Can the addition of surfactants to NaOCl irrigation impact on the percentage of voids of root canal filling?

This study evaluated the impact of canal irrigation using surfactants associated to NaOCl on the percentage of voids of root canal filling through micro-computed tomographic (micro-CT) analysis. 27 mandibular mesial roots with Vertucci type II canal configuration with isthmus were selected and scanned in a micro-CT device. The specimens were assigned to three groups (n = 9), according to the irrigation solution during instrumentation: 2.5% NaOCl without additives (control), 2.5% NaOCl with 0.1% Benzalkonium Chloride and 2.5% NaOCl with 0.1% Tween 80. After obturation, the specimens were rescanned, and the percentage of voids were calculated. Data were analysed using one-way ANOVA with a significance level of 5%. The percentage of voids were similar among the groups (p > 0.05). None of the specimens showed completely voids-free areas. The addition of surfactants to NaOCl irrigation did not improve the quality of root canal filling of mandibular mesial root canals.

Final Endodontic Irrigation with 70% Ethanol Enhanced Calcium Hydroxide Removal from the Apical Third.

INTRODUCTION: The purpose of this study was to evaluate the cleanliness of root canal walls and dentinal tubules after attempting to remove the calcium hydroxide dressing with different irrigant solutions and the use of nonactivated irrigation or passive ultrasonic irrigation (PUI). METHODS: After root canal instrumentation, 80 single-rooted teeth were filled with calcium hydroxide mixed with propylene glycol and 0.1% rhodamine B dye and inserted into canals with a Lentulo spiral. The calcium hydroxide dressing was initially removed with 10 mL saline solution and reinstrumentation with the master apical file. Then, the samples were randomly assigned into 8 experimental groups (n = 10) according to the irrigant solution with or without PUI: 2.5% sodium hypochlorite, 17% ethylenediaminetetraacetic acid + 1.25% sodium lauryl ether sulfate (EDTA-T), 37% phosphoric acid, or 70% ethanol. A final flush with 5 mL saline solution was performed. The percentage of clean root canal walls and the depth of clean dentinal tubules were measured with images of confocal laser scanning microscopy. The groups were compared using the 2-way analysis of variance test with the Bonferroni post hoc test for depth analysis and the Kruskal-Wallis with Dunn post hoc test for the perimeter analysis. RESULTS: Irrigation with 70% ethanol presented a significantly higher percentage of clean root canal walls and a higher depth of clean dentinal tubules when compared with irrigation with 2.5% sodium hypochlorite and 17% EDTA-T for both irrigation methods (P < .05). No differences were observed between nonactivated irrigation or PUI protocols (P > .05). CONCLUSIONS: Seventy percent ethanol enhanced calcium hydroxide removal from the apical root third compared with 2.5% sodium hypochlorite or 17% EDTA-T.

Effect of low-level laser therapy on postoperative endodontic pain: An updated systematic review.

OBJECTIVE: To evaluate the influence of low-level laser therapy (LLLT) on postoperative pain after endodontic treatment. METHODS: The PICOS strategy was used to identify randomized clinical trials comparing low-level laser therapy and mock laser therapy to manage postoperative pain after endodontic treatment, retreatment, and endodontic surgery. An electronic search was performed in MEDLINE through PubMed, Web of Science, LILACS, Scopus and Cochrane Library, OpenGrey and Google Scholar. Quality assessment was performed using the Cochrane Collaboration's tool for assessing the risk of bias. The quality of evidence was rated on the basis of the GRADE approach. RESULTS: Twelve studies were included in the qualitative synthesis. Within the 12 studies, 7 articles were classified as "low risk of bias," 4 studies were considered "unclear risk of bias" and 1 study was considered "high risk of bias." Six studies evaluated the postoperative pain after primary root canal treatment, two studies after root canal retreatment and four after periapical surgery. Most of the studies reported significantly less postoperative pain after LLLT in different time periods; two studies found no differences. The certainty of evidence was classified as low and very low to treatment / retreatment and endodontic surgery, respectively. CONCLUSIONS: Based on the limited quality evidence, most of the included studies reported significantly less postoperative pain after LLLT. However, the lack of standardization in laser parameters, use of medications and the certainty of evidence classified as low and very low indicate the need for further studies.

Effect of intracanal cryotherapy application on postoperative endodontic pain: a systematic review and metaanalysis.

OBJECTIVES: To assess the influence of intracanal cryotherapy application on postoperative pain after endodontic treatment. MATERIALS AND METHODS: A systematic review (SR) was conducted in seven databases. Articles that were published up to 04 February 2020 were included and randomized clinical trials that used a cold saline solution for final irrigation to manage postoperative endodontic pain were compared with those that used a saline solution at room temperature. Metaanalysis was performed to assess postoperative pain after 6, 24, 48, and 72 h using a random effects model, a confidence interval of 95%, and heterogeneity tested by the I2 index. The certainty of evidence was rated using GRADE. RESULTS: Qualitative and quantitative analysis included eight and six studies, respectively. Individuals treated with cryotherapy presented lower means of postendodontic pain than the controls, 6 and 24 h after endodontic treatment (MD - 1.30 [- 2.32, - 0.28] p = 0.01 and SMD - 0.68 [ - 1.21, - 0.16] p = 0.01, respectively, with very low certainty of evidence). After 48 and 72 h, both groups demonstrated similar means of postendodontic pain (MD - 0.06 [- 0.18, 0.07] p = 0.38 and SMD - 0.54 [- 1.18, - 0.11] p = 0.10, with high and low certainty of evidence, respectively). CONCLUSIONS: Based on the limited quality evidence, intracanal cryotherapy application reduced postoperative endodontic pain after 6 and 24 h. New clinical trials are needed to support the result of this review. CLINICAL SIGNIFICANCE: This SR provides information about the use of intracanal cryotherapy in clinical practice, guides clinicians to make evidence-based decisions and suggests recommendations for further high-quality studies.

Effect of sodium ascorbate on bond strength and metalloproteinases activity in bleached dentin.

AIM: This study evaluated the effect of sodium ascorbate (SA) on the proteolytic activity of matrix metalloproteinases (MMPs) and investigated the related effects on the bond strength of bleached dentin. MATERIALS AND METHODS: Eighty freshly extracted human third molars were randomly divided according to treatment (bleaching or SA application), type of analysis (microshear or measuring MMP activity), and post-bleaching time to assess bond strength (24 hrs or 30 days). Data from both analyses were subjected to one-way analysis of variance to detect differences among groups, followed by Tukey's multiple comparison test (p≤0.05). RESULTS: Dental bleaching significantly reduced bond strength values when the adhesive strategy was performed after 24 hrs (despite the SA treatment) or 30 days after the bleaching procedure. However, after 30 days, the bond strength values of the groups who received bleaching or SA application were similar to those of the unbleached group. Dental bleaching caused the activation of MMPs, and SA did not influence this activity. CONCLUSION: It was concluded that SA does not affect the activity of MMPs or the bond strength in bleached dentin immediately after the bleaching treatment.

Metastatic Renal Cell Carcinoma to the Oral Cavity.

Metastases to the oral cavity are extremely rare events, representing less than 1% of all malignant oral tumors. Renal cell carcinoma constitutes about 3% of solid tumors in adults, and it is the most frequent kidney neoplasm, representing about 90% of kidney malignancies. Due to the silent growth of this neoplasm, most patients have no symptoms and the diagnosis is belated, usually after metastases. The present study reports an additional patient of metastatic renal cell carcinoma to the oral cavity regarding the clinical and pathologic features.