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

Developments in resin-based composites

With the phasing down of dental amalgam use in response to the Minamata Convention, it is likely that resin-based composite restoratives will be the dental material of choice for the direct restoration of compromised dentition in the UK, at least for the foreseeable future. The current materials have a finite lifespan, with failures predominately due to either secondary caries or fracture. Consequently, there is considerable in vitro research reported each year with the intention of producing improved materials. This review describes the recent research in materials designed to have low polymerisation shrinkage and increased mechanical properties. Also described is research into materials that are either antimicrobial or are designed to release ions into the surrounding oral environment, with the aim of stimulating remineralisation of the surrounding dental tissues. It is hoped that by describing this recent research, clinicians will be able to gain some understanding of the current research that will potentially lead to new products that they can use to improve patient treatment in the future.

Provides an overview of recent research developments aimed at improving the performance of resin-based composites.

Details the recent developments in monomers and fillers to produce resin-based composites that either have lower polymerisation shrinkage or better mechanical properties compared to current commercially available products.

Describes recent research on developing resin-based composites that can act as potential sources of antimicrobial or remineralising agents.

Stainless steel crown vs bulk fill composites for the restoration of primary molars post-pulpectomy: 1-year survival and acceptance results of a randomized clinical trial

BACKGROUND

A key factor for the success and longevity of the endodontic treatment is sealing of the cavity after restorative treatment.

AIM

The aim of this randomised clinical trial was to evaluate the 1-year survival of endodontic treatment in primary molars restored with stainless steel crowns (SSCs) and bulk fill composite resin (BF). As a secondary outcome, the acceptance of both children and parents was evaluated.

DESIGN

Ninety-one 3- to 8-year-old children with at least one primary molar requiring endodontic treatment were selected. Participants were randomized to SSC or BF and evaluated after 1, 3, 6, and 12 months. An acceptance questionnaire was completed immediately after the treatment. The primary outcome was the endodontic treatment success, evaluated in the intention-to-treat (ITT) population using the Kaplan-Meier and non-inferiority Cox regression analyses, with a non-inferiority limit of 15%. Sensitivity analysis between the success rates after 1 year was performed using Miettinen-Nurminen's method. The Mann-Whitney test was used to compare the treatment acceptance (α = 5%).

RESULTS

The survival rate after 1 year was BF = 75% and SSC = 88% (HR = 1.41; 90% CI 0.57-3.43). ITT analysis showed a success rate of BF = 86.7% and SSC = 82.6% (RR = 0.95; 0.78-1.16). The non-inferiority hypothesis between the survival of endodontic treatment could not be proved in both analyses (P > .05). The overall acceptance scores did not differ between the restorative groups (P > .05).

CONCLUSION

This study failed to show non-inferiority of BF compared with the SSC. The materials were well accepted by both children and their parents.

Laboratory methods to simulate the mechanical degradation of resin composite restorations

OBJECTIVES

This study reviewed the literature to identify in vitro approaches that have been used to simulate the mechanical degradation and fatigue of resin composite restorations.

METHODS

A search for articles was carried out in 4 databases and included studies in which composite restorations were bonded to teeth and subject to cyclic loading. Articles were assessed for eligibility, and the following items were the extracted from the included studies: authors, country, year, materials tested, simulation device and details including load magnitude and frequency, number of cycles, type of antagonist, test medium, and temperature. Data were analyzed descriptively.

RESULTS

The 49 studies included showed a high level of heterogeneity in methods, devices, and test parameters. Nineteen different simulation devices were used, applying loads varying between 30 and 2900 N, and frequencies varying between 0.4 and 12 Hz. The load and frequency used most often were ~ 50 N (63.3%) and 1.5-1.7 Hz (32.7%). The number of cycles varied between 10 K and 2.4 M, 1.2 M was the most prevalent (40.8%). The majority of studies combined cyclic loading with at least one additional aging method: static liquid storage, thermo-mechanical cycling applied simultaneously, and thermal cycling as a discrete aging step were the three most frequent methods. The overall evidence indicated reporting problems, and suggested a lack of clinical validation of the research methods used.

SIGNIFICANCE

Validation studies, underlying clinical supporting data, and better reporting practices are needed for further improving research on the topic. Specific suggestions for future studies are provided.

Factors Associated with Extraction following Root Canal Filling in Adults

Essentially, root fillings are performed to preserve natural teeth. Over time, however, some root-filled teeth will inevitably be extracted. The aim of this historical prospective cohort study in the adult Swedish population was to identify factors associated with extractions within 5 y of registration of a root filling. The cohort consisted of all those whose root fillings had been reported to the tax-funded Swedish Social Insurance Agency (SSIA) in 2009. Demographic data on the individuals registered with a root filling (sex, age, country of birth, disposable income, educational level, and marital status) were received from Statistics Sweden or the SSIA. Dental care setting, tooth type, and any registration of subsequent restorations within 6 mo were received from the SSIA. Multivariable regression analysis was used, and P < 0.05 was considered statistically significant. In total, 216,764 individuals had been registered with at least 1 root filling. Individuals (n = 824) without complete data were excluded from the analyses. After 5 y, 9.3% of the root-filled teeth had been registered as extracted. Logistic regression analysis found significant associations for all variables except country of birth, disposable income, and educational level. The highest odds ratios for extractions were associated with the type of restoration: teeth with no registration of any restoration and teeth with a direct restoration combined with a post were 3 times more likely to undergo extraction than teeth restored with an indirect restoration combined with a post and core. Overall, high odds ratios for extractions were associated with any type of composite restoration, including composite fillings and crowns combined with or without any post. In summary, after root filling in the Swedish adult population, several individual- and tooth-specific variables were associated with extraction. The reasons for the extractions remain to be studied further.

Thirty-six-month clinical evaluation of posterior high-viscosity bulk-fill resin composite restorations in a high caries incidence population: interim results of a randomized clinical trial

OBJECTIVES

This study compared the clinical performance of two bulk-fill (BF) and one conventional resin composite in a population with a high caries incidence.

MATERIALS AND METHODS

A total of 138 class I and II restorations were performed and randomly divided into three groups (n = 46) with equal allocation: Filtek BF (FBF; 3M ESPE), Tetric EvoCeram BF (TBF; Ivoclar Vivadent), and control Filtek Z250 (Z250; 3M ESPE). The evaluations were performed using the USPHS and FDI criteria at baseline and after 12 and 36 months by a previously calibrated evaluator. The Friedman and Wilcoxon tests for paired data were used for statistical analysis (α = 0.05).

RESULTS

The DMFT index at baseline was 9.44, with 87% from the decayed component. After 36 months, 108 restorations (n = 36) were evaluated. Two failures were observed for TBF at marginal adaptation and recurrence of caries, resulting in a survival rate of 94.44% and an annual failure rate (AFR) of 1.26%. No equivalence was observed between the criteria for surface roughness, marginal adaptation, and discoloration.

CONCLUSIONS

The 36-month clinical performance of high-viscosity BF resin composites was comparable to conventional incremental-filled resin composites. The FDI criteria better presented the restorations' clinical success. However, in the case of failure, both criteria provided the same result.

CLINICAL RELEVANCE

High-viscosity bulk-fill resin composites showed excellent performance after 36 months in a high caries incidence population. It can be considered a simplified alternative restoration method that reduces operating time and minimizes possible operator errors.

Pulp Vitality and Longevity of Adhesive Restorations Are Not Affected by Selective Carious Removal: A Multicenter Clinical Trial

The aim of this multicenter randomized clinical trial was to evaluate the pulp vitality and survival rate of adhesive restorations performed on posterior deciduous teeth after non-selective (NSCR) or selective (SCR) carious tissue removal over 33 months. One hundred and seven children (average age 4-8 years, SD 1.4) with at least two active moderate cavitated lesions in dentin were included. Teeth were randomized and submitted to NSCR or SCR before composite resin restoration. Restorations were clinically and radiographically assessed at baseline, 6, 12, 18, 24, and 33 months by a blinded, trained, and calibrated operator in each center. The characteristics of the restorations were recorded according to FDI criteria and were considered as restorative failures when scores 4 or 5 were presented. Pulp vitality was measured by clinical and radiographic examinations, and those teeth that presented any signs or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. Data were analyzed by a Cox regression model with shared frailty, considering two outcomes: pulp and restorative. A total of 278 restorations (137 after NSCR and 141 after SCR) were performed at baseline in four different centers and there was no loss in the follow-up period. Survival rate was 97.1 and 87.1% for pulp and for restorative outcome, respectively. The overall annual failure rate was 7%. There were no differences in the failure risk according to the treatment group, center, and all the clinical and demographic variables, regardless of outcome. Composite restorations of active moderate deep carious lesions performed on posterior primary teeth show satisfactory survival for restorative and pulp outcome after a 33-month follow-up, regardless of the technique executed for carious tissue removal.

Practice based research in dentistry: an alternative to deal with clinical questions

Clinical interventions in dental practice should be determined based on the best scientific evidence available. Well-designed randomized clinical trials (RCTs) provide important evidence supporting the efficacy of interventions and are usually considered as the best primary evidence. However, the strict criteria adopted by most RCTs reduce their external validity since some findings from these studies might not work under usual conditions. On the other hand, practice-based research (PBR) studies have been designed to better define the effectiveness of clinical interventions under settings closer to "real-world" conditions. Therefore, this review aimed to describe different PBR designs discussing some advantages and limitations of such studies. The stimulus to organization PBR networks is discussed since the studies performed by these networks involve large number of clinicians and important conclusions can be drawn. Designs of observational studies including surveys and cohort studies based on practice are presented. Survey methods are important to know the behavior of practitioners regarding diagnostic and decision of treatment. Cohorts allow assessing different cofounders contributing to some outcome since large sample sizes and long follow-up periods can be observed in some of these studies. Pragmatic trials designed to take place in real-world clinical practice settings are also discussed as a useful design to assess the effectiveness of clinical interventions. In conclusion, this review sought to present PBR studies as alternative designs to answer clinical questions, but not replacing randomized clinical trials.

Disparities in Access to Oral Health Care

In the United States, people are more likely to have poor oral health if they are low-income, uninsured, and/or members of racial/ethnic minority, immigrant, or rural populations who have suboptimal access to quality oral health care. As a result, poor oral health serves as the national symbol of social inequality. There is increasing recognition among those in public health that oral diseases such as dental caries and periodontal disease and general health conditions such as obesity and diabetes are closely linked by sharing common risk factors, including excess sugar consumption and tobacco use, as well as underlying infection and inflammatory pathways. Hence, efforts to integrate oral health and primary health care, incorporate interventions at multiple levels to improve access to and quality of services, and create health care teams that provide patient-centered care in both safety net clinics and community settings may narrow the gaps in access to oral health care across the life course.

Survival of composite restorations after selective or total caries removal in primary teeth and predictors of failures: A 36-months randomized controlled trial

OBJECTIVES

The aim of this study was to assess the survival of composite restorations after selective (SCR) or total caries removal (TCR) and determine predictors of failures after 36 months.

METHODS

120 teeth with deep occlusal or occlusal-proximal carious lesions were randomly divided into control (TCR; n = 54; 69% Class II) and test (SCR; n = 66; 63% Class II) groups. Clinical evaluation was applied using the USPHS criteria, and the presence of Charlie or Delta scores at the marginal integrity were considered as a failure.

RESULTS

The overall survival rate of restorations was 68% after 36 months, 81% for TCR and 57% for SCR (p = 0.004). The multivariable Cox Regression model demonstrated that restorations performed after SCR had 3.44 times greater probability of failure compared to TCR (p = 0.006). The other two predictors for failure of restorations were teeth with Class II cavities (hazard ratio = 3.3) and children with gingival bleeding over 20% (hazard ratio = 2.5).

CONCLUSIONS

Performing composite restorations after SCR in primary teeth had success rate significantly lower than restorations performed after TCR. Complex cavities and worst patient´s oral hygiene were found to be predictors of failure of restorations.

CLINICAL SIGNIFICANCE

Although SCR has been demonstrating high rates of pulp preservation, clinicians should consider that composite restorations fail in a higher frequency compared to TCR in primary teeth and, in some circumstances, may be preferable in terms of restoration longevity.

Performance of Adhesives and Restorative Materials After Selective Removal of Carious Lesions: Restorative Materials with Anticaries Properties

Selective carious tissue-removal strategies require specific considerations in selection of restorative materials. A tight marginal seal placed over hard dentin and sound enamel is essential. For selective removal of carious tissue with permanent restoration, bioactive materials, such as high-viscosity glass-ionomer cement (HV-GIC) or calcium silicates, may be preferred over caries-affected firm or leathery dentin to improve remineralization. HV-GICs have the best clinical evidence of caries-arresting effect and demonstrate sufficient longevity as long-term provisional restorations that can later be used in open or closed sandwich restorations. As with any material, oral health maintenance remains important for long-term survival of restorations.

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.