Vitamin D deficiency is a risk factor for delayed tooth eruption associated with persistent primary tooth.

OBJECTIVE: To verify the association between 25(OH)D level and polymorphisms in the vitamin D receptor gene (VDR) with the disturbance in the dental development and eruption. DESIGN: A total of 183 children from two datasets were evaluated. The first dataset was a case-control (15:15) designed to assess if persistent primary tooth (PPT) is associate with serum 25(OH)D level and with genetic polymorphisms in VDR. The second dataset of genomic DNA samples from 54 children with delayed tooth eruption (DTE) and 99 controls were analysed to verify if genetic polymorphisms in VDR (rs2228570 and rs739837) are associated with DTE. The 25(OH)D and the genotyping/allele distribution were analysed using the T-test and chi-square test, respectively. RESULTS: The level of 25(OH)D in the PPT group (24.9 ± 6.4 mg/mL) was significantly lower than the control (30.0 ± 7.0 mg/mL) (p=.047). Our data show that children with 25(OH)D deficiency are more likely to present PPT (OR = 2.36; 95%CI: 1.51, 3.70). The rs739837 and rs2228570 polymorphisms were not associated with DTE (OR = 1.44; 95%CI: 0.87, 2.39 and OR = 0.80; 95%CI: 0.45, 1.44, respectively). CONCLUSIONS: Vitamin D deficiency is a risk factor for PPT.

GHR and IGF2R genes may contribute to normal variations in craniofacial dimensions: Insights from an admixed population.

INTRODUCTION: This study aimed to determine whether single nucleotide polymorphisms in the growth hormone receptor (GHR) and insulin-like growth factor 2 receptor (IGF2R) genes are associated with different craniofacial phenotypes. METHODS: A total of 596 orthodontic and 98 orthognathic patients from 4 cities in Brazil were included for analyses. Angular and linear cephalometric measurements were obtained, and phenotype characterizations were performed. Genomic DNA was collected from buccal cells and single nucleotide polymorphisms in GHR (rs2910875, rs2973015, rs1509460) and IGF2R (rs2277071, rs6909681, rs6920141) were genotyped by polymerase chain reactions using TaqMan assay. Genotype-phenotype associations were assessed in the total sample (statistical significance was set at P <8.333 × 10-3) and by a meta-analytic approach implemented to calculate the single effect size measurement for the different cohorts. RESULTS: Rare homozygotes for the GHR rs2973015 showed increased measurements for the lower anterior facial height (ANS-Me) and mandibular sagittal lengths (Co-Gn and Go-Pg). In contrast, common homozygotes for the IGF2R rs6920141 presented reduced measurements for these dimensions (ANS-Me and Go-Pg). Furthermore, the less common homozygotes for IGF2R rs2277071 had reduced maxillary sagittal length (Ptm'-A'). The meta-analytical approach replicated the associations of rs2973015 with ANS-Me, rs2277071 with Ptm'-A', and rs6920141 with Go-Pg. CONCLUSIONS: Our results provide further evidence that GHR contributes to the determination of mandibular morphology. In addition, we report that IGF2R is a possible gene associated with variations in craniofacial dimensions. Applying meta-analytical approaches to genetic variation data originating from likely underpowered samples may provide additional insight regarding genotype and/or phenotype associations.

RANKL is associated with persistent primary teeth and delayed permanent tooth emergence.

BACKGROUND: Tooth eruption is a process that is not fully understood. AIM: To evaluate whether genetic polymorphisms for RANK/RANKL/OPG are associated with delayed tooth emergence. To evaluate whether the relative expression of this genes is associated with persistent primary teeth. DESIGN: To evaluate whether genetic polymorphisms for RANK/RANKL/OPG could be involved in delayed tooth emergence, saliva samples from 160 children, aged 6-13 years old, were analysed. To test if there is correlation between gene expression of RANK/RANKL/OPG in children with delayed tooth emergence and persistent primary teeth, periapical tissue from 15 children with persistent primary teeth and from 15 control subjects were collected for qPCR analysis. RESULTS: Fifty-six children with delayed tooth emergence (35%) had at least one permanent tooth with delayed emergence. The T allele in RANKL (rs9594738) increased the risk of delayed tooth emergence (P = 0.02; OR = 1.71, 95%CI 1.09-2.75). The relative gene expression for RANKL and the ratio RANKL/OPG in children with delayed tooth emergence and persistent primary teeth were lower compared to controls (P = 0.02 and P = 0.005, respectively). CONCLUSIONS: Data suggest that the polymorphism rs9594738 in RANKL is associated with delayed permanent tooth emergence. Moreover, reduced relative gene expression of RANKL in periapical tissue is associated with persistent primary teeth.

Microleakage of Sealants after Phosphoric Acid, Er: YAG Laser and Air Abrasion Enamel Conditioning: Systematic Review and Meta-Analysis.

PURPOSE: The aim of this systematic review and meta-analysis is to answer the focused question: Does the application of phosphoric acid, Er:YAG laser and air abrasion enamel conditioning methods previous to the oclusal sealant application in human permanent molars influence the microleakage? STUDY DESIGN: A literature research was carried out in the Pubmed Medline, Web of Science, Scopus and Cochrane databases using with the MeSH terms and keyword search strategy. A supplemental hand search of the references of retrieved articles was also performed. Inclusion criteria comprised ex vivo studies (extracted teeth) with permanent human teeth that used chemical (phosphoric acid) or mechanical (Er:YAG laser and air abrasion) conditioning methods previous the sealant application. The studies should evaluate microleakage as an outcome. Meta-analysis pooled plot were obtained comparing the microleakage after pre-treatment with phosphoric acid, Er:YAG and air abrasion enamel conditioning for sealant application using RevMan software. RESULTS: The search resulted in 164 articles, 55 records were excluded because they were duplicated. The analysis of titles and abstracts resulted in the exclusion of 105 studies. Four studies were included in the systematic review and the meta-analysis. According to the risk of bias evaluation, the four studies were considered low risk of bias. The meta-analysis showed that phosphoric acid had lower microleakage than Er:YAG laser (p < 0.001) and air abrasion (p < 0.001), with heterogeinity of I2 = 0% and I2 = 71%, respectively. It was not found statistical difference when compared phosphoric acid and phosphoric acid combined with Er:YAG laser and air abrasion (p > 0.05). CONCLUSION: The evidence supports that the pretreatment with phosphoric acid leads lower microleakage in oclusal sealants than Er:YAG laser and air abrasion.

Tissue response to root canal irrigation systems in dogs' teeth with apical periodontitis.

OBJECTIVES: The aim of this study was to compare the efficacy of apical negative pressure irrigation (ANP) and passive ultrasonic irrigation (PUI) with apical positive pressure irrigation (PP-conventional irrigation) in the periapical repair of dogs' teeth with apical periodontitis. METHODS: Forty-nine mesial and distal root canals of premolars of three dogs with experimentally induced periapical lesions were subjected to a single-session root canal treatment. The teeth were randomly assigned to three groups: ANP, PUI, and PP (control). After 180 days, the animals were euthanized, and the anatomic pieces were removed and subjected to histotechnical processing for morphological and morphometric histological analyses of hematoxylin and eosin (HE)-stained sections under conventional and fluorescence microscopy. Periapical lesion size before and 180 days after root canal treatment was measured by periapical radiographic examination. Tartrate-resistant acid phosphatase (TRAP) histoenzymology was performed for osteoclast counting and Brown and Brenn staining to assess bacteria. Data were analyzed statistically by the Kruskal-Wallis test (α = 5 %). RESULT: There were no statistically significant differences among the groups regarding periapical lesion size in the radiographic evaluation (p = 0.91). In the comparison of histopathological parameters, group ANP presented more homogeneous results. There was a statistically significant difference (p = 0.02) between groups ANP and PP, with better results for group ANP in which milder infiltrate inflammatory was observed. No statistically significant difference (p > 0.05) was found among the groups with respect to periodontal ligament space, presence of mineralized tissue resorption, size of the periapical lesions, and number of osteoclasts. CONCLUSION: Although the three irrigation systems elicited similar periapical tissue response with respect to almost all evaluated parameters, ANP presented the mildest inflammatory infiltrate, suggesting an advantage over PP in the indication for clinical use. CLINICAL RELEVANCE: Irrigation of the root canal systems is an extremely important step in root canal treatment. Therefore, it is of relevance to evaluate the efficacy of these systems by in vivo experimental models to provide scientific background for the clinical practice.

Children's toothbrush contamination in day-care centers: how to solve this problem?

OBJECTIVE: To evaluate the contamination level of toothbrushes by mutans streptococci (MS) and the efficacy of antimicrobial solutions: cetylpyridinium chloride 0.05 % (CPC; Cepacol™) and chlorhexidine 0.12 % (CHX; Periogard™), to disinfect toothbrushes of preschool-aged children in day-care centers. MATERIAL AND METHODS: Fifty-two children were randomly divided into three groups, and a three-stage changeover system was used with a 1-week interval between each stage. Solutions were used by a different group of children in each stage. Children were submitted to a 1 minute brushing without dentifrice, performed by a professional calibrated, followed by random spraying over the bristles of brushes. Process and microbiological analysis were realized, and four brushes of each group were analyzed by scanning electron microscopy (SEM). RESULTS: Friedman's test at 5 % significance level revealed difference between the antimicrobial solutions (p < 0.01). MS were detected in 100 % cases of toothbrushes sprayed with sterile tap water (control) and in 66.7 % after spraying with CPC, but it was not detected formation of colonies/biofilms after spraying with CHX. The data were confirmed by SEM. CONCLUSIONS: The toothbrushes were contaminated with MS after a single brushing. CLINICAL RELEVANCE: Although CPC has shown good results in comparison with the control, CHX showed greater efficacy in disinfection bristles of toothbrushes.

Mutans streptococci remained viable on toothbrush bristles, in vivo, for 44 h.

BACKGROUND: Toothbrushes harbor a high number of cariogenic microorganisms. AIM: To investigate the viability of mutans streptococci (MS) on toothbrushes bristles and the production of extracellular polysaccharide (ECP) related to drying time. DESIGN: Twenty children were submitted to brushing without dentifrice. Toothbrushes were kept at room temperature from 0 to 48 h and then submitted to microbiological processing. The number of MS colonies/biofilms was expressed according to scores: 0=no colonies were detected; 1=1 to 50; 2=51 to 100; 3=over 100. The amount of ECP was evaluated according to scores: 0=absence; 1=ECP recovering until 50% of the surface; 2=ECP recovering more than 50% of the surface. Data were analyzed by Wilcoxon test (α=5%). RESULTS: At the periods of 0 to 16 h, the toothbrushes had intense bacterial contamination (score 3). From the 18-h, there was a statistically significant decrease in the MS viability (P=0.0078), with predominance of score 1 on periods of 20 to 44 h. The most detected ECP amount was at 0- and 12-h period (P<0.05) with reduction until 32-h period. CONCLUSIONS: Mutans streptococci remained viable on toothbrushes bristles, in vivo, for 44 h.

Assessing the Accuracy, Completeness, and Reliability of Artificial Intelligence-Generated Responses in Dentistry: A Pilot Study Evaluating the ChatGPT Model.

BACKGROUND: Artificial intelligence (AI) can be a tool in the diagnosis and acquisition of knowledge, particularly in dentistry, sparking debates on its application in clinical decision-making. OBJECTIVE: This study aims to evaluate the accuracy, completeness, and reliability of the responses generated by Chatbot Generative Pre-Trained Transformer (ChatGPT) 3.5 in dentistry using expert-formulated questions. MATERIALS AND METHODS: Experts were invited to create three questions, answers, and respective references according to specialized fields of activity. The Likert scale was used to evaluate agreement levels between experts and ChatGPT responses. Statistical analysis compared descriptive and binary question groups in terms of accuracy and completeness. Questions with low accuracy underwent re-evaluation, and subsequent responses were compared for improvement. The Wilcoxon test was utilized (α = 0.05). RESULTS: Ten experts across six dental specialties generated 30 binary and descriptive dental questions and references. The accuracy score had a median of 5.50 and a mean of 4.17. For completeness, the median was 2.00 and the mean was 2.07. No difference was observed between descriptive and binary responses for accuracy and completeness. However, re-evaluated responses showed a significant improvement with a significant difference in accuracy (median 5.50 vs. 6.00; mean 4.17 vs. 4.80; p=0.042) and completeness (median 2.0 vs. 2.0; mean 2.07 vs. 2.30; p=0.011). References were more incorrect than correct, with no differences between descriptive and binary questions. CONCLUSIONS: ChatGPT initially demonstrated good accuracy and completeness, which was further improved with machine learning (ML) over time. However, some inaccurate answers and references persisted. Human critical discernment continues to be essential to facing complex clinical cases and advancing theoretical knowledge and evidence-based practice.

Knowledge, attitudes, and psychosocial impacts among Brazilian Pediatric Dentists during COVID-19 pandemic.

In this study, we evaluated the knowledge, attitudes, and psychosocial impacts among Brazilian pediatric dentists during the COVID-19 pandemic. A cross-sectional study with primary data collection was carried out using an online structured questionnaire. Data were submitted to descriptive analysis by using absolute and relative frequencies. A chi-square test was used for association analysis and log-linear regression models to estimate the prevalence ratio (5%). The population comprised mostly women and knowledge regarding COVID-19 was satisfactory (above 80% in most items). N95 masks and faceshields were used, albeit 64.22% reported difficulty in providing dental care to children due to the need for extra Personal Protective Equipment. Thirty eight percent provided urgency/emergency dental care, 59.78% performed invasive procedures, 59.56% used high speed handpieces, 8.44% started using cariostatics, and 6.22% introduced the use of chemomechanical caries removal agents. Fear for the future (PR = 1.21) and use of medications (for anxiety, depression, or insomnia) increased (PR = 1.16) among the ones who had wage losses. Brazilian pediatric dentists have knowledge about COVID-19, and attitudes in their clinical routines changed due the pandemic. Financial life was harmed and a negative impact of the pandemic in psychosocial aspects of workers was found.

A scanning electron microscopy study of diseased root surfaces conditioned with EDTA gel plus Cetavlon after scaling and root planing.

In the present investigation, a scanning electron microscopy analysis was performed to evaluate the effects of the topical application of ethylenediaminetetraacetic acid (EDTA) gel associated with Cetavlon (EDTAC) in removing the smear layer and exposing collagen fibers following root surface instrumentation. Twenty-eight teeth from adult humans, single rooted and scheduled for extraction due to periodontal reasons, were selected. Each tooth was submitted to manual (scaling and root planing) instrumentation alone or combined with ultrasonic instruments, with or without etching using a 24% EDTAC gel. Following extraction, specimens were processed and examined under a scanning electron microscope. A comparative morphological semi-quantitative analysis was performed; the intensity of the smear layer and the decalcification of cementum and dentinal surfaces were graded in 12 sets using an arbitrary scale ranging from 1 (area covered by a smear layer) to 4 (no smear layer). Root debridement with hand instruments alone or combined with ultrasonic instruments resulted in a similar smear layer covering the root surfaces. The smear layer was successfully removed from the surfaces treated with EDTAC, which exhibited numerous exposed dentinal tubules and collagen fibers. This study supports the hypothesis that manual instrumentation alone or instrumentation combined with ultrasonic instrumentation is unable to remove the smear layer, whereas the subsequent topical application of EDTAC gel effectively removes the smear layer, uncovers dentinal openings and exposes collagen fibers.

An Epigallocatechin-3-gallate Formulation Developed for Endodontic Use: A Physicochemical and Biological Evaluation.

INTRODUCTION: Although epigallocatechin-3-gallate (EGCG) from green tea has been successfully used in the prevention and treatment of several infectious and immunoinflammatory diseases because of its proven anti-inflammatory, antioxidant, antimicrobial, and antiresorptive role, its use as an intracanal dressing has not been proposed. The aim of this study was to develop a formulation based on EGCG for endodontic use by assessing its physicochemical and biological properties. METHODS: Initially, physicochemical characterization of EGCG was performed by ultraviolet-visible and fluorescence spectroscopy to evaluate if the properties were maintained in acidic pH and time (1-6, 24, and 27 hours). After that, biological studies evaluated the developed formulation of EGCG at different concentrations (1.25, 5, 10, and 20 mg/mL). The tissue compatibility with subcutaneous tissue of mice was evaluated by plasma leakage after 24 hours and the examination of macroscopic and microscopic features at 7, 21, and 63 days after the insertion of polyethylene tubes containing the formulations. The repair of experimentally induced periapical lesions in dog's teeth by radiographic and histopathologic analysis was also evaluated. The scores were statistically analyzed by the chi-square and Fisher exact test. Analysis of variance followed by the Tukey posttest were used for the quantitative analysis. The significance level was 5%. RESULTS: The physicochemical characterization performed under ultraviolet-visible spectrophotometry showed that the EGCG properties remained unaltered in acid pH and function of time, keeping its wavelength to 274 nm. Macroscopic parameters evaluated at 7, 21, and 63 days showed that all concentrations presented no epithelial ulceration or presence of mild superficial tissue necrosis, edema, or vascularization with no significant difference in the control group. During all periods of microscopic examination, all groups presented the absence of abscess foci and edema and the presence of fibrous capsule and neovascularization. The presence of reparative tissue with a gentle presence of neutrophilic inflammatory cells was also observed for all groups, except for the calcium hydroxide paste group, which presented a more pronounced inflammation and tissue necrosis at days 7 and 21 (P < .001). At day 63, all groups presented an absence of inflammatory infiltrate and necrosis. The evaluation of dog teeth showed that treatment with the EGCG formulation provided a reduction of the periapical radiolucent area and allowed the repair of apical and periapical tissues (P > .05). CONCLUSIONS: The developed formulation based on EGCG from green tea presented physicochemical stability and tissue compatibility and provided the repair of periapical lesions when used as an intracanal dressing.

Efficacy of green tea and its extract, epigallocatechin-3-gallate, in the reduction of cariogenic microbiota in children: a randomized clinical trial.

OBJECTIVE: This study was conducted to evaluate and compare the antimicrobial efficacy of green tea and its extract epigallocatechin-3-gallate (EGCG) as a mouthwash in children. DESIGN: The study group included 47 children aged 5-12 years at high caries risk and prevalence. Children selected were asked to rinse with one of the substances (EGCG, green tea, chlorhexidine and distilled water) for one min. A non-stimulated salivary sample (2 mL) was collected at baseline and after rinsing. The concentration of cariogenic microorganisms (mutans streptococci and lactobacilli) was determined before and after rinsing based on the count of colony-forming units (CFU). CFU were counted with the aid of a stereomicroscope through the perfunctory identification of the morphological characteristics of CFU. The microbial reduction percentage was then calculated. RESULTS: The analysis of the effectiveness of the treatments showed that there was a significant reduction in relation to the values obtained before and after the mouthwash, both for mutans streptococci (pCHX = 0.001; pEGCG = 0.001; pGreen Tea = 0.005; pDistilled Water = 0.018) and lactobacilli (pCHX = 0.001; pEGCG = 0.002; pGreen Tea = 0.008; pDistilled Water = 0.033). The percentage of microbial reduction of both cariogenic microorganisms caused by the EGCG solution was higher than green tea and distilled water, but less than CHX. The percentage of microbial reduction by the EGCG solution for mutans streptococci was 79.9%, green tea 68.3%, distilled water 50.6% and CHX 95.5%. For lactobacilli, the percentage reduction of all solutions was relatively lower when compared to mutans streptococci. For the EGCG solution it was 72.09%, followed by green tea 59.17% and distilled water 41.96%, but less than CHX 86.02%. CONCLUSION: Rinsing with EGCG solution reduced the levels of mutans streptococci and lactobacilli in the oral cavity of children. Although EGCG had better antimicrobial activity than green tea, this study supports the effectiveness of both as an antibacterial mouthwash option. Both EGCG and green tea could be used as alternatives to chlorhexidine-based mouthwashes.

Clinical, microbiological, and immunological evaluation of patients in corrective orthodontic treatment.

BACKGROUND: The objective was to analyze clinical, microbiological, and immunological periodontal parameters in patients in corrective orthodontic treatment. MATERIALS AND METHODS: Twenty-eight patients were selected. Plaque index (PI), bleeding on probing (BOP), width of keratinized gingiva, levels of 40 bacterial species, and of 3 cytokines (IL-1ß, MMP-8, and TNF-α) in gingival crevicular fluid (GCF) were evaluated at T0, before orthodontic treatment; T1, 6 months; and T2, 12 months post-treatment. Non-parametric, Friedman, Wilcoxon, ANOVA, and Spearman correlation coefficient tests were used for statistical analyses, with the significance level of 5%. RESULTS: No significant difference was found for the width of keratinized gingiva, but PI presented a significant increase at T1 and T2 (p < 0.05) when compared with T0. The percentage of sites with BOP increased significantly from T0 to T1 (p < 0.05); however, at T2, the values decreased and did not differ anymore from T0 (p > 0.05). In the microbiological analysis, red complex pathogens were in significantly greater proportions in T2 compared with T0 (p < 0.05). There was no statistically significant difference in the cytokine levels between the periods but there was a positive correlation between BOP and IL-1ß (r = 0.49 p = .01) and TNF-α (r = 0.39 and p = .05). CONCLUSION: In conclusion, corrective orthodontic treatment caused clinical periodontal alterations regarding biofilm accumulation and gingival bleeding, with alteration of periodontopathogens.

Electromyographic evaluation in children having rapid maxillary expansion.

INTRODUCTION: The aim of this study was to analyze the electromyographic activity of the masseter and temporalis muscles of children having rapid maxillary expansion (RME) with a bonded rapid maxillary expansion appliance. METHODS: The sample consisted of 27 children (mean age, 8.6 years) with posterior crossbite who required RME treatment. Electromyographic activity of the masseter and temporalis muscles was analyzed before treatment and after the appliance was removed. The mean interval between the 2 analyses was 5 months. Muscular activity was electromyographically analyzed in rest position, and with maximum voluntary dental clenching and chewing. Differences in the 2 measurements were evaluated by using paired t tests. RESULTS AND CONCLUSIONS: Electromyographic analysis showed that activity of the masseter and temporalis muscles increased significantly after the expansion appliance was removed during rest, dental clenching, and habitual chewing.

Interferon-gamma, interleukin-10, Intercellular adhesion molecule-1, and chemokine receptor 5, but not interleukin-4, attenuate the development of periapical lesions.

This study examines the role of Th1 (interferon-gamma [IFN-gamma]) and Th2 (interleukin-4 [IL-4] and IL-10) cytokines, an intercellular adhesion molecule (ICAM-1), and a chemokine receptor (CCR5) in the pathogenesis of periapical lesions at different stages of development in knockout mice. For lesion induction, the first molar was opened and inoculated with 4 bacterial strains and left open to the oral environment. After 21 and 42 days, the IFN-gamma, IL-10, ICAM-1, and CCR5 knockout animals presented periapical lesions larger than those of wild-type animals. There was no statistically significant difference between periapical lesions induced in IL-4 knockout and wild-type animals during the periods evaluated. Our findings suggest an important role for IFN-gamma, IL-10, ICAM-1, and CCR5 in the pathogenesis of experimentally induced pulp infection and bone destruction as endogenous suppressor of periapical lesion development, whereas IL-4 appears to present a nonsignificant effect on periapical lesion modulation.

Strategies and dental care in the treatment of patients with myelomeningocele.

Myelomeningocele (MMC) is a congenital malformation that occurs in the embryonic period, characterized by failure in closure of the caudal portion of the neural tube during central nervous system formation. Alterations and complications can be associated with this condition, such as hydrocephalus, neurogenic bladder, orthopedic problems, and motor and cognitive impairment. This patients with MMC also have predisposition to develop latex allergy and high caries risk and activity due to deficient oral hygiene, fermentable carbon hydrate-rich diet and prolonged use of sugar-containing oral medications. This paper reports the oral findings and dental treatment in a 15-year-old female patient diagnosed with MMC and describes the strategies used to improve dental treatment conditions and reduce the impact of associated risks to her health. The measures and precautions adopted in this case could be useful to reduce the barriers for patients with the same condition to access oral health care: regular visits to the dentist, initiating as early as possible; frequent reinforcement of oral homecare instructions and diet counseling; minor adaptions to the dental chair and dental office to improve ease of access due to patients' mobility problems; prevention of latex-related allergic reactions; reduction of gag reflex during dental procedures.

Evaluation of chlorhexidine toxicity injected in the paw of mice and added to cultured l929 fibroblasts.

Because chlorhexidine (CHX) has been recommended as either an endodontic irrigant or root canal dressing, this study aimed to characterize, in vivo, the lesion induced by injections of CHX in the paw of mice at selected time intervals (24 and 48 hours and 7 and 14 days) and, in vitro, the mode of cell death, necrosis and/or apoptosis, and the cellular stress caused by exposition of cultured L929 fibroblasts to ascending concentrations of CHX for 24 hours. CHX injected in the subplantar space of the hind paw of mice induced severe toxic effects, as evidenced by necrotic changes in the epidermis, dermis, and subcutaneous tissue in association with reactive inflammatory response, particularly at higher concentrations. In addition, in cultured fibroblasts, CHX induced apoptosis at lower concentrations and necrosis at higher concentrations and increased expression of heat-shock protein 70, an indicator of cellular stress. Taken together, these findings suggest that CHX may have an unfavorable effect on the resolution of apical periodontitis.

Effects of Rosiglitazone on the Outcome of Experimental Periapical Lesions in Mice.

INTRODUCTION: The purpose of this study was to evaluate a protocol for systemic administration of rosiglitazone in mice in order to stimulate apoptosis of osteocytes in the jaws and to evaluate the effect of osteocyte apoptosis induced by rosiglitazone in the progression of periapical lesions in mice at 7, 21, and 42 days. METHODS: C57BL/6 mice at 4-5 weeks of age were used. In phase 1, mice (n = 24) were treated with rosiglitazone (gavage, 10 mg/kg dose) or without (phosphate-buffered saline + 10% dimethyl sulfoxide) for 1, 2, or 3 weeks. We used the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and 4'-6-diamidino-2-phenylindole methods for quantification of apoptotic cells. In phase 2, mice (n = 30) received rosiglitazone for 2 weeks or just vehicle for 1 week (n = 30), and periapical lesions were induced for 7, 21, or 42 days. We performed the measurement of periapical lesions, tartrate-resistant acid phosphatase staining, dual-energy x-ray absorptiometry for the evaluation of bone mineral density (BMD) in long bone, and gene evaluation using real time quantitative polymerase chain reaction of osteocyte markers (Sost, Hyou1, and Dmp1) and receptor activator of nuclear factor kappa-B ligand (RANKL) (Tnfsf11). RESULTS: It was observed that systemic administration of rosiglitazone for 2 weeks showed apoptosis of osteocytes in a more expressive manner. In phase 2, in the groups that received rosiglitazone, a trend toward larger periapical lesions was observed (P > .05). Rosiglitazone also induced a greater number of osteoclasts and a greater expression of Sost and Hyou1 at 21 days of lesions. Moreover, there were no statistically significant differences in RANKL and Dmp1 expression or in the BMD of femurs. CONCLUSIONS: Rosiglitazone stimulated apoptosis of osteocytes, interfering in the progression of periapical lesions in mice.

Knowledge, attitudes, and psychosocial impacts among Brazilian Pediatric Dentists during COVID-19 pandemic

Abstract: In this study, we evaluated the knowledge, attitudes, and psychosocial impacts among Brazilian pediatric dentists during the COVID-19 pandemic. A cross-sectional study with primary data collection was carried out using an online structured questionnaire. Data were submitted to descriptive analysis by using absolute and relative frequencies. A chi-square test was used for association analysis and log-linear regression models to estimate the prevalence ratio (5%). The population comprised mostly women and knowledge regarding COVID-19 was satisfactory (above 80% in most items). N95 masks and faceshields were used, albeit 64.22% reported difficulty in providing dental care to children due to the need for extra Personal Protective Equipment. Thirty eight percent provided urgency/emergency dental care, 59.78% performed invasive procedures, 59.56% used high speed handpieces, 8.44% started using cariostatics, and 6.22% introduced the use of chemomechanical caries removal agents. Fear for the future (PR = 1.21) and use of medications (for anxiety, depression, or insomnia) increased (PR = 1.16) among the ones who had wage losses. Brazilian pediatric dentists have knowledge about COVID-19, and attitudes in their clinical routines changed due the pandemic. Financial life was harmed and a negative impact of the pandemic in psychosocial aspects of workers was found.