Matheus Albino Souza

Objectives: Sodium hypochlorite (NaOCl) exhibits antimicrobial activity. However, it is associated with negative effects in endodontics, such as cytotoxicity and alterations in the mechanical properties of root dentin, leading to the search for new alternatives. Hypochlorous acid (HClO) exhibits antimicrobial activity and low cytotoxicity as irrigation solution. Therefore, the aim of this study was to evaluate the influence of HClO on the mechanical properties of root dentin. Material and Methods: Samples were obtained from 120 mandibular bovine incisors, which were distributed into four experimental groups: microhardness (30 teeth/60 samples), flexural strength (15 teeth/60 samples), cohesive strength (15 teeth/60 samples), and fracture resistance (60 teeth/60 samples). For all tests, the samples were subdivided into six groups ( n = 10): G1: distilled water (DW); G2:1% NaOCl; G3:2.5% NaOCl; G4:5.25% NaOCl; G5:250 ppm HClO; and G6:500 ppm HClO. The irrigation protocol was set at 30 min. Then, a Vickers tester was used to evaluate microhardness, and flexural strength, cohesive strength, and fracture resistance were evaluated in a universal testing machine. One‐way ANOVA and Tukey tests were used for multiple comparisons in all evaluations ( α = 5%). Results: The highest microhardness was observed in DW, 250 ppm HClO and 500 ppm HClO, with no statistical differences between them ( p > 0.05). The highest flexural and cohesive strength were observed in DW, 1% NaOCl, HClO 250 ppm, and HClO 500 ppm, with no statistical differences between them ( p > 0.05). Regarding the fracture resistance, there were no statistical differences between all groups ( p > 0.05). Conclusion: It was concluded that HClO preserved the mechanical properties of root dentin.

The aim of present study was to evaluate the influence of final irrigation protocols for removal of photosensitizer activated by ultrasonic device(US) on the bond strength(BS) of gutta-percha/bioceramic sealer and fiberglass posts/self-adhesive cement to root dentin. One hundred single-rooted teeth were used, being 50 roots used to assess the BS of filling material and 50 to assess the BS of restorative material. After sample preparation, photodynamic therapy with US was performed, using 0.01% methylene blue as photosensitizer and diode laser as light source. The 50 roots of each evaluation were randomly divided into five groups (n=10), according to irrigation protocol for photosensitizer removal: G1 – distilled water + US; G2 – 17% EDTA; G3–17% Glycolic acid(GA); G4 – 17% EDTA + US; G5 – 17% GA+US. Then, 50 roots were filled with gutta-percha/Bio-C bioceramic sealer and 50 roots were filled with fiber glass posts/Rely-X U200 self-adhesive cement. In both, the roots were sectioned to obtain 1 mm thick dentin/material discs, and the push-out test was performed. Failure patterns were observed under optical microscope. Specific statistical analysis was performed (α=5%). In both evaluations, BS was significantly higher in groups 4(17% EDTA + US) and 5(17% GA + US) when compared to all other groups( p < 0.05). Regarding the failure patterns, no statistically significant difference was found between groups ( p > 0.05), with a predominance of cohesive failure in all groups. The association of US with EDTA and GA for photosensitizer removal improved the BS of filling/restorative material to root dentin.

Objective: To evaluate the antimicrobial action, cytotoxicity, pH, flow, and radiopacity of an experimental paste for primary teeth. Material and Methods: Root canals of 50 extracted human teeth were inoculated with Enterococcus faecalis and divided into five groups (n=10): G1 - distilled water (negative control); G2 - zinc oxide-eugenol (ZOE) paste; G3 - calcium hydroxide (Ca(OH)2) paste; G4 - iodoform paste; and G5 - experimental paste containing chlorhexidine, (Ca(OH)2), neomycin sulfate, and barium sulfate. Colony-forming unit counts assessed antimicrobial activity. Cytotoxicity was analyzed in fibroblast cells through cell viability assays. pH and flow were measured with colorimetric strips and dispersion diameter, respectively. Radiopacity was compared to an aluminum scale using digital radiography. Statistical analysis was performed at α=5%. Results: High antimicrobial activity and radiopacity were observed in groups 2 (ZOE paste), 3 (Ca(OH)2 paste), 4 (iodoform paste), and 5 (experimental paste) (p<0.05). The highest cell viability was found in groups 1 (distilled water), 4 (iodoform paste), and 5 (experimental paste) (p<0.05). Groups 3 and 5 showed the highest pH values, while flow was highest for groups 3 (Ca(OH)2 paste), 4 (iodoform paste), and 5 (experimental paste) (p<0.05). Conclusion: The experimental paste demonstrated a satisfactory antimicrobial effect, cytocompatibility, an alkaline pH, adequate flow, and radiopacity, comparable to conventional pastes, and has potential for clinical application.

Objective: To evaluate the mechanical properties of dentin under the effect of grape seed extract (GSE) as intracanal medication (ICM). Material and Methods: Ninety-six single-rooted bovine teeth were divided into groups, as follows: control group (Ctrl), without any dentin treatment; groups treated with Ca(OH)2 (Ca7, Ca15 and Ca30); and GSE (GSE7, GSE15 and GSE30), with direct contact between dentin and ICM for different durations of 7, 15 and 30 days. The samples underwent tests of maximum fracture load (FL), flexural strength (σf), cohesive strength (σc), and elastic modulus (E) of the remaining root. For statistical analysis, one-way ANOVA was used, followed by Dunnett's test to verify whether ICMs interfere with dentin properties. Two-way ANOVA (ICM and application time) and Tukey's test were also used, considering the groups treated with different ICM at different intervals. All analyses were performed at p ≤ 0.050. Results: GSE had a less pronounced effect on dentin's mechanical properties compared to Ca(OH)2. GSE showed less interference with FL (p=0.000), σf (p=0.002), and σc (p=0.000). It was observed that the duration of exposure to ICM had a negative impact on FL (p=0.002) and σc (p=0.031). ICM (p=0.080) and the application time (p=0.985) did not significantly affect E. Moreover, the application time of ICM did not have a significant impact on σf (p=0.169). Conclusion: Grape seed extract did not affect the mechanical properties of bovine dentin when used as intracanal medication.

Introduction: The aim of the present study was to evaluate the diagnostic accuracy of Reveal autofluorescent dental loupes for detecting biofilm, demineralization, and caries around orthodontic brackets. Methods: Sixty patients were selected, being thirty patients without orthodontic treatment (control group) and thirty patients undergoing orthodontic treatment (experimental group). The 30 patients without orthodontics treatment were clinically evaluated by two previously calibrated evaluators, who assessed the presence of biofilm, demineralization, and incipient caries on the buccal surface of the upper anterior teeth by using two methods: G1 (n=30)-visual method; G2 (n=30)-Reveal® method. The 30 patients with orthodontic treatment were evaluated in the same way. In both groups, a scoring system was assigned to evaluate the variables of the study. For statistical analysis, an average score for each patient was calculated by adding the scores for each tooth and dividing by the number of teeth evaluated. A statistical comparison was performed by the Wilcoxon signed-ranks test (α = 0.05). Results: The Reveal method was more effective at detecting biofilm in patients without orthodontic treatment (p < 0.05). There were no statistically significant differences between the Reveal method and the visual method in detecting demineralization and caries (p > 0.05). Furthermore, the Reveal method was more efficient in detecting biofilm and demineralization in patients with orthodontic treatment (p < 0.05) and showed no statistically significant differences compared to the visual method in detecting caries (p > 0.05). Conclusions: The Reveal autofluorescent dental loupes effectively detected biofilm, demineralization, and incipient caries around orthodontic brackets.

This study evaluated bond strength of glass fiber posts to root dentin using push‐out (PO) and diametral compression (DC), testing glycolic acid as a conditioner and varying dentin moisture. An additional aim was to test whether DC can be an alternative test to PO for bond strength assessment. Eighty bovine teeth were divided into eight groups (n = 10) defined by the use of either 37% glycolic acid or 37% phosphoric acid (PA) on moist or wet dentin before bonding with either Adapter SingleBond/RelyX ARC or One Step Plus/Duo‐Link Bisco. Each tooth provided discs with an internal diameter of 2 mm, external diameter of 5 mm, and height of 2 mm, which underwent PO and DC. Finite element analysis (FEA) was carried out on 3D models. When analyzing PO results through linear regression, the highest values of bond strength were observed using glycolic acid on wet dentin in the cervical and middle thirds of the teeth. Analyzing DC results, the only statistical influence on values was the dental thirds. The scatterplot of the DC results and the PO bond strength values indicated no relationship between the results of the two tests (r = 0.03; p = 0.64). PO test detected more sensitive changes in bond strength values than DC.

Aim: to evaluate the occurrence of maxillofacial infection cases, which were treated at local hospital, identifying the main risk factors that determine the need for hospitalization of patients and the factors associated with staying length. Methods: A retrospective review of 191 records of patients with maxillofacial infection of odontogenic origin was performed, statistically evaluated by frequency and percentage of involvement, p values (based on the chi-square test) and odds ratio with a 95% confidence interval. A p-value <0.05 was considered statistically significant. Results: Among all the 191 patients, 31 had some harmful habits, such as smokers (13%) and alcoholics (1%). In addition, 39 patients reported some general health problem, such as systemic arterial hypertension (8.3%), depression (6.8%), diabetes (3.6%) and some immunosuppression (1.57%). Involvement of infection in deep facial spaces was present, with 119 patients presenting a deeper infection (62.3%) and 72 patients a superficial infection (37.7%). The most prevalent clinical signs and symptoms in the initial evaluation were pain (91.1%) and edema (90.1%), followed by erythema/hyperemia (44.5%), trismus (37.7%), abscess (30.9%), cellulitis (27.7%), f istula (16.8%), fever (16.8%), dysphagia (11%), dehydration (9.9%), odynophagia (7.9% ) and dyspnea (3.7%). Pulp necrosis was considered a risk factor for treatment in a hospital environment (0.032) and root canal treatment decreases the risk of hospitalization (p=0.002). Considering the evaluated patients, 146 (76.4%) were admitted and 45 (37.7%) were not admitted for hospitalization after initial clinical evaluation. Conclusion: there is a high occurrence of maxillofacial infection cases of dental origin, considering that involvement of infection in deeper facial spaces, as well as presence of pain, edema, erythema/hyperemia, trismus, abscess, cellulitis and pulp necrosis, represent the main risk factors for hospitalization and staying length.

This study evaluated the incidence of unfilled second mesiobuccal (MB2) canals and periapical lesions in first maxillary molars using CBCT e-Vol DX software. Hence, 326 CBCT images of first maxillary molars of patients undergoing endodontic treatment were selected. The e-Vol DX software performed a retrospective review of these images, recording the presence or absence of MB2 canals, filling, and periapical lesions in first maxillary molars. Specific statistical analysis was performed at a 5% significance level. Unfilled MB2 canals were highly frequent in first maxillary molars and significantly associated with periapical lesions in the mesiobuccal root of these teeth (p<0.05). The CBCT e-Vol DX software effectively detected MB2 canals, and unfilled canals may be associated with periapical lesions.

Resumo Objetivos: avaliar a sujidade de limas rotatórias e reciprocantes após instrumentação e procedimentos de limpeza pré-esterilização. Materiais e métodos: 24 limas rotatórias e as 24 limas reciprocantes foram divididas, aleatoriamente, em dois grandes grupos. No primeiro grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, em seis subgrupos (SG): SG1 (controle negativo 1/n=1) – 1 lima rotatória não submetida à instrumentação; SG2 (controle negativo 2/n=1) – 1 lima reciprocante não submetida à instrumentação; SG3 (controle positivo 1/n=1) – 1 lima rotatória submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG4 (controle positivo 2/n=1) – 1 lima reciprocante submetida à instrumentação e não submetida a qualquer protocolo de limpeza; SG5 (grupo teste/n=10) – 10 limas rotatórias submetidas à instrumentação e submetidas ao protocolo de lavagem manual; SG6 (grupo teste/n=10) – 10 limas reciprocantes submetidas à instrumentação e submetidas ao protocolo de lavagem manual. No segundo grupo, as 12 limas rotatórias e as 12 limas reciprocantes foram divididas, aleatoriamente, nos mesmos subgrupos, substituindo, nos subgrupos 5 e 6, a lavagem manual pela lavagem em cuba ultrassônica. A análise do nível de sujidade foi realizada por microscopia eletrônica de varredura (MEV), sendo os dados submetidos ao teste de Kruskal-Wallis, com nível de significância de 5%. Resultados: a menor média de sujidade entre os grupos experimentais foi encontrada no SG5 do G1, sem diferença significante em relação aos demais grupos testados (p>0,05). Conclusão: conclui-se que os protocolos de limpeza testados não foram completamente efetivos para a remoção de sujidade das limas endodônticas.Palavras-chave: limas; limpeza; reciprocante; rotatório; sujidade.