Synthesis of a Calcium Silicate Cement Containing a Calcinated Strontium Silicate Phase.

Objectives: The positive effects of strontium on dental and skeletal remineralization have been confirmed in the literature. This study aimed to assess the properties of a calcium silicate cement (CSC) containing a sintered strontium silicate phase. Materials and Methods: The calcium silicate and strontium silicate phases were synthesized by the sol-gel technique. Strontium silicate powder in 0 (CSC), 10 (CSC/10Sr), 20 (CSC/20Sr), and 30 (CSC/30Sr) weight percentages was mixed with calcium silicate powder. Calcium chloride was used in the liquid phase. X-ray diffraction (XRD) of specimens was conducted before and after hydration. The setting time and compressive strength were assessed at 1 and 7 days after setting. The set discs of the aforementioned groups were immersed in the simulated body fluid (SBF) for 1 and 7 days. The ion release profile was evaluated by inductively coupled plasma-optical emission spectrometry (ICP-OES). Biomineralization on the specimen surface was evaluated by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Data were analyzed by the Kolmogorov-Smirnov test, one-way and mixed ANOVA, Levene's test, and LSD post hoc test (P < 0.05). Results: Except for an increasement in the peak intensity of hydrated specimens, XRD revealed no other difference in the crystalline phases of hydrated and nonhydrated specimens. The compressive strength was not significantly different at 1 and 7 days in any group (P > 0.05). The setting time significantly decreased by an increase in percentage of strontium (P < 0.05). Release of Ca and Si ions significantly decreased by an increase in percentage of strontium (P < 0.05). SEM/EDS showed the formation of calcium phosphate deposits at 1 and 7 days. Conclusion: Incorporation of 10-30 wt% sintered strontium silicate phase as premixed in CSC can significantly decrease the setting time without compromising the compressive strength or biomineralization process of the cement.

The association of endodontic prognostic factors with the presence of periapical lesion, its volume, and bone characteristics in endodontically treated molars: a cross-sectional study.

BACKGROUND: This study intended to evaluate the association between several endodontic prognostic factors with the presence of periapical lesions (PLs), their volume, and bone characteristics including cortical bone destruction (CBD) and buccal plate bone height (BPBH) in root-filled molar teeth using cone-beam computed tomography. METHODS: A collection of 143 scans of endodontically treated maxillary/mandibular first or second molars recorded over 8 years, were obtained from a specialized radiology center. Data on prognostic factors including tooth number, gender, jaw type, the status and number of missed canals, obturation length, restoration type, presence of a separated instrument, presence of a post or screw in the canals, and presence of perforation were collected. The assessed outcomes included PL presence, PL volume, CBD, and BPBH. The association between prognostic factors and outcomes was evaluated using multiple logistic regression models with adjusted covariates and multifactorial ANOVA at a significance level of 0.05. RESULTS: A total of 282 molars from 82 women and 50 men with a mean age of 40.6 ± 12.27 were included. Among those, 139 teeth presented PL with a mean volume of 18.68 mm3. CBD was prevalent in 137 teeth and the mean BPBH appeared to be 9.45 mm. The presence of a missed canal (OR = 10.022, P < .05), underfilled canal (OR = 3.725, P < .05), overfilled canal (OR = 15.859, P = .018), and perforation (OR = 15.261, P = .013) was significantly associated with PLs. None of the prognostic factors could considerably contribute to the CBD (P > .05). The presence of a missed canal was positively associated with the PL volume (P < .05). Similarly, missed canals (P < .05), perforation (P < .05), and separated instruments (P = .004) were associated with a significantly reduced BPBH. CONCLUSIONS: Overfillings, perforations, missed canals, and underfillings were identified as remarkable predictors of PL, arranged in descending order of their respective impact. The only factor capable of significantly increasing the PL volume was the missed canal. In brief, obturation length errors, perforations, missed canals, and separated instruments were robustly correlated with endodontic failure, which highlights the importance of mitigating the potential for errors by following the fundamentals of endodontics.

Effect of Photodynamic Therapy on the Pushout Bond Strength of Resin-Based and Calcium Silicate-Based Endodontic Sealers.

Introduction: This study aimed to assess the effect of photodynamic therapy (PDT) on the pushout bond strength (PBS) of resin-based and calcium silicate-based endodontic sealers. Methods: Forty single-canal teeth were assigned to four groups. After root canal preparation by the crown-down technique and smear layer removal, groups 1 and 2 served as the control group, and groups 3 and 4 underwent PDT by using a low-level diode laser as the light source and methylene blue as the photosensitizer (MB). The root canals in groups 1 and 3 were filled with AH26 sealer while the root canals in groups 2 and 4 were filled with Endoseal TCS. The samples were sectioned at 4, 8, and 12 mm from the apex tip (1mm thick slices). The PBS test was performed, and the mode of failure was determined in the coronal, middle, and apical thirds. The data were analyzed by the Kruskal-Wallis, Friedman, and Dunn tests. Results: No significant difference was noted in the PBS of resin-based and calcium silicate-based sealers in the apical, middle, or coronal thirds in the application of PDT (P>0.05). The PBS of AH26 was significantly higher than that of Endoseal TCS (P<0.05). Cohesive failure was the dominant mode of failure in the AH26 groups, while mixed failure was the dominant failure mode in the Endoseal TCS groups. Conclusion: PDT had no significant effect on the PBS of resin-based and calcium silicate-based sealers.

Analgesic Efficacy of Ketoprofen Transdermal Patch versus Ibuprofen Oral Tablet on Postendodontic Pain in Patients with Irreversible Pulpitis: A Randomized Clinical Trial.

Materials and Methods: In this randomized clinical trial, 64 patients who had mandibular first and second molars with irreversible pulpitis were randomly divided into two groups (n = 32) by stratified permuted block randomization. The experimental group used 60 mg KTP every 6 hours, and the control group received 400 mg ibuprofen tablets every 6 hours for 1 day. The severity of pain experienced by patients was quantified before and at 2, 4, 8, 12, 24, and 48 hours after endodontic treatment, using the numerical rating scale (NRS). Data were analyzed by using the t-test, Mann-Whitney test, and generalized estimating equation (GEE) (alpha = 0.05). Results: The pain score was not significantly different between the two groups at the baseline or any other postoperative time point (P > 0.05). The reduction in the pain score was significant in both groups from 2 to 10 hours and 10 to 48 hours, postoperatively (P < 0.001). The interaction effect of time and group was not significant on the postoperative pain score in the abovementioned time intervals, and the pattern of pain reduction was the same over time in both groups (P > 0.05). Conclusion: Both KTP and ibuprofen effectively decreased postendodontic pain. Considering the comparable pattern of pain reduction, KTP can be used as an alternative to ibuprofen tablets for effective pain control after endodontic treatment of mandibular first and second molars with irreversible pulpitis.

Effect of Non-thermal Plasma Therapy on Pushout Bond Strength of Epoxy Resin and Tricalcium Silicate-Based Endodontic Sealers.

Introduction: The current study aimed to assess the effect of non-thermal plasma (NTP) on the pushout bond strength (PBS) of epoxy resin and tricalcium silicate-based endodontic sealers. Methods: Forty single-canal extracted teeth were decoronated at the coronal region, underwent root canal preparation, and were assigned to four groups (n=10) for the application of AH26 sealer, NTP+AH26 (P-AH26), Endoseal TCS sealer, and NTP+Endoseal TCS sealer (P-TCS). The root canals were sectioned into 1 mm slices, and the PBS value was measured in a universal testing machine. Data were analyzed by the Friedman, Kruskal-Wallis, and Dunn tests (P<0.05). Results: The PBS of TCS and P-TCS groups was not significantly different (P>0.05). The PBS of the P-AH26 group was significantly lower than that of the AH26 group in the middle third (P<0.05). The PBS of the AH26 group was higher than the other groups in all sections. The PBS in the apical third was lower than other sections in all groups (P<0.05). Conclusion: NTP had no significant effect on the PBS of Endoseal TCS. NTP significantly decreased the PBS of AH26 sealer in the middle third but had no significant effect on its bond strength in other sections.

Biocompatibility of an experimental endodontic sealer (Resil) in comparison with AH26 and AH-Plus in rats: An animal study.

Background. This experimental study sought to assess the biocompatibility of Resil, an experimental epoxy resin-based sealer, in comparison with AH26 and AH-Plus sealers in rats. Methods. Twelve male Wistar rats weighing 400 to 500 grams were evaluated in this experimental study. Four polyethylene tubes containing Resil, AH-Plus, AH26 sealers, and an empty tube were implanted subcutaneously in rats. The degree of inflammation, type of inflammatory cells present, foreign body reaction, quality of connective tissue, and presence of fibrotic capsule were evaluated histopathologically at 7 and 30 days after implanting the tubes to assess the biocompatibility of sealers. Data were analyzed using the Chi-square test. Results. At 7 days, the degree of inflammation in Resil group was almost similar to AH26 group, and 66.7% of rats showed moderate inflammation. AH-Plus group showed less inflammation than Resil and AH26 (50% of rats showed low degree of inflammation), At 30 days, the inflammatory status of all groups was the same, and 83.3% of rats showed very low degree of inflammation. The inflammatory response during the experiment decreased from day 7 to day 30 in all groups. The neutrophil count (P=0.00), fibrotic capsule (P=0.01) and the amount of granulation tissue (P=0.05) significantly decreased from day 7 to day 30 in Resil group. Conclusion. Resil sealer showed appropriate biocompatibility at 7 and 30 days after subcutaneous implantation in rats, comparable to AH26 and AH-Plus. Clinical studies are required to confirm these results.

Efficacy of Different Ibuprofen Formulations with Two Prescription Methods on Post Endodontic Pain of Teeth with Irreversible Pulpitis: A Randomized Clinical Trial.

Introduction: Pain management during root canal therapy and after that is of great importance in endodontics. This study aimed to compare the effect of two non-steroidal anti-inflammatory drugs (NSAIDs); ibuprofen and ibuprofen lysine with two methods of prescription on pain after single-visit root canal treatment of first and second mandibular molar teeth with irreversible pulpitis. Materials and Methods: This randomized study recruited subjects experiencing moderate to severe pain from a tooth diagnosed with symptomatic irreversible pulpitis (n=120). Subjects were randomized to receive 400 mg ibuprofen acid or 400 mg ibuprofen lysine regularly or on demand. The primary objective was to measure changes in pain scores at post-operative time frames of 6, 12, 18, 24, 48 and 72 hours after the root canal treatment on a 0-10 numerical rating scale (NRS). Independent T-test, Non-parametric Kruskal-Wallis Test and Friedman Test were used to analyze the data. Results: Kruskal-Wallis analysis showed a significant difference in NRS score between on-demand ibuprofen group and regular ibuprofen group and also between regular ibuprofen lysine group and regular ibuprofen group at 6 hours after the treatment (P<0.05). But no remarkable difference was observed in the recorded mean pain intensity of four study groups in the other time frames (P>0.05). Conclusions: Based on this randomized clinical trial, there was no significant difference in the pain intensity of patients using ibuprofen and ibuprofen lysine. Additionally, there was no significant difference in the degree of pain between the on-demand and regular groups, despite the fact that patients in the on-demand group used less medications. Due to the multiple negative effects of NSAIDs, it would be wise to prescribe ibuprofen on demand.

Association of Inflammatory Periapical Lesions with Maxillary Sinus Abnormalities: a Retrospective Cone-Beam Computed Tomography Study.

STATEMENT OF THE PROBLEM: Odontogenic infections such as periapical lesions (PLs) can cause changes in the adjacent tissues. Infection of the maxillary posterior teeth can be easily transmitted to the maxillary sinus and cause changes in the maxillary sinus mucosa. Cone-beam computed tomography (CBCT) has high accuracy and sensitivity for detection of odontogenic lesions and is efficient for maxillary sinus assessment. PURPOSE: This study aimed to assess the maxillary sinuses for abnormalities such as mucosal thickening, polyps, and periostitis, and evaluate the periapical status of maxillary posterior teeth considering the presence of PLs, their size and distance from the sinus floor by evaluating CBCT images. MATERIALS AND METHOD: This retrospective, cross-sectional study evaluated the CBCT scans of 143 patients, depicting the posterior maxilla with at least one premolar or molar tooth present in this region. Sinus abnormalities (mucosal thickening, sinus polyps, and periostitis) and presence/ absence of PLs, its size, and its distance from the sinus floor were all assessed on CBCT scans. Data were analyzed using the Chi-square test in SPSS version 21 (a= 0.05). RESULTS: PLs were observed in 31.2% of the cases. In presence of PLs, mucosal thickening was noted in 56.8%, sinus polyps in 29.6% and periostitis in 1.3% of the maxillary sinuses. All teeth with a CBCT periapical index (CBCTPAI) score of 5 were associated with sinus abnormalities; there was neither correlation between the sizes of lesions, nor their distance from the sinus floor with sinus abnormalities (p> 0.05). CONCLUSION: PLs in the posterior maxilla have a direct correlation with the maxillary sinus abnormalities. However, the size or distance of PLs from the sinus floor had no significant effect on the frequency of sinus abnormalities.

Evaluation of Chemical and Physical Properties of an Experimental Endodontic Sealer in Comparison with AH-26 and AH-Plus.

Introduction: This study aimed to assess the physical and chemical properties of an experimental endodontic resin sealer (Resil) compared with AH-26 and AH-Plus. Methods and Materials: In this in vitro experimental study, dimensional stability (by measurement of length; n=5), pH (using a pH meter; n=5), and antibacterial activity (by agar diffusion test; n=8) of Resil, AH-26 and AH-Plus were evaluated and compared using one-way ANOVA and Tukey's test. Results: All three groups showed significant expansion from day 1 to day 30 (P<0.05). The difference in the mean dimensional changes between the AH-Plus and experimental sealer was significant (P=0.020). Two hours after mixing, the pH of experimental sealer (Resil) was significantly lower than that of AH-Plus (P<0.001) and higher than that of AH-26 (P<0.001). Antibacterial activity of the experimental sealer before and after setting was significantly higher than that of the other two sealers (P<0.001). Conclusion: The results of this in vitro study showed that the experimental sealer had greater 1 to 30 days dimensional changes than the other two sealers. It had an alkaline pH, and showed superior antibacterial activity compared with AH-26 and AH-Plus. It may be possible to use this sealer in the clinic after animal studies because an epoxy resin based sealer with lower price and more appropriate properties is favorable.

Cytotoxicity of Endodontic Irrigants on Human Periodontal Ligament Cells.

INTRODUCTION: Root canal irrigation has an extremely important role in the success of endodontic treatment. During endodontic treatment, the irrigants will be in contact with pulpal and periapical tissues. The purpose of this study was to clarify the potential toxicological implications of NaOCl, EDTA, MTAD, CHX and QMix on periapical and periodontal tissues. METHODS AND MATERIALS: Cytotoxicity of solutions was evaluated on cultured human periodontal ligament (hPDL) that were carefully removed from the middle third of premolar roots. Cytotoxicity of the materials was assessed after 1, 5 and 15 min of exposure using the Mosmann's Tetrazolium Toxicity (MTT) assay. Optical density of the solution was read at 540-690 nm wavelength. The intensity of color generated correlated with the percentage of viable cells. Data were statistically analyzed using repeated measures ANOVA followed by Bonferroni test. RESULTS: The mean percentage of viable cells in all experimental groups was significantly different from sterile saline groups at all time points (P<0.0001). The mean percentage of viable cells significantly decreased over time in MTAD and NaOCl groups. The lowest and highest cytotoxicity belonged to MTAD and EDTA groups, respectively at all the time points (P<0.05). CONCLUSION: MTAD had the lowest cytotoxicity compared to NaOCl, CHX, QMix and EDTA. These impacts have been time dependent. These irrigation fluids may cause unfavorable effects on vital tissues.

Cytotoxicity of Two Experimental Epoxy Resin-Based Sealers.

INTRODUCTION: Many endodontic sealers are available, but search for the ideal sealer continues. This study aimed to assess the cytotoxicity of two experimental endodontic sealers in comparison with AH-26 resin sealer. METHODS AND MATERIALS: This in vitro study was conducted on conventional and experimental root canal sealers: AH-26, an epoxy resin experimental sealer A (ES-A) composed of calcium tungstate, zirconium oxide, aerosil, bismuth oxide, titanium oxide, hexamine and an epoxy resin and experimental sealer B (ES-B) with compositions similar to ES-A except for the presence of imidazoline as a catalyst. The experimental sealers containing nano-particles were mixed with 37.5% of an epoxy resin. The extraction of five samples of each experimental sealer (A, B) and AH-26 sealer were subjected to MTT assay in the form of set and fresh at 1, 24 and 72 h with 1, 10, 100% dilution according to the International Standard ISO:10993-2012. Data were analyzed using the one-way ANOVA. RESULTS: The set ES-A had the least cytotoxicity from the first hour but the cytotoxicity of ES-B and AH-26 extraction decreased over time. In fresh form, except for 100% concentration, ES-A showed the least cytotoxicity compared to the other two sealers. CONCLUSION: All three sealers had high cytotoxicity in 100% concentration but had low cytotoxicity in 10% and 1% concentrations.

Physical Properties and Chemical Characterization of Two Experimental Epoxy Resin Root Canal Sealers.

INTRODUCTION: The aim of this in vitro study was to evaluate the setting time, flow, film thickness, solubility, radiopacity and characterization analysis of three epoxy resin based sealers including two experimental sealers and AH-26. METHODS AND MATERIALS: Five samples of each material were evaluated for setting time, flow, film thickness, solubility and radiopacity according to ISO 6876 Standard. Characterization of sealers was performed under the scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Statistical evaluation was performed using the Kruskal-Wallis test. RESULTS: In this study, AH-26 showed more radiopacity and flow compared to two other experimental sealers (P<0.05). However, both sealers had lower setting time than AH-26 (P<0.05). No statistical differences were found regarding film thickness, solubility and radiopacity (P>0.05). The characterization analysis exhibited relatively similar microstructure of AH-26 sealer to the experimental root canal sealers. CONCLUSION: According to the result of this study, all tested root canal sealers had acceptable properties based on ISO 6876 standard criteria.

Efficacy of Video-Assisted Instruction on Knowledge and Performance of Dental Students in Access Cavity Preparation.

INTRODUCTION: The conventional method of teaching endodontics has some drawbacks. Due to the small size of the oral cavity, students cannot closely observe the clinical procedure. Use of new teaching modalities such as the intraoral camera may obviate this problem. This study assessed the effect of video-assisted clinical instruction in dentistry (VACID) on dental student's knowledge and performance in access cavity preparation during endodontic treatment. METHODS AND MATERIALS: In this interventional study, twenty six undergraduate students were equally divided into two groups and received instructions on access cavity preparation via conventional demonstration (CD) or VACID using intraoral camera plus conventional demonstration. Students' knowledge was assessed before and after the demonstration. The scores obtained by students were compared between the two groups. Data were analyzed using the Mann Whitney U test. RESULTS: No significant difference was found between the two groups in knowledge and performance scores of students about pulp chamber removal, under-extension, over-extension, gouging, perforation or finding the main and extra canals. However, use of intraoral camera significantly reduced the number of student visits to instructors for problem solving (P=0.001). CONCLUSION: VACID is an effective educational method and as efficient as conventional demonstration in endodontics; as a result it can be used in combination with conventional teaching.

The Effect of Smear Layer on Antimicrobial Efficacy of Three Root Canal Irrigants.

INTRODUCTION: One of the main goals of endodontic treatment is to decrease the harboring bacteria within the root canal system and dentinal tubules. This experimental study attempted to investigate the antibacterial efficacy of three root canal irrigants in the presence and absence of smear layer (SL). METHODS AND MATERIALS: A total of 210 sound extracted human single-rooted teeth were prepared. After creating the SL and its removal in half of the samples, they were infected with Candida albicans (C. albicans) and Actinomyces israelii (A. israelii). A total of 180 specimen were used to assess the antimicrobial efficacy of the three irrigants in presence and absence of SL, 24 specimen were placed in the positive and negative controls, 2 samples were utilized for scanning electron microscopy (SEM) analysis and 2 were used for Gram staining. Then, they were exposed to irrigants including 2.61% sodium hypochlorite (NaOCl), 0.2% chlorhexidine gluconate (CHX) and 1% povidone-iodine (PI) for 5, 30 and 60 min. Presence/absence of test microorganisms was determined by incubation of specimens in test tubes containing brain-heart infusion (BHI) broth and then measuring the colony forming units (CFU) on BHI agar. A cumulative logistic model was used to analyze the ordinal response. RESULTS: The 2.61% solution of NaOCl was significantly more effective than 0.2% CHX and the latter was more efficient than 1% PI for decreasing fungal and microbial infection of dentinal tubules in the presence and absence of SL. CONCLUSION: The presence of smear layer decreased the efficacy of antimicrobial irrigants. The minimum time required for elimination of fungal/microbial infection was 30 min.

Effect of Anticipatory Guidance Presentation Methods on the Knowledge and Attitude of Pregnant Women Relative to Maternal, Infant and Toddler's Oral Health Care.

OBJECTIVE: The prenatal period is the best time for health interventions. The aim of this study was to evaluate the effects of different methods of anticipatory guidance presentation on the change of knowledge and attitude of pregnant women regarding oral healthcare in the mother, infant and toddler. MATERIALS AND METHODS: In this quasi-experimental study, 90 pregnant women attended one health center in Zahedan, Iran; they were divided into direct intervention, indirect intervention and control groups. A self-reported questionnaire was completed before intervention. The guidance was presented to the direct intervention group, by PowerPoint and to the indirect group by pamphlet. Immediately after the intervention, the questionnaire was completed by intervention groups and two months later by all participants. Difference in the scores at start and end was calculated. Mann-Whitney, Kruskal-Wallis with Dunn's post hoc and Friedman with K-W post-hoc tests were used for statistical analysis. The data was analyzed using SPPS version 19 software at a significance level of 0.05. RESULTS: The change in scores of knowledge relevant to maternal, infant and toddler's oral health and attitude toward maternal oral healthcare had significant differences in the three studied groups (P>0.05), The changes of scores in the four mentioned variables in the intervention groups were significantly higher than controls. In comparison between the intervention groups, the change in score of knowledge about maternal oral healthcare was significantly higher in the direct intervention group (P=0.023). CONCLUSION: Anticipatory guidance presentation led to change in the score of knowledge about maternal, infant and toddler's oral health and attitude towards maternal oral health in comparison to no presentation. The direct presentation had superiority over indirect in increasing knowledge about maternal oral healthcare.

Application of laser in oral surgery.

In this review collected from the literature on usage of laser in oral minor surgery based on a Medline search in the time period between the years: 2008 and 2013, the most current evidence on laser-assisted oral minor surgery is going to be surveyed.