P = .2475) than nondiabetic patients.

CONCLUSIONS

Diabetic patients may be at increased risk for the development of peri-implantitis and an increased frequency of hygiene visits may reduce peri-implant diseases.

Does Implant-Abutment Interface affect Marginal Bone Levels around Implants?

OBJECTIVE

The use of dental implants with different types of surface roughness and implant-abutment interface has brought about a situation of marginal bone loss. Therefore, the aim of this study was to analyze and compare marginal bone levels of different types of osseointegrated dental implants with platform switch (Group A: Ankylos, Mannheim, Germany) and platform match (Group B: Dentsply Xive, Mannheim, Germany, and Group C: MIS Implant Technologies, Karmiel, Israel).

MATERIALS AND METHODS

One hundred and seven patients (52 men and 55 women) with a mean age of 54.79 (standard deviation ± 12.35) years and a total of 321 dental implants (Group A, n = 198; Group B, n = 58; and Group C, n = 65) placed in a private practice between April 2006 and May 2015 were retrospectively analyzed. In addition to demographic information and implant characteristics, marginal bone levels were evaluated by Image J (Wayne Rasband, National Institute of Health, Maryland) program.

RESULTS

The mean age of all patients was 54.79 ± 12.35 years, and 51.5% of them were women. Implants supporting fixed bridge were most commonly used in all groups (65%), whereas only 20% were restored with a single crown and 15% with overdentures. In total, 47.5% of all implants showed no marginal bone loss. Mean bone loss in Group A was significantly lower (0.81 ± 1.60 mm) as compared to Group B (1.58 ± 1.59 mm) and Group C (1.18 ± 1.36) (p < 0.005).

CONCLUSION

Among different types of dental implants, platform switch seems to preserve marginal bone levels and increase the long-term success of dental implants.