Tooth discoloration induced by endodontic sealers and cervical limit: 1-year in vitro evaluation.

This laboratory study aimed to evaluate the influence of endodontic sealer and cervical limit of root filling on the discoloration of root canal treated teeth. Bovine incisors were randomly distributed into six experimental groups and control (n=21/group), according to the endodontic sealer used [AH Plus (AP); MTA Fillapex (MF) and Sealer Plus BC (SPB)] and the cervical limit of root filling [dental cervix (DC) or 2 mm in apical direction (2mm-AD)]. Tooth discoloration (ΔE) was evaluated by a digital spectrophotometer using the CIED2000 method. Color assessments were performed immediately before (baseline), 1 week, 1, 3, 6 months, and 1 year after obturation. Data were analyzed by ANOVA and Tukey's post-hoc tests (α=5%). Teeth filled with the three sealers showed perceptible tooth discoloration (ΔE≥2.7) in 1 week, maintaining similar values over time. There was a significant difference between MF and SPB sealers in the 2mm-AD groups. In addition, 2mm-AD groups promoted significantly lower discoloration than DC groups for AH (3 months) and SPB (1 and 3 months) sealer,s. Teeth filled with AP, MF, and SPB sealers displayed discoloration from 1 week to one year, with differences between MF and SPB sealers. A cervical limit of filling material at 2 mm from the dental cervix seems more advisable, promoting lower crown discoloration.

Biocompatibility of three different root canal sealers, experimental study.

OBJECTIVES: This study was assessed the biocompatibility of three different root canal sealers (Well-Root St, GuttaFlow Bioseal, and AH-Plus) following implantation in rat subcutaneous tissues, using histopathological immunohistochemical analysis. METHODS: Four groups of eighty-four male rats each underwent subcutaneous dorsal implantation of a polyethylene tube, either empty or filled. Tissues were collected, fixed, and processed for histological analysis after 7, 15, and 30 d. Slides were photographed and digitally processed to identify lymphocytes and macrophages using Cluster of differentiation 3 (CD3) and cluster of differentiation 68 (CD68) markers, respectively. P was set at 0.05, when lymphocyte and macrophage infiltration was compared between groups and observation times using one-way analysis of variance (ANOVA). RESULTS: Histopathological analysis of all groups revealed an inflammatory reaction followed by the emergence of a fibrous capsule after 7 days. After 30 days, the thickness of the fibrous capsule and the inflammatory response subsided. CD3 staining for immunohistochemical analysis revealed that the AH-Plus group had the highest mean percentage of lymphocyte infiltration at 7 and 15 days, followed by the Well-Root St, GuttaFlow Bioseal, and Control groups. After 30 days, no discernible difference was observed between the groups in terms of the mean percentage of lymphocyte infiltration. After 7, 15, and 30 days, there was a significant difference in the mean percentage of macrophage infiltration across the groups, as demonstrated by CD68 staining. After 7, 15, and 30 days, the AH-Plus group had the highest mean percentage of macrophage infiltration, followed by the Well-Root St. and GuttaFlow Bioseal groups, while the control group had the lowest mean percentage. CONCLUSION: All observational periods showed minimal inflammatory reactions to GuttaFlow Bioseal. After subcutaneous tissue implantation in a rat model, the initial inflammatory reactions to Well-Root St and AH-Plus had abated by day 30, and all tested sealers had outstanding biocompatibility.

Calcium Silicate-based Sealer Extrusion into the Mandibular Canal: 3 Different Recovery Outcomes-A Report of 3 Cases.

The use of calcium silicate-based sealers (CSSs) is increasing in dentistry as a result of their favorable properties. The inadvertent extrusion of these sealers into the mandibular canal (MC) can result in temporary or permanent neurosensory alterations. Three different recovery outcomes of CSS extrusion into the MC after endodontic treatment of mandibular molars confirmed by cone-beam computed tomographic imaging are described. In Case 1, CSS from the mesiolingual canal of tooth #31 was extruded into the MC during obturation. The patient reported paresthesia. The symptoms of paresthesia were completely resolved by 9 months. In Case 2, CSS from the mesial canals of tooth #30 was extruded into the MC during obturation. A "plasmalike spreading pattern" of the extruded sealer was observed on the radiographs. The patient reported paresthesia and dysesthesia. In addition, the patient complained of hyperalgesia with heat and mechanical allodynia. The symptoms continued to persist during follow-up. At 22 months, the patient still reported persistent paresthesia, hyperalgesia, and mechanical allodynia, affecting the ability to eat. In Case 3, CSS from the distal canal of tooth #31 was extruded into the MC during obturation. The patient did not report any paresthesia or dysesthesia. All 3 patients elected a follow-up approach and monitoring rather than surgical intervention. These cases illustrate the need for the development of guidelines for the management of iatrogenic CSS extrusion into the MC because such an occurrence may result in permanent, temporary, or no neurosensory alterations.

Do resin-based sealers increase post-operative pain following root-canal treatment?

Design Systematic review. Case selection This systematic review had a focused and structured research question in term of PICO (Population, Intervention, Comparison and Outcomes). Patients included within the study were those with undergoing primary root canal treatment on a permanent tooth. The intervention was obturation with gutta percha and a resin-based sealer in comparison to obturation with gutta percha and another sealer type. The primary outcome being measured was post-operative pain incidence and/or intensity. An additional, secondary outcome, aimed to assess analgesic intake following treatment.Data analysis Data analysis was carried out by two independent reviewers using a specifically designed template which gave a concise summary of the study included within the review. The form allowed the following details to be recorded: whether a single operator completed treatment; pulpal status; irrigants used; sealer placement technique and type; obturation technique and quality; evaluation time; and outcome measures. An assessment was carried out of each study to ascertain the risk of bias which was categorised as low risk, having some areas of concerns or high risk.Six studies were included within the quantitative analysis which involved analysis of post-operative pain experiences at specified intervals. Qualitative data analysis was completed using a digital software package which allowed comparable results to be combined.Results The results from this systematic review demonstrated no significant difference in post-operative pain incidence between endodontic treatment using resin or non-resin sealers. While seven of the studies had high risk of overall bias, four were deemed low risk, and the majority of studies confirmed that there was no significant difference in the intensity of pain between the two groups. This review also confirmed that analgesic intake is not increased in patients where resin-based sealers are used when compared to non-resin sealers.Conclusion There is no significant difference in post-operative pain when resin-based root canal sealers are used when compared to other root canal sealers. For both resin and non-resin sealers, analgesics use, pain incidence post-operatively and intensity of pain reduce after 24 hours.

Paresthesia as a Result of Endodontic Sealer Extrusion: A Systematic Review.

AIM: The aim of this systematic review is to accumulate the available evidence on management approaches as well as factors resulting in the development of paresthesia due to sealer extrusion. MATERIALS AND METHODS: A literature search was conducted in MEDLINE, EMBASE, and Web of Science and Cochrane Central Register of Controlled Trials up to March 2022, accompanied by a manual search of journals, textbooks, and grey literature. Inclusion criteria were studies on adult patients experiencing paresthesia related to sealer extrusion. The quality of included studies was appraised using a custom set of criteria. RESULTS: A total of 102 publications were identified, and 9 of them fulfilled the inclusion criteria. All of the included studies were case reports describing a total of 10 patients. The predetermined data were independently extracted and evaluated by four reviewers. CONCLUSION: Because of the low amount and quality of available evidence, conclusions on the factors resulting in paresthesia due to sealer extrusion cannot be drawn. The management approach remains empirical. The need for prospective studies is highlighted. The future case reports in endodontics ought to be reported in a uniform and methodological way. CLINICAL SIGNIFICANCE: Paresthesia as a result of endodontic sealer extrusion is an alarming complication of endodontic treatment that general dentists need to be aware of. Although worrying, for both clinician and patient, it is a manageable complication and early diagnosis is important; thus, dentists need to be educated on this topic.

Inferior alveolar nerve injury due to the extrusion of calcium hydroxide during endodontic treatment: A case report.

Although many materials are used for root canal fillings in endodontic treatment, calcium hydroxide has been preferred for many years due to its bactericidal effect and biocompatibility. Calcium hydroxide can be applied in more than one form. In this case study, calcium hydroxide in viscous form, applied into the root canal during endodontic treatment, overflowed from the apical part of the tooth to the inferior alveolar nerve canal. Postoperative paraesthesia was observed in the patient. Dental volumetric tomography was performed to study the extent of sealer in the inferior alveolar nerve canal. Considering the short resorption time of the calcium hydroxide paste, no surgical intervention was performed on the patient. After 6 months, the root canal material was completely resorbed, and paraesthesia decreased. At the 3-year follow-up, the patient's paraesthesia had completely disappeared.

Do resin-based root canal sealers cause more postoperative pain than other sealers? A systematic review of clinical studies and meta-analysis.

OBJECTIVE: To evaluate whether root canal obturation with resin-based sealers increases the incidence and intensity of postoperative pain compared to other sealer types. DATA SOURCES: Medline, Scopus, Web of Science, Google Scholar, Cochrane Library, and gray literature were searched through December 2020. Clinical studies evaluating postoperative pain after obturation with resin-based sealers and other sealer types were included. Risk of bias was assessed through the Cochrane RoB 2.0 tool for randomized clinical trials (RCTs) and ROBINS-I tool for non-randomized clinical trials (nRCTs). Pooled relative risks (RR), standardized mean differences (SMD), and 95% confidence intervals were calculated for quantitative analyses. Of 524 studies, 11 clinical studies (eight RCTs and three nRCTs) involving 1,123 teeth were included. Four studies were assigned low risk of overall bias while seven studies presented high risk of overall bias. Quantitative analyses were performed with six studies for pain incidence, five studies for pain intensity, and four studies for analgesic intake. There was no significant difference between resin- based sealers and other sealer types in postoperative pain incidence at 24 hours (RR 1.102, P = .53), 48 hours (RR 0.943, P = .93), 72 hours (RR 1.019, P = .93), and 1 week (RR 0.559, P = .31), in pain intensity at 12 hours (SMD 0.100, P = .35), 24 hours (SMD 0.090, P = .25), and 48 hours (SMD 0.217, P = .26), and in analgesic intake at 24 hours (RR 2.253, P = .15) and 72 hours (RR 0.650, P = .59). CONCLUSION: Based on the available evidence, resin-based sealers do not increase the postoperative pain incidence, intensity, and analgesic intake compared to other sealer types.

[Short-term efficacy of three root canal filling methods in endodontic treatment of chronic periapical inflammation].

PURPOSE: To provide a reference basis for clinical selection of a reasonable and effective root canal treatment by comparing the short-term clinical efficacy of three root canal filling methods in the treatment of chronic periapical inflammation. METHODS: One hundred and twenty patients with chronic periapical inflammation who received root canal filling between October 2019 and October 2020 were randomly divided into 3 groups, with 40 patients in each group. All patients received root canal filling, group A was filled with iRoot SP paste by matched-taper single cone obturation technique, group B was filled with AH-plus paste by warm vertical condensation, and group C filled with AH-plus paste by cold lateral condensation. Root canal filling time in the three groups was calculated, pain score 24 h after treatment was determined using visual analogue scale/score(VAS), and periapical index(PAI) was used to evaluate radiographs. SPSS 22.0 statistical software was applied for data analysis. RESULTS：Root canal filling times in the three groups were (75.50±7.44) s in group A, (85.38±3.46) s in group B and (102.33±3.32) s in group C, the differences were statistically significant (P<0.05); the incidence of postoperative pain in the three groups was 25% in group A, 25% in group B and 32.5% in group C, the difference was not statistically significant(P>0.05). There was no significant difference between group A and group B, but significant difference existed between group A, group B and group C. The results of comparison of PAI scores showed a time effect was F=498.93, P<0.001, suggesting significant difference in total PAI scores at different time points; a group effect was F=0.91, P=0.406, suggesting no significant difference in total PAI scores of the 3 groups; an interaction effect of time and group was F=0.44, P=0.777, suggesting that there was no significant difference in total PAI scores of the 3 groups at the time points. The total effective rate at 3 and 12 months was 97.5%, 97.3% in group A, 97.5%, 97.2% in group B and 90%, 91.9% in group C, the difference was not statistically significant(P>0.05). CONCLUSIONS： Compared with the other 2 root canal filling methods, the iROOT SP paste matched-taper single cone obturation technique is clinically effective in terms of time saving and increasing the comfort of the patients' visit.

Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices-a 2-year in vitro study.

OBJECTIVES: To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. MATERIALS AND METHODS: Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro-Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). RESULTS: Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. CONCLUSIONS: Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. CLINICAL RELEVANCE: APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

Cytotoxicity and cytokine production by calcium silicate-based materials on periodontal ligament stem cells.

This study investigated the effect of three commercial calcium silicate-based materials (CSBM) on cytotoxicity and pro-and anti-inflammatory cytokines production in cultured human periodontal ligament stem cells (hPDLSCs). Culture of hPDLSCs was established and characterized. Extracts of Bio-C Sealer (Angelus, Londrina, PR, Brazil), MTA Fillapex (Angelus, Londrina, PR, Brazil) and PBS Cimmo HP (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brazil) were prepared by placing cement specimens (5 x 3 mm) in culture medium. Then, the extracts were serially two-fold diluted (1, 1:2, 1:4, 1:8, 1:16) and inserted into the cell-seeded wells for 24, 48 and 72 h for MTT assays. TNF-α and IL-10 cytokines were quantified by ELISA at 24h-cell supernatants. Data were analyzed by ANOVA and Tukey's test (α = 0.05). All CSBM exhibited some cytotoxicity that varied according to extract concentration and time of evaluation. MTA Fillapex presented the highest cytotoxic effects with significant reduction of metabolic activity/cell viability when compared to Bio-C Sealer and Cimmo HP®. TNF-α was significantly upregulated by the three tested cements (p < 0.05) while only MTA Fillapex significantly upregulated IL-10 in comparison to control. Taken collectively, the results showed that PBS Cimmo HP®, Bio-C Sealer and MTA Fillapex present mild and transient cytotoxicity and slightly induced TNF-α production. MTA Fillapex upregulated IL-10 release by hPDLSCs.

Spectrophotometric evaluation of coronal discoloration induced by bioceramic root canal filling materials / Evaluación espectrofotométrica de la decoloración coronal inducida por materiales biocerámicos de obturación del conducto radicular

The aim of this study is to evaluate the crown discoloration induced by bioceramic root canal filling materials (OrthoMTA and iRoot SP) compared to AH Plus. Material and Methods: Sixty intact mandibular single rooted premolars were sectioned 2 mm below the cemento-enamel junction, prepared, and randomly assigned into four groups according to the root filling materials: OrthoMTA, iRoot SP, AH Plus and unfilled. Results: Before placement of the materials in the pulp chamber and the coronal third of the root, the spectral reflectance lines of the crowns were recorded by a digital spectrophotometer at baseline, and after filling at 1 week and 1, 3 and 6 months and ∆Ε values were calculated. All materials used induced clinically perceptible crown discoloration (∆Ε>3.7) and no significant difference was detected between these materials (p>0.05). Regardless of the material, discoloration progressed significantly within the three months (p<0.05) however, at 6 months, the discoloration reduced for AH Plus and no further increase for bioceramic materials was detected. Conclusion: Bioceramic root filling materials tested induced clinically perceptible crown discoloration and their application in the esthetic zone should be performed with caution.

Objetivo: El objetivo de este estudio es evaluar la decoloración de la corona inducida por materiales biocerámicos de obturación del conducto radicular (OrthoMTA e iRoot SP) en comparación con AH Plus. Material y Métodos: Se seccionaron sesenta premolares mandibulares de raíz única intactos, 2 mm por debajo de la unión cemento-esmalte, se prepararon y se asignaron al azar en cuatro grupos de acuerdo con los materiales de obturación radicular: OrthoMTA, iRoot SP, AH Plus y sin relleno. Resultados:Antes de la colocación de los materiales en la cámara pulpar y el tercio coronal de la raíz, las líneas de reflectancia espectral de las coronas se registraron con un espectrofotómetro digital al inicio del estudio, y a la semana 1, así como a 1, 3 y 6 meses, y los valores ?? fueron calculados. Todos los materiales utilizados indujeron una decoloración de la corona clínicamente perceptible (??> 3,7) y no se detectaron diferencias significativas entre estos materiales (p> 0,05). Independientemente del material, la decoloración progresó significativamente dentro de los tres meses (p<0.05); sin embargo, a los 6 meses, la decoloración se redujo para AH Plus y no se detectó ningún aumento adicional para los materiales biocerámicos. Conclusiones: Los materiales biocerámicos de obturación radicular probados indujeron una decoloración de la corona clínicamente perceptible y su aplicación en la zona estética debe realizarse con precaución.

Cytotoxicity and cytokine production by calcium silicate-based materials on periodontal ligament stem cells

Abstract This study investigated the effect of three commercial calcium silicate-based materials (CSBM) on cytotoxicity and pro-and anti-inflammatory cytokines production in cultured human periodontal ligament stem cells (hPDLSCs). Culture of hPDLSCs was established and characterized. Extracts of Bio-C Sealer (Angelus, Londrina, PR, Brazil), MTA Fillapex (Angelus, Londrina, PR, Brazil) and PBS Cimmo HP (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brazil) were prepared by placing cement specimens (5 x 3 mm) in culture medium. Then, the extracts were serially two-fold diluted (1, 1:2, 1:4, 1:8, 1:16) and inserted into the cell-seeded wells for 24, 48 and 72 h for MTT assays. TNF-α and IL-10 cytokines were quantified by ELISA at 24h-cell supernatants. Data were analyzed by ANOVA and Tukey's test (α = 0.05). All CSBM exhibited some cytotoxicity that varied according to extract concentration and time of evaluation. MTA Fillapex presented the highest cytotoxic effects with significant reduction of metabolic activity/cell viability when compared to Bio-C Sealer and Cimmo HP®. TNF-α was significantly upregulated by the three tested cements (p < 0.05) while only MTA Fillapex significantly upregulated IL-10 in comparison to control. Taken collectively, the results showed that PBS Cimmo HP®, Bio-C Sealer and MTA Fillapex present mild and transient cytotoxicity and slightly induced TNF-α production. MTA Fillapex upregulated IL-10 release by hPDLSCs.

Resumo Este estudo investigou o efeito de três materiais comerciais à base de silicato de cálcio (CSBM) na citotoxicidade e na produção de citocinas pró e antiinflamatórias em células-tronco do ligamento periodontal humano (hPDLSCs). Cultura de hPDLSCs foi estabelecida e caracterizada. Extratos de Bio-C Sealer (Angelus, Londrina, PR, Brasil), MTA Fillapex (Angelus, Londrina, PR, Brasil) e PBS Cimmo HP® (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brasil) foram preparados com a colocação de espécimes dos cimentos (5 x 3 mm) em meio de cultura. Em seguida, os extratos foram diluídos (1, 1: 2, 1: 4, 1: 8, 1:16) e inseridos nos poços semeados de células para ensaio de citotoxicidade por meio de MTT por 24, 48 e 72 h. As citocinas TNF-α e IL-10 foram quantificadas por ELISA em sobrenadantes de células de 24 h. Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). Todos os CSBM exibiram alguma citotoxicidade que variou de acordo com a concentração do extrato e o tempo de avaliação. O MTA Fillapex apresentou os maiores efeitos citotóxicos com redução significativa da atividade metabólica / viabilidade celular quando comparado ao Bio-C Sealer e Cimmo HP®. O TNF-α foi regulado positivamente pelos três cimentos testados (p <0,05), enquanto apenas o MTA Fillapex regulou positivamente a liberação de IL-10 em comparação com o controle. Tomados em conjunto, os resultados mostraram que PBS Cimmo HP®, Bio-C Sealer e MTA Fillapex apresentam citotoxicidade leve e transitória e induziram a produção de TNF-α. O MTA Fillapex regulou positivamente a liberação de IL-10 por hPDLSCs.

Comparison of Postobturation Pain Experience after Apical Extrusion of Calcium Silicate- and Resin-Based Root Canal Sealers.

INTRODUCTION: This study compared the intensity of postobturation pain after unintentional apical extrusion of calcium silicate-based root canal sealers (EndoSequence BC Sealer [Brasseler USA, Savannah, GA] and Bio-C Sealer [Angelus, Londrina, PR, Brazil]) with a resin-based sealer (AH Plus; Dentsply Sirona, York, PA). METHODS: A total of 330 patients referred for root canal treatment on molar teeth with asymptomatic irreversible pulpitis were recruited. Root canals were prepared using WaveOne Gold instruments (Dentsply Sirona) in a crown-down technique and irrigated with 2% chlorhexidine gel and saline solution. Next, patients were randomly distributed into 3 groups according to the root canal sealer used (n = 110): AH Plus, BC Sealer, and Bio-C Sealer. Root canal filling was then accomplished with a vertical compaction technique. Patients presenting with an unintentional extrusion of sealers (n = 13/group) were assessed for postobturation pain experience using a visual descriptor scale ranging from 0-10 at 6-, 12-, 24-, and 48-hour and 1-week intervals after treatment. Mixed analysis of variance repeated measures were used to assess the results (α = 0.05). RESULTS: The extrusion rate was similar for all sealers (~12%). There was no significant difference in the postobturation pain results between the root canal sealers evaluated (P > .05). However, after the time interval of 12 hours, AH Plus (P = .04073) and Bio-C Sealer (P = .04327) demonstrated a significant reduction in pain, whereas BC Sealer did not show differences in pain intensity, even in the maximum period evaluated of 1 week (P > .05). CONCLUSIONS: The occurrence of unintentional apical extrusion of calcium silicate-based root canal sealers presents similar postoperative pain results compared with resin-based sealers with low-intensity pain.

Tooth and temporary filling material fractures caused by Cavit, Cavit W and Coltosol F: an in vitro study.

BACKGROUND: Tooth fractures can occur after temporary inter-appointment endodontic filling, resulting in not preserving and thus extraction of the affected tooth. The purpose of this investigation was therefore to evaluate the tooth substance fracture potential given by the expansion of endodontic temporary filling materials. METHODS: Tooth and access cavities were prepared in 80 mandibular molars. Four groups of 20 teeth each (Cavit, Cavit W and Coltosol F and control) were included. To simulate a clinical situation, the teeth were endodontically pre-treated and a calcium hydroxide dressing was placed. The cavities were filled with the corresponding temporary filling material, with exception of the control group, and kept submerged in distilled water for 15 days. The teeth were examined every 24 h by two calibrated observers under a stereomicroscope (7.5×), fractures of the temporary filling material and tooth structure were photo-documented, and the results statistically analyzed. Kaplan-Meier survival analysis were calculated to illustrate (survival = no fracture) probabilities to evaluate the time when the temporary filling material, tooth structure or both together occurred. Log-rank test was performed in order to assess significant differences between the materials and the subgroups used. RESULTS: Fractures were observed only in the Coltosol F group (p < 0.01), at the end of the observation period, a total of 13 teeth (65%) showed temporary filling material and eight teeth (40%) showed tooth structure fractures. No fractures in the pulp chamber area were observed at the end of the observation period in any group. CONCLUSIONS: Within the limitations of the current in vitro study, the results obtained suggest that tooth structure fractures caused by a temporary filling material can occur during endodontic treatment, thus compromising the success of the treatment.

Outcome Assessment of Teeth with Necrotic Pulps and Apical Periodontitis Treated with Long-term Calcium Hydroxide.

INTRODUCTION: The aim of this retrospective, cohort case series was 2-fold: (1) to evaluate the outcomes of teeth with necrotic pulps and apical periodontitis using long-term calcium hydroxide (Ca[OH]2) (healing was assessed via the periapical index [PAI] system) and (2) to explore the possible association of fractures in relation to long term Ca(OH)2 exposure. METHODS: A total of 242 cases, diagnosed with pulpal necrosis and apical periodontitis, were treated with long-term Ca(OH)2 using a standardized protocol. Injectable and powdered Ca(OH)2 were placed sequentially in the root canal system. All cases were re-evaluated within a 3-month period until radiographic healing was observed. Clinical and radiographic evaluations were performed annually. Pre- and postoperative periapical radiographs were evaluated using the PAI system. RESULTS: Of the 242 cases, 219 participants completed their treatment with annual follow-up. The average Ca(OH)2 time was 5.4 months with a range of 1-12 months. Overall, by the latest follow-up visit, 90.0% (197/219) were classified as "healed." The overall mean preoperative and postoperative PAI scores were 4.07 (±0.80) and 1.76 (±0.70), respectively. Kappa statistics showed an almost perfect agreement for inter-rater (κ = 0.91) and intrarater (κ = 0.95) reproducibility for both examiners. CONCLUSIONS: Within the limitations of this study, the use of long-term Ca(OH)2 in the treatment of teeth with necrotic pulps and apical periodontitis resulted in a predictable high outcome. There was no association observed between long-term Ca(OH)2 use and the incidence of fractures during this study. Ca(OH)2 is a suitable material of choice as an interappointment dressing for teeth diagnosed with pulpal necrosis and apical periodontitis.

Postobturation Pain Associated with Tricalcium Silicate and Resin-based Sealer Techniques: A Randomized Clinical Trial.

INTRODUCTION: The incidence of immediate postobturation pain associated with 2 sealer techniques was compared and potential prognostic factors identified. METHODS: Patients referred for endodontic treatment were recruited with informed consent. Root canals were debrided and teeth rendered asymptomatic before random allocation to receive TotalFill BC (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) or AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). Patients blinded to the sealer reported their postobturation pain experience 1, 3, and 7 days after treatment. Blinded and calibrated assessors independently reviewed treatment quality, sealer extrusion, and radiographic data under standardized conditions. RESULTS: One hundred sixty eligible patients (163 teeth, 95.3%) returned their pain diary. No postobturation pain difference was found between the 2 sealers (P > .05), although the AH Plus sealer technique was significantly associated with extrusion beyond the apex (P < .05; odds ratio [OR] = 3.02; 95% confidence interval [CI], 1.39-6.57). Thirty-three (20.6%) patients reported pain on day 1 (median 1 = very mild pain), 16 (10.0%) on day 3 (median 1 = very mild pain), and 9 (5.6%) on day 7 (median 2 = mild pain). The prognostic factors were as follows: (1) moderate/severe preoperative pain (OR = 4.41; 95% CI, 1.42-13.76 on day 3 and OR = 5.16; 95% CI, 1.17-22.78 on day 7), (2) provoked preoperative pain (OR = 4.24; 95% CI, 1.40-12.78 on day 3 and OR = 5.35; 95% CI, 1.27-22.51 on day 7), (3) pulpless tooth (OR = 0.11; 95% CI, 0.02-0.57 on day 3), and (4) sonic activation during treatment (OR = 3.02; 95% CI, 1.39-6.57 on day 1 and OR = 3.01; 95% CI, 1.05-8.59 on day 3). CONCLUSIONS: There was no significant difference in pain experience between teeth filled using AH Plus or TotalFill BC Sealer 1, 3, and 7 days after obturation. Patient- and treatment-related factors could influence postobturation pain.

Tooth discoloration and the effects of internal bleaching on the novel endodontic filling material SavDen® MTA.

BACKGROUND/PURPOSE: Mineral trioxide aggregate (MTA) was widely used in endodontic therapy as bioceramic material. Although MTA has high biocompatibility, it may lead to tooth discoloration. The aim of this study was to investigate the discoloration of two different bioceramic materials and the effects of internal bleaching. METHODS: Thirty single-canal mandibular premolars were extracted and randomly assigned to three groups (n = 10), white ProRoot® MTA, SavDen® MTA and a control group. Endodontic access opening, cleaning and shaping were performed, then the teeth were obturated using the two bioceramic materials. Tooth color was recorded at baseline, day 1, and 1, 2, 4, 6, 8, 12, 16, and 24 weeks after treatment. At the end of 24 weeks, sodium perborate was used to perform internal bleaching. Tooth color was recorded at 1, 2, and 6 weeks subsequently. Teeth were measured using a DeguDent® spectrophotometer, and data were transformed into Commission Internationale de l'Eclairage (CIE) L∗a∗b∗ system. RESULTS: Teeth treated with white ProRoot® MTA showed significant color change and decrease in L∗ value. Internal bleaching leaded to decrease of the ΔE∗ value for all three groups and increase in the L∗ value. There was no difference in tooth discoloration between SavDen® MTA and the control group after obturation and internal bleaching. CONCLUSION: In terms of visual perception, white ProRoot® MTA tends to cause black and blue discoloration. SavDen® MTA, formulated with calcium lactate gluconate, could be used to reduce tooth discoloration in endodontic treatment.

Spectrophotometric Analysis of Coronal Tooth Discoloration Induced by Tricalcium Silicate Cements in the Presence of Blood.

INTRODUCTION: New tricalcium silicate cements have been shown to induce less coronal discoloration. The purpose of this in vitro study was to evaluate the degree of color change induced by various silicate materials in the presence and absence of blood. METHODS: One hundred human extracted anterior single-canal teeth were sectioned to standardized root lengths, accessed, and instrumented. Eight random experimental groups and 2 control groups were created wherein specimens were filled with experimental materials below the buccal cementoenamel junction as follows: EndoSequence RRM putty (Brasseler USA, Savannah, GA), EndoSequence RRM fast set putty (Brasseler USA), Biodentine (Septodont, Saint-Maur-des-Fossés, France), and white mineral trioxide aggregate (Dentsply Sirona, York, PA) either with the presence or absence of blood. Blood-only and saline-only samples were used for the positive and negative controls. After incubation in 100% humidity at 37°C, color changes were evaluated with a spectrophotometer (Ocean Optics, Dunedin, FL) on days 0, 30, 60, and 180 after material placement. Data were transformed into Commission International de I'Eclairage's L∗a∗b color values, and corresponding ΔE values were calculated. The 1-way analysis of variance test was performed for statistical analysis. RESULTS: Discoloration was observed in all specimens in the presence of blood. There was no statistical significance when comparing different materials in contact with blood. Intragroup observation at various time points, Biodentine, and EndoSequence RRM fast set putty showed significant difference between the presence and absence of blood at 180 days (P < .05). CONCLUSIONS: Contamination with blood of tricalcium silicate materials has the potential to cause coronal tooth discoloration.

Combined effects of calcium hydroxide and photobiomodulation therapy on apexogenesis of immature permanent teeth in dogs.

Treatment of high-risk traumatic immature teeth due to incomplete root development is challenging. Apexogenesis is currently the ideal treatment option that allows normal root development. The purpose of this study was to evaluate the apexogenesis process of immature permanent teeth of dogs when co-administered with calcium hydroxide and photobiomodulation therapy (PBMT). A total of 36 immature permanent anterior and premolar teeth were selected from three 4-6-month-old dogs of Iranian mixed generation. The teeth were categorized into two groups, calcium hydroxide with laser irradiation (CHL) and calcium hydroxide without laser irradiation (CH). All the selected teeth received calcium hydroxide pulpotomy. After restoring teeth with amalgam, the CHL group received gallium­aluminum-arsenide (GaAlAs) diode laser (810 nm, 4.2 J/cm2, 0.3 W, 9 s,CW) on apical one-third of both buccal and lingual roots. The irradiation was repeated every 48 h for fourteen days. Intravenous tetracycline was used to observe newly formed dentin in the first, third, seventh, and fourteenth days. The distance between tetracycline lines (DTL) was examined by Fluorescence microscopy. Generalized estimating equations (GEE) were used for data analysis. In all assessments, the mean DTL were greater in the CHL group. However, the two groups had no significant differences in the amount of deposited dentin between the first and third, third and seventh, and first and seventh lines. Meanwhile, there was a significant difference between the two groups in terms of the distances between lines 7 and 14, 1 and 14 and also 3 to 14 (P < .001). In other words, from the 7th day onwards, there was a significant difference between the two groups. Within the limitation of this study, the combination therapy of PBMT and pulpotomy with calcium hydroxide accelerated apexogenesis in immature permanent dogs' teeth.

Respiratory Symptoms of Exposure to Substances in the Workplace among Bulgarian Dental Students: a Self-report Questionnaire Survey.

BACKGROUND: Dental students are at high risk of developing adverse respiratory reactions as a result of their practical work during their dentistry degree program when they come into contact with multiple airborne irritants and allergens. AIM: To estimate the prevalence of respiratory symptoms of exposure to substances in the workplace and associated risk factors in Bulgarian dental students. RESULTS: The prevalence of self-reported respiratory symptoms related to the pre-clinical and clinical training courses of the dentistry program was 12.4%. According to logistic regression analysis, the most important risk factors for work-related respiratory symptoms were a personal history of allergic rhinoconjunctivitis (odds ratio (OR) 6.34, 95% confidence interval (CI): 3.14-12.78), atopic dermatitis (OR 2.81, 95%CI: 1.26-6.26), and exposure to chemicals from dental environment for more than 6 hours a day (OR 3.60, 95%CI: 1.21-10.70). CONCLUSION: The results of this study suggest that work-related respiratory symptoms are frequent among dental students and indicate the need for efforts to establish effective primary preventive programs for occupational respiratory disorders at national level.