Restoration Survival: Revisiting Patients' Risk Factors Through a Systematic Literature Review

Longevity of composite restorations in posterior teeth placed by dental students: a 12-year retrospective study

OBJECTIVES

To evaluate the longevity of resin composite restorations placed in posterior teeth by dental students, using data from electronic records from 2008 to 2019.

MATERIALS AND METHODS

Demographic (gender and age) and clinical variables (dental group, position in dental arch, and the number of restored surfaces) were evaluated. The 5-year follow-up was assessed according to the day the restoration was placed. Kaplan-Meier curves were generated to calculate the annual failure rate. Data were analyzed by Chi-Square, Kruskal-Wallis, and Mann-Whitney tests (α = 0.05).

RESULTS

In total, 3.883 records relative to return periodicity were analyzed. The final sample consisted of 900 restorations from 479 patients. The majority were females, aged between 31 and 60. In total, 256 failures were reported (success rate = 78%), showing an annual failure rate of 2.05%. The main reasons for failures were restoration replacement (55.5%), endodontics (21.9%), prosthetics (14.5%) and extraction (8.2%). There was a higher risk of failure in restorations involving three or more surfaces (p = 0.000) and in patients over 60 years (p < 0.001). In females (p = 0.030), molars (p = 0.044), and maxillary teeth (p = 0.038) failed in a shorter time.

CONCLUSIONS

Resin composite restorations placed in permanent posterior teeth by dental students had high survival rates. The main reason for failure was the replacement of restorations. The age group and the number of restored surfaces significantly affected the success of the restorations.

CLINICAL RELEVANCE

The electronic health records over 12 years showed that 78% of the resin restorations in posterior teeth placed by dental students were successful for a minimum of five years.

Clinical performance comparison between lithium disilicate and hybrid resin nano-ceramic CAD/CAM onlay restorations: a two-year randomized clinical split-mouth study

A total of 20 lithium disilicate glass-ceramics (IPS e.max CAD, Ivoclar Vivadent) and 20 resin nano-ceramic (Voco Grandio Blocks) onlay restorations were performed in 20 patients using a split-mouth design to compare the two-year clinical performance of lithium disilicate and resin nano-ceramic onlay restorations. Both restorations were evaluated at baseline, one-year, and two-year clinical follow-ups based on the modified United States Public Health Service (USPHS) criteria. Chi-square and Fisher's exact tests showed no statistically significant difference between Voco Grandio and IPS e.max ceramic restorations for all evaluated parameters during the different follow-up periods (p > 0.05). Cochrane's and MC-Nemar's tests indicated statistically significant differences regarding color match within the Voco Grandio group. They also indicated statistically significant differences in marginal discoloration, marginal adaptation, surface texture, and postoperative hypersensitivity within both ceramic material groups (p < 0.05). Kaplan-Meier curve indicated that the survival rate of both ceramic materials was 90%. After two years of clinical service, IPS e.max CAD and Voco Grandio onlay restorations exhibited similar clinical performance.

OCCLUSAL APPLIANCES MIGHT BE CLINICALLY EFFICIENT IN TREATING SLEEP BRUXISM

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Minakuchi H, Fujisawa M, Abe Y, Iida T, Oki K, Okura K, Tanabe N, Nishiyama A. Managements of sleep bruxism in adult: A systematic review. Jpn Dent Sci Rev. 2022; 58:124-36.

SOURCE OF FUNDING

None was reported.

TYPE OF STUDY/DESIGN

Systematic review.

Effectiveness of adhesive containing MDPB: A practice-based clinical trial

OBJECTIVES

This prospective practice-based trial assessed the longevity of composite restorations made with an adhesive containing an antibacterial monomer compared to a conventional adhesive.

METHODS

9 general practices in the Netherlands were provided with two composite resin adhesives, each for a period of 9 months. Adhesive P contained the quaternary ammonium salt MDPB, and Adhesive S was a control. Patient's age and caries risk, as well as tooth type/number, reason for restoration placement, used restorative material and adhesive, and restored surfaces were recorded. All interventions carried out on these teeth in the 6 years after restoration were extracted from the electronic patient records, along with their date, type, reason, and surfaces. Two dependent variables were defined: general failure, and failure due to secondary caries. All data handling and multiple Cox regression analysis were carried out in R 4.0.5.

RESULTS

11 dentists from 7 practices made 10,151 restorations over a period of two years in 5102 patients. 4591 restorations were made with adhesive P, whereas 5560 were made with adhesive S. The observation period was up to 6.29 years, median observation time was 3.74 years. Cox regression showed no significant difference between the two adhesive materials when corrected for age, tooth type and caries risk, for general failure nor failure due to caries.

SIGNIFICANCE

No difference in restoration survival could be shown between composite restorations made using an adhesive containing MDPB and control. Restorations made with the adhesive containing MDPB also did not fail more or less frequently due to secondary caries. This trial is registered on clinicaltrials.gov with identifier NCT05118100.

Short-term Clinical and Microbiological Performance of Resin-modified Glass Ionomer Cement Containing Chlorhexidine for Atraumatic Restorative Treatment

Aim

This study evaluated the short-term clinical and microbiological performance of resin-modified glass ionomer cement (RM-GIC) cement containing chlorhexidine (CHX) for atraumatic restorative treatment (ART) in primary teeth.

Materials and methods

The clinical trial was conducted in 36 children that received ART in primary molars either with GIC (group I, n = 18) or GIC containing 1.25% CHX (group II, n = 18). The survival rate of restorations was checked 7 days, 3, and 6 months after their application when saliva and biofilm were collected for microbiological assessment of mutans streptococci (MS) counts. Data were analyzed using the Kruskal-Wallis/Mann-Whitney U tests for clinical analysis and microbiological evaluations (p < 0.05).

Results

The survival rate of restorations was similar comparing groups I with II. Microbiological analysis showed a significant reduction in MS levels 7 days after the treatment in both saliva and biofilm of children treated with RM-GIC containing CHX (group II); however, MS counts at 3 and 6 months did not differ from the initial counts.

Conclusion

A total of 1.25% CHX improved the microbiological properties of GIC in the short term without impairing the clinical performance of ART restorations.

Clinical significance

Glass ionomer cement (GIC) containing CHX could be an alternative in ART procedures with the objective of promoting an additional antimicrobial effect, which is interesting for children with high counts of MS during the initial phase of adaptation to dental treatment.

How to cite this article

da Silva ME, de Sena MD, Colombo NH, et al. Short-term Clinical and Microbiological Performance of Resin-modified Glass Ionomer Cement Containing Chlorhexidine for Atraumatic Restorative Treatment. Int J Clin Pediatr Dent 2023;16(S-1):S27-S32.

Tracheobronchial tooth and dental prosthesis aspirations: 15 cases

BACKGROUND

Tracheobronchial foreign body is uncommon in adults. Among foreign body aspirations, tooth and dental prosthesis aspiration is a very rare condition. In the literature, dental aspiration is generally found as a case report and there is no single-center case series. In this study, we aimed to present our clinical experience in 15 cases with tooth and dental prosthesis aspiration.

METHODS

Data from 693 patients who presented to our hospital for foreign body aspiration between the years 2006 and 2022 were analyzed retrospectively. Fifteen cases who aspirated tooth and dental prostheses as foreign bodies were included in our study.

RESULTS

Foreign bodies were removed by rigid bronchoscopy in 12 (80%) cases and fiberoptic bronchoscopy in 2 (13.3%) cases. In one of our cases, foreign body was expected with cough.When evaluated in terms of foreign body, partial upper anterior tooth prosthesis in 5 (33.3%) cases, partial anterior lower tooth prosthesis in 2 (13.3%) cases, dental implant screw in 2 (13.3%) cases, lower molar crown in 1 (6.6%) case, lower jaw bridge prosthesis in 1(6.6%) case, upper jaw bridge prosthesis in 1(6.6%) case, broken tooth fragment in 1(6.6%) case, upper molar tooth crown coating in 1(6.6%) case and upper lateral incisor tooth in 1(6.6%) case were observed.

CONCLUSION

Dental aspirations can also occur in healthy adults. Anamnesis is the most important factor in diagnosis and diagnostic bronchoscopic procedures should be performed in cases where adequate anamnesis cannot be obtained.

Associated factors and treatment options for sleep bruxism in children: an umbrella review

Data on clinical management options for sleep bruxism in the primary dentition are inconclusive. This umbrella review aimed to synthesize the available evidence from systematic reviews (SRs) on the associated factors and treatment approaches for clinical management of sleep bruxism in children. A search was conducted in the MEDLINE/PubMed, Web of Science, Embase, and OpenGrey databases up to March 2022. SRs published on sleep bruxism in children containing data on associated factors or treatment outcomes were included. The AMSTAR-2 tool was used to assess the methodological quality of SRs. The search identified 444 articles, of which six were included. Sleep conditions, respiratory changes, personality traits, and psychosocial factors were the associated factors commonly identified. Treatments included psychological and pharmacological therapies, occlusal devices, physical therapy, and surgical therapy. All SRs included presented a high risk of bias. Overlapping of the included studies was considered very high. The best evidence available to date for the management of sleep bruxism in children is based on associated factors, with sleep duration and conditions, respiratory changes, as well as personality traits and psychosocial factors being the most important factors commonly reported by studies. However, there is currently insufficient evidence to make recommendations for specific treatment options.

Disinfection of caries-affected dentin using potassium titanyl phosphate laser, Rose bengal and Ozonated water on shear bond strength of deciduous teeth

AIM

To assess the efficacy of disinfection of caries-effected dentin (CAD) using KTP laser and different decontamination methods using ozonated water (OW), Rose Bengal photosensitizer (RBP), chlorhexidine (CHX), and Er, YAG laser on the shear bond strength (SBS) of adhesive resin bonded to deciduous teeth.

MATERIAL AND METHODS

A total of 50 extracted and radiographically verified carious primary molars were collected and scrutinized according to ICDAS criteria. Specimens were allocated randomly into five groups (n = 10) as per the type of CAD disinfectants. KTP laser, OW, RBP, CHX (control), and Er, YAG laser. After cavity sanitization, a resin adhesive (prime and bond NT) was smeared on the dentinal exterior followed by incremental composite filling. SBS evaluation was performed by employing specimens in the universal testing machine. The debonded surface was assessed under 40x magnification in a stereomicroscope to ascertain fracture mode. Statistical analysis was done by using the ANOVA and the Post Hoc Tukey multiple comparison tests (p < 0.05).

RESULTS

The highest SBS was exhibited by group 2 i.e., when OW was employed for CAD disinfection (10.25 ± 0.24 MPa). Whereas, the lowest SBS bond value was unveiled by samples in group 3 when RBP was applied for dentin surface sanitization (7.85 ± 0.59 MPa).CAD disinfection with KTP laser (8.25 ± 0.41 MPa), CHX (8.19 ± 0.73 MPa), and RBP displayed comparable bond values (p > 0.05).

CONCLUSION

Ozonated water and Er, YAG laser could be employed as cavity disinfectants in primary teeth as they demonstrated better shear bond strength without jeopardizing the adhesive binding capacity of restorative resins bonded to caries-affected dentin.

Managements of sleep bruxism in adult: A systematic review

This systematic review aimed to update the management of sleep bruxism (SB) in adults, as diagnosed using polysomnography (PSG) and/or electromyography (EMG). Management methods covered were oral appliance therapy (OAT) with stabilization splints, cognitive-behavioral therapy (CBT), biofeedback therapy (BFT), and pharmacological therapy. A comprehensive search was conducted on MEDLINE, Cochrane Library, and Web of Science up to October 1st, 2021. Reference list searches and hand searches were also performed by an external organization. Two reviewers for each therapy independently performed article selection, data extraction, and risk of bias assessment. The reviewers resolved any disagreements concerning the assortment of the articles by discussion. Finally, 11, 3, 14, and 22 articles were selected for each therapy. The results suggested that OAT tended to reduce the number of SB events, although there was no significant difference compared to other types of splints, that the potential benefits of CBT were not well supported, and that BFT, rabeprazole, clonazepam, clonidine, and botulinum toxin type A injection showed significant reductions in specific SB parameters, although several side effects were reported. It can be concluded that more methodologically rigorous randomized large-sample long-term follow-up clinical trials are needed to clarify the efficacy and safety of management for SB.

Deterioration of anterior resin composite restorations in moderate to severe tooth wear patients: 3-year results

OBJECTIVES

Deterioration in anterior resin composite restorations placed in tooth wear patients was investigated after 36 months.

MATERIALS AND METHODS

Data collected prospectively for 47 participants of the Radboud Tooth Wear Project were used (41 ± 8 years, 90% male, n = 270 restorations). Restorations were individually evaluated using intraoral photographs and 3D scans to rate modified FDI scores and to record the presence of degradation features. Four groups with distinct combinations of composites and techniques were assessed, and multivariable logistic regression models were used to analyze the data (p < 0.05).

RESULTS

For all groups together, early degradation signs were present at 1 month: irregularities (41.5%) and ditching (7.4%) were observed at the surface and adhesive interfaces. The frequency of irregularities decreased in the 36-month evaluation (37%), but ditching (12.2%) and fractures (10.7%) were more common. The most frequent deterioration (based on photographs) was observed for staining (44%) and loss of luster (31%). In 3D scans, the most frequent were for wear (25%), marginal adaptation (24%), and the presence of irregularities (19%). Canines had 5.5 times more chances of deterioration by ditching than incisors (p < 0.001). The differences between composites and restorative techniques were minor.

CONCLUSIONS

A continuous degradation process of restorations placed in tooth wear patients was observed in anterior teeth restored with different composites, with a progression of the deterioration over 36 months.

CLINICAL RELEVANCE

When placing anterior resin composite restorations in tooth wear patients, it could be important to establish realistic expectations and the need for checkup appointments.

Longevity of immediate rehabilitation with direct metal-wire reinforced composite fixed partial dentures

OBJECTIVES

This study aimed to analyze the longevity of direct metal-wire reinforced composite fixed partial dentures (MRC-FPD) and factors influencing their survival and success.

METHODS

Within one private practice 513 MRC-FPD were directly applied. The preparation of a proximal cavity in abutment teeth was not limited. MRC-FPD were reinforced by one to three metal-wires. At the last follow-up MRC-FPD were considered successful, if they were still in function without any need of therapy. MRC-FPD were considered as survived, if they were repaired or replaced. Multi-level Cox proportional hazard models were used to evaluate the association between clinical factors and time.

RESULTS

Mean follow-up period (range) was 59(2-249) months. Seventy-three bridges did not survive (cumulative survival rate(CSR):86%) and further 129 bridges had received a restorative follow-up treatment (CSR:61%). AFR was 2.2% for survival and 8.6% for success. In multivariate analysis MRC-FPD with> 1 wire showed a up to 2.3x higher failure rate than MRC-FPD with one wire(p ≤ 0.023). Dentist's experience in designing MRC-FDP (p ≤ 0.017), patient's caries risk (p ≤ 0.040) and bruxism (p = 0.033) significantly influenced the failure rate: the more experience, the lower caries risk and bruxism, the lower the failure rate.

SIGNIFICANCE

For directly prepared metal-wire reinforced composite bridges high survival and moderate success rates were observed. MRC-FPD might, thus, be an immediate, short- and medium-term solution for replacing missing teeth. However, several factors on the levels of practice (dentist's experience in designing MRC-FDP), patient (bruxism, caries risk) and restoration (number of wires) were identified as significant predictors for the failure rate. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00021576).

Clinical performance of resin-matrix ceramic partial coverage restorations: a systematic review

Objective

To evaluate clinical performance of the new CAD/CAM resin-matrix ceramics and compare it with ceramic partial coverage restorations.

Materials and methods

An electronic search of 3 databases (The National Library of Medicine (MEDLINE/PubMed), Scopus, and the Cochrane Central Register of Controlled Trials) was conducted. English clinical studies published between 2005 and September 2020 that evaluated the clinical performance of CAD/CAM resin-matrix ceramics inlays, onlays, or overlays were selected. The primary clinical question was applied according to PICOS strategy (Population, Intervention, Comparison, Outcome, Study design). The included studies were individually evaluated for risk of bias according to the modified Cochrane Collaboration tool criteria.

Results

A total of 7 studies were included according to the established inclusion and exclusion criteria. From the included studies, 6 were randomized clinical trials while one study was longitudinal observational study without control group. According to the results of the included studies, the success rate of CAD/CAM resin-based composite ranged from 85.7 to 100% whereas the success rate reported for ceramic partial coverage restorations ranged from 93.3 to 100%. Fractures and debondings are found to be the most common cause of restorations failure.

Conclusion

CAD/CAM resin-based composite can be considered a reliable material for partial coverage restorations with clinical performance similar to glass ceramic restorations. However, this result needs to be confirmed in long-term evaluations.

Clinical relevance

CAD/CAM resin-based composites provide a potential alternative to ceramic indirect restorations. However, clinicians must be aware of the lake of knowledge regarding long-term outcome.

Comparison of two clinical approaches based on visual criteria for secondary caries assessments and treatment decisions in permanent posterior teeth

Background

This cross-sectional study aimed to compare two clinical approaches based on visual criteria for secondary caries assessments and treatment decisions in permanent posterior teeth.

Methods

The two clinical visual criteria tested for the assessments of restored teeth were: FDI criteria—based on the caries presence, marginal adaptation and staining criteria, adapted from the FDI (International Dental Federation) criteria and CARS criteria—"Caries Associated with Restorations or Sealants" (CARS) criteria described by the International Caries Classification and Management System. Adults were randomized according to the criteria. One calibrated examiner assessed the restorations and assigned the treatment according to the criteria. The primary outcome was replacement indication.

Results

A total of 185 patients were included, totalling 718 restorations. The strongest correlation founded between the methods was for the presence of caries lesions (Rho = 0.829). A moderate correlation (Rho = 0.420) was founded between the treatment decisions proposed by the CARS and by the FDI criteria. The multilevel regression analysis showed that the FDI criteria indicated five times more replacements when compared to the CARS (< 0.001). Also, using the FDI criteria restorations were 2.7 times more related to caries around restorations (p < 0.001) compared to the other criterion.

Conclusions

The visual criteria used on the restoration's assessment directly influences the treatment decision to intervene or not on the restoration. The use of a minimally invasive based approach for assessing secondary caries may prevent overtreatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02112-6.

Randomized controlled trial on the performance of direct and indirect composite restorations in patients with severe tooth wear

OBJECTIVE

The study aimed to evaluate survival and failure behavior of Direct Composite Restorations (DRC) and Indirect Composite Restorations (ICR) on molars and anterior teeth, in a Randomized Controlled Trial (RCT).

METHODS

Patients with generalized severe tooth wear were included, and randomly assigned to one of 2 protocols: (1) DCR: All teeth were restored with directly applied micro-hybrid composite restorations (Clearfil AP-X, Kuraray) for load bearing areas and nano-hybrid composite restorations (IPS Empress Direct, Ivoclar Vivadent) for buccal veneers; (2) ICR: First molars were restored with indirect composite 'tabletop' restorations and maxillary anterior teeth were restored with indirect palatal veneer restorations (Clearfil Estenia C&B, cemented with Panavia F, Kuraray). Remaining teeth were restored directly. Restorations were evaluated after 3 years, focusing on clinical acceptability. Statistical analysis was performed using Kaplan Meier curves, Annual Failure Rates (AFRs), and univariate Cox regression analyses (p < 0.05).

RESULTS

41 patients (age: 36.6 ± 6.6y) were evaluated after 3 years (40.0 ± 2.2 m). 408 restorations on first molars and palatal veneers on maxillary anterior teeth were part of this RCT, with 220 DCRs and 188 ICRs. No differences in survival between treatment modality for palatal veneers for any failure criteria were found. Tabletop restorations on first molars showed a considerable higher failure rate for ICR compared to DCR (p = 0.026, HR: 3.37, 95%CI = 1.16-9.81).

SIGNIFICANCE

In this RCT, directly applied composite restorations showed superior behavior compared to the indirect composite restorations, when used in the molar region.

The survival time of restorations is shortened in patients with dry mouth

OBJECTIVES

The aim of this retrospective data collection study was to determine the effect size of dry mouth on the survival of restorations and teeth.

METHODS

The data were collected from the electronic patient files of City of Oulu Public Dental Services (Finland). Study population consisted of 71 dry mouth patients and 142 control patients. The survival of 3208 restorations were analyzed using Kaplan-Meier survival curves and multivariate Cox regression analysis with shared frailty for patients. Separate analyses were performed for the survival of the teeth.

RESULTS

The hazard ratio of restorations in dry mouth patients was 2.08 (95% CI: 1.65-2.63) compared to the control patients. For the dry mouth patients, the fixed prosthetic crowns outlasted composite fillings of all sizes, but the difference increased concomitantly with the filling size. The dry mouth patients had hazard ratio of 1.98 (95% CI: 1.02-3.82) for tooth extractions compared to the control patients. The teeth with fixed prosthetic crowns outlasted the teeth with direct restorative materials.

CONCLUSIONS

The survival time of restorations and teeth are severely shortened in patients with dry mouth. Especially the survival time of the large composites is short in dry mouth patients whereas fixed prosthetic crowns have acceptable survival time also in dry mouth patients.

CLINICAL SIGNIFICANCE

When informing a dry mouth patient on the expected survival of a restoration or tooth, one should take into account that dry mouth patients´ restorations and teeth have severely shortened survival time.

Prospective clinical evaluation of chairside-fabricated zirconia-reinforced lithium silicate ceramic partial crowns-5-year results

OBJECTIVES

A university-based randomized clinical study evaluated the 5-year performance of chairside-fabricated zirconia-reinforced lithium silicate (ZLS)-ceramic partial crowns.

MATERIAL AND METHODS

Forty-five patients were restored with 61 chairside-fabricated ZLS-restorations (Cerec SW 4.2, Dentsply Sirona, Germany; Vita Suprinity, Vita Zahnfabrik, Germany). Deviating from the manufacturers' recommendations, restorations with reduced minimum material thicknesses (MMT) were fabricated: group 1, MMT = 0.5-0.74 mm (n = 31); group 2, MMT = 0.75-1.0 mm (n = 30). For luting, a self-adhesive cement (SAC) or a total-etch technique with a composite cement (TEC) was applied. Statistical evaluation was performed by time-to-event analysis (Kaplan-Meier). Possible covariates of the survival (SVR) and success rates (SCR), evaluated in a Cox regression model, were MMT, restoration position (premolar/molar), and cementation technique (SAC vs. TEC).

RESULTS

Forty patients (54 restorations, premolars, n = 23; molars, n = 31) participated in the 5-year follow-up. Five losses due to ceramic fractures occurred in group 1 (n = 28) (SVR: 83.0% [95% confidence interval (CI): 0.71-0.96]). Group 2 (n = 26) showed no losses (SVR: 100%). The success rate for partial crowns placed on premolars was 100% and 69% (95% CI: 0.54-0.84) for molar restorations. Recementation was required in 4 restorations with SAC (SCR: 86% [95% CI: 0.73-0.99]; SCR-DC: 100%). Restorations in group 2 showed a significantly reduced risk of material fracture hazard ratio (HR) = 0.09, p = 0.0292) compared with the restorations in group 1. Molar partial crowns showed an increased risk for a clinical intervention (HR = 5.26, p = 0.0222) compared to premolar restorations.

CONCLUSIONS

Material thickness and position of the restoration are risk factors influencing the survival and success rate of ZLS-ceramic partial crowns.

CLINICAL RELEVANCE

Observation of an MMT of at least 0.75-1.0 mm for ZLS-ceramics is essential to avoid material-related fractures.

CLINICAL TRIAL REGISTRATION

German Clinical Trails Register (trial number: DRKS00005611).

Needs for re-intervention on restored teeth in adults: a practice-based study

OBJECTIVES

Evaluate the need for re-intervention on dental coronal restorations in adults seen in a network of general dental practitioners (ReCOL).  MATERIALS AND METHODS: This observational, cross-sectional, multicenter study involved 40 practitioners and 400 patients. Coronal restoration failures (needing re-intervention for unsatisfactory outcomes) were assessed with a simplified rating scale of seven criteria from the FDI World Dental Federation. The oral health status, the risk factors, and Oral Health Impact Profile-14 were also examined. Previous restoration characteristics (extent, technique, material) were analyzed according to the need for re-intervention (yes/no), the age group, and the risk profile. Qualitative variables were compared between "re-intervention" and "no re-intervention" group using Fisher exact test.

RESULTS

The need for re-intervention was estimated at 74% (95% CI: 70; 79); it increased with age (49 to 90%), unfavorable risk profile (82 vs. 62%), and extent of the filling (32, 39, 44, and 44% on 1, 2, 3 surfaces, and crowns, respectively). More posterior than anterior teeth were restored (median per patient: 6 vs. 1) or needed re-intervention (median per patient: 1 vs. 0).

CONCLUSIONS

The needs for re-intervention in adults are still high within a context of ever-changing materials and techniques, simplified and rationalized decision-makings, and demands for patient involvement.

CLINICAL RELEVANCE

Meeting these needs requires the following: (i) consensus definitions and assessment methods for "failure" and (ii) reliable feedbacks on materials, procedures, and satisfaction. Building large and detailed databases fed by networks of motivated practitioners will help analyzing complex success/failure data by artificial intelligence and guiding treatment and research.

Clinical Evaluation of Resin Composite CAD/CAM Restorations Placed by Undergraduate Students

To evaluate the clinical outcomes of resin composite CAD/CAM restorations in a prospective cohort study, and to assess patient and operator satisfaction after restoration placement, 59 indirect resin composite were placed by supervised undergraduate students, of which 43 restorations were followed over a mean period of 28 months (14–44 months) and evaluated using USPHS criteria. Patient and operator satisfaction levels were assessed using a visual analogue scale (VAS) after restoration placement. A total of 37 patients and 47 restorations were included for further study. Four teeth were extracted—three due to extensive drug-induced secondary caries in the same patient, and one tooth due to large periapical periodontitis after 44 months of service. The overall survival rate was 91.4%, and success rate was 87.2%. Differences between baseline and endpoint scores were significant for marginal discoloration (p < 0.05) and adaptation (p < 0.001). Color match (p < 0.05) and surface texture (p < 0.001) differed significantly, affecting all restoration types. VAS scores for patient and operator satisfaction showed a significant rank correlation (p < 0.01), and pairwise comparison showed significant differences for mean overall patient and operator VAS scores (p < 0.001). Lava Ultimate CAD/CAM may be considered a suitable material for overlays and endocrown restorations when combined with IDS, air abrasion, and MDP-containing adhesive systems. Marginal disintegration may present in inlays and onlays over time.

Survival of direct composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities

OBJECTIVES

This study aimed to assess the survival of direct composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities.

MATERIALS AND METHODS

Survival of composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities was retrospectively analyzed. Failure was defined as the need for replacement of at least one surface of the original restoration or extraction of the tooth. Individual-, tooth-, and restoration-related factors were obtained from dental records. Five-year mean annual failure rate (mAFR) and median survival time were calculated (Kaplan-Meier statistics). The effect of potential risk factors on failure was tested using univariate log-rank tests and multivariate Cox-regression analysis (α = 5%).

RESULTS

A total of 728 restorations in 101 patients were included in the analysis. The survival after 5 years amounted to 67.7% (5-year mAFR: 7.5%) and median survival time to 7.9 years. Results of the multivariate Cox-regression analysis revealed physical disability (HR: 50.932, p = 0.001) and combined intellectual/physical disability (HR: 3.145, p = 0.016) compared with intellectual disability only, presence of a removable partial denture (HR: 3.013, p < 0.001), and restorations in incisors (HR: 2.281, p = 0.013) or molars (HR: 1.693, p = 0.017) compared with premolars to increase the risk for failure.

CONCLUSION

Composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities showed a reasonable longevity as 67.7% survived at least 5 years.

CLINICAL RELEVANCE

Survival of composite restorations depends on risk factors that need to be considered when planning restorative treatment in patients with intellectual and/or physical disabilities. NCT04407520.

Aspiration of the dental crown in an elderly patient

The aspiration of objects and foreign bodies requires quick and systematic care. During emergent orotracheal intubation, accidental dental crown release can cause a threat to the patient's life. This paper aimed to report a case of foreign body (dental prosthetic crown) aspiration and its management and discuss alternative approaches. An 81-year-old male patient, who was admitted to the hospital's intensive care unit (ICU) for meningitis, presented with altered consciousness, and decreased oxygen saturation. He underwent emergent orotracheal intubation. After intubation, chest radiography was performed to check for proper orotracheal tube positioning and lung expansion. The resultant images revealed the presence of a foreign body within the right lower lobe bronchus in the shape of a dental crown. The foreign body, intubation cannula and basket clamp were successfully removed, followed by reintubation of the patient. The foreign body was a prosthetic upper premolar dental crown (24). While care should be taken to avoid complications, if a foreign body is aspirated during emergent orotracheal intubation, endoscopic removal appears safe and effective. Careful creation, placement, maintenance, and preservation of prosthetic crowns are critically important in elderly patients.

Reconfigurable Dual Peptide Tethered Polymer System Offers a Synergistic Solution for Next Generation Dental Adhesives

Resin-based composite materials have been widely used in restorative dental materials due to their aesthetic, mechanical, and physical properties. However, they still encounter clinical shortcomings mainly due to recurrent decay that develops at the composite-tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal this interface, but the adhesive seal is inherently defective and readily damaged by acids, enzymes, and oral fluids. Bacteria infiltrate the resulting gaps at the composite-tooth interface and bacterial by-products demineralize the tooth and erode the adhesive. These activities lead to wider and deeper gaps that provide an ideal environment for bacteria to proliferate. This complex degradation process mediated by several biological and environmental factors damages the tooth, destroys the adhesive seal, and ultimately, leads to failure of the composite restoration. This paper describes a co-tethered dual peptide-polymer system to address composite-tooth interface vulnerability. The adhesive system incorporates an antimicrobial peptide to inhibit bacterial attack and a hydroxyapatite-binding peptide to promote remineralization of damaged tooth structure. A designer spacer sequence was incorporated into each peptide sequence to not only provide a conjugation site for methacrylate (MA) monomer but also to retain active peptide conformations and enhance the display of the peptides in the material. The resulting MA-antimicrobial peptides and MA-remineralization peptides were copolymerized into dental adhesives formulations. The results on the adhesive system composed of co-tethered peptides demonstrated both strong metabolic inhibition of S. mutans and localized calcium phosphate remineralization. Overall, the result offers a reconfigurable and tunable peptide-polymer hybrid system as next-generation adhesives to address composite-tooth interface vulnerability.

Effect of Cavity Disinfectants on Adhesion to Primary Teeth-A Systematic Review

Some authors have been proposing the use of cavity disinfectants in order to reduce, or even eliminate, the effect of the microorganisms present in a dental cavity before a restoration is placed. The aim of this study was to evaluate the effect of different cavity disinfectants on bond strength and clinical success of composite and glass ionomer restorations on primary teeth. The research was conducted using Cochrane Library, PubMed/MEDLINE, SCOPUS, and Web of Science for articles published up to February 2021. The search was performed according to the PICO strategy. The evaluation of the methodological quality of each in vitro study was assessed using the CONSORT checklist for reporting in vitro studies on dental materials. Sixteen in vitro studies and one in situ study fulfilled the inclusion criteria and were analyzed. Chlorhexidine was the most studied cavity disinfectant, and its use does not compromise dentin bonding. Sodium hypochlorite is a promising alternative, but more research on its use is required to clearly state that it can safely be used as a cavity disinfectant for primary teeth. Although other disinfectants were studied, there is a low-level evidence attesting their effects on adhesion, therefore their use should be avoided.

Longevity of posterior composite restorations in children suffering from early childhood caries-results from a retrospective study

OBJECTIVES

This retrospective study aimed to evaluate health status as a new patient risk factor and analyze its influence on the survival of posterior composite restorations in patients with early childhood caries (ECC).

MATERIALS AND METHODS

Patients who received dental treatment of ECC under general anesthesia (GA) and attended at least one follow-up visit were included in this study. A total of 907 patient records were evaluated retrospectively through patient examination forms and panoramic radiographs. Kaplan-Meier survival probability analysis with log-rank test was used to assess the posterior composite restorations' longevity up to 24 months. Furthermore, risk factors were determined using Cox regression multivariate analysis.

RESULTS

A total of 5063 posterior composite restorations were assessed. Following the Cox regression analysis to determine the effect of risk factors on longevity of composite restorations, findings revealed that the survival probability of composite fillings was significantly lower in patients with systemic disease (p = 0.00). Filling materials were compared based on the survival probabilities and results were further discussed. There was no significant relationship between age, gender, and the survival of the restoration; however, the child's health status (p = 0.00) and caries risk status (p = 0.05) significantly affected survival. Moreover, the type of arch and pulp intervention influenced the restoration's survival.

CONCLUSION

Systemic disease has a detrimental influence over longevity of composite restorations. Therefore, considering the reduced survival rates of the composite restorations for children who have systemic disease, alternative non-invasive treatment options should be considered.

CLINICAL RELEVANCE

This study's novelty is the observation of drastically reduced survival of composite restorations in children with systemic disease.

Treatment options for large posterior restorations: a systematic review and network meta-analysis

BACKGROUND

The best treatment option for large caries in permanent posterior teeth is still a matter of uncertainty in dental literature. The authors conducted a network meta-analysis to address the challenges related to rehabilitation of these teeth.

TYPES OF STUDIES REVIEWED

The authors selected prospective and retrospective studies that compared at least 2 different treatment alternatives for permanent teeth with a minimum of 5 years of follow-up. The authors searched databases from MEDLINE, Scopus, Cochrane Library, and Web of Science in October 2019 without language or year of publication restrictions.

RESULTS

From 11,263 studies identified, 43 studies fulfilled the eligibility criteria and were included in the final review. Only 13 studies were randomized controlled trials and were classified as low risk of bias. Gold (annual failure rate of 0.29%) and metal ceramic (annual failure rate of 0.52%) crowns performed better for indirect restorations and direct resin composite performed better for direct restorations (annual failure rate of 2.19%). The most substantial comparisons were between feldspathic and glass ceramics, followed by direct resin composite and amalgam; there were no statistically significant differences between these interventions. Results of the pairwise meta-analysis showed mainly glass ionomer as significantly more prone to failure than amalgam and direct composite resin.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Reference standard direct and indirect materials except for glass ionomer can be used for restorations of large posterior caries.

One-year clinical performance of lithium disilicate versus resin composite CAD/CAM onlays

To compare the 1-year clinical performance of lithium disilicate and resin composite CAD/CAM onlay restorations. Twenty patients that required two restorations in posterior teeth, with at least one cusp to be covered, received two onlays. One was made with IPS e.max CAD (Ivoclar-Vivadent) and the other with Lava Ultimate (3M Oral Care). Two blind observers evaluated the restorations at baseline and 1 year after the onlays were cemented, according to FDI criteria. At each recall, digital photographs, bite-wing radiographs and impressions of the restorations were taken for SEM evaluation of the interface. Results were analyzed by Mann–Whitney U and Wilcoxon tests (p < 0.05). At baseline and in the 1-year recall, both CAD/CAM materials exhibited excellent results in most criteria with similar esthetic, functional and biological properties (p > 0.05). However, deterioration in surface lustre (p = 0.020) and color match/translucency (p = 0.039) were detected for IPS e.max CAD onlays after 1-year. Under SEM evaluation, there were no statistically differences in micromorphological criteria at baseline nor after a year between IPS e.max CAD and Lava Ultimate onlays. Conclusion: After 1 year of clinical service IPS e.max CAD and Lava Ultimate onlays showed a similar clinical performance that needs to be confirmed in long-term evaluations.

An In-Vitro Comparative Evaluation of Pre-treatment With Nano-Silver Fluoride on Inhibiting Secondary Caries at Tooth Restoration Interface

Introduction and aim

Dental caries is the global burden worldwide and has a negative effect on the quality of life. Restorative materials in pediatric dentistry have shown satisfactory properties; however, the highest failures are still reported due to the occurrence of secondary caries. The article aims to assess the effectiveness of pre-treatment with nano-silver fluoride (NSF) in inhibiting secondary caries at the tooth restoration interface.

Materials and methods

Forty tooth specimens were prepared from 20 newly extracted human premolar teeth by sectioning the tooth mesiodistally. Class V cavities were prepared on each specimen at enamel dentin junction. Specimens were randomly distributed into four groups (n=10): 1) glass ionomer cement (GIC) restoration, 2) composite restoration 3) NSF pre-treatment + GIC restoration, 4) NSF pre-treatment + composite restoration. After sterilization, specimens were subjected to artificial caries formation by pH cycling method for 14 days. Specimens were sectioned and mounted to evaluate the demineralization by using the Vickers microhardness test. Outer lesion depth was measured at the tooth restoration interface on digital radiographs. Data was analyzed using Student unpaired t-test, one-way ANOVA, and Tukey honestly significant difference (HSD) post hoc test.

Results

The mean microhardness value of pre-treated GIC and composite group with NSF was more than the non-treated NSF group, with a significant difference at the enamel, indicating lesser demineralization. Outer lesion depth was lesser in the pre-treated group showing better tooth restoration integrity with a statistically significant difference between the groups.

Conclusion

Pre-treatment with NSF is beneficial in increasing the resistance of GIC and composite resin restoration to secondary caries formation.

How to intervene in the caries process: proximal caries in adolescents and adults-a systematic review and meta-analysis

OBJECTIVES

For an ORCA/EFCD consensus, this systematic review assessed the question "How to intervene in the caries process in proximal caries in adolescents and adults".

MATERIAL AND METHODS

Separating between the management of initial and cavitated proximal caries lesions, Medline via PubMed was searched regarding non-operative/non-invasive, minimally/micro-invasive and restorative treatment. First priority was systematic reviews or randomized controlled trials (RCTs), otherwise cohort studies. After extraction of data, the potential risk of bias was estimated depending on the study type, and the emerging evidence for conclusions was graded.

RESULTS

Regarding non-invasive/non-operative care (NOC), no systematic reviews or RCTs were found. In cohort studies (n = 12) with a low level of evidence, NOC like biofilm management and fluoride was associated with a low proportion and slow speed of progression of initial proximal lesions. Minimally/micro-invasive (MI) treatments such as proximal sealants or resin infiltration (four systematic reviews/meta-analyses) were effective compared with a non-invasive/placebo control at a moderate level of evidence. Data on restorative treatment came with low evidence (5 systematic reviews, 13 RCTs); with the limitation of no direct comparative studies, sample size-weighted mean annual failure rates of class II restorations varied between 1.2 (bulk-fill composite) and 3.8% (ceramic). Based on one RCT, class II composite restorations may show a higher risk of failure compared with amalgam.

CONCLUSIONS

Proximal caries lesions can be managed successfully with non-operative, micro-invasive and restorative treatment according to lesion stage and caries activity.

CLINICAL RELEVANCE

Proximal caries treatment options like non-operative, micro-invasive and restorative care should be considered individually.

Antimicrobial Peptide-Polymer Conjugates for Dentistry

Bacterial adhesion and growth at the composite/adhesive/tooth interface remain the primary cause of dental composite restoration failure. Early colonizers, including Streptococcus mutans, play a critical role in the formation of dental caries by creating an environment that reduces the adhesive's integrity. Subsequently, other bacterial species, biofilm formation, and lactic acid from S. mutans demineralize the adjoining tooth. Because of their broad spectrum of antibacterial activity and low risk for antibiotic resistance, antimicrobial peptides (AMPs) have received significant attention to prevent bacterial biofilms. Harnessing the potential of AMPs is still very limited in dentistry-a few studies have explored peptide-enabled antimicrobial adhesive copolymer systems using mainly nonspecific adsorption. In the current investigation, to avoid limitations from nonspecific adsorption and to prevent potential peptide leakage out of the resin, we conjugated an AMP with a commonly used monomer for dental adhesive formulation. To tailor the flexibility between the peptide and the resin material, we designed two different spacer domains. The spacer-integrated antimicrobial peptides were conjugated to methacrylate (MA), and the resulting MA-AMP monomers were next copolymerized into dental adhesives as AMP-polymer conjugates. The resulting bioactivity of the polymethacrylate-based AMP conjugated matrix activity was investigated. The antimicrobial peptide conjugated to the resin matrix demonstrated significant antimicrobial activity against S. mutans. Secondary structure analyses of conjugated peptides were applied to understand the activity differential. When mechanical properties of the adhesive system were investigated with respect to AMP and cross-linking concentration, resulting AMP-polymer conjugates maintained higher compressive moduli compared to hydrogel analogues including polyHEMA. Overall, our result provides a robust approach to develop a fine-tuned bioenabled peptide adhesive system with improved mechanical properties and antimicrobial activity. The results of this study represent a critical step toward the development of peptide-conjugated dentin adhesives for treatment of secondary caries and the enhanced durability of dental composite restorations.

Repair increases the survival of failed primary teeth restorations in high-caries risk children: a university-based retrospective study

OBJECTIVES

We investigated factors associated with failure of adhesive restorations in primary teeth and whether repair may increase the survival of failed restorations placed in high-caries risk children.

MATERIALS AND METHODS

The sample comprised children who attended a university dental service to perform restorative treatment in primary teeth. Data were collected retrospectively from clinical records to assess the longevity of restorations. The outcomes were calculated in two levels: "Success" (Level 1)-when any re-intervention was considered as failure; "Survival" (Level 2)-when repaired restorations were considered clinically acceptable. The Kaplan-Meier survival test was used to analyze the longevity of restorations. Multivariate Cox regression with shared frailty was used to assess factors associated with failures (p < 0.05).

RESULTS

A total of 584 primary teeth restorations (178 patients) were included in the analysis. The longevity of restorations up to 36 months (Level 1) was 34.8% (AFR 29.6%). Multi-surface restorations showed significantly more failures than single-surface ones (HR 1.69; 95% CI 1.18, 2.41), and endodontically treated teeth presented more failures compared to vital teeth (HR 2.22; 95% CI 1.35, 3.65). There was an increase in restoration survival when repair was not considered as failure (p < 0.001). The survival of repaired restorations (Level 2) reached 43.7% (AFR 24.1%).

CONCLUSIONS

Adhesive restorations placed in primary teeth of high-caries risk children showed restricted longevity; however, the repair of failed restorations has increased its survival over time.

CLINICAL RELEVANCE

Repair is a more conservative and technically simple procedure that increases the survival of failed restorations in primary teeth.

Risk Factors for Dental Restoration Survival: A Practice-Based Study

To improve patient dental care, it is necessary to identify possible risk factors for the failing of restorations. This practice-based cohort study investigated the performance and influence of possible risk factors at the level of the practice, patient, tooth, and restoration on survival of direct class II restorations. Electronic patient files from 11 Dutch general practices were collected, and 31,472 restorations placed between January 2015 and October 2017 were analyzed. Kaplan-Meier statistics were performed; annual failure rates (AFRs) were calculated; and variables were assessed by multivariable Cox regression analysis. The observation time of restorations varied from 0 to 2.7 y, resulting in a mean AFR of 7.8% at 2 y. However, wide variation in AFRs existed among the operators, varying between 3.6% and 11.4%. A wide range of patient-related variables is related to a high risk for reintervention: patient age (elderly: hazard ratio [HR], 1.372), general health (medically compromised: HR, 1.478), periodontal status (periodontal problems: HR, 1.207), caries risk and risk for parafunctional habits (high: HR, 1.687), restorations in molar teeth (HR, 1.383), restorations placed in endodontically treated teeth (HR, 1.890), and multisurface restorations (≥4 surfaces: HR, 1.345). Restorations placed due to fracture were more prone to fail than restorations placed due to caries. When patient-related risk factors were excluded, remaining risk factors considerably changed in their effect and significance: the effect of operator, age of the patient, and endodontic treatment increased; the effect of the diagnosis decreased; and the socioeconomic status became significant (high: HR, 0.873). This study demonstrated that a wide variation of risk factors on the practice, patient, and tooth levels influences the survival of class II restorations. To provide personalized dental care, it is important to identify and record potential risk factors. Therefore, we recommend further clinical studies to include these patient risk factors in data collection and analysis.

Impact of individual-risk factors on caries treatment performed by general dental practitioners

OBJECTIVE

This prospective study investigated how individual patient risk factors impacted non-operative and operative treatment decisions in a dental practice-based research network in The Netherlands.

METHODS

Data from were collected from 11 dental practices, whose patients visited the practice at least once during the observation period (January 2015 to September 2017). Descriptive analysis was performed, followed by multiple logistic regression.

RESULTS

The records of 39,690 patients were analyzed. Approximately one-half of the population (n = 21,056) underwent a restoration procedure during the observation period, of which 5981 (28.4%) were classified with fair oral hygiene, and 5341 (25.4%) with a high risk for caries. The population without restorative intervention (n = 18,634) consisted mainly of patients with good oral health (n = 5132 [27.5%]) and low risk for caries (n = 7792 [41.8%]). A high risk for caries was associated with a greater chance of preventive instruction (odds ratio [OR] 1.60), applications of topical fluoride (OR 1.20) or sealants (OR 1.39), and restorative interventions (OR 5.72). There was wide variation among practices regarding the treatment provided.

CONCLUSION

Of the 11 general dental practices that participated in this study, there was a higher chance of patients with a high risk for caries to receive preventive instructions, and professionally applied topical fluoride and sealants in the majority of practices promoting a personalized treatment approach to patients with caries.

CLINICAL SIGNIFICANCE

A more personalized treatment approach for patients with caries was associated with a higher prevalence of high caries risk patients in the majority of practices. More studies, however, are needed to investigate whether general dental practitioners consider the assessment of individual patient risk factors in planning personalized treatment strategies.

A practice based longevity study on single-unit crowns

OBJECTIVES

This retrospective longitudinal study aimed to assess the longevity of single unit crowns placed by several dentists and to investigate risk factors associated with crown failures.

METHODS

From patient files, longevity of 3404 full crown restorations placed in 1557 patients by 8 Dutch dentists between 1996 and 2011 were analyzed. Annual failure rates (AFRs) were calculated and variables associated with failure (success and survival of crowns) were assessed by multivariate Cox-regressions analysis with shared frailty for patients.

RESULTS

Most of crowns were PFM (63.8%) placed in molars (58.1%) and non endodontically treated teeth (65.4%). The observation time of restorations varied from 3 weeks to 11 years with a mean of 7 years, resulting in a mean AFR at 11 years of 2.1% and 0.7% for success and survival of crowns, respectively. Among dentists a relevant variation for type of interventions was observed with AFR varying between 1.2% and 3.5%. The most significant risk factor for failure of crowns was the presence of an endodontic treatment, resulting in Hazard ratios of 1.31 for success [95%CI 1.07-1.61] and 1.89 [95%CI 1.35-2.65] for survival of crowns. Tooth type, tooth position (jaw) and gender showed also a significant influence on success of crowns. For survival, increase in patients' age results in a higher risk for failure.

CONCLUSIONS

Overall, crowns placed by a selected group of dentist showed a good to acceptable success and survival rates, mainly dependent from the practice. The presence of an endodontically treated tooth was a significant risk factor leading to more failures.

Restorations in primary teeth: a systematic review on survival and reasons for failures

BACKGROUND

Several restorative materials with specific indications are used for filling cavities in primary teeth.

AIM

To systematically review the literature in order to investigate the longevity of primary teeth restorations and the reasons for failure.

DESIGN

Electronic databases were screened, and eligible studies were hand-searched to find longitudinal clinical studies evaluating the survival of restorations (class I, class II, and crown) placed with different materials in primary teeth with at least one year of follow-up.

RESULTS

Thirty-one studies were included, and a high bias risk was observed. Overall, 12,047 restorations were evaluated with 12.5% of failure rate. A high variation on annual failure rate (AFR) was detected (0-29.9%). Composite resin showed the lowest AFRs (1.7-12.9%). Stainless steel crowns (SSC) had the highest success rate (96.1%). Class I restorations and restorations placed using rubber dam presented better AFR. The main reason for failure observed was secondary caries (36.5%).

CONCLUSIONS

An elevated number of failures were observed due to recurrent caries, highlighting the need for professionals to work with a health-promoting approach. The high variation on failure rate among the materials can be due to children's behavior during the procedure, which demands short dental appointments and a controlled environment.

Fabrication of hybrid crosslinked network with buffering capabilities and autonomous strengthening characteristics for dental adhesives

Ingress of bacteria and fluids at the interfacial gaps between the restorative composite biomaterial and the tooth structure contribute to recurrent decay and failure of the composite restoration. The inability of the material to increase the pH at the composite/tooth interface facilitates the outgrowth of bacteria. Neutralizing the microenvironment at the tooth/composite interface offers promise for reducing the damage provoked by cariogenic and aciduric bacteria. We address this problem by designing a dental adhesive composed of hybrid network to provide buffering and autonomous strengthening simultaneously. Two amino functional silanes, 2-hydroxy-3-morpholinopropyl (3-(triethoxysilyl)propyl) carbamate and 2-hydroxy-3-morpholinopropyl (3-(trimethoxysilyl)propyl) carbamate were synthesized and used as co-monomers. Combining free radical initiated polymerization (polymethacrylate-based network) and photoacid-induced sol-gel reaction (polysiloxane) results in the hybrid network formation. Resulting formulations were characterized with regard to real-time photo-polymerization, water sorption, leached species, neutralization, and mechanical properties. Results from real-time FTIR spectroscopic studies indicated that ethoxy was less reactive than methoxy substituent. The neutralization results demonstrated that the methoxy-containing adhesives have acute and delayed buffering capabilities. The mechanical properties of synthetic copolymers tested in dry conditions were improved via condensation reaction of the hydrolyzed organosilanes. The leaching from methoxy containing copolymers was significantly reduced. The sol-gel reaction provided a chronic and persistent reaction in wet condition-performance that offers potential for reducing secondary decay and increasing the functional lifetime of dental adhesives.

STATEMENT OF SIGNIFICANCE

The interfacial gaps between the restorative composite biomaterial and the tooth structure contributes to recurrent decay and failure of the composite restoration. The inability of the material to increase the pH at the composite/tooth interface facilitates the outgrowth of more cariogenic and aciduric bacteria. This paper reports a novel, synthetic resin that provides buffering capability and autonomous strengthening characteristics. In this work, two amino functional silanes were synthesized and the effect of alkoxy substitutions on the photoacid-induced sol-gel reaction was investigated. We evaluated the neutralization capability (monitoring the pH of lactic acid solution) and the autonomous strengthening property (monitoring the mechanical properties of the hybrid copolymers under wet conditions and quantitatively analyzing the leachable species by HPLC). The novel resin investigated in this study offers the potential benefits of reducing the risk of recurrent decay and prolonging the functional lifetime of dental adhesives.

Higher experience of caries and lower income trajectory influence the quality of restorations: A multilevel analysis in a birth cohort

OBJECTIVES

This study aimed to evaluate the quality of posterior restorations (amalgam or composite) placed in adults from a birth cohort and its association with clinical and socioeconomic determinants experienced during their life course.

METHODS

A representative sample (n=539) of all 5914 births occurring in Pelotas (Brazil) in 1982 was prospectively investigated. Quality of posterior restorations (satisfactory or unsatisfactory) was assessed at 31 yrs-old, using modified USPHS criteria. Trained and calibrated dentists performed clinical examination. Explanatory variables included demographic and socioeconomic, oral health and dental service utilization patterns during the life course. Tooth related variables (type of tooth, material, size of cavity) were also analyzed. Untreated caries and socioeconomic status were assessed by group-based trajectories analyses. Multilevel Regression models were used to determine factors associated with restoration outcomes.

RESULTS

In total 2123 restorations (53% composite) were evaluated of which 107 (5%) were assessed as failed. The main reasons for failure were tooth/restoration fracture (50.5%) and secondary caries (30.7%). Failures in posterior restorations showed a significant association with socioeconomic aspects (lower tertile of income at age 30 - prevalence ratio (PR) 2.21 [95% CI 1.19-4.09]), clinical variables (trajectory of higher untreated caries - PR 2.11 [95% CI 1.23-3.61]) and also with tooth-related factors (Restorations involving three or more surfaces - PR 5.51 [95% CI 3.30-9.19]) after adjustment for each other.

CONCLUSIONS

These findings suggest that, although tooth-related variables have an important role in restoration longevity, patient-related factors, such as socioeconomic variables and untreated caries are also associated with failure and should be taken into account when evaluating longevity of posterior restorations.

CLINICAL SIGNIFICANCE

This was the first study assessing long-term trajectory of untreated caries, showing an association between higher experience of caries during the life-course and unsatisfactory restorations. The findings suggest that individual related factors should be considered when planning treatment and in future research evaluating the longevity of dental restorations.

Clinical studies in restorative dentistry: Design, conduct, analysis

OBJECTIVE

Clinical studies should be one main aspect underlying dentists' decision-making towards dental materials. Study design, conduct, analysis and reporting impact on the usefulness of studies. We discuss problems with current studies and highlight areas where improvement might be possible.

METHODS

Based on systematically and non-systematically collected data, we demonstrate where and why current studies in clinical dentistry deliver less-than-optimal results. Lending from general medicine, we suggest ways forward for clinical dental material science.

RESULTS

Randomized controlled (efficacy) trials remain a major pillar in dental material science, as they reduce selection bias and, if well-designed and conducted, have high internal validity. Given their costs and limited external validity, alternatives like practice-based or pragmatic controlled trials or observational studies can complement the evidence-base. Prior to conduct, researchers should focus on study comparators and setting (answering questions with relevance to clinical dentistry), and pay attention to statistical power, considering the study aim (superiority or non-inferiority trial), the expected event rate, and attrition. Study outcomes should be chosen on the basis of a core outcome set or, if not available, involving patients and other stakeholders. Studies should be registered a priori, and reporting should adhere to standards. Possible clustering should be accounted for during statistical analysis.

SIGNIFICANCE

Many clinical studies in dental material science are underpowered, and of limited validity and usefulness for daily decision-making. Dental researchers should mirror existing efforts in other medical fields in making clinical studies more valid and applicable, thus contributing to better dental care.

Should my composite restorations last forever? Why are they failing?

Composites resins have become the first choice for direct anterior and posterior restorations. The great popularity is related to their esthetic appearance and reduced need of sound tissue removal as compared with former treatments. Several studies have demonstrated that composite restorations may last long in clinical service. In this review we discuss the factors playing a role on the long-term longevity. Composite restorations have demonstrated a good clinical performance with annual failure rates varying from 1% to 3% in posterior teeth and 1% to 5% in anterior teeth. Factors related to the patients such as caries risk and occlusal stress risk, in addition to socioeconomic factors, may affect the survival significantly. Characteristics of the clinical operators, particularly their decision making when it comes to observing or approaching an existing restoration, are decisive for longevity. Cavity features such as the number of restored walls, composite volume, and presence of endodontic treatment are of major importance and may dictate the service time of the restorative approach. The choice of restorative composite seems to have a minor effect on longevity provided that appropriate technical procedures are used. The main reasons for failure in posterior teeth are secondary caries and fracture (restoration or tooth/restoration), while in anterior teeth esthetic concerns are the main reasons leading to restoration failures. Composite resin restorations can be considered a reliable treatment as long as both the professional and the patient are aware of the factors involved in restoration failures.