Analysis of Dental Enamel Surface Submitted to Fruit Juice Plus Soymilk by Micro X-Ray Fluorescence: In Vitro Study.

OBJECTIVE: This paper aimed to analyze the in vitro industrialized fruit juices effect plus soy to establish the erosive potential of these solutions. MATERIALS AND METHODS: Seventy bovine incisors were selected after being evaluated under stereomicroscope. Their crowns were prepared and randomly divided into 7 groups, using microhardness with allocation criteria. The crowns were submitted to the fruit juice plus soy during 15 days, twice a day. The pH values, acid titration, and Knoop microhardness were recorded and the specimens were evaluated using X-ray microfluorescence (µXRF). RESULTS: The pH average for all juices and after 3 days was significantly below the critical value for dental erosion. In average, the pH value decreases 14% comparing initial time and pH after 3 days. Comparing before and after, there was a 49% microhardness decrease measured in groups (p < 0.05). Groups G1, G2, G5, and G6 are above this average. The analysis by µXRF showed a decrease of approximately 7% Ca and 4% P on bovine crowns surface. Florida (FL) statistical analysis showed a statistically significant 1 difference between groups. Thus, a tooth chance to suffer demineralization due to industrialized fruit juices plus soy is real.

Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion.

This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n = 20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer's instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α = 5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p < 0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p < 0.001). Cross section and motion influenced the results, despite tip standardization.

IS GUTTACORE MORE EASILY REMOVED FROM THE ROOT CANAL THAN THERMAFIL? AN EX-VIVO STUDY.

GuttaCore is a new cross-linked gutta-percha carrier. Its handling time and ease of removal were compared with those of a plastic carrier (Thermafil) and the continuous wave of condensation technique (control). Forty-five maxillary central incisors were randomly divided 3 groups according to filling technique and retreatment was carried out in all samples with NiTi rotary files, hand files and ultrasonic inserts. Time required for filling removal was recorded. Roots were then split longitudinally and photographed under 5x magnification, and residual filling material was quantified. Removal time was significantly longer for Thermafil (7.10 minutes) than GuttaCore (2.91 minutes) and the control group (1.93 minutes) (p < 0.001). The amount of residual filling material did not differ among the groups: Thermafil 8.31%, GuttaCore 6.27 and control 8.68% (p > 0.05). In conclusion, replacing plastic core with cross-linked gutta-percha allows easier removal of carrier from the root canal. The remnants of filling material in all samples illustrate that retreatment remains a challenge in endodontics.

Postoperative Pain after Use of the WaveOne Gold and XP-endo Shaper Systems: A Randomized Clinical Trial.

INTRODUCTION: The present study aimed to clinically compare the incidence of postoperative pain after endodontic treatment of posterior teeth using the WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland) and XP-endo Shaper (XPES; FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems. METHODS: In a single-blind randomized clinical trial, 148 vital teeth with an indication for conventional endodontic therapy for prosthetic purposes were treated by 5 specialists following a preestablished protocol. All participants were unaware of the treatment they received. The teeth were randomly divided into 2 groups (n = 74) according to the instrumentation system used (the WOG group and XPES group). The treatments were performed in a single session. The participants were asked to rate the intensity of postoperative pain on a visual analog scale (no pain, mild pain, moderate pain, and severe pain) after 24, 48, and 72 hours and 7 days. RESULTS: The incidence of postoperative pain was higher in the XPES group after 24, 48, and 72 hours compared with those in the WOG group (P < .05). Two participants in the WOG group experienced severe postoperative pain after 24 hours. None of the participants in either group reported pain after 7 days (P > .05, Mann-Whitney test). CONCLUSIONS: Postoperative pain is expected after preparation of the root canal system with the WOG and XPES systems tested, but it only persists for a short period. Although more common after the use of the XPES system, the pain was classified as mild at all time points.

Recommendations for Managing Endodontic Emergencies during Coronavirus Disease 2019 Outbreak.

INTRODUCTION: The management of endodontic emergencies has been particularly challenging during the coronavirus disease 2019 (COVID-19) outbreak because of the possible generation of airborne particles and aerosols. The aim of this report was to contribute to the practice of endodontics by proposing a general protocol for the management of emergencies showing the rationale for remote diagnosis, clinical procedures, and the use of personal protective equipment and barriers at the dental office during the COVID-19 outbreak. METHODS: A review of the literature was conducted up to May 2020 on relevant institutional sites, aiming to retrieve the best updated evidence. The reporting considered the Reporting Tool for Practice Guidelines in Health Care statement. RESULTS: Recommendations from Cochrane Oral Health, the American Dental Association, and the Centers for Disease Control and Prevention were included along with the American Association of Endodontists resources and scientific articles that addressed the issue. CONCLUSIONS: The proposed protocol could contribute to the management of endodontic emergencies at the dental office during the COVID-19 outbreak.

Bacterial Reduction after Gutta-Percha Removal with Single vs. Multiple Instrument Systems.

INTRODUCTION: The aim of this study was to evaluate the effectiveness of a reciprocating single-instrument system (Reciproc-REC) compared with combined continuously rotating multiple-instrument systems [D-Race (DR) and BioRace (BR)] in reducing Enterococcus faecalis (E.f.) after gutta-percha removal. METHODS AND MATERIALS: Forty-six extracted human maxillary incisors were prepared and contaminated with E.f. strain (ATCC 29212) for 30 days. The samples were obturated and randomly divided into two experimental groups for gutta-percha removal (n=23): a REC group (R50) and a DR/BR group (DR1, DR2 and BR6). A standardized irrigation with 0.9% saline solution was performed. Root canal samples were taken with paper points before (S1) and after (S2) the removal of gutta-percha to establish bacterial quantification by culture. The time required for gutta-percha removal was also recorded. Positive and negative control groups (n=6) were used to test bacterial viability and control asepsis, respectively. Data were analysed using t-Student and one-way ANOVA tests (5% margin of error). RESULTS: The mean percentage of bacterial reduction was significantly higher in DR/BR group (84.2%) than in REC group (72.3%) (P<0.05). The mean time for obturation removal was 74.00 sec in REC group and 107.53 sec in DR/BR group (P<0.05). CONCLUSION: The combined continuously rotating multiple-instrument system was more effective in reducing bacteria after the removal of gutta-percha than the single-instrument system. None of the tested systems was able to completely eliminate root canal infection after gutta-percha removal. Thus, additional techniques should be considered.

Hardened exogenous material after extrusion of calcium hydroxide with barium sulfate: Case study and histopathologic and laboratory analyses.

BACKGROUND AND OVERVIEW: Although calcium hydroxide (Ca[OH]2) paste associated with barium sulfate (BaSO4) is considered a safe agent, there is a lack of clinical research on its effects on periodontal and submucosal tissues. The aim of the authors was to report the effects of extrusion of Ultracal XS paste (Ultradent Products) in 2 cases. The authors also analyzed the paste constituents and compared them with the proportion reported by the manufacturer and the material extruded. CASE DESCRIPTION: The authors present 2 cases in which root canals were restored with Ultracal XS paste after cleaning and shaping, and there was unintentional overextension of the paste into periradicular tissues, with a hardened exogenous material observed associated with inflammatory signs and symptoms. A biopsy was performed, and the material was subjected to histopathologic analysis and characterization through scanning electron microscopy, energy dispersive x-ray spectroscopy, Fourier transform infrared spectroscopy, and x-ray diffraction. CONCLUSIONS: BaSO4 and calcium carbonate (CaCO3) were associated with a hardened material after Ultracal XS paste extrusion. The Ca(OH)2 percentage on the Ultracal XS paste was approximately 2 times greater than the proportion reported by the manufacturer. PRACTICAL IMPLICATIONS: Ca(OH)2 with BaSO4 paste application should be performed carefully, and its extrusion to periradicular and submucosal tissues should not occur. Its extrusion may result in the formation of a persistent exogenous material of hardened consistency associated with inflammatory signs and symptoms.

Evaluation of Apically Extruded Debris during Root Canal Retreatment Using ProTaper Next and Reciproc in Severely Curved Canals.

INTRODUCTION: To compare the apical extrusion of debris produced during root obturating material removal from severely curved root canals using either Reciproc (REC) or ProTaper Next (PTN) systems. METHODS AND MATERIALS: Twenty-six mesial canals of lower molars were instrumented, filled and allocated into two groups (n=13). Micro-computed tomographic images were performed to determine the root canal configuration (Vertucci's type IV) and initial volume of obturation. One Eppendorf tube was assigned per canal and weighed (10-4g) before and after removal of the obturating material. The difference between the initial and final weights was calculated and statistically evaluated. RESULTS: Apical extrusion of debris was confirmed in all samples, and the mean amount of apical extrusion was similar between both groups (0.061±0.014 g in PTN vs. 0.065±0.016 g in REC samples) (P<0.05). CONCLUSION: Both systems caused apical extrusion of debris with no differences between PTN and REC systems.

Efficacy of ProTaper NEXT Compared with Reciproc in Removing Obturation Material from Severely Curved Root Canals: A Micro-Computed Tomography Study.

INTRODUCTION: The aim of this study was to compare the remaining root canal obturation, volume of dentin removed, and apical transportation after retreatment of severely curved root canals by using Reciproc (REC) or ProTaper NEXT (PTN) systems. METHODS: Twenty-eight mesial canals of mandibular molars were instrumented and then obturated with gutta-percha and sealer and allocated into 2 balanced groups (n = 14), the REC group (R25 file) and the PTN group (X3 and X2 files). Micro-computed tomography analysis was performed to assess the percentage of residual obturation material, the amount of dentin removed, and apical transportation. The effective time for the removal of obturation and procedural errors were recorded. RESULTS: Obturation was effectively removed from the root canal in the REC and PTN groups (P ≤ .001), and the percentages of remaining obturation material were similar between both groups (84.8% PTN vs 86.5% REC) (P > .05). The amount of dentin removed (3.17 ± 2.64 mm(3) PTN versus 3.50 ± 2.82 mm(3) REC), apical transportation (at 1 mm: 0.096 ± 0.189 mm PTN versus 0.093 ± 0.186 mm REC; at 3 mm: 0.059 ± 0.069 mm PTN versus 0.082 ± 0.080 mm REC; at 5 mm: 0.097 ± 0.093 mm PTN versus 0.133 ± 0.138 mm REC), and the working time (269.69 ± 19.25 seconds PTN versus 268.62 ± 16.37 seconds REC) were also similar in both groups (P > .05). One file fractured in the REC group. CONCLUSIONS: Both systems were equally effective in the removal of obturation from severely curved canals and can be used for retreatment. Neither system could completely remove the obturation material; therefore, additional techniques are needed to improve cleaning of the root canal.

Shaping Ability of Single-file Systems with Different Movements: A Micro-computed Tomographic Study.

INTRODUCTION: This study aimed to perform a rigorous sample standardization and also evaluate the preparation of mesiobuccal (MB) root canals of maxillary molars with severe curvatures using two single-file engine-driven systems (WaveOne with reciprocating motion and OneShape with rotary movement), using micro-computed tomography (micro-CT). METHODS AND MATERIALS: Ten MB roots with single canals were included, uniformly distributed into two groups (n=5). The samples were prepared with a WaveOne or OneShape files. The shaping ability and amount of canal transportation were assessed by a comparison of the pre- and post-instrumentation micro-CT scans. The Kolmogorov-Smirnov and t-tests were used for statistical analysis. The level of significance was set at 0.05. RESULTS: Instrumentation of canals increased their surface area and volume. Canal transportation occurred in coronal, middle and apical thirds and no statistical difference was observed between the two systems (P>0.05). In apical third, significant differences were found between groups in canal roundness (in 3 mm level) and perimeter (in 3 and 4 mm levels) (P<0.05). CONCLUSION: The WaveOne and One Shape single-file systems were able to shape curved root canals, producing minor changes in the canal curvature.

Success rates for removing or bypassing fractured instruments: a prospective clinical study.

INTRODUCTION: The objective of this study was to evaluate the success rates of standardized techniques for removing or bypassing fractured instruments from root canals and determine whether visualization of the fractured instrument with the aid of an operating microscope has any impact on the success rates. METHODS: In this prospective study, attempts were made to visualize 112 fractured instruments under a dental operating microscope after creating a straight-line access to the fragment. By using ultrasonic tips alone or associated with bypassing, the Ruddle technique was attempted to remove the 68 visible instruments. Bypassing was performed for the 44 nonvisible fragments. The χ(2) test was performed to assess whether any significant difference occurred between the success rates observed for the visible and nonvisible fractured instrument groups. RESULTS: The overall success rate (removal and bypassing) was 70.5% (n = 79). In the visible fragment group, the success rate was 85.3% (n = 58), and in the nonvisible fragment group it was 47.7% (n = 21). Success rates were significantly higher when the fragment was visible (P = .0009). CONCLUSIONS: The standardized techniques used in this study for removing or bypassing fractured instruments were effective, and approximately 2 times greater success rate was obtained when the fragment was visible inside the root canal compared with when it was nonvisible.

Analysis of the effect of ultrasonic agitation on the cleaning of root canals using different periods during the final irrigation

Introduction: The ultrasonic agitation was introduced as an adjuvant to conventional chemo-mechanical debridement during endodontic treatment to overcome the persistence of biofilms. Objective: To verify the cleaning of root canals irrigated with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), with or without an ultrasonic agitation, using different time periods and images obtained by scanning electron microscope (SEM). Material and methods: Forty mandibular incisors were cleaned, shaped and randomly divided into five groups according to the final irrigation protocol: SH10 group (ultrasonic agitation with NaOCl for 10 s), SH30 group (ultrasonic agitation with NaOCl for 30 s), SHE30 group (ultrasonic agitation with NaOCl and EDTA for 10 s), SHE90 group (ultrasonic agitation with NaOCl and EDTA for 30 s), and control group (NaOCl and EDTA without ultrasonic agitation). The teeth were prepared and analyzed by SEM at ×2000. The Kruskal-Wallis test was used with a 5% level of significance. Results: For the cervical and medial thirds, there was no statistically significant difference in cleaning among the protocols used (p > 0.05). For the cleaning of the apical third, SHE90 group demonstrated a significant difference (p < 0.05), as compared to the control and SH10 groups. Conclusion: For the final irrigation, an ultrasonic agitation with NaOCl and EDTA for 30 s allowed a better cleaning of the debris in the apical third of the root canal.

Comparação da taxa de sucesso de quatro soluções anestésicas no bloqueio do nervo alveolar inferior em pacientes com pulpite irreversível. Estudo prospectivo, randomizado, duplo-cego

Objetivo: comparar a eficácia de quatro soluções anestésicas para o bloqueio do nervo alveolar inferior (BNAI) em pacientes com pulpite irreversível. Métodos: esse estudo prospectivo, randomizado e duplo-cego incluiu 60 pacientes adultos que compareceram ao serviço de atendimento de urgência da PUC-Campinas, São Paulo, Brasil. Os pacientes foram divididos aleatoriamente em quatro grupos,com 15 indivíduos cada, e receberam o bloqueio do nervo alveolar inferior: Grupo ART - 2 tubetes de articaína 4% com epinefrina 1:100.000; Grupo LID - 2 tubetes de lidocaína 2%com epinefrina 1:100.000; Grupo PRI - 2 tubetes de prilocaína 3% com felipressina 0,03U.I.; e Grupo MEP - 2 tubetes de mepivacaína 2% com epinefrina 1:100.000. Iniciou-se o acesso cirúrgico após 10 minutos do bloqueio do nervo alveolar inferior e o paciente foi instruído a relatar qualquer sensibilidade ou dor que sentisse durante o procedimento.O BNAI foi considerado bem-sucedido quando o procedimento de acesso e instrumentação foi realizado sem dor para o paciente. Se o paciente sentisse dor, o procedimento era interrompido e a anestesia considerada como insucesso.Resultados: foi utilizado o teste estatístico qui-quadrado para analisar os resultados (α=5%) e não houve diferença significativa (p>0,05) na taxa de sucesso do bloqueio do nervo alveolar inferior entre os grupos: ART = 53,33%, PRI = 46,66% e MEP = 53,33%. Porém, a taxa no grupo LID foi estatisticamente inferior (20%) à dos demais grupos(p<0,05). Conclusão: nenhuma das soluções anestésicas apresentou um índice de sucesso aceitável para o bloqueio do nervo alveolar inferior em pacientes com pulpite irreversível em molares inferiores. A solução de lidocaína 2% com epinefrina 1:100.000 apresentou o pior resultado, quando comparado ao dos demais grupos