Effect of Type of Resin Composite Material on Porosity, Interfacial Gaps and Microhardness of Small Class I Restorations.

AIM: This study aimed to compare the best restorative approach for the conservative class I cavity by comparing flowable and nanohybrid composites versus the placement technique regarding surface microhardness, porosity, and presence of interface gaps. MATERIALS AND METHODS: Forty human molars were divided into four groups (n = 10). Standardized class I cavities were prepared and restored using one of the following materials: Group I - Flowable composite placed by incremental technique; group II - Flowable composite placed in one increment; group III - Nanohybrid composite placed by incremental technique; and group IV - Nano-hybrid composite placed in one increment. After finishing and polishing, specimens were sectioned into two halves. One section was chosen randomly for the Vickers microhardness (HV) evaluation and the other section was used for the assessment of porosities and interfacial adaptation (IA). RESULTS: The surface microhardness range was 28.5-76.2 (p < 0.05), mean pulpal microhardness range was 27.6-74.4 (p < 0.05). Flowable composites had lower HV than conventional counterparts. The mean pulpal HV of all materials exceeded 80% of occlusal HV. Restorative approaches did not statistically differ in porosities. However, IA percentages were higher in flowable materials compared to nanocomposites. CONCLUSION: Flowable resin composite materials have lower microhardness than Nanohybrid composites. In small class I cavities, the number of porosities was similar between the different placement techniques and the interfacial gaps were highest in the flowable composites. CLINICAL SIGNIFICANCE: The use of nanohybrid resin composite to restore class I cavities will result in better hardness and less interfacial gaps compared to flowable composites.

Prevalence of Temporomandibular Disorder-Related Pain among Adults Seeking Dental Care: A Cross-Sectional Study.

Objectives: Temporomandibular disorders (TMD) are a constellation of painful conditions that affect the craniofacial complex. The etiology and risk factors of these conditions have been extensively studied; however, the data available describing the epidemiology of TMD in the Middle East are scarce. We aimed to estimate the prevalence and risk factors of TMD-related pain in a sample population of dental school clinic patients. Methods: This observational cross-sectional study used a translated and culturally adapted temporomandibular disorders pain screener, a part of the Diagnostic Criteria/Temporomandibular Disorders (DC/TMD) criteria instrument, and questions related to demographic characteristics and risk factors for TMD. Data were analyzed through chi-square and Mann-Whitney U tests using SPSS. Results: The sample population included 199 participants (66% female and 34% male). The prevalence of TMD-related pain was 26.8% (n = 42); men and women did not differ statistically in their TMD-related pain. TMD-related pain cases differed significantly on the Center for Epidemiologic Studies Depression Scale (CES-D) and body pain scores compared with noncases. Conclusion: The prevalence of TMD-related pain in the clinical sample population was high. Hence, the onus is on dental health services to screen and educate patients on TMD conditions regularly.

Errors in light-emitting diodes positioning when curing bulk fill and incremental composites: impact on properties after aging.

OBJECTIVES: This study aimed to evaluate the effect of improper positioning single-peak and multi-peak lights on color change, microhardness of bottom and top, and surface topography of bulk fill and incremental composites after artificial aging for 1 year. MATERIALS AND METHODS: Bulk fill and incremental composites were cured using multi-peak and single-peak light-emitting diode (LED) following 4 clinical conditions: (1) optimal condition (no angulation or tip displacement), (2) tip-displacement (2 mm), (3) slight tip angulation (α = 20°) and (4) moderate tip angulation (α = 35°). After 1-year of water aging, the specimens were analyzed for color changes (ΔE), Vickers hardness, surface topography (Ra, Rt, and Rv), and scanning electron microscopy. RESULTS: For samples cured by single-peak LED, the improper positioning significantly increases the color change compared to the optimal position regardless of the type of composite (p < 0.001). For multi-peak LED, the type of resin composite and the curing condition displayed a significant effect on ΔE (p < 0.001). For both LEDs, the Vickers hardness and bottom/top ratio of Vickers hardness were affected by the type of composite and the curing condition (p < 0.01). CONCLUSIONS: The bulk fill composite presented greater resistance to wear, higher color stability, and better microhardness than the incremental composite when subjected to improper curing. The multi-peak LED improves curing under improper conditions compared to single-peak LED. Prevention of errors when curing composites requires the attention of all personnel involved in the patient's care once the clinical relevance of the appropriate polymerization reflects on reliable long-term outcomes.

Improper Light Curing of Bulkfill Composite Drives Surface Changes and Increases S. mutans Biofilm Growth as a Pathway for Higher Risk of Recurrent Caries around Restorations.

How dentists cure a resin-based material has deleterious effects on the material's properties and its interaction with surrounding dental tissues. Biofilm accumulation has been implicated in the pathogenesis of carious lesions around dental restorations, with its composition manifesting expressed dysbiosis in patients suffering from dental caries. To evaluate the influence of varying radiant exposure on the degree of conversion (DC%), Streptococcus mutans biofilm growth, and surface roughness of bulk-fill composites under different light-curing conditions. Two light-curing units (LCU) at 600 and 1000 mW/cm2 were used to simulate curing conditions with different angulations (∢20° and ∢35°) or 2 mm-distance displacements of the LCU tip. The radiant exposure (RE) was assessed, and the composites were analyzed for DC%. Biofilm formation was induced over the bulk-fill composites and analyzed via colony-forming units counting and scanning electron microscopy (SEM). The surface roughness was analyzed via a profilometer and SEM after biofilm formation. Curing conditions with different angulation or displacement decreased RE compared to the "optimal condition". The moderately (∢35°) angulated LCU tip and low (600 mW/cm2) radiant emittance significantly reduced the DC% (p < 0.05). The difference in DC% between the top and bottom of the composites ranged from 8 to 11% for 600 mW/cm2 and 10 to 20% for 1000 mW/cm2. Greater S. mutans biofilm and surface changes were found in composites with non-optimal RE delivery (e.g., tip displacement and angulation) (p < 0.05). Inadequate polymerization of bulk-fill composites was associated with more biofilm accumulation and surface topography changes. Overall, non-optimally performed curing procedures reduced the amount of delivered RE, which led to low DC%, more biofilm formation, and higher surface roughness. The improper light-curing of bulk-fill composites compromises their physicochemical and biological properties, which could lead to inferior clinical performance and reduced restorative treatments' longevity.

Caries among adult patients with controlled celiac disease: A cross-sectional study.

INTRODUCTION: Celiac disease (CD) is one of the most common chronic gastrointestinal disorders in the world. Currently, the literature about the dental profiles of patients with celiac disease is sparse and no studies have reported on the oral conditions and caries status of CD patients in Kuwait. OBJECTIVE: This study investigated the association between CD and caries experience. METHODS: Two groups were examined; study and control. The study group consisted of controlled celiac disease patients. The control group consisted of subjects who were matched for age and gender to the study group participants. Both groups received clinical and radiographic examinations of their oral cavity. Parameters recorded for the study purposes were-dental caries index (decayed, missing, and filled teeth), salivary flow rates (stimulated and unstimulated), salivary buffering capacity and Lactobacilli and mutans Streptococci bacterial counts. RESULTS: Patients with CD had statistically significant fewer missing teeth than the controls. There were no other significant differences. Measured stimulated and unstimulated salivary flow rates and salivary buffering capacity showed no statistical differences. Bacterial counts revealed no significant differences. CONCLUSION: Adult patients with controlled CD showed fewer missing teeth than their counterparts. Other caries and salivary parameters showed no statistical differences between the two groups.

Underperforming light curing procedures trigger detrimental irradiance-dependent biofilm response on incrementally placed dental composites.

OBJECTIVES: Insufficient radiant exposure (J/cm2) may provide an early trigger in a cascade of detrimental responses on incrementally-place composite, especially the bottom layer. This study aimed to assess the influence of poor radiant exposure, the degree of conversion (%DC), water sorption/ solubility and S. mutans biofilm formation on conventional, incrementally placed composites and to establish a relationship between these factors. METHODS: Two light units operating at 600 and 1000 mW/cm2 and four most common operator-dependent curing conditions had the radiant exposure (RE) recorded. All the specimens were subjected to S. mutans biofilm model for 14 days. The %DC, biofilm formation expressed by colony-forming units (CFU), water sorption/ solubility and surface roughness/ SEM were assessed. Data were submitted to two-way ANOVA and Tukey post-hoc test (α = 0.05). Pearson correlation was also determined. RESULTS: The influence of RE on S. mutans CFU values and DC are dependent on the curing conditions and irradiance (p < 0.05). A negative relationship was observed between RE and biofilm formation. The operator-dependent curing conditions have shown RE reduction varying from 49.4% to 73.5% in relation to control. The difference in DC between top/bottom of cylinder varied from 13% to 21% for 1000 mW/cm2and from 29% to 53% for LCU600. The roughness, solubility and salivary sorption were greater for low RE. CONCLUSION: Poor, deficient curing procedures provide an early trigger in a negative pathway of events for incrementally-place dental composite including a biological response by increased biofilm formation by S. mutans, a relevant factor for secondary caries development. SIGNIFICANCE: The susceptibility to variation in the outcomes was RE -dependent. The optimization of the curing procedures ensures the maximum performance in the chain of events involved in the light curing process of resin-based materials and potentially reduce the risk factors of secondary caries development.

Layered Base Plate Blocks and Operative Dentistry Skills.

AIM: Preclinical dental training is essential for the development of psychomotor skills necessary for clinical practice. The study aimed to investigate the impact of teaching with a layered base plate blocks on cavity preparations and students' self-perceived confidence, readiness, and ability. MATERIALS AND METHODS: A cross-sectional study recruited 52 dental students into two groups; one trained (test) with layered base plate and the other without (control). Students answered an eight-question survey to assess self-perceived confidence, readiness, and ability for performing cavity preparation at the start of their first preclinical operative dentistry course. Students prepared one molar tooth for a class I cavity and two for class II cavities. Preparations were assessed for different elements of depth and outline extension by two blinded examiners. RESULTS: Statistically significant differences were found between the median scores with respect to the preparation of class II cavities among students exposed to layered base plate (Mann-Whitney U-test, p < 0.05). There were no significant differences between the median scores awarded with respect to the preparation of class I cavity. A statistically significant difference was reported in self-perceived confidence among students who trained with the layered base plate (x2, p < 0.05). CONCLUSION: Training on the layered base plate blocks increased students' initial confidence level in performing cavity preparations, and improved the preparation skills in class II cavity. CLINICAL SIGNIFICANCE: This study explores the methods of enhancing motor skills taught in preclinical operative dentistry courses, especially in short academic programs.

Oral Cancer Screening among Smokers and Nonsmokers.

AIMS AND OBJECTIVES: The aim of visual systematic screening is early identification of oral cancer (OC) precursor lesion. OC mortality improves when cancer is identified at early stages. This is important in patients whose lifestyle choices render them at higher risk of developing OC. This study described the prevalence of OC screening among smokers and nonsmokers in Kuwait and ascertained demographic predictors. MATERIALS AND METHODS: This cross-sectional study utilized a self-administered online survey in English and Arabic through Survey Monkey® and disseminated using the social networking app "WhatsApp." The survey included 21 questions on demographics, smoking status, and knowledge of OC. Screening questions were adopted from the Maryland Cancer Screening and Risk Behavior Survey. Data were analyzed using the computer software "Statistical Package for Social Sciences, SPSS version 24.0" (IBM Corp, Armonk, NY, USA). RESULTS: The study included 404 Kuwaiti respondents, 311 (77%) nonsmokers and 93 (23%) smokers. Prevalence of OC screening was 7.2, 7.7% among nonsmokers and 5.4% in smokers. Only 36.6% were aware of OC, with more nonsmokers (38.9%) than smokers (29%). Logistic regression revealed twice more males likely to go for screening than females and with the likelihood of those being in the age group of 25-44 years four times more (P < 0.012) than other age groups. CONCLUSION: There was low prevalence of screening and poor awareness of OC among sampled. Increased efforts are needed by health professionals to spread awareness and improve knowledge on OC and demand the inclusion of screening during their routine and opportunistic oral examinations.

Factors influencing success of radiant exposure in light-curing posterior dental composite in the clinical setting.

PURPOSE: (1) To conduct a comprehensive review of the literature on factors influencing the radiant exposure of resin-based composite (RBC) restorations and (2) To fully understand the appropriate way of using the light curing units (LCUs) to perform restorations with optimal mechanical/physical properties. METHODS: A PubMed search identified recent publications in English that addressed the factors affecting the longevity of the RBC restorations and the optimal usage of LCUs. RESULTS: RBCs require light-induced polymerization of methacrylate monomers present in its composition to reach acceptable mechanical and physical properties. Complete polymerization of the RBC is never reached, and the maximum degree of conversion (DC) varies from 40 to 80%. The amount of radiant exposure (Joules/cm²) required for the commencement of polymerization becomes a core driver for the quality of the RBCs. Insufficient radiant exposure may lead to low strength behavior and susceptibility to degradation, thereby shortening the lifespan of restorations inside the mouth. This suggests that there are factors affecting the radiant exposure during clinical procedures; these factors can be categorized as material-related, LCU-related and operator-related factors. CLINICAL SIGNIFICANCE: Proper light-curing techniques are critical for delivering an adequate amount of radiant exposure to RBCs. Adequate light curing decreases the number of underexposed RBC restorations, improves their mechanical and physical properties and accordingly, increases their clinical longevity.

Risk Factors for Facial Pain: Data from the Osteoarthritis Initiative Study.

AIMS: Temporomandibular disorder (TMD) is believed to be co-morbid with rheumatologic conditions such as Osteoarthritis (OA). We determine 30-day prevalence and cumulative incidence, and risk factors for facial pain in a cohort of subjects who either had or were at risk of developing symptomatic radiographic knee osteoarthritis (SRKOA). METHODS: Poisson regression models examined whether age, sex, race, Center for Epidemiologic Studies-Depression Scale (CES-D) score, number of painful joints, and presence of SRKOA were risk factors for facial pain in 4,423 subjects at baseline and in 3,472 subjects at 24 and/or 48 months follow-up. RESULTS: At baseline, 30-day period prevalence of facial pain was 9.25%; and 30-day cumulative incidence at 24-months and at 48-months was 5.9% and 4.9%, respectively. Factors associated with prevalence and incidence of facial pain were: younger age, female sex, (CES-D) score, and a larger number of painful joints. For each increase in age of one year, the incidence of facial pain decreased by 1%. Women had a 96% higher incidence than men, and each unit increase of (CES-D) score was associated with a 2% increase in the incidence of facial pain. For every additional painful joint, there was a 21% increase in the incidence of facial pain. Subjects with SRKOA had a 33% increase in the incidence of facial pain compared to those with risk factors for SRKOA. CONCLUSION: OA and TMD share several risk factors. The risk factors identified in cross-sectional analysis of prevalence are similar to those identified in longitudinal analysis on incidence.