Impact of dental treatment and the severity of traumatic dental injuries on the quality of life of Brazilian schoolchildren.

BACKGROUND/AIMS: Traumatic dental injuries (TDI) are most prevalent during adolescence and infancy, and they have an important impact on the oral health-related quality of life (OHRQoL). The aim of this study was to assess the effect of dental treatment and the severity of TDI on the OHRQoL of schoolchildren in public schools in Brazil. MATERIALS AND METHODS: This cross-sectional study evaluated schoolchildren aged 11 to 14 years in Brasilia, Brazil. The criteria used for the examinations were TDI-O'Brien criteria; Dental caries-DMFT criteria; and malocclusion-the Dental Aesthetic Index. The impact of oral health on the children's quality of life was assessed with the Child Perceptions Questionnaire (CPQ11-14 ) that was completed by the children while on the school premises. Socio-demographic information was also collected from the parents. Statistical analysis was performed using non-parametric and association tests, as well as linear regression. RESULTS: A total of 20.2% of the students had some TDI in their permanent anterior teeth; 20% of traumatized teeth were treated, and 80% were not treated. Sorting by severity, 75.1% of the schoolchildren had a TDI involving only the enamel, and 24.9% had a TDI extending beyond the enamel. Significant differences were observed between the severity of a TDI and the total scores of CPQ11-14 (Kruskal-Wallis; p = 0.0026), emotional well-being (p = 0.0006), and social well-being (p = 0.0001) when the group with TDI extending beyond the enamel was compared with the other groups (control and with TDI involving only the enamel), even after adjustment for socio-demographic and clinical variables. For oral symptoms and functional limitation, no differences were observed among the groups. CONCLUSIONS: Dental trauma and fractures extending beyond the enamel, treated or not, have a negative impact on the OHRQoL of schoolchildren, suggesting effects on self-perception and in the social and emotional spheres.

Reattachment of fractured teeth using a multimode adhesive: Effect of different rewetting solutions and immersion time.

BACKGROUND/AIMS: Following coronal tooth fracture, keeping the fragment hydrated is of the utmost importance in the tooth fragment bonding technique. The aim of this study was to evaluate the effects of different immersion times in different storage media on multimode adhesive bonding between reattached fragments and teeth. MATERIALS AND METHODS: A total of 195 bovine incisors were fractured and randomized into the following storage groups (n = 15): G0-control group (sound tooth); GA-saline solution: for 1 hour (A1) or 24 hours (A2); GB-artificial saliva: for 1 hour (B1) or 24 hours (B2); GC-coconut water: for 1 hour (C1) or 24 hours (C2); GD-tap water: for 1 hour (D1) or 24 hours (D2); GE-milk: for 1 hour (E1) or 24 hours (E2); GF-dry (dehydration): for 1 hour (F1) or 24 hours (F2). Tooth fragments were then reattached using a multimode adhesive in a self-mode technique with a flowable resin composite. Fracture resistance was evaluated in a universal testing machine under a compressive load (1 mm/min). The data were submitted to two-way analysis of variance and the post hoc Tukey test (5%). RESULTS: The group submitted to the dehydration factor (GF) exhibited a mean value of 599.1 ± 144.2 N, while those submitted to all hydration protocols (GA, GB, GC, GD, GE) exhibited a mean value of 751.8 ± 285.4 N. Dehydration significantly affected the fracture strength values (P = .005). No significant interaction between the rewetting solutions was observed (P > .05). CONCLUSIONS: Hydration of the tooth fragment increased fracture resistance, regardless of the storage solution and/or immersion time.

Influence of adhesive restorations on diffusion of H2O2 released from a bleaching agent and its toxic effects on pulp cells.

PURPOSE: To assess the influence of adhesive restorations on hydrogen peroxide (H2O2) diffusion through enamel and dentin and its cytotoxicity to pulp (MDPC-23) cells. MATERIALS AND METHODS: Sound and resin-restored enamel/dentin disks were stored in water for 24 h or 6 months and adapted to artificial pulp chambers. Bleaching gels with 20% or 35% H2O2 were applied to the enamel surface for 45 min, and a culture medium in direct contact with the dentin surface (extract) was applied for 1 h to the MDPC-23 cells. Cell metabolism (MTT assay) and cell morphology (SEM) were assessed. The amount of H2O2 in the extracts was also quantified (peroxidase/leuco-crystal violet reaction). RESULTS: A significant reduction in cell metabolism was observed between the group bleached with the 35% gel and the control group (sound, nonbleached) (p < 0.05). The H2O2 diffusion was directly related to its concentration in the bleaching gel. The variables "presence of restoration" and "time of water storage" did not significantly influence H2O2 diffusion or cell metabolism for either of the bleaching gels (p > 0.05). All bleached groups presented alterations in cell morphology related to the concentration of H2O2 in the bleaching gel. CONCLUSION: The reduction in cell metabolism and the changes in cell morphology were H2O2-concentration dependent, having no relationship with the presence of either new or aged adhesive restorations on teeth subjected to bleaching therapies.

COVID-19 pandemic and its impact on dental students: A multi-institutional survey.

PURPOSE/OBJECTIVES: To investigate dental students' perceptions and concerns regarding the COVID-19 pandemic, their coping strategies and support resources, and their perceived stress levels. METHODS: A customized 19-item survey and the perceived stress scale (PSS) were applied to undergraduate dental students from the US, Spain, Ireland, Chile, India, and Brazil between April 10 and July 5, 2020. Linear modeling and mediation analysis were used to explore the relationships among demographics, stressors, coping mechanisms, social support, and stress RESULTS: A total of 4475 students responded to the survey. The majority (72.4%) were women, and 52.3% had no COVID-19 training at the time of the survey. The students reported that they had to accommodate to changes in patient care (96.6%) and didactic learning (95.2%) activities, while 88.5% of the respondents indicated at least one of their courses moved online. Transition to online courses went "smoothly with some troubles" for 51.8% of the respondents, and 48.3% perceived the faculty as prepared for the online transition; however, 45.9% reported feeling extremely concerned about the impact of COVID-19 on their education. The average PSS score was 21.9 of 40 (moderate stress). Multivariate models were built for participants with full data (n = 3899). Being male, having completed more dental coursework, and perceiving a smoother transition were associated with lower PSS scores; more concern about academic progress was associated with higher PSS. Faculty support mediated the relationship between a smoothness of transition and concern about academic progress and PSS scores CONCLUSION: Stress caused by the pandemic may be alleviated by smoother transition and good faculty support.

Selective carious tissue removal using subjective criteria or polymer bur: study protocol for a randomised controlled trial (SelecCT).

INTRODUCTION: Selective (incomplete/partial) carious tissue removal is suitable for treating deep carious lesions in teeth with vital, asymptomatic pulps. In the periphery of a cavity, removal to hard dentin is performed, while in pulpo-proximal areas, leathery or soft dentin is left to avoid pulp exposure. As the decision of what contains 'soft' or 'leathery' dentin is subjective, using self-limiting burs which help to standardise the hardness of the remaining dentin, has been suggested to increase the reliability of carious tissue removal. The trial compares subjectively measured selective carious tissue removal in deep lesions in primary teeth with objectively measured selective removal with a self-limiting bur (Polybur, Komet). METHODS AND ANALYSIS: A community-based single-blind clustered randomised controlled superiority trial nested into a larger evaluation is performed. Recruitment for this trial has been concluded. We have recruited 115 children aged 6-8 years with ≥1 vital primary molar with a deep dentin lesion. The unit of randomisation was the child, with all eligible molars per child treated identically. Treatment was performed in a mobile dental unit. Subjective and objective carious tissue removal was performed at random. Teeth were restored using glass ionomer cement (Equia Forte, GC). Our primary outcome will be the time until complications occur, evaluated via multilevel survival analysis. Secondary outcomes will be the time until extraction is needed, subjective satisfaction of the child with the treatment (measured using a Likert scale) and cost-effectiveness. Re-examination will be performed after 12, 24 and 36 months (the final examination is expected in 2020). ETHICS AND DISSEMINATION: This trial has been approved by the Ethics Committee of the Health Sciences of the University of Brasília (CAAE 51310415.0.0000.0030). Trial results will be published in peer-reviewed journals and presented on conferences. TRIAL REGISTRATION NUMBER: NCT02754466.

Cytotoxic effect of a 35% hydrogen peroxide bleaching gel on odontoblast-like MDPC-23 cells.

OBJECTIVE: This study evaluated transenamel and transdentinal cytotoxic effects of a bleaching gel on the MDPC-23 cell line. STUDY DESIGN: Discs obtained from bovine incisors were placed in a metallic device to simulate an in vivo pulp chamber. Groups were formed according to the enamel surface treatment: G1: 35% H(2)O(2) bleaching gel; G2: 35% H(2)O(2) bleaching gel + halogen light; G3: halogen light; and G4: control. Cell metabolism was evaluated by the methyltetrazolium assay and cell morphology by scanning electron microscopy. RESULTS: Cell metabolism decreased by 31.7%, 41.6%, and 11.5% in G1, G2, and G3, respectively. Cytotoxic effects observed in G2 were significantly more severe compared with G3 and G4. In G1 and G2, a smaller number of viable cells with major morphologic alterations remained adhered to dentin. CONCLUSION: The bleaching gel associated with light presented transenamel and transdentinal cytotoxic effects characterised by direct damage to odontoblasts and decrease of their metabolic activity.