Brazilian dental journal最新文献

The aim was to evaluate in vitro cytotoxicity and genotoxicity of Bio-C Repair (BCR), compared to Endosequence BC Root Repair (ERRM), MTA Angelus (MTA-Ang), and MTA Repair HP (MTA-HP). MC3T3 osteoblastic cells were exposed to extracts of the repairing bioceramic cements. After 1, 3, and 7 days, cytotoxicity and genotoxicity were evaluated by MTT and Micronucleus tests, respectively. Cells not exposed to biomaterials were used as a negative control. Data were compared using ANOVA two-way, followed by the Tukey Test (α=5%). MTA-Ang and MTA-HP showed no difference in relation to control regarding cytotoxicity in any experimental times. BCR and ERRM reduced cell viability after 3 and 7 days (p<0.05); however, the reduction caused by BCR was less than that caused by ERRM. Considering the micronucleus formation, all biomaterials caused an increase after 3 and 7 days (p<0.05), being greater for the BCR and ERRM groups. It can be concluded that BCR is non-cytotoxic in osteoblastic cells, as well as MTA-Ang e MTA Repair HP. BCR and ERRM showed greater genotoxicity than others tested biomaterials.

This study aimed to assess and correlate initial surface roughness and frictional resistance of rectangular CuNiTi wires inserted in different self-ligating brackets. The sample consisted of 40 bracket-wire sets (rectangular CuNiTi wires of 0.017" x 0.025" and passive self-ligating brackets) divided into four groups (n=10): metallic self-ligating bracket and metallic CuNiTi wire (G1); metallic self-ligating bracket and rhodium-coated CuNiTi wire (G2); esthetic self-ligating bracket and metallic wire (G3); esthetic self-ligating bracket and rhodium-coated CuNiTi wire (G4). The initial surface roughness of the wires was examined with a Surfcorder roughness meter, model SE1700. Later, frictional resistance was assessed in an Instron 4411 universal testing machine at a speed of 5 mm/min, in an aqueous medium at 35°C. Microscopic analyses of surface morphology were performed with scanning electron microscopy, using an LEO 1430, with magnifications of 1000X. Generalized linear models were applied, considering the 2 x 2 factorial (bracket type x wire type), at a 5% significance level. Regardless of bracket type, the groups with esthetic wires presented higher initial surface roughness than the groups with metallic wires (p<0.05). There was no significant difference between the different bracket-wire sets for frictional resistance and no significant correlation between frictional resistance and initial surface roughness in the environment studied. It is concluded that esthetic wires presented higher initial surface roughness but did not interfere with the frictional resistance between brackets and wires.

This study analyzes the characteristics of the top 100 most-cited papers related to tooth bleaching. A literature search was performed on the Web of Science up to March 2022. The number of citations was cross-matched with the citation count on Scopus and Google Scholar. The following data were collected: number and density of citations; authorship; year and journal of publication; study design and thematic; keywords; institution and country of origin. Spearman's correlation and Poisson regression were used to determine associations between the number of citations and study characteristics. The VOSviewer software was used to generate collaborative network maps for the authors and keywords. The number of citations ranged from 66 to 450. Papers were published between 1981 and 2020. The most frequent study design and topic were laboratory-based studies and 'interaction of the bleaching agent with dental tissues', respectively. Cochran M, Loguercio AD, Matis B, Reis A, and Suliman M were the authors with the highest number of papers. The countries with the most papers were the United States of America (USA) (28%) and Brazil (20%). Indiana University and State University of Ponta Grossa were the institutions with the most papers (6% each). There was a very strong correlation among the number of citations of the three databases. The 100 most-cited papers related to tooth bleaching were mainly published by the USA and Brazil, with laboratory-based studies addressing topics related to the effects of bleaching agents on tooth structure being the most prevalent.

The objective of this study was to map, through a scoping review, the evidence available in the literature on the use of platelet concentrates in compromised patients undergoing oral surgeries. Searches were performed in electronic databases for clinical studies with compromised patients undergoing oral surgery who used platelet concentrates. Only studies published in English were included. Two independent researchers carried out the selection of studies. The study design and objective, surgical procedure and platelet concentrate used, systemic involvement, analyzed outcome, and main results were extracted. A descriptive analysis of the data was performed. Twenty-two studies met the eligibility criteria and were included. Case series was the most frequent study design among the included studies (41.0%). In terms of systemic disability, 19 studies reported patients with cancer and related to surgical treatment 16 studies reported patients underwent treatment for osteonecrosis related to the use of the drug. The most used platelet concentrate was pure platelet-rich fibrin (P-PRF). In general, most studies recommend the use of platelet concentrates. Thus, the results of this study suggest that the evidence related to the use of platelet concentrates in compromised patients when undergoing oral surgeries is still initial. Also, most studies assessed the use of platelet concentrates in patients with osteonecrosis.

Natrosol and Aristoflex® AVC polymers are widely applied in the cosmetic industry and have recently been applied as a thickener option in the composition of dental bleaching gels, with the purpose to reduce the adverse effects on enamel mineral components. The aim of this study was to evaluate the color variation (ΔE* ab, ΔE00, ∆WID), surface roughness (Ra), and mineral content quantification (Raman Spectroscopy) of dental enamel after bleaching treatment with experimental gel-based on 10% carbamide peroxide (CP), containing Carbopol, Natrosol, and Aristoflex® AVC. Sixty bovine teeth were randomly divided into 6 groups (n=10): Negative Control (NC) - no treatment; Positive Control (PC) - Whiteness Perfect 10% - FGM; CP with Carbopol (CPc); CP with Natrosol (CPn); CP with Aristoflex® AVC (CPa); NCP - no thickener. Data were analyzed, and generalized linear models (∆WID -T0 x T1) were used for repeated measurements in time for Ra and with a study factor for ΔE* ab and ΔE00. For the evaluation of the mineral content, data were submitted to one-way ANOVA and Tukey tests. For enamel topographic surface analysis the Scanning Electron Microscope (SEM) was performed. A significance level of 5% was considered. ΔE* ab and ΔE00 were significantly higher for CPc, CPn, CPa, and NCP groups. (∆WID) showed a significantly lower mean than the other groups for NC in T1. After bleaching (4-hour daily application for 14 days), Ra was higher in the CPc, CPn, and PC groups. For CPa, Ra was not altered. No significant difference was found in the quantification of mineral content. CPa preserved the surface smoothness more effectively. Aristoflex® AVC is a viable option for application as a thickener in dental bleaching gels, presenting satisfactory performance, and maintaining the whitening efficacy of the gel, with the advantage of preserving the surface roughness of tooth enamel without significant loss of mineral content.

This study aimed to compare the survival of replanted teeth that followed the 2012 or the 2020 International Association of Dental Traumatology (IADT) guidelines. Sixty-two permanent replanted teeth were retrospectively assessed (IADT 2012, n = 45; IADT 2020, n = 17). Five years after replantation (from January 2017 to December 2021), clinical and radiographic examinations were performed. A significance level of 95% was considered to evaluate the outcomes. Thirty-one teeth (50.0%) remained in their sockets and 31 (50.0%) were lost due to external root resorption. Of the 25 (40.3%) teeth replanted within one hour, 16 (64.0%) remained in their sockets, and 9 (36.0%) were lost. Twenty-two (71.0%) of all 31 lost teeth had an extra-alveolar time of more than one hour. Twelve teeth remained in their sockets without resorption: 8 (66.7%) were replanted within one hour, 2 (16.7%) followed the 2012 IADT, and 2 (16.7%) the 2020 IADT guidelines for late replantation. There was a significant difference (p <0.05) in the extra-alveolar time (< one hour), but without difference between the guidelines in late replantation (p > 0.05). Replanted teeth following both, 2012 or 2020 IADT guidelines, have similar clinical outcomes. The extra-alveolar time of less than one hour was demonstrated to be important to keep the permanent tooth in its socket.

The present study aims to evaluate the effect of different glide path instruments on the cyclic fatigue resistance of reciprocating endodontic instruments after three uses in mandibular molars. Eighteen Wave One Gold Primary reciprocating instruments were selected and randomly divided into three groups according to the glide path instrument: G1 - manual file K #15, G2 - Wave One Glider reciprocating instrument, and G3 (control group) - glide path was not performed. The reciprocating instruments were tested on mandibular molars and subdivided into three other groups: a new instrument, an instrument with a previous single-use, and an instrument with two previous uses. After the endodontic instrumentation, the instruments were subjected to the cyclic fatigue resistance test using an appropriate tool. The data were submitted to the Shapiro-Wilk test, and subsequently the Kruskal-Wallis test with a significance level of 5%. The results showed no statistical difference between the groups. Thus, it was concluded that the creation of a glide path did not affect the cyclic fatigue resistance of the reciprocating instrument. In addition, the reuse of final preparation instruments up to two times proved to be safe since no fractures were observed in the tested instruments.

This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey's test; and Ra, by 2-way ANOVA, repeated measures, and Tukey's test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

This study aimed to evaluate the effect of nicotine administration on the osseointegration of a superhydrophilic implants surface on rat tibiae. Thirty-two rats were used and divided into 2 groups according to the administration or not of nicotine: HH - Installation of implants with superhydrophilic surfaces in healthy animals; and HN - Installation of implants with superhydrophilic surfaces in animals subjected to nicotine administration. The animals were euthanized 15 and 45 days after implant placement (n = 8). Osseointegration was assessed by means of biomechanical analyses (removal torque), microcomputed tomography (volume of bone around the implants- %BV/TV), and histomorphometry (bone-implant contact -%BIC and the bone area between implant threads -%BBT). The animals subject to the nicotine administration presented lower removal torque than the control animals at the 45-day period (21.88 ± 2.80 Ncm vs. 17.88 ± 2.10 Ncm). The implants placed in the control rats presented higher %BIC (54.26 ± 6.59% vs. 39.25 ± 4.46%) and %BBT (50.57 ± 5.28% vs. 32.25 ± 5.24%) than the implants placed in nicotine animals at 15-day period. The nicotine administration reduces the osseointegration at 15 days, however, the superhydrophilic surface equalized the osseointegration in nicotine-exposed animals compared with healthy animals after 45 days of implant placement.

The objective of this work was to evaluate the mechanical performance of Z350 resin composite modified with Bombyx mori cocoons silk nanoparticles for dental applications. Four experimental groups were analyzed G0% = Filtek Z350 resin composite (control); G1% = Filtek Z350 with 1% of silk nanoparticles; G3% = Filtek Z350 with 3% of silk nanoparticles; G5% = Filtek Z350 with 5% of silk nanoparticles. It was employed scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, 3-point flexural strength test, Knoop hardness test, and surface roughness. From 3-point flexural strength tests the control group presented the best results G0% = 113.33 MPa (±23.73). The higher flexural modulus was shown by groups G3% = 29.150 GPa (±5.191) and G5% = 34.101 GPa (±7.940), which are statistically similar. The Knoop microhardness test has shown statistical difference only among the G3% group between the top 80.78 (± 3.00) and bottom 68.80 (±3.62) and no difference between the groups. The roughness test presented no statistical difference between the groups. The incorporation of silk nanoparticles reduced the flexural strength of Z350 resin composite. The surface roughness and microhardness tests showed no changes in any of the groups studied.