EVALUATION OF INTRAOPERATIVE PAIN OCCURRENCE AND NEED FOR SUPPLEMENTAL ANESTHESIA DURING EMERGENCY DENTAL CARE

Aims: This study aimed to evaluate the intraoperative pain (IOP) occurrence in situations of symptomatic irreversible pulpitis (SIP) and symptomatic apical periodontitis (SAP). Materials and Methods: Patients who sought emergency care presenting a diagnosis of SIP or SAP were included. IOP was measured with a Visual Analogue Scale (VAS) after five minutes of local anesthesia, during access to the pulp chamber, root canal exploration and at the end of procedures. In cases where pain was reported during treatment, supplementary anesthesia was performed. Pain scores were recorded and analyzed using a generalized estimating equation model with posthoc comparisons. Results: 56 patients were included. 35 had a diagnosis of SIP; and 21 a diagnosis of SAP. Mean preoperative pain scores for SAP and SIP were 6.69 (±1.54) and 6.39 (±1.48), respectively (p>0.05). In patients with SIP, significant differences were observed between: preoperative scores and other time points; scores after five minutes of local anesthesia and other time points; scores during pulp chamber access and at the end of procedures; and scores during root canal exploration and at the end of procedures (p<0.05). In patients with SAP, significant differences were observed between preoperative pain scores with all other time points (p<0.05). Chi-square test indicated an association between diagnosis and the need for supplementary anesthesia (p<0.05). Conclusions: In conclusion, there is a strong relationship between reduction of moderate/severe pain after application of local anesthesia. The need for supplemental anesthesia is significantly associated to the diagnosis of symptomatic irreversible pulpitis.

Pulse oximetry as a dental pulp test: A scoping review to identify barriers hindering the use of oximeters in clinical practice.

Background and Objective: Although medical pulse oximeters are considered effective for endodontic diagnoses, the method remains uncommon in current dental practice. The aim of the present scoping review was to investigate clinical factors that exert a negative impact on the use of pulse oximeters in dental practice. Methods: This study followed the PRISMA-ScR guidelines and the protocol was prospectively registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/3GQCE). A comprehensive search of the MEDLINE (via PubMed), Cochrane Library, and Web of Science databases was performed in December 2022 for articles published in English or Spanish. All types of clinical studies were included, except comments, letters to the editor, and abstracts. Two independent investigators analyzed 45 full-text articles. Data extraction included general characteristics, oxygen saturation levels, and limiting factors/barriers to the use of oximeters as pulp testers. Results: The search of the databases yielded 1,300 records and 38 were included (quantitative data extraction was performed for 35 and three articles were systematic reviews). Publications were highest in number between 2016 and 2017, with an evident reduction occurring after 2021. The oxygen saturation level for sound/vital maxillary anterior teeth was 84.99% (overall mean). The main limiting factors/barriers were i) the difficulty in maintaining the two light-emitting diodes parallel during pulp tests, ii) infrared light diffraction by enamel/dentin/gingiva, and iii) the diversity of patient ages in studies. Conclusion: This scoping review encountered noteworthy findings associated with the impracticability of using medical pulse oximeters as dental pulp testers. The recent decrease in the frequency of published studies compared to approximately seven years ago may imply a negative trend in the use of the method.

ASSESSMENT OF TORSION RESISTANCE OF GLIDE PATH ROTARY INSTRUMENTS

NiTi endodontic instruments for glide path are the most susceptible to fractures inside the root canal, mainly as a result of high torsional stress. Objective: The present study investigated the resistance to torsion and angular deflection of instruments destined for the glide path: ProGlider #16.02; T-File #17.02 and the MK Life #16.02. Materials and methods: Thirty rotating NiTi glide path instruments (n=10) with 25mm lengths were selected. The torsion test was performed based on ISO 3630-01 (1992). Three millimeters from the tip of the instruments, it was attached to a small load cell by a lever arm connected to the torsion shaft. Torsional strength and angular deflection were evaluated. Fracture surfaces were examined by scanning electron microscopy with magnifications of 1000x and 5000x in the cross section, and 50x in the lateral section. Statistical analysis was performed using the Kruskal-Wallis H test, followed by the Down's post hoc test. Results: The ProGlider instrument showed greater torsional strength (p<0.05) compared to the T-File (p<0.05) and MK Life (p<0.05), respectively. However, the T-File showed greater angular deflection (p<0.05) than the other groups tested. Conclusion: It can be concluded that the ProGlider instrument presented greater torque for the fracture, while the T-File instrument presented greater angular deflection.

Influence of rotary and reciprocating kinematics on the accuracy of an integrated apex locator.

We evaluated in vitro the influence of nickel-titanium instruments kinematics on the accuracy and variation of root canal working length measurements, performed with an integrated apex locator, at glide path and at the end of shaping. Forty-four mandibular incisors, included in an alginate model, were allocated at random to two groups: reciprocating and rotary. Working length was determined at glide path stage and at the end of shaping. Measurements given by the integrated apex locator were matched with visual measurements. The apex locator accuracy was based on inter-group comparison. The variation in working length was based on intra-group comparison. Kinematics influenced the accuracy of measurements only after shaping (p < 0.05), and not in the glide path (p > 0.05). Rotary had values closer to the visual measurements. Diminishing of measures occurred after shaping for reciprocating (p < 0.05); and at glide-path stage for rotary (p > 0.05). The integrated apex locator was more accurate with rotary kinematics.

Medications Used for Prevention and Treatment of Postoperative Endodontic Pain: A Systematic Review.

OBJECTIVE: Prevention and management of postoperative endodontic pain is a common challenge for the endodontists. This systematic review was conducted to evaluate the efficacy and safety of medicament therapeutic protocols in the prevention and management of endodontic pain. METHODS: A literature search was undertaken in MEDLINE, Cochrane Library, LILACs, and SciELO, for articles published until December 2017, without year restriction and written only in English. An additional search was performed in the references of the retrieved studies. Study eligibility criteria, participants, and interventions: The inclusion criteria were randomised clinical trials that evaluated the use of medications to prevent or control moderate to severe pain in adult patients, using a visual analog scale as a tool for pain measurement. The primary outcome evaluated was the reduction of pain scores. The second outcome evaluated was the need for additional analgesia and the occurrence of adverse events. STUDY APPRAISAL AND SYNTHESIS METHODS: The quality assessment of the included studies was performed following the Jadad scale to measure the likelihood of bias in pain research reports. RESULTS: After removing duplicates and excluding the studies that did not meet the selection criteria, ten studies were included tin the systematic review. Among these studies, five studies administered the medications before the endodontic procedures and five studies after. These studies evaluated non-opioid analgesics (acetaminophen), opioid analgesics (tramadol and codeine), nonsteroidal anti-inflammatories (ibuprofen, flurbiprofen, ketorolac tromethamine, etodolac, tenoxicam, and naproxen), steroidal anti-inflammatory (prednisolone) or the association of medications to prevent or control postoperative pain. It was possible to establish a significant relationship between the use of additional analgesics and periapical diagnosis. Adverse events were not observed when the administration occurred before the endodontic procedure. When it was administered after the procedure, adverse reactions were reported in 2 of 3 trials included in the analysis. LIMITATIONS: A restricted number of randomised clinical trials were found, and the difference in the methodology of the studies did not meet the definition of a systemic treatment protocol for prevention or control of postoperative pain. CONCLUSION: Nonsteroidal anti-inflammatory drugs are the most common medicament to prevent and control postoperative pain, with ibuprofen being the most investigated. There is a significant association between the use of additional analgesics and periapical diagnoses.

Cytotoxicity and Bioactivity of Calcium Silicate-based Cements in a Culture of Stem Cells from the Apical Papilla.

Introduction: The present in vitro study evaluated the cytotoxicity and bioactivity of commonly-used calcium silicate-based cements in a culture of stem cells from the apical papilla (SCAPs). Materials and Methods: NeoMTA Plus (Avalon Biomed), BiodentineTM (Septodont) and MTA HP Repair (Angelus) cements were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and sulphorhodamine-B (SRB) viability assays. Cells were seeded (1*104 cells mL-1) in 96-well plates and exposed to 1:4 diluted extract in 24 h and 72 h. For the analysis of bioactivity, alkaline phosphatase (ALP) enzyme activity and Alizarin Red S (AZR) were assessed after 24 h of cell culture in 12-well plates (1*104 cells mL-1), where cells were exposed to 1:4 diluted extract on days 1 and 7. Minimum Essential Eagle's Medium alpha modification was used as control. ANOVA and Tukey's post hoc test were used to compare the different cements at each experimental time point. Results: No significant differences were found between the cements and the control specimens on MTT at 24 h and 72 h (P>0.05); however, the calcium silicate-based cement materials showed higher cell viability compared to the control group (P<0.05). In the 24-h SRB, NeoMTA Plus showed lower cell viability than BiodentineTM and MTA HP Repair (P<0.05), with all groups similar to the control group (P>0.05). Compared to 24-h results, only NeoMTA Plus presented increased cell viability at 72 h (P<0.05). ALP activity was similar across the materials at 1 day (P>0.05). ALP activity was higher for BiodentineTM when compared to NeoMTA Plus (P<0.05), nevertheless, it was similar to MTA HP Repair and control groups (P>0.05) at 7 days. At 1- and 7-day periods of AZR assay, BiodentineTM presented higher levels of mineralized nodule formation (P<0.05). Conclusion: All evaluated calcium silicate-based cements demonstrated cell viability and bioactivity, suggesting that these (bio)materials may be indicated for use in regenerative dentine-pulp complex procedures.

Reference values for pulp oxygen saturation as a diagnostic tool in endodontics: a systematic review and meta-analysis.

OBJECTIVES: This systematic review aimed to identify mean oxygen saturation values (SpO2) using pulse oximetry in permanent maxillary anterior teeth. MATERIALS AND METHODS: The MEDLINE, Scientific Electronic Library Online, Cochrane Central Register of Controlled Trials, EMBASE, and Literatura Latino Americana em Ciências da Saúde electronic databases were searched. Combinations and variations of "oximetry" AND "dental pulp test" were used as search terms. Studies reporting means and standard deviations of SpO2 values were included. Two reviewers independently extracted data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Heterogeneity was assessed using the I 2 statistic, and all analyses were performed using R software. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool and the Newcastle-Ottawa scale. RESULTS: Of the 251 studies identified, 19 met the eligibility criteria and were included (total sample, 4,541 teeth). In the meta-analysis, the mean SpO2 values were 84.94% (95% confidence interval [CI], 84.85%-85.04%) for the central incisors, 89.29% (95% CI, 89.22%-89.35%) for the lateral incisors, and 89.20% (95% CI, 89.05%-89.34%) for the canines. The studies were predominantly low-quality due to the high risk of bias associated with the index test, unclear risk regarding patient selection, and concerns about outcome assessment. CONCLUSIONS: Although most studies were low-quality, the oxygen saturation levels in normal pulp could be established (minimum saturation, 77.52%). Despite the risk of bias of the included studies, the reference values reported herein are clinically relevant for assessments of changes in pulp status. TRIAL REGISTRATION: International Prospective Register of Systematic Reviews Identifier: CRD42018085598.

Remoção de obturações endodônticas de Endosequence BC/CPoint em canais radiculares curvos usando instrumentos rotatórios ou reciprocantes / Removal of Endosequence BC/CPoint endodontic fillings in curved root canals using rotary or reciprocating instruments

Objetivo: O presente estudo usou micro-CT para avaliar a quantidade de material obturador remanescente em canais radiculares curvos que tinham sido obturados com cimento Endosequence BC/Cpoint ou com cimento AH/ guta-percha, depois do retratamento utilizando instrumentos rotatórios ou reciprocantes. Métodos: Sessenta canais mesiovestibulares de molares superiores foram instrumentados até MTwo #35.04. As amostras foram randomicamente alocadas em quatro grupos (n=15): os canais do G1 e G2 foram obturados com AH/guta-percha, e os canais do G3 e G4 foram obturados com BC/Cpoint. O material obturador foi removido usando instrumentos rotatórios ou reciprocantes ­ G1 e G3: R25 Reciproc + reinstrumentação com R40; e G2 e G4: Sistema ProTaper Universal Retratamento + reinstrumentação com MTwo 40.06. Micro-CTs foram usadas para medir a quantidade de material obturador remanescente (mm3 ) para o canal inteiro e para cada terço, em dois momentos: 1) após a remoção do material obturador; e 2) após a reinstrumentação. Resultados: Após a remoção do material obturador, BC/CPoint permaneceu mais dentro do canal do que AH/guta-percha quando o canal inteiro (29,92% x 19,25%, p=0,0290) e o terço apical foram analisados. Após a reinstrumentação, BC/CPoint permaneceu mais do que AH/guta-percha somente no terço apical. Protocolos de tratamento com instrumentos rotatórios ou reciprocantes removeram material obturador sem diferença para AH/guta-percha (G1 e G2: p> 0,05) e BC/CPoint (G3 e G4: p> 0,05). Conclusões: BC/Cpoint é mais difícil de ser removido de canais radiculares curvos do que AH/guta-percha. Instrumentos rotatórios e reciprocantes têm habilidade similar na remoção de material obturador (AU).

Objective: This study used micro-CT to evaluate the amount of remaining filling material in curved root canals obturated with Endosequence BC Sealer/Cpoint or AH/gutta-percha after a rotary or reciprocating retreatment. Methods: Sixty mesiobuccal canals of maxillary molars were instrumented up to MTwo #35.04. Samples were randomly assigned to four groups (n=15): canals from G1 and G2 were filled with AH/gutta-percha, and canals from G3 and G4 were filled with BC/Cpoint. Filling material was removed using rotary or reciprocating instruments: G1 and G3: R25 Reciproc + re-shaping with R40; and G2 and G4: ProTaper Universal Retreatment system + re-shaping with MTwo 40.06. Micro-CT was used to measure the remaining amount of filling material (mm3 ), for the whole canal, and for each third, in two moments: 1) after filling removal and 2) after canal re-shaping. Results: After filling removal, BC/CPoint remained more into the canal than AH/Gutta-percha when the whole canal (29.92% x 19.25%, p = 0.0290) and the apical third were analyzed. After re-shaping, BC/CPoint remained more than AH/Gutta-percha only in the apical third. Rotary or reciprocating retreatment protocols removed filling material without difference for AH/gutta-percha (G1 and G2: p > 0.05) and BC/CPoint (G3 and G4: p > 0.05). Conclusion: BC/Cpoint is more difficult to be removed from curved root canals than AH/gutta-percha. Reciprocating and rotary instruments have similar ability to remove filling material (AU).

Interference of coronal enamel and dentin thickness and ambient light on pulse oximetry interpretation.

This study evaluated the interference of enamel and coronal dentin thickness and ambient light in pulse oximetry interpretation, using SaO2the human finger as a reference. Forty-two intact human permanent mandibular molars were sectioned mesiodistally in the central portion. Buccal and lingual dentin surfaces were drilled, and 4 mm, 3 mm and 2 mm enamel/dentin thicknesses were interposed between finger and device, after which SaO2 levels were measured by finger pulse oximetry. A reference device was designed to align pulse oximeter light-emitting diode, buccal surface of tooth, little finger, lingual surface of tooth and photodiode. Variables were described as means and standard deviation, and the confidence interval was reported. Repeated measures analysis of variance (ANOVA) was used to compare the groups, followed by Bonferroni correction. Student t test for paired samples was used to determine presence of ambient light (α = 0.05). Mean SaO2 level was lower at 4.0 ± 0.2 mm thickness, regardless of presence or absence of ambient light (92.7% and 89.3%). The other thicknesses yielded values of 95.5% and 94.5% at 3.0 ± 0.2 mm, and 96.4% and 96.0% at 2.0 ± 0.2 mm (p < 0.001). There were significant differences between SaO2 values at 4.0 ± 0.2 mm, 3.0 ± 0.2 mm and 2.0 ± 0.2 mm thicknesses, in the presence of ambient light. Mean SaO2 level in positive control was 96.3%, and mean pulse rate was 69.5 bpm in presence of ambient light; in the absence of light, these values were 96% and 70.5 bpm. Enamel and dentin thickness interfere with SaO2, regardless of presence or absence of ambient light. The lowest SaO2 levels were found for the thickest tooth samples.

Cytocompatibility and cell proliferation evaluation of calcium phosphate-based root canal sealers.

OBJECTIVES: This study aimed to evaluate the cell viability and migration of Endosequence Bioceramic Root Canal Sealer (BC Sealer) compared to MTA Fillapex and AH Plus. MATERIALS AND METHODS: BC Sealer, MTA Fillapex, and AH Plus were placed in contact with culture medium to obtain sealers extracts in dilution 1:1, 1:2 and 1:4. 3T3 cells were plated and exposed to the extracts. Cell viability and migration were assessed by 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT) and Scratch assay, respectively. Data were analyzed by Kruskal-Wallis and Dunn's test (p < 0.05). RESULTS: The MTT assay revealed greater cytotoxicity for AH Plus and MTA Fillapex at 1:1 dilution when compared to control (p < 0.05). At 1:2 and 1:4 dilutions, all sealers were similar to control (p > 0.05) and MTA Fillapex was more cytotoxic than BC Sealer (p < 0.05). Scratch assay demonstrated the continuous closure of the wound according to time. At 30 hours, the control group presented closure of the wound (p < 0.05). At 36 hours, only BC Sealer presented the closure when compared to AH Plus and MTA Fillapex (p < 0.05). At 42 hours, AH Plus and MTA Fillapex showed a wound healing (p > 0.05). CONCLUSIONS: All tested sealers demonstrated cell viability highlighting BC Sealer, which showed increased cell migration capacity suggesting that this sealer may achieve better tissue repair when compared to other tested sealers.

Interference of coronal enamel and dentin thickness and ambient light on pulse oximetry interpretation

Abstract This study evaluated the interference of enamel and coronal dentin thickness and ambient light in pulse oximetry interpretation, using SaO2the human finger as a reference. Forty-two intact human permanent mandibular molars were sectioned mesiodistally in the central portion. Buccal and lingual dentin surfaces were drilled, and 4 mm, 3 mm and 2 mm enamel/dentin thicknesses were interposed between finger and device, after which SaO2 levels were measured by finger pulse oximetry. A reference device was designed to align pulse oximeter light-emitting diode, buccal surface of tooth, little finger, lingual surface of tooth and photodiode. Variables were described as means and standard deviation, and the confidence interval was reported. Repeated measures analysis of variance (ANOVA) was used to compare the groups, followed by Bonferroni correction. Student t test for paired samples was used to determine presence of ambient light (α = 0.05). Mean SaO2 level was lower at 4.0 ± 0.2 mm thickness, regardless of presence or absence of ambient light (92.7% and 89.3%). The other thicknesses yielded values of 95.5% and 94.5% at 3.0 ± 0.2 mm, and 96.4% and 96.0% at 2.0 ± 0.2 mm (p < 0.001). There were significant differences between SaO2 values at 4.0 ± 0.2 mm, 3.0 ± 0.2 mm and 2.0 ± 0.2 mm thicknesses, in the presence of ambient light. Mean SaO2 level in positive control was 96.3%, and mean pulse rate was 69.5 bpm in presence of ambient light; in the absence of light, these values were 96% and 70.5 bpm. Enamel and dentin thickness interfere with SaO2, regardless of presence or absence of ambient light. The lowest SaO2 levels were found for the thickest tooth samples.

Effect of dental bleaching on pulp oxygen saturation in maxillary central incisors - a randomized clinical trial.

OBJECTIVE: To assess pulp oxygen saturation levels (SaO2) in maxillary central incisors after dental bleaching. MATERIALS AND METHODS: 80 participants (160 teeth) were randomly allocated to four groups: G1 In-office bleaching with two applications of 35% hydrogen peroxide (HP) (20 minutes), followed by at-home bleaching with 10% carbamide peroxide (CP) (2 hours/day for 16 days); G2 - Same protocol as G1, plus desensitizing toothpaste; G3 - In-office bleaching with 35% HP and one application of placebo gel (20 minutes), followed by at-home bleaching with 10% CP (2 hours/day for 16 days); and G4 - Same protocol as G3, plus desensitizing toothpaste. Pulp SaO2 levels were measured before (T0) and immediately after (T1) in-office bleaching; on the 5th (T2), 8th (T3), 12th (T4), and 16th days of at-home bleaching (T5); and on the 7th (T6) and 30th (T7) days. Mean (SD) pulp SaO2 levels were compared within groups by generalized estimating equations (GEE) and Student's t-test (P<0.05). RESULTS: Mean pulp SaO2 at T0 was 84.29% in G1, 84.38% in G2, 84.79% in G3, and 85.83% in G4. At T1, these values decreased to 81.96%, 82.06%, 82.19%, and 81.15% in G1, G2, G3, and G4 respectively, with significant difference in G4 (P<0.05). During home bleaching, pulp SaO2 levels varied in all groups, with 86.55%, 86.60%, 85.71%, and 87.15% means at T7 for G1, G2, G3, and G4, respectively; G2 presented significant difference (P<0.05). CONCLUSIONS: Pulp SaO2 level in maxillary central incisors was similar at baseline, reducing immediately after in-office bleaching, regardless of using desensitizing toothpaste and increasing at 30 days after dental bleaching.

Effect of dental bleaching on pulp oxygen saturation in maxillary central incisors - a randomized clinical trial

Abstract Objective To assess pulp oxygen saturation levels (SaO2) in maxillary central incisors after dental bleaching. Materials and Methods 80 participants (160 teeth) were randomly allocated to four groups: G1 In-office bleaching with two applications of 35% hydrogen peroxide (HP) (20 minutes), followed by at-home bleaching with 10% carbamide peroxide (CP) (2 hours/day for 16 days); G2 - Same protocol as G1, plus desensitizing toothpaste; G3 - In-office bleaching with 35% HP and one application of placebo gel (20 minutes), followed by at-home bleaching with 10% CP (2 hours/day for 16 days); and G4 - Same protocol as G3, plus desensitizing toothpaste. Pulp SaO2 levels were measured before (T0) and immediately after (T1) in-office bleaching; on the 5th (T2), 8th (T3), 12th (T4), and 16th days of at-home bleaching (T5); and on the 7th (T6) and 30th (T7) days. Mean (SD) pulp SaO2 levels were compared within groups by generalized estimating equations (GEE) and Student's t-test (P<0.05). Results Mean pulp SaO2 at T0 was 84.29% in G1, 84.38% in G2, 84.79% in G3, and 85.83% in G4. At T1, these values decreased to 81.96%, 82.06%, 82.19%, and 81.15% in G1, G2, G3, and G4 respectively, with significant difference in G4 (P<0.05). During home bleaching, pulp SaO2 levels varied in all groups, with 86.55%, 86.60%, 85.71%, and 87.15% means at T7 for G1, G2, G3, and G4, respectively; G2 presented significant difference (P<0.05). Conclusions Pulp SaO2 level in maxillary central incisors was similar at baseline, reducing immediately after in-office bleaching, regardless of using desensitizing toothpaste and increasing at 30 days after dental bleaching.

Effect of At-Home Bleaching on Oxygen Saturation Levels in the Dental Pulp of Maxillary Central Incisors.

The present study assessed oxygen saturation (SaO2) levels before, during, and after at-home bleaching treatment in the pulps of healthy maxillary central incisors. SaO2 levels were measured in 136 healthy maxillary central incisors using a pulse oximeter. The bleaching protocol consisted of 10% carbamide peroxide gel placed in individual trays and used for four hours daily for 14 days. SaO2 levels were assessed before bleaching (T0), immediately after the first session (T1), on the 7th day of treatment (T2), on the 15th day (the day following the last session) (T3), and 30 days after completion of the bleaching protocol (T4). Data were statistically analyzed using generalized estimating equations (GEE), Student's t test (p<0.05) and Pearson's correlation. Mean pulp SaO2 levels were 85.1% at T0, 84.9% at T1, 84.7% at T2, 84.3% at T3, and 85.0% at T4. Gradual reductions in SaO2 levels were observed, with significant differences (p<0.001) during the course of home bleaching treatment. However, 30 days after the end of the bleaching protocol, SaO2 levels returned to baseline levels. Home bleaching caused a reversible transient decrease in SaO2 levels in the pulps.

Effect of at-home bleaching on oxygen saturation levels in the dental pulp of maxillary central incisors

Abstract The present study assessed oxygen saturation (SaO2) levels before, during, and after at-home bleaching treatment in the pulps of healthy maxillary central incisors. SaO2 levels were measured in 136 healthy maxillary central incisors using a pulse oximeter. The bleaching protocol consisted of 10% carbamide peroxide gel placed in individual trays and used for four hours daily for 14 days. SaO2 levels were assessed before bleaching (T0), immediately after the first session (T1), on the 7th day of treatment (T2), on the 15th day (the day following the last session) (T3), and 30 days after completion of the bleaching protocol (T4). Data were statistically analyzed using generalized estimating equations (GEE), Student's t test (p<0.05) and Pearson's correlation. Mean pulp SaO2 levels were 85.1% at T0, 84.9% at T1, 84.7% at T2, 84.3% at T3, and 85.0% at T4. Gradual reductions in SaO2 levels were observed, with significant differences (p<0.001) during the course of home bleaching treatment. However, 30 days after the end of the bleaching protocol, SaO2 levels returned to baseline levels. Home bleaching caused a reversible transient decrease in SaO2 levels in the pulps.

Resumo Este estudo verificou o grau de saturação de oxigênio (SaO2) pulpar antes, durante e após o clareamento dental caseiro em incisivos centrais superiores hígidos. O nível de SaO2 foi verificado em 136 incisivos centrais superiores hígidos usando oxímetro de pulso. A técnica de clareamento empregou peróxido de carbamida 10% em moldeira individual por quatro horas diárias durante 14 dias. Os níveis de SaO2 foram analisados antes do clareamento (T0), imediatamente após a primeira sessão (T1), no sétimo dia de tratamento (T2), no décimo quinto dia (um dia após a última sessão) (T3) e 30 dias após o término do clareamento dental (T4). A análise estatística utilizou o modelo de equações de estimações generalizadas (GEE), teste t de Student (p<0,05) e correlação de Pearson. Os níveis médios de SaO2 pulpar foram 85,1% em T0, 84,9% em T1, 84,7% em T2, 84,3% em T3 e 85,0% em T4. Foi observada uma redução gradual dos níveis de SaO2, com diferenças significantes (p<0,001) durante o clareamento dental caseiro. No entanto, 30 dias após o término do clareamento dental, houve retorno aos valores iniciais. O clareamento dental caseiro provocou uma diminuição transitória reversível no grau de SaO2 pulpar.

Mesiolingual Canal Prevalence in Maxillary First Molars assessed through Different Methods.

AIM: Evaluate the prevalence of mesiolingual canal prevalence orifice in mesiobuccal roots of maxillary first molars using five methods of visualization. MATERIALS AND METHODS: About 73 first permanent maxillary molars were analyzed. Visual clinical analysis of the presence of the fourth canal was performed using a straight end-odontic exploratory probe (EXDG16®) and a K10 manual file (SybronEndo®). Dental elements that were not located on the fourth canal were analyzed with the aid of a magnifying glass (Zeiss®) with a 2.5-fold increase and those teeth in which the fourth canal was not found went through the examination with clinical surgical microscope (OPTO®) with magnification of 20 times with both the explorer and endodontic file. Next, a periapical radiography of the teeth was performed in the teeth in which the mesiolingual canal was not yet found to observe the presence or absence of the fourth canal. Afterward, the teeth in which the canal was not yet located were scanned using the microtomography equipment (SkyScan®), at 100 kV and 100 µA, with an isotropic resolution of 16 µm. RESULTS: The mesiolingual canal was located in 70 teeth (95.8%) and in only 3 teeth it was not identified. CONCLUSION: The visual method in the fourth canal search has limitations, whereas the composite magnifying glass, the clinical surgical microscopy, and the computerized microtomography are efficient methods for locating the fourth canal in the upper first molars. CLINICAL SIGNIFICANCE: The anatomical complexity of the first maxillary molars is one of the factors that leads to high failure rates in the endodontic treatments of this group of teeth. In most clinical situations, the mesiolingual canal goes unnoticed by professionals, since conventional radiographs do not always allow the visualization of all root canals. Determining an effective method for locating the mesiolingual canal is of paramount importance to the success of endodontic treatment.

Comparação da resistência à compressão entre materiais restauradores provisórios na endodontia: estudo in vitro / Comparison of compressive strength between temporary restorative materials in endodontics: in vitro study

Objetivo: este trabalho avaliou in vitro a resistência à compressão (RC) de diferentes materiais restauradores provisórios utilizados na endodontia: G1 (Vitremer®), G2 (Bioplic®), G3 (Coltosol ®) e G4 (IRM®). Material e método: Foram feitos 8 corpos de prova (n=8) de cada material totalizando 32 amostras (n=32) em matriz de silicone altura de 3,5mm e 6 mm de largura. Metade das amostras (n=16) foram mantidas 7 dias em soro fisiológico em estufa a 37ºC e a outra metade (n=16) mantidas por 14 dias e então foram submetidos ao ensaio de resistência a compressão, em uma máquina de Ensaios Universal (Emic 200) à velocidade de 0,5mm/min com uma célula de capacidade de carga de 200 kgf. Os dados obtidos em Mpa foram submetidos ao teste ANOVA a um critério, Tukey para comparações múltiplas (p<0,05) e por último T-test para amostras pareadas. Resultados: houve diferença estatisticamente significativa entre os grupos em 7 dias (p=0,000) sendo os grupos G1 e G2 iguais entre si (420,72 Mpa e 396,50 Mpa), porém em 14 dias não houve diferença entre os 4 grupos (p=0,104). O T-test mostrou a diferença entre os diferentes períodos de tempo dos grupos sendo G1 e G2 sem diferença estatística (p=0,178 e p=0,066), mas entre os grupos G3 e G4 houve diferença estatística (p=0,001 e p=0,000). Conclusão: O material a base de ionômero de vidro (Vitremer®) e a base de resina (Bioplic®) apresentaram os maiores valores em 7 dias. Em 14 dias os grupos não apresentaram diferenças estatísticas entre si, tiveram o mesmo comportamento apesar dos materiais à base de óxido de zinco (IRM® e Coltosol®) apresentarem maiores valores de resistência a compressão.

Objective: this study compared in vitro the compreesive strengt (CS) of the diferents materials used in endodontics: G1 (Vitremer®), G2 (Bioplic®), G3 (Coltosol®) e G4 (IRM®). Were made 8 specimens (n= 8) of each material, totalizing 32 samples (n=32) in a silicone matrix of 3,5mm height and 6mm diameter. Half the samples (n=16) was held 7 days in saline solution in an oven at 37ºC, and the other half (n=16) in 14 days and then subjected to the CS test in a universal machine (Emic 200), at a crosshead spreed of 0,5mm/min. Data in Mpa were submitted to one-way ANOVA, Tukey test for multiplex comparisons (p<0,05) and finally T-test for paired samples. Results: there was a statistically significant difference between the groups in 7 days (p=0,000), being the G1 and G2 equal to each other (420,72 Mpa e 396,50 Mpa), but in 14 days there was not a statically significant difference between the 4 groups (p=0,104). The T-test showed the difference between the different periods of the groups being G1 and G2 without statically difference (p=0,178 and p=0,066), between G3 and G3 groups there was significant differences (p=0,001 e p=0,000). Conclusion: materials based on glass ionomer (Vitremer®) and resinous (Bioplic®) showed higher values in 7 days. In 14 days the groups did not show statistically differences each other, had the same behavior dispite the fact that zinc oxide materials (Coltosol® and IRM®) had higher valuer of compressive strenght.

Diagnostic Efficacy of Four Methods for Locating the Second Mesiobuccal Canal in Maxillary Molars.

INTRODUCTION: The major cause for failure of root canal therapy is the inability to recognize the presence of all canals of the root canal system. Auxiliary tools, such as magnifying loupe, operative microscope and computed tomography (CT) images are used to facilitate the location of canals. The objective of the present survey was to evaluate the diagnostic efficacy of four methods for detecting the second canal of mesiobuccal roots (MB2) of permanent maxillary molars. METHODS AND MATERIAL: A total of 147 extracted human maxillary molars were assessed. The floor of the pulp chamber was inspected by an endodontist to find MB2 canals. Analyses were performed without magnification (direct visual method), using a loupe (with 3.5× magnification), and using a microscope (with 16× magnification). A fourth analysis was conducted using cone-beam computed tomography (CBCT) images. Teeth were sectioned horizontally into three parts (cervical, medial and apical thirds) to confirm the presence of MB2 canals (reference standard method). Sensitivity, specificity, and positive/negative predictive values were calculated for each method. RESULTS: No statistically significant differences were observed in the frequency of MB2 found between the microscope and the reference standard or between CBCT and the reference standard. CBCT had higher sensitivity (0.88), specificity (0.88), positive (0.84) and negative (0.91) predictive value than the other three methods. CONCLUSION: CBCT was the most accurate method for detecting the MB2 and it had a diagnostic efficacy similar to that of the reference standard method.

Comparação in vitro da sorção e da solubilidade de quatro materiais restauradores provisórios em endodontia / In vitro comparison of the sorption and solubility properties of temporary restorative materials used in endodontics

Objetivo: Este estudo comparou as propriedades de sorção e solubilidade de materiais restauradores provisórios utilizados em endodontia. Material e método: Foram confeccionados 60 corpos de prova, divididos em quatro grupos: G1-IRM® (Dentsply), G2- Coltosol® (Coltene), G3- Riva Light Cure® (SDI), G4 Clip F® (Voco) e pesados após 24h em balança analítica de precisão. Após, foram imersas em água destilada por 12 dias e pesados novamente. Retornaram à estufa a 37 °C por 24h. Resultados: Apresentaram diferenças estatisticamente significativas entre os grupos para sorção e solubilidade. O grupo G4 apresentou menor grau de sorção com diferença estatística dos demais grupos (0,0000087). Os níveis de sorção, encontrados nos grupos G3 (0,0000313) e G1 (0,0000493), apresentam- -se estatisticamente semelhantes entre si e o G2 (0,0000573) foi estatisticamente semelhante ao G1(0,0000493). Quanto à solubilidade, G1 (0,0000107) apresentou o menor nível com diferença estatística em relação aos demais grupos. Os valores de solubilidade, em ordem crescente, foram verificados respectivamente nos grupos G4 (-0,0000213), G3 (-0,000064) e G2 (-0,0002693). Conclusões: 1. Materiais provisórios fotoativados apresentaram os menores resultados quanto à sorção de água; 2. Compostos à base de óxido de zinco e eugenol apresentaram o menor nível de solubilidade comparado com todos os outros materiais provisórios e 3 - compostos livres de eugenol de uso imediato obtiveram os maiores valores tanto de sorção quanto de solubilidade.

Objective: This study compared the sorption and solubility properties of temporary restorative materials used in endodontics. Material and method: 60 specimens were divided into four groups: G1-IRM® (Dentsply), G2-Coltosol® (Coltene), G3-Riva Light Cure® (SDI), G4 Clip F® ) and weighed after 24 hours in precision analytical balance scale. Afterwards, they were immersed in distilled water for 12 days and weighed again. They returned to the stove at 37 ° C for 24 hours. Results: There were statistically significant differences between the groups for sorption and solubility. The G4 group presented lower degree of sorption with statistical difference of the other groups (0.0000087). The sorption levels, found in groups G3 (0.0000313) and G1 (0.0000493), were statistically similar to each other and G2 (0.0000573) was statistically similar to G1 (0.0000493). Regarding solubility, G1 (0.0000107) presented the lowest level with statistical difference in relation to the other groups. The solubility values, in ascending order, were respectively verified in groups G4 (-0.0000213), G3 (-0.000064) and G2 (-0.0002693). Conclusion: 1. Temporary photoactivated materials presented the lowest results regarding sorption of water; 2. Compounds based on zinc oxide and eugenol showed the lowest level of solubility compared to all other provisional materials and 3. eugenolfree compounds of immediate use obtained the highest values of both sorption and solubility.

Oxygen Saturation in the Dental Pulp of Maxillary Premolars in Different Age Groups - Part 1.

The aim of this study was to determine oxygen saturation levels in the dental pulp of maxillary premolars in different age groups. A total of 120 human maxillary premolars with normal dental pulps were selected covering the following age groups: 20-24, 25-29, 30-34, 35-39 and 40-44 years (n=24 each group). Oxygen saturation was assessed using pulse oximetry. Analysis of variance was used to assess differences in oxygen saturation levels and Tukey's test was used to identify the age groups that differed from each other. Significance was set at 0.05. Mean oxygen saturation of 120 premolars was 86.20% considering all age groups. Significantly reduced levels were found in the oldest group compared to the other groups: 40 to 44 years - 80.00% vs. 89.71, 87.67, 88.71, and 84.80% for age groups 20-24, 25-29, 30-34, 35-39 years, respectively. The mean oxygen saturation levels were similar between 20 and 39 years of age (86.20%) in the whole sample, but reduced significantly in the 40-44-year age group, suggesting that older patients present lower oxygen saturation results even in the absence of pulp tissue injury.