Influence of the timing of periodontal intervention on periapical/periodontal repair in endodontic-periodontal lesions: a systematic review.

INTRODUCTION: This study is aimed at answering the following question: "Does the timing of periodontal intervention influence the periapical/periodontal repair in endodontic-periodontal lesions?". MATERIAL AND METHODS: Six electronic databases were systematically searched for studies published up to April 2022, without restriction of language or year of publication, following the PIOS strategy: (P) adult patients with a diagnosis of endodontic-periodontal lesions, (I) endodontic and periodontal treatment, (O) periapical and periodontal healing, and (S) clinical studies. Risk of bias assessment was performed with the revised Cochrane risk of bias tools for randomized trials (RoB 2) and non-randomized interventions (ROBINS-I). The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: Three studies (one prospective, one retrospective, and one randomized clinical trial) were included in the present review. Non-randomized studies had a critical and serious risk of bias. The randomized clinical trial had some concerns risk of bias. Non-randomized studies reported that the endodontic intervention should be performed previous to the periodontal intervention. Randomized clinical trial reported improvements when endodontic and periodontal interventions were performed simultaneously. GRADE analysis showed a very low quality of evidence for both randomized and nonrandomized studies. CONCLUSIONS: Based on the evidence from the included studies, although it is suggested that the endodontic treatment should be performed prior to periodontal treatment, it is not possible to assure the best treatment sequence for endodontic-periodontal lesions. CLINICAL RELEVANCE: Evidences suggests that although the endodontic intervention should be the first therapy of choice, it was not possible to specify the best time to perform the periodontal intervention.

Effect of music during endodontic treatment on patients' anxiety: a systematic review of randomized clinical trials.

OBJECTIVES: Endodontic treatment is one of the most fearful procedures among dentistry, and the use of music during the procedure has been evaluated to control patients' anxiety. This systematic review has been conducted to provide a synthesis of the state of knowledge in this field and aimed to answer the following question: "Can music therapy reduce patient's state anxiety during endodontic treatment?". METHODS: A search was performed in six electronic databases (PubMed, Cochrane Library, Scopus, Web of Science, EMBASE, and Open Gray) for articles published until April 2022. The eligibility criteria, based on the PICOS strategy, were as follows: (P) patients undergoing endodontic treatment; (I) exposure to music; (C) no music; (O) patients' anxiety; (S) only randomized clinical trials. The risk of bias was analyzed according to the Cochrane Risk of Bias tool for randomized controlled trials (RoB 2). The strength of evidence from the included studies was assessed using the Grading of Assessment, Development, and Assessment Recommendations (GRADE) tool. RESULTS: Five eligible studies were retrieved. A low to high risk of bias was verified. Descriptive analysis showed an effect in favor of music intervention, with differences among state anxiety, heart rate and blood pressure. CONCLUSIONS: With a very low quality of evidence, dental care professionals may consider playing background music during endodontic treatment since it is a cost-effective and easy alternative to trying to reduce dental anxiety. CLINICAL RELEVANCE: Five studies were included in this systematic review and showed, with a very low quality of evidence, that music may reduce state anxiety levels on patients during root canal treatment.

Do orthodontic movements of traumatized teeth induce dental pulp necrosis? A systematic review.

INTRODUCTION: Usually, orthodontic movements encompass children and young adult patients, which are more susceptible to the occurrence of traumatic dental injuries. It is necessary to understand whether the effects of orthodontic movements on traumatized teeth could induce pulp necrosis. The aim of this study was to answer the following question: "Do orthodontic movements of traumatized teeth induce dental pulp necrosis?". MATERIAL AND METHODS: Searches were performed for studies published up to May 11, 2023, in the MEDLINE/PubMed, Cochrane Library, Scopus, SciELO Citation Index, Web of Science, EMBASE, and Grey Literature Report databases, without restriction for language or year of publication. The revised Cochrane risk of bias tools for nonrandomized interventions (ROBINS-I) was used to assess the quality of the included studies. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: Of 2671 potentially relevant studies, five were included. Four were classified as having a moderate risk of bias and one as a serious risk of bias. It was reported a higher susceptibility to pulp necrosis in teeth subjected to orthodontic movements with history of trauma involving periodontal tissues. Additionally, orthodontic movements of traumatized teeth with total pulp obliteration had an increased risk of pulp necrosis. GRADE analysis presented a moderate certainty of evidence. CONCLUSIONS: An increased risk for pulp necrosis when traumatized teeth are subjected to orthodontic movements was verified. However, this is based on evaluations performed with subjective tests. Further well-designed studies are necessary to confirm this trend. CLINICAL RELEVANCE: Clinicians must be aware of the possibility of pulp necrosis. However, endodontic treatment is recommended when verified signs and symptoms of pulp necrosis.

Do NSAIDs used prior to standard inferior alveolar nerve blocks improve the analgesia of mandibular molars with irreversible pulpitis? An umbrella review.

INTRODUCTION: The aim of the present umbrella review was to answer the following question: "Does the use of NSAIDs as premedication increase the efficacy of the standard inferior alveolar nerve block on teeth with symptomatic irreversible pulpitis?" MATERIAL AND METHODS: Systematic reviews with and without meta-analyses that evaluated the influence of premedication on anesthetic efficacy of the inferior alveolar nerve in symptomatic irreversible pulpitis of mandibular molars were searched in six electronic databases (MEDLINE/PubMed, Scopus, Web of Science, Cochrane Library, EMBASE, and Grey Literature Reports), without the restriction of language or year of publication. A Measurement Tool to Assess systematic Reviews (AMSTAR 2) was used to evaluate the quality of the included studies. RESULTS: Twelve systematic reviews were included. Only one did not perform a meta-analysis. The AMSTAR 2 overall confidence ranged from very low to high. In general, the main findings of the systematic reviews were that non-steroidal anti-inflammatory drugs (e.g., ibuprofen, oxicam, diclofenac, association of ibuprofen with acetaminophen, and ketorolac) increased the success rate of the inferior alveolar nerve block. CONCLUSIONS: From the "very low" to "high"-quality evidence available, this umbrella review concluded that NSAIDs as premedication acts through cyclooxygenase pathways and block the synthesis of specific prostaglandins that complicate the mechanism of action of the anesthesia, improving its success rate. CLINICAL RELEVANCE: Non-steroidal anti-inflammatory drugs can increase the success rate of the anesthetic technique of inferior alveolar nerve block efficacy in situations of mandibular molars with symptomatic irreversible pulpitis.

Head and neck radiotherapy effects on the dental pulp vitality and response to sensitivity tests: A systematic review with meta-analysis.

BACKGROUND: Experimental studies are controversial regarding the effects of radiotherapy for head and neck cancer (HNC) on the dental pulp. Therefore, a systematic review of clinical studies is necessary to investigate whether alterations in pulp status occur. OBJECTIVES: To evaluate the evidence on radiotherapy for HNC and pulp status. METHODS: A systematic search of articles published until November 2021 was performed in the MEDLINE/PubMed, Cochrane Library, Web of Science (All Databases), Scopus, EMBASE, and Open Grey databases. The eligibility criteria were based on the PICOS strategy, as follows: (P) vital teeth of adult patients with intraoral and/or oropharyngeal cancer; (I) radiotherapy; (C) control group or values of the same tooth before radiotherapy (basal values); (O) pulpal status after radiotherapy; and (S) clinical studies. The Cochrane Risk of Bias in Nonrandomized Studies of Interventions tool was used to assess the quality of the included studies. Meta-analyses were performed using fixed and random effects. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: Six studies were included for qualitative analysis. Five were classified as serious risk of bias and one as moderate risk of bias. Four studies reported altered pulp responses to cold thermal tests after radiotherapy initiation. Meta-analyses were performed using three included studies. From these, all were included in the meta-analysis for pulp response values to cold sensitivity test immediately after radiotherapy initiation (risk ratio: 0.00 [CI: 0.00, 0.02], p < .00001; I2  = 0%); and two in the meta-analysis for pulp response values to cold sensitivity test after 4-5 months of radiotherapy (risk ratio: 0.01 [CI: 0.00. 0.06], p < .00001; I2  = 0%). Two reported progressively higher readings to pulp response in the electrical test after radiotherapy initiation (mean difference: -11.46 [-13.09, -9.84], p < .00001; I2  = 68%). Two studies demonstrated a pulp oxygen saturation (SpO2 ) decrease at the end of radiotherapy; and an increase after 4-6 months of radiotherapy beginning. And other demonstrated normal dental pulp SpO2 4-6 years after treatment. GRADE analysis presented a moderate certainty of evidence. DISCUSSION: This review verified that radiotherapy for HNC causes significant alterations on the dental pulp responses, but does not seem to induce pulp necrosis. Significant limitations regarding controlling for confounding factors, classification of interventions, and measurement of outcomes were verified, evidencing the need for well-designed studies. CONCLUSIONS: This systematic review demonstrated that radiotherapy for HNC induced significant changes in the pulp response with moderate quality of evidence. Such altered responses cannot determine pulp status accurately.

The prevalence of apical periodontitis in patients prior to hematopoietic cell transplantation: a systematic review.

Objectives: This systematic review addressed the question: "What is the prevalence of apical periodontitis in patients prior to hematopoietic cell transplantation?" Materials and Methods: A systematic search was conducted in MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Grey Literature Report. Eligibility criteria were based on the condition, content, and population strategy: the condition was the radiographic prevalence of apical periodontitis, the content comprised patients scheduled for hematopoietic stem cell transplantation, and the population consisted of adult and pediatric patients. The revised Risk of Bias in Nonrandomized Studies of Exposure tool was used to assess the quality of studies. The Grading Recommendations Assessments, Development, and Evaluation (GRADE) tool was used to assess the quality of evidence. Results: Eight studies were included in this review. The average number of patients with apical periodontitis was 15.65% (range, 2.1%-43.34%). One study was classified as having a very high risk of bias, 1 with a high risk of bias, and 6 with some concern for bias. GRADE analysis showed a very low certainty of evidence. Significant limitations concerning the absence of control over confounding variables were identified. Conclusions: With the caveat of the very low quality of evidence in the studies reviewed, there was a low to moderate prevalence of apical periodontitis in patients prior to undergoing hematopoietic cell transplantation.

Effect of Obturation Techniques on the Quality of Root Canal Fillings: A Systematic Review and Meta-analysis of in Vitro Studies.

Introduction: The current study aimed to compare the quality of root canal obturation performed with cold lateral condensation with other obturation techniques. Materials and Methods: Diverse Search was conducted using six electronic/academic databases following PICOS (i.e. population, intervention, control, outcomes, and study design) strategy: (P) Extracted mature permanent teeth; (I) Obturation techniques except for cold lateral condensation; (C) Cold lateral condensation tyechnique; (O) Quality of root canal obturation; and (S) In vitro studies assessing parameters using micro-computed tomography. The statistical method used for the meta-analyses was the "inverse variance DerSimonian-Laird test". The heterogeneity data was calculated using the T2, Cochran Q test, and I2 statistics. Results: Fifteen studies were included for the final analysis; one had a low risk of bias, eight a moderate risk, and six a high risk of bias. Ten studies were selected for meta-analyses; three studies comparing cold lateral condensation with carrier-based gutta-percha techniques [P=0.96; mean difference (MD)=-0.02; confidence interval (CI): (-0.77, 0.73); I2=21%]; three comparing cold lateral condensation with single-cone techniques [P=0.75; MD=-0.39; CI: (-2.77, 1.99); I2=92%]; two comparing cold lateral condensation and thermo-plasticized injectable techniques [P=0.37; MD=5.91; CI: (-7.13,18.94); I2=99%]; and five comparing cold lateral condensation with warm vertical condensation techniques [P<0.0001; MD=5.29; CI=(2.84, 7.74); I2=92%]. The overall effect reported significant results [P=0.0003; MD=2.69; CI=(1.23, 4.16); I2=96%]; favoring fewer voids and gaps for the other used obturation techniques. Conclusions: Cold lateral condensation and single-cone techniques presented no statistical differences. Nonetheless, Warm vertical condensation technique had better results compared to cold lateral condensation.

Increased Prevalence of Periapical Lesions in Osteoporosis Patients: A Systematic Review.

Assessing scientific literature about prevalence of periapical lesions in individuals with osteoporosis in comparison to those without osteoporosis. Systematic searches were conducted up to November 24th, 2023 in Cochrane Library, EMBASE, MEDLINE/PubMed, SCOPUS, Web of Science and Grey Literature Reports databases. Only observational studies were included. The ROBINS-E tool, a revised Cochrane instrument for assessing bias in nonrandomized exposure studies, was employed. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool was utilized to evaluate the certainty of the evidence. From 484 studies, three were included. One of them was categorized as having an exceptionally high risk of bias, while two were deemed to have certain concerns. Two studies reported that osteoporotic patients may have more chances to present a periapical lesion compared to non-osteoporotic patients. One study reported no differences between groups. The GRADE analysis indicated a markedly low level of certainty in the evidence. The present review indicates that osteoporotic patients may present more periapical lesions compared to non-osteoporotic patients. This statement should be cautiously interpreted and further well-designed studies are needed. (EEJ-2023-09-123).

Effect of ultrasonic activation on setting time, pH and calcium ion release, solubility, and chemical structure of calcium silicate sealers.

This study evaluated the setting time, pH, calcium ion release, solubility, and chemical structure of four calcium silicate sealers after ultrasonic activation (UA). Five sealers were evaluated: Sealer Plus (SP - control); Sealer Plus BC (SPBC), Bio C Sealers (BCS), Endosequence BC Sealer (EBC), and BioRoot RCS (BR). Ten groups were created based on the use or not of ultrasonic activation: SP; SP/UA; SPBC; SPBC/UA; BCS; BCS/UA; EBC; EBC/UA; BR; and BR/UA. Setting time was performed based on ISO 6876:2012 and ASTM C266-07 specifications. Solubility at 24hs, based on ISO 6876:2012. pH and calcium release were evaluated at 1, 24, 72, and 168hs. Raman spectroscopy was used to evaluate structural changes. Quantitative data were analyzed using One-Way ANOVA and Tukey post-hoc test (α=5%). Raman spectroscopy results were qualitatively analyzed. Setting times and solubility of all sealers were not affected by UA (p>0.05). The highest solubility was found for BCS, BCS/UA; and BR, BR/UA (p<0.05). After 24hs, calcium silicate sealers had higher pH than SP and SP/UA (p<0.05). BR and BR/UA had the highest pH at all time points. SP and SP/UA had stable pH at all time points. SP and SP/UA had the lowest calcium release values at all time points (p<0.05). EBC and EBC/UA calcium release significantly differ at 24,72 and 168hs (p<0.05). No chemical changes were observed during Raman spectroscopy. In conclusion, ultrasonic activation affected calcium ion release only for EndoSequence BC Sealer. Ultrasonic activation did not influence the initial and final setting time, solubility, pH, and chemical structure of any investigated sealers.

Dentinal tubule penetration of sodium hypochlorite in root canals with and without mechanical preparation and different irrigant activation methods.

Objectives: This study evaluated the dentinal penetration depth of 2.5% sodium hypochlorite (NaOCl) in root canals with and without preparation and different irrigant activation protocols. Materials and Methods: Sixty-three bovine mandibular incisors were randomly allocated to 6 groups (n = 10): G1, preparation + conventional needle irrigation (CNI); G2, preparation + passive ultrasonic irrigation (PUI); G3, preparation + Odous Clean (OC); G4, no preparation + CNI; G5, no preparation + PUI; G6, no preparation + OC; and CG (negative control; n = 3). Samples were filled with crystal violet for 72 hours. Irrigant activation was performed. Samples were sectioned perpendicularly along the long axis, 3 mm and 7 mm from the apex. Images of the root thirds of each block were captured with a stereomicroscope and analyzed with an image analysis software. One-way analysis of variance, followed by the Tukey post hoc test, and the Student's t-test were used for data analysis, with a significance level of 5%. Results: The NaOCl penetration depth was similar when preparation was performed, regardless of the method of irrigation activation (p > 0.05). In the groups without preparation, G6 showed greater NaOCl penetration depth (p < 0.05). The groups without preparation had a greater NaOCl penetration depth than those with preparation (p = 0.0019). Conclusions: The NaOCl penetration depth was similar in groups with root canal preparation. Without root canal preparation, OC allowed deeper NaOCl penetration. The groups without preparation had greater NaOCl penetration than those undergoing root canal preparation.

Pharmacological Management of Anxiety on Pain Occurrence During Root Canal Treatment: A Systematic Review.

OBJECTIVE: To answer the question: 'Does the pharmacological management of dental anxiety influence pain occurrence during root canal treatment?' METHODS: Searches on MEDLINE/PubMed, Cochrane Library, Web of Science, Scopus, EMBASE and Open Grey were conducted until September 02, 2022. Only randomised clinical trials were included. The Cochrane risk of bias tool for randomized trials (RoB 2) was used. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: Initial screening resulted in 811 studies. Three hundred seventy-three were excluded for being duplicates. Of 438 eligible papers, ten studies met the inclusion criteria and were selected for full-text reading. Four studies were included in the final analysis. Three studies had a low risk of bias, and one was a high risk. GRADE demonstrated a low quality of evidence. CONCLUSION: There is insufficient evidence to determine whether the pharmacological control of anxiety can influence intraoperative pain occurrence. (EEJ-2022-08-096).

Disinfectant effectiveness of chlorhexidine gel compared to sodium hypochlorite: a systematic review with meta-analysis.

This study aimed to compare the disinfectant ability of chlorhexidine (CHX) gel and sodium hypochlorite (NaOCl). Systematic searches were conducted from inception until December 8th, 2022 (MEDLINE/PubMed, Cochrane Library, Web of Science, Scopus, Embase, and Grey Literature databases). Only randomized clinical trials were included. The revised Cochrane risk of bias tools for randomized trials were used to assess the quality of studies. Meta-analyses were performed. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation tool. Six studies were included. Five had a low risk of bias and 1 had some concerns. Three studies assessed bacterial reduction. Two were included in the meta-analysis for bacterial reduction (mean difference, 75.03 [confidence interval, CI, -271.15, 421.22], p = 0.67; I2 = 74%); and 3 in the meta-analysis for cultivable bacteria after chemomechanical preparation (odds ratio, 1.03 [CI, 0.20, 5.31], P = 0.98; I2 = 49%). Five studies assessed endotoxin reduction. Three were included in a meta-analysis (mean difference, 20.59 [CI, -36.41, 77.59], p = 0.48; I2 = 74%). There seems to be no difference in the disinfectant ability of CHX gel and NaOCl, but further research is necessary.

Evaluation of cyclic and torsional fatigue resistance of several heat-treated reciprocating nickel-titanium instruments.

This study investigated the cyclic fatigue and torsional resistance of Unicone Plus (UCP 25.06), Unicone (UC 25.06), Reciproc Blue (RB 25.08) and Wave One Gold (WOG 25.07) performed at body temperature (35° ± 1°C). Time and number of cycles to fracture (NCF), as well as torque and angular deflection were recorded. Fractured surfaces were evaluated by scanning electron microscopy (SEM). Data were analysed using one-way ANOVA and Holm-Sidak's tests for multiple comparison. The RB had a significantly higher time to fracture, followed by the WOG and UCP (p < 0.05). Regarding the NCF, there was no significantly difference between RB and WOG (p > 0.05). UC presented highest torque values and the lowest angular deflection (p < 0.05). SEM analysis demonstrated typical failures features in both cyclic and torsional fatigue tests. Overall, UC had the lowest time, NCF and angular deflection at fracture. RB presented the highest time to fracture and angular deflection values.

Does photobiomodulation on the root surface decrease the occurrence of root resorption in reimplanted teeth? A systematic review of animal studies.

This review aimed to answer the following question "Does photobiomodulation treatment of the root surface decrease the occurrence of root resorption in reimplanted teeth?" Electronic searches were performed in the MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Grey Literature Report databases. Risk of bias was evaluated using SYRCLE Risk of Bias tool. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool was used to assess the certainty of evidence. In total, 6 studies were included. Five studies reported a reduced occurrence of root resorption in teeth that received photobiomodulation treatment of the root surface prior to replantation. Only 1 study reported contradictory results. The photobiomodulation parameters varied widely among studies. GRADE assessment showed a low certainty of evidence. It can be inferred that photobiomodulation treatment of the root surface prior to replantation of teeth can reduce the occurrence of root resorption. Nonetheless, further clinical studies are needed. Trial Registration: PROSPERO Identifier: CRD42022349891.

Impact of Nonsurgical Treatment of Asymptomatic Apical Periodontitis on the Oral Health-related Quality of Life: A Prospective Study.

Introduction: The aim of this study was to evaluate the impact of nonsurgical root canal treatment (nRCT) and the healing of asymptomatic apical periodontitis (AAP) on the oral health-related quality of life (OHRQoL) in a Brazilian population. Materials and Methods: This prospective longitudinal observational study included 56 adults, in which 84 teeth with asymptomatic apical periodontitis underwent nonsurgical root canal treatment. Socio-demographic and medical data were collected; the primary outcome oral health-related quality of life was measured by the short form of the Oral Health Impact Profile (OHIP-14). Statistical analysis was carried out by Mann-Whitney U-test, and changes in the oral health-related quality of life scores post-treatment were estimated by Student t-test. Results: The mean age was 51.0±15.2 years, with 53.5% of females. Overall, nRCT significantly improved the OHRQoL (P<0.001, effect size=0.76). Gender (female) was associated with a higher OHRQoL after nRCT (P<0.05). OHIP-14 showed a significant reduction six months after root canal treatment compared to baseline scores. Conclusion: Present findings revealed that nonsurgical root canal treatment improved the oral health-related quality of life in patients with asymptomatic apical periodontitis.

Does the ultrasonic activation of calcium silicate-based sealers affect their physicochemical properties?

This study aimed to evaluate the influence of ultrasonic activation (UA) on the physicochemical properties of hydraulic calcium silicate-based sealers. Nine experimental conditions were created based on the hydraulic calcium silicate-based sealers (Bio-C Sealer, Sealer Plus BC and Bio Root RCS) and the ultrasonic activation (no activation [NA], 10 seconds, and 20 seconds). Then the experimental groups were BC-NA, BC-10, BC-20, SPBC-NA, SPBC-10, SPBC-20, BR-NA, BR-10, and BR-20. Activation was performed with an ultrasonic insert 20/.01. The mold for the physicochemical analysis was filled and evaluated according to the ANSI/ADA specification nº. 57: initial and final setting time, flow, radiopacity and solubility. Tests were also performed to evaluate pH and calcium ion release with experimental periods of 1, 24, 72, and 168 hours with a pH meter and colorimetric spectrophotometer. Data were analyzed by one-way analysis of variance and post-hoc Tukey tests. The significance level was set at 5%. The time of UA progressively delayed the initial setting time for all hydraulic calcium silicate-based sealers (p < 0.05). Twenty seconds of UA increased the mean flow values of Sealer Plus BC and Bio-C Sealer compared to NA (p < 0.05). UA did not influence the radiopacity and solubility of the tested sealers (p > 0.05). UA for 20 seconds enhanced the pH levels and the calcium ion release of Sealer Plus BC and Bio-C Sealer at 168h (p < 0.05). UA for twenty seconds interferes with some physicochemical properties of hydraulic calcium silicate-based sealers.

Effects of estrogen deficiency on the progression of apical periodontitis. A systematic review of preclinical studies.

BACKGROUND: To answer the review's question "Does estrogen deficiency influence on the progression of apical periodontitis?" METHODS: Systematic searches were performed in MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, EMBASE, and Grey Literature Report databases, without restriction for language or year of publication. The eligibility criteria were based on the PICOS strategy, as follows: (P) animals with estrogen deficiency; (I) induction of apical periodontitis; (C) animals without estrogen deficiency (control group or sham surgery); (O) bidimensional and/or tridimensional measures of apical periodontitis progression; (S) studies in animal models. Risk of bias was performed with SYRCLE Risk of Bias tool. Certainty of evidence was assessed with GRADE. RESULTS: In total, 12 studies were included according to eligibility criteria. All studies (100%) demonstrated that the estrogen deficiency influence the apical periodontitis progression. Most studies performed a histomorphometric analysis evaluating bone loss area (58.3%), radiographic bone loss area (41.7%), bone volume assessment with microcomputed tomography (25%), fluorescence microscopy lesion area in mm2 (16.7%), and radiographic density assessment in one study (8.3%). The most frequent period of analysis was 21 days after lesion induction (75%). GRADE assessment showed a moderate certainty of evidence. DISCUSSION: The included studies demonstrated several limitations regarding randomization, blinding and description of baseline characteristics. All studies showed that an hypoestrogenic condition can favor an increased progression of apical periodontitis. Further clinical studies are necessary to confirm this correlation. CONCLUSIONS: In animal models, the estrogen deficiency significantly impact on the progression of apical periodontitis generating larger lesions comparing to healthy sham animals.

Genotoxicity and Cytotoxicity Comparison of Calcium Silicate-Based and Resin-Based Sealers on Human Periodontal Ligament Stem Cells.

OBJECTIVE: This study aimed to assess the genotoxicity and cytotoxicity of Sealer Plus BC (SBC), AH Plus (AHP) and MTA Fillapex (MTF). METHODS: Human periodontal ligament dental stem cells (hPDLSCs) from third molars were isolated and cultured in a clonogenic medium. Cells were maintained in an incubator, and cell growth was monitored daily. hPDLSCs were characterised under flow cytometry and stem cell surface markers. The tested groups were a control group, SBC, AHP and MTF. Each sealer was prepared according to the manufacturer's instructions and placed in a clonogenic medium to produce a conditioned media. Conditioned media were then diluted to 10% to be placed in contact with culture cells in cell viability assay afterwards. The cells were harvested and plated into 96 wells culture plates. Genotoxicity was assessed by evaluation of micronucleus formation and cytotoxicity by MTT-based assay. All experiments were performed in triplicate. Data normality was verified by the Kolmogorov-Smirnov test. Statistical analysis for genotoxicity was performed with Kruskal-Wallis and Dunn's tests and two-way ANOVA for cytotoxicity, both with a significance level of 5%. RESULTS: Cells expressed typical levels of mesenchymal stem cell surface markers. No differences in the number of micronuclei were observed among all groups (P>0.05). In all periods analysed (24, 48, and 72 h), the sealers presented statistically different results for cell viability (P<0.05), with SBC presenting the lowest cytotoxicity, followed by the control group, MTF, and AHP. CONCLUSION: All sealers presented low genotoxicity, and Sealer Plus BC presented the lowest cytotoxicity.

Effect of A Clinical-Replicable Cooling Protocol on the Cyclic Fatigue Resistance of Heat-Treated Nickel-Titanium Instruments.

Introduction: The aim of this study was to evaluate the bending and cyclic fatigue resistance of Wave One Gold (WOG) and X1 Blue (X1B) instruments when tested at body temperature (36°C ± 1°C) with and without subjected to an alloy cooling protocol. Materials and Methods: A total of sixty instruments (n=30) were tested. Forty instruments (n=20) were randomly selected and divided into two groups: body temperature (BT; n=20) and body temperature with cooling protocol (CP; n=20). Cyclic fatigue test was performed until fracture in a conventional stainless-steel device with water bath equipment to simulate body temperature. CP group instruments were subjected to 5 seconds of spray cooling every 30 seconds. Time to fracture was recorded in seconds. Resistance to bending at an angle of 45 degrees was evaluated using twenty instruments (n=10). Fractured surfaces were examined under scanning electron microscopy (SEM). Statistical analysis was performed at a 5% significance level. Results: There was no difference in the cyclic fatigue resistance between instruments in BT groups (P>0.05). Cooling protocol significantly increased the cyclic fatigue resistance of X1B instruments (P=0.0003) and WOG instruments (P=0.0003). Results: WOG instruments had a significantly lower cyclic fatigue resistance compared to X1B instruments in CP group (P=0.0001). There were no significant differences between the values of resistance increase presented by the instruments after cooling (P>0.05). Bending test presented no statistically significant differences between the tested instruments (P>0.05). Both instruments in both groups showed typical features of cyclic fatigue behavior under SEM. Conclusions: X1 Blue #25.06 and WaveOne Gold #25.07 instruments presented similar cyclic fatigue resistance. The investigated clinical-replicable cooling protocol improved the cyclic fatigue resistance of the tested instruments, with X1 Blue #25.06 presenting a greater cyclic fatigue resistance after cooling. Both instruments presented a similar bending capacity.

Influence of the root canal filling technique on the success rate of primary endodontic treatments: a systematic review.

Objectives: This study aimed to investigate the influence of different obturation techniques compared to cold lateral compaction on the success rate of primary non-surgical endodontic treatments. Materials and Methods: Systematic searches were performed for studies published up to May 17th, 2022 in MEDLINE/PubMed, Cochrane Library, Web of Science, Scopus, EMBASE, and Grey Literature Reports. Randomized clinical trials and nonrandomized (nonrandomized clinical trials, prospective or retrospective) studies that evaluated the success rate of primary non-surgical endodontic treatments obturated with the cold lateral compaction (control) and other obturation techniques were included. The revised Cochrane risk of bias tools for randomized trials (RoB 2) and nonrandomized studies of interventions (ROBINS-I) were used to evaluate the risk of bias. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool was used to evaluate the certainty of evidence. Results: Eleven studies (4 randomized clinical trials (RCTs), 4 prospective, and 3 retrospectives) were included. Two RCTs were classified as having some concerns risk of bias and 2 as a low risk of bias. Two nonrandomized studies were classified as having a critical risk of bias and 5 as having a moderate risk of bias. The GRADE analysis demonstrated a very low to moderate certainty of evidence. Conclusions: This systematic review generally evidenced no differences in the success rate of primary non-surgical endodontic treatments when the cold lateral compaction technique and other obturation techniques are performed. Further well-designed studies are still necessary.