Attributable fractions, modifiable risk factors and risk stratification using a risk score for peri-implant pathology

Long-Term Outcome of Dental Implants in Immediate Function Inserted on Autogenous Grafted Bone

Background: There is a need for long-term evidence of immediate function dental implants inserted in grafted bone. The aim of this retrospective study was to investigate the outcome of full-arch rehabilitations supported by implants in grafted bone. Methods: Thirty-six patients (women: 24; men: 12; average age: 53.5 years) were included (225 implants). Primary outcome measure: to assess implant cumulative success rates evaluated through life tables. Secondary outcome measures: to evaluate implant and prosthetic survival, marginal bone loss, and the incidence of both biological and mechanical complications. Results: Twenty-five implants were unsuccessful giving a dental implant CS rate of 88.1% at 14 years and a 76.8% survival estimation (Kaplan−Meier) using the patient as the unit of analysis. No prosthesis was lost. Average MBL at 10 years was 2.01 mm. The incidence of biological complications was 36%, with smoking affecting it significantly (p < 0.001). The incidence of mechanical complications was 86.1% (45.2% and 54.8% in provisional and definitive prosthesis, respectively. Conclusions: The rehabilitation of atrophic maxillae through dental implants in immediate function inserted in grafted bone is a valid treatment alternative, despite the relevant rate of implant failures and incidence of complications.

Impact of tilted implants for implant-supported fixed partial dentures: A systematic review with meta-analysis

STATEMENT OF PROBLEM

The use of tilted implants has been considered a suitable option for completely edentulous patients. However, consensus on their clinical performance is lacking, specifically for partial rehabilitation.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the marginal bone loss and implant survival rate of tilted implants compared with those of axial implants for implant-supported fixed partial dentures (ISFPDs).

MATERIAL AND METHODS

A systematic search of the MEDLINE/PubMed, Web of Science, Embase, Cochrane, and ProQuest databases and reference lists for articles published until May 2022 was performed by 2 independent reviewers without language or publication date restrictions. A meta-analysis was performed using the RevMan version 5.4 program. Quality assessments were performed using the Newcastle-Ottawa scale.

RESULTS

Nine studies were included, totaling 258 participants and 604 implants (269 tilted implants and 335 axial implants). No significant differences were found between the tilted and axial implants for the implant survival rate (P=.81; risk ratio: 1.14). However, higher marginal bone loss values were observed for tilted implants (P=.001; mean difference: 0.12 mm). No significant heterogeneity was observed in either analysis.

CONCLUSIONS

No significant relationship was found between tilted and axial implants for ISFPD rehabilitation. However, tilted implants presented greater risks of marginal bone loss than axial implants.

Influence of Implant Impression Methods, Polymer Materials, and Implant Angulation on the Accuracy of Dental Models

The paper presents the influence of impression methods, polymer materials, and implant angulation on the accuracy of the definitive working model for the production of implant-supported dental restorations, based on the analysis of results obtained using different impression methods, materials, and parallel and angulated implants. The study findings indicate that all aforementioned factors impact the accuracy of the definitive working model. Specifically, 20° implant angulation in relation to the vertical plane has a greater impact on the impression accuracy compared to parallel implants. The open and splint method in combination with addition silicone, as well as the splint method and polyether combination yielded more accurate results when using implants under 20° angulation compared to other method and material combinations. The splint method in combination with addition silicone resulted in the smallest mean deviations from the center of the parallel implant base compared to other combinations of methods and materials. Analysis results further revealed statistically significant differences in the measured indicators across impression methods, implants, and polymer materials.

The 10 Year Outcomes of Implants Inserted with Dehiscence or Fenestrations in the Rehabilitation of Completely Edentulous Jaws with the All-on-4 Concept

Background: There is a need for a long-term evidence of implants placed in challenging conditions. The aim of this study was to investigate the outcome of full-arch rehabilitations with the All-on-4 concept for implants inserted with dehiscence or fenestrations. Methods: This retrospective cohort study included 123 patients (dehiscence, n = 87 patients; fenestrations, n = 28 patients; both conditions, n = 8 patients), with a total of 192 implants in immediate function presenting dehiscence (n = 150), fenestrations (n = 40), or both conditions (n = 2). Primary outcome measures were cumulative implant survival (CSurR) and success (CSucR) rates. Secondary outcome measures were prosthetic survival, marginal bone loss, and incidence of biological complications. Results: CSurRs were 94.1% (overall), 95.6% (dehiscence), and 88.1% (fenestrations) at 10 years using the patient as the unit of analysis. Smoking affected implant failure significantly (p = 0.019). Implant-level CSurRs and CSucRs at 10 years were 96.2% and 93.5% (overall), 97.2% and 94.6% (dehiscence), and 90.0% and 87.6% (fenestrations), respectively. Average bone resorption at 5 and 10 years was 1.22 mm and 1.53 mm, respectively. Biological complications occurred in 18 patients (n = 18 implants). Conclusions: Implants inserted with dehiscence or fenestrations demonstrate good long-term outcomes with overall high success and survival rates and low average marginal bone resorption, despite an inferior outcome in implants with fenestrations and smoking’s negative effect.

Ten-year follow-up of full-arch rehabilitations supported by implants in immediate function with nasal and full-length palatine bicortical anchorage on the anterior maxilla

PURPOSE

To evaluate the immediate function of anterior maxillary implants.

METHODS

One hundred nine patients (42 males and 67 females; average age 55.2 years; range 38-81 years) were followed for 10 years. One hundred eighty-eight implants using nasal and full-length palatine cortical anchorage were inserted in the anterior section of the maxilla together with 188 tilted implants placed posteriorly. Outcome measures were implant success and survival, prosthesis survival, bone loss, and the incidence of biological and mechanical complications. Cumulative success and survival were computed through Kaplan-Meyer product limit estimator (at patient level) and life tables (implant level).

RESULTS

Four patients lost one implant each, giving a 10-year cumulative survival rate of 95.8% and 97.7% using the patient and the implant as the unit of analysis, respectively. The prosthesis survival rate was 98.2%, and the average marginal bone loss was 1.79 mm (1.06 mm). The cumulative success rate was 89.1% and 92.5% using the patient and the implant as the unit of analysis, respectively.

CONCLUSION

Full-arch fixed prosthetic rehabilitations supported by immediately functional implants inserted in the anterior maxilla with bicortical anchorage together with posterior-tilted implants are viable in the long term.

Comparison of Two Risk Assessment Scores in Predicting Peri-Implantitis Occurrence during Implant Maintenance in Patients Treated for Periodontal Diseases: A Long-Term Retrospective Study

Background: There is a need for reliable risk assessment tools to better predict peri-implantitis occurrence. This study compared the long-term prognosis value of two models of risk assessment scoring in predicting peri-implantitis. Methods: Seventy-three patients with treated periodontitis representing 232 implants and attending long-term implant maintenance were evaluated. The Periodontal Risk Assessment (PRA) score, which combines only periodontal risk factors/indicators, and the Implant Risk Assessment (IRA) score, which combines both periodontal and implant risk factors/indicators, were calculated during implant maintenance. Peri-implantitis was defined by the presence of probing depth ≥6 mm with bleeding on probing/suppuration and bone level ≥3 mm. Analyses were performed at the patient level. Results: The mean implant follow-up was 6.5 years. Peri-implantitis incidence was 17.8%, and high-risk PRA and IRA percentages were 36.9% and 27.3%, respectively. High-risk PRA and IRA were significantly associated with peri-implantitis incidence, with hazard ratio (HR) = 4.8 and 3.65, respectively. Risk factors/indicators considered separately showed reduced associations with peri-implantitis. Conclusions: The PRA score combining periodontal parameters and IRA score combining both periodontal and implant parameters have comparable value in predicting peri-implantitis. These scores could allow practicians to intercept the risk of peri-implantitis and to manage follow-up modalities in patients with treated periodontitis.

Impact of Mechanical Complications on Success of Dental Implant Treatments: A Case-Control Study

Objective  This study aimed to investigate the impact of mechanical complications on outcome measures for implant dentistry.

Materials and Methods  This case–control study included 282 patients with mechanical complications occurring in fixed prosthetic rehabilitation supported by immediate function implants with external connection (cases) and 282 individuals without mechanical complications (control). Pairing was performed for sex, age (range = 3 years), and follow-up months (range = 11 months). The primary outcome measure was implant survival, while the secondary outcome measures were marginal bone loss and biological complication parameters (peri-implant pathology, soft tissue inflammation, fistula formation, and abscess formation).

Statistical Analysis  Cumulative implant survival was estimated by using life tables. Descriptive statistics with 95% confidence intervals (CI) and inferential statistics (Chi-square test) were performed to evaluate differences between cases and controls. The significance level was set at 5%.

Results  The average follow-up duration was 8.5 years. Mechanical complications included prosthetic fracture ( n = 159), abutment loosening ( n = 89), prosthetic screw loosening ( n = 20), milled abutment ( n = 12), milled prosthetic screw ( n = 1), and decemented crown ( n = 1). Implant failure occurred in one patient from the control group, with survival rates of 100 and 99.6% for cases and controls, respectively ( p = 0.317). The average marginal bone loss was 1.72 (95% confidence interval [CI]: 1.60–1.84) for cases and 1.55 (95% CI: 1.45–1.65) for controls ( p = 0.068). Biological complications were observed in 90 patients, with significant differences between cases ( n = 54) and controls ( n = 36; p = 0.038).

Conclusion  Mechanical complications did not significantly influence survival or marginal bone loss; nevertheless, there is a need for studies with longer follow-up duration. Mechanical complications also significantly influence the incidence of biological complications.

A Prognostic Model for the Outcome of Nobel Biocare Dental Implants with Peri-Implant Disease after One Year

Background: This investigation, based on a 1-year retrospective cohort study, aimed to estimate and validate a prognostic model for ailing and failing implants due to peri-implant disease. Methods: A total of 240 patients (male: 97; female: 143; average age of 57.3 years) with at least one ailing or failing implant were included: 120 patients for model derivation and 120 patients for model validation. The primary outcome measure was the implant status: success, defined as the arrest of the disease, or failure defined as implant extraction, prevalence or re-incidence of peri-implant disease). Potential prognostic risk indicators were collected at the baseline evaluation. The relative risk (RR) was estimated for the predictors through logistic regression and the c-statistic (95% confidence interval) was calculated for both derivation and validation sets. The significance level was set at 5%. Results: The risk model retrieved the prognostic factors age (RR = 1.04), history of Periodontitis (RR = 3.13), severe peri-implant disease status (RR = 3.26), implant length (RR = 3.52), early disease development (RR = 3.99), with good discrimination in both the derivation set (0.763 [0.679; 0.847]) and validation set (0.709 [0.616; 0.803]). Conclusions: A prognostic risk model for estimating the outcome of implants with peri-implant disease is available, with a good performance considering the c-statistic evaluation.

Adult Patient Risk Stratification Using a Risk Score for Periodontitis

Background: There is a need for analytical tools predicting the risk of periodontitis. The purpose of this study was to estimate and evaluate a risk score for prediction of periodontitis. Materials and methods: This case-cohort study included a random sample of 155 cases (with periodontitis) and 175 controls (randomly sampled from the study population at baseline) that were followed for 3-year. A logistic regression model was used with estimation of the risk ratio (RR) for each potential predictor. Results: The risk model included the predictors “age > 53 years” (RR = 0.53), “smoking” (RR = 2.9), “gingivitis at baseline” (RR = 3.1), “subgingival calculus at baseline” (RR = 1.9), “history of periodontitis” (RR = 2.3), and “less than 2 observations in the first year of follow-up” (RR = 3.7). Patients were distributed into three risk groups based on the preanalysis risk: low risk, moderate risk, and high risk. The risk score discrimination (95% confidence interval (CI)) was 0.75 (0.70; 0.80) (p < 0.001, C-statistic). Conclusions: The risk score estimated in the present study enabled to identify patients at higher risk of experiencing periodontitis and may be considered a useful tool for both clinicians and patients.

A Peri-Implant Disease Risk Score for Patients with Dental Implants: Validation and the Influence of the Interval between Maintenance Appointments

Background: There is a need for tools that provide prediction of peri-implant disease. The purpose of this study was to validate a risk score for peri-implant disease and to assess the influence of the recall regimen in disease incidence based on a five-year retrospective cohort. Methods: Three hundred and fifty-three patients with 1238 implants were observed. A risk score was calculated from eight predictors and risk groups were established. Relative risk (RR) was estimated using logistic regression, and the c-statistic was calculated. The effect/impact of the recall regimen (≤ six months; > six months) on the incidence of peri-implant disease was evaluated for a subset of cases and matched controls. The RR and the proportional attributable risk (PAR) were estimated. Results: At baseline, patients fell into the following risk profiles: low-risk (n = 102, 28.9%), moderate-risk (n = 68, 19.3%), high-risk (n = 77, 21.8%), and very high-risk (n = 106, 30%). The incidence of peri-implant disease over five years was 24.1% (n = 85 patients). The RR for the risk groups was 5.52 (c-statistic = 0.858). The RR for a longer recall regimen was 1.06, corresponding to a PAR of 5.87%. Conclusions: The risk score for estimating peri-implant disease was validated and showed very good performance. Maintenance appointments of < six months or > six months did not influence the incidence of peri-implant disease when considering the matching of cases and controls by risk profile.

Risk Score to Predict Dental Caries in Adult Patients for Use in the Clinical Setting

BACKGROUND

There is a need for risk prediction tools in caries research. This investigation aimed to estimate and evaluate a risk score for prediction of dental caries.

MATERIALS AND METHODS

This case-cohort study included a random sample of 177 cases (with dental caries) and 220 controls (randomly sampled from the study population at baseline), followed for 3 years. The risk ratio (RR) for each potential predictor was estimated using a logistic regression model. The level of significance was 5%.

RESULTS

The risk model for dental caries included the predictors: "presence of bacterial plaque/calculus" (RR = 4.1), "restorations with more than 5 years" (RR = 2.3), ">8 teeth restored" (RR = 2.0), "history/active periodontitis" (RR = 1.7) and "presence of systemic condition" (RR = 1.4). The risk model discrimination (95% confidence interval) was 0.78 (0.73; 0.82) (p < 0.001, C-statistic). Patients were distributed into three risk groups based on the pre-analysis risk (54%): low risk (

CONCLUSIONS

The present study estimated a simple risk score for prediction of dental caries retrieved from a risk algorithm with good discrimination.

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Key Words

• caries
• epidemiology
• risk
• tooth

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MESH Headings Collapse

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Affiliation(s)

Miguel de Araújo Nobre Research and Development Department, Maló Clinic, 1600-042 Lisbon, Portugal.
Ana Sezinando Dentistry Department, Maló Clinic, 4100-130 Porto, Portugal.
Inês Fernandes Dentistry Department, Maló Clinic, 1600-042 Lisbon, Portugal.
Paulo Maló Clinical Director, Maló Clinic, 1600-042 Lisbon, Portugal.

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Five-year outcome of a retrospective cohort study comparing smokers vs. nonsmokers with full-arch mandibular implant-supported rehabilitation using the All-on-4 concept

The aim of this study was to compare the 5-year outcome of full-arch mandibular fixed prosthetic rehabilitation using the All-on-4 concept in smoking and nonsmoking patients. This retrospective cohort study included 200 patients (n = 100 smokers, n = 100 nonsmokers), 119 women and 81 men, with an average age of 53.7 years, rehabilitated in immediate function with 800 implants. Implant cumulative survival rate estimation (Kaplan-Meier with log-rank test) and marginal bone resorption (MBR) at 5 years (Mann-Whitney test) were compared between both groups. Multivariable analysis was used to investigate potential risk indicators for MBR ≥ 2.8 mm at 5 years. Nine patients (4.5%) were lost to follow-up. Four patients lost eight implants, specifically one nonsmoking patient (n = 1 implant) and three smoking patients (n = 7 implants), resulting in a cumulative survival rate estimation of 99.0% and 96.9% for nonsmokers and smokers, respectively (P = 0.296). The average (standard deviation) MBR at 5 years was 1.68 mm (0.76 mm) and 1.98 mm (1.02 mm) for nonsmokers and smokers, respectively (P = 0.045). Smoking (odds ratio = 2.92) was the only risk indicator significantly associated with MBR ≥ 2.8 mm in multivariable analysis. Smoking should not be an absolute contraindication for rehabilitation of the edentulous mandible through the All-on-4 concept; however, smoking habits were significantly associated with MBR ≥ 2.8 mm.