Evaluation of Clinical Periodontal Indices and Serum Interleukin-27 by One-stage Full-mouth Disinfection and Quadrant Scaling and Root Planing in Periodontitis.

INTRODUCTION: One-stage oral disinfection technique has been developed to prevent cross-contamination between the treated and untreated areas between treatment sessions. Considering the role of inflammatory mediators in periodontitis, this study has been designed to compare the effects of one-stage oral disinfection with quadrant scaling and root planing (Q-SRP) on serum interleukin-27 (IL-27) levels in patients with moderate-to-advanced periodontitis. MATERIALS AND METHODS: In this study, two groups were considered. One group was treated with one-stage full-mouth oral disinfection (FMD), while the other group was treated with Q-SRP. In each group, 20 patients with chronic periodontitis were randomly selected based on the inclusion criteria. To evaluate the periodontal status, the clinical parameters of bleeding on probing (BOP), clinical attachment level (CAL), and probing depth (PD) were measured before treatment as well as at 2- and 4-month intervals after treatment. At the same intervals, the immunological index of the study (serum IL-27) was measured by special laboratory kits. The data were analyzed using the Statistical Package for the Social Sciences, version 16 (SPSS 16) software. In this study, p-value < 0.05 was considered statistically significant. RESULTS: The results of this study indicate that there has been an elevation in the mean of serum IL-27 after treatment in both treatment groups. There is no significant difference between the levels of IL-27 in the FMD group during the study period (p = 0.20). All periodontal indices (BOP, CAL, and PD) show clinical improvement in each group (p < 0.001). However, no significant difference was observed in the improvement of periodontal indices of CAL and PD (p < 0.05). CONCLUSION: According to the findings of this study, it can be said that both FMD and Q-SRP improve the periodontal indices and increase the serum level of the inflammatory mediator IL-27 in patients with periodontitis. CLINICAL SIGNIFICANCE: Considering the benefits of the FMD method, such as patient and dentist comfort, systemic effects, and its cost-effectiveness, use of this method is suggested in patients suffering from periodontitis.

Comparison of Setting Time of White Mineral Trioxide Aggregate with and without Disodium Hydrogen Phosphate at Different Liquid-to-powder Ratios.

AIM: The present study was conducted with the objective of evaluating the effect of different liquid-to-powder ratios on setting time of white mineral trioxide aggregate (WMTA) and the effect of adding disodium hydrogen phosphate (Na2HPO4) to white MTA (NAMTA). MATERIALS AND METHODS: Sixty samples were prepared in plastic annular molds with a diameter of 10 mm and a height of 2 mm in order to record setting time where white MTA was placed in 30 samples and 2.5 wt% mixture of Na2HPO4 with white MTA was placed in other 30 samples. Setting times in different ratios of liquid to powder (50, 60, and 70%) and at different times including 5, 10, 15, 20, 25, 30, 40, and 50 minutes as well as 1, 1.5, 2.5, 3, 3.5, and 4 hours were measured with Vicat. Statistical Package for the Social Sciences version 16 software was used to examine the differences between groups. The values of p < 0.05 were considered to be statistically significant in this study. RESULTS: The average setting time of samples in two WMTA and NAMTA was 182.17 ± 57.86 and 67.00 ± 14.42 respectively, and this difference was statistically significant (p < 0.001). Also, the average setting time of samples in ratio groups of 50, 60, and 70% were 146.00 ± 75.90, 85.00 ± 31.71, and 142.5 ± 64.47 respectively, and results showed that there was no significant difference between groups. CONCLUSION: Adding 2.5 wt% of Na2HPO4 mixture to white MTA reduces the setting time, which is lower than the WMTA in 50, 60, and 70% liquid-to-powder ratios. CLINICAL SIGNIFICANCE: According to the findings of this study, it can be seen that adding Na2HPO4 to white MTA is a good way to reduce setting timing in clinical dentistry, especially in one-visit treatments.

Evaluation of the Antifungal Effect of Chicory Extracts on Candida Glabrata and Candida Krusei in a Laboratory Environment.

AIM: This research has evaluated the extract's antifungal effects on Candida glabrata and Candida krusei in a laboratory environment. MATERIALS AND METHODS: In this research, to evaluate the antifungal effect and the minimal inhibitory concentration (MIC) determination of chicory extract, the Clinical and Laboratory Standards Institute (CLSI) was used. Candida glabrata and C. krusei funguses were procured from the Tehran Pasteur Institute; they were grown in the relative growing environment according to the required conditions. Also for further assurance about the macrodilution method reality, the agar well diffusion method was used. Finally, the obtained results were analyzed using the Statistical Package for the Social Sciences version 16 software. RESULTS: The MIC for the chicory extract was 50 µg/mL for C. krusei and 100 µg/mL for C. glabrata. On the contrary, in the evaluation of different concentrations of the chicory extract by the agar well diffusion method, C. krusei's lack of growth in similar concentrations was greater than that of C. glabrata. As a result, the findings related to both the methods of agar well diffusion and MIC prevention concentration maximization proved that C. krusei sensitivity to the chicory extract is more compared with the sensitivity of C. glabrata. CONCLUSION: Chicory extract has the benefits of low price, accessibility, and proper taste as compared with nystatin. It also has fewer side effects, and after a clinical test, it could be considered a proper candidate as an antifungal drug against infections caused by C. krusei and C. glabrata. CLINICAL SIGNIFICANCE: The results obtained from this research have shown that chicory extract has antifungal features and is the best choice as an antifungal drug because of its low price, accessibility, and proper taste as compared with nystatin.

Prevalence of Dental Malocclusions in Patients admitted to the Department of Orthodontics, School of Dentistry, Tabriz, in 2016.

AIM: This study is aimed at investigating the prevalence of disorders among patients referred to Tabriz Dental School in 2016. MATERIALS AND METHODS: This research was conducted in a cross-section method and taken from all patients admitted during this period. Classification of dental occlusion in patients was based on Angle's definition, skeletal classification was based on Steiner's analysis, and overjet and overbite values and other patient-related information were imported from the records in the extractive sector and in specific forms. After reviewing the data, the forms of individual patients were inputted into the computer and analyzed. RESULTS: In terms of dental condition, the prevalence of malocclusion CL.I, malocclusion CL.II, and malocclusion CL.III was respectively, 50, 36.8, and 13.2%. In terms of overjet condition, 13.9% of patients had normal overjet, 67.1% had increased overjet, 8.9% had reduced overjet, and 10.1% had reversed overjet. In terms of overbite, 17.7% of patients had normal overbite, 53.2% had increased overbite, 8.9% had decreased overbite, 15.2% had open bite, and 5.1% had deep bite. Skeletally, 24.1% of patients had skeletal abnormalities CL.I, 62% had skeletal deformities CL.II, and 13.9% had skeletal CL.III. CONCLUSION: The most common dental malocclusion among patients was related to CL.I and the most common skeletal malocclusion was related to CL.II, and malocclusions of CL.III had the least prevalence both dentally and skeletally. There was no significant relationship between dental and skeletal malocclusions and also between different malocclusions and gender. CLINICAL SIGNIFICANCE: Knowledge of the prevalence of different types of dental and jaw anomalies is considered as the first step in the evaluation and treatment of these disorders. It is worth mentioning that the results of the study can be used in treatment planning required in the province and even in the country.

Comparison of Proinflammatory Cytokine Levels in Gingival Crevicular Fluid around Dental Implants with Ceramic and Titanium Abutments.

BACKGROUND: Considering the high success rate of osseoin-tegration, there is ever-increasing use of dental implants. The mechanisms and biologic response of peri-implant tissues are different depending on the biocompatibility of the implant material. The aim of this study was to compare the proinflammatory cytokine levels in the gingival crevicular fluid (GCF) around dental implants with ceramic and titanium abutments. MATERIALS AND METHODS: All the patients with dental implants referring to two private offices of two prosthodontists from June to August 2016 were examined in relation to implant health, and eligible subjects, based on inclusion criteria, were included in this study with a slit-mouth design. In this context, on one side titanium implants and, on the other side, ceramic implants were used. Samples were collected from the peri-implant sulcus in each patient and sent to the immunology laboratory for determination of interleukin (IL)-6 and IL-1ß proinflammatory cytokine levels using an enzyme-linked immunosorbent assay kit. Data were analyzed with Statistical Package for the Social Sciences version 16. Statistical significance was set at p < 0.05. RESULTS: The results showed lower levels of IL-1ß and IL-6 in the GCF around ceramic abutments compared with titanium implants. In addition, statistical comparison between IL-6 and IL-1ß levels showed higher levels of IL-6 around titanium and ceramic abutments compared with IL-1ß levels. CONCLUSION: Based on the results of this study, the human body immune response to ceramic abutments is much better than that to titanium implants. CLINICAL SIGNIFICANCE: Considering that proinflammatory cytokine levels in GCF around ceramic abutments are lower than titanium ones, ceramic abutments are preferred for clinical usage.

Comparison between the Radiographic and Clinical Rates of Success for TheraCal and MTA in Primary Tooth Pulpotomy within a 12-Month Follow-Up: A Split-Mouth Clinical Trial.

Background: The present study was conducted for contrasting the efficacy of TheraCal and MTA for primary molar pulpotomy. Methods: During the current split-mouth randomized clinical trial, 90 bilateral primary molars from 45 healthy 5- to 8-year-old children were pulpotomized using TheraCal in one bilateral tooth and MTA in the other, randomly. Glass ionomer (GI) was used to cover these materials. Then, the treated teeth were restored with stainless steel crowns (SSC) and followed up clinically and radiographically at months 6 and 12 after treatment for any pulpotomy failure indications. Finally, data were analyzed by chi-square test considering p value < 0.05 as statistically significant. Results: Among 82 teeth available at the final follow-up session, the total success rates were 98.1% and 99.3% for TheraCal and MTA, respectively, showing no significant difference between the two groups (p > 0.05). Conclusion: TheraCal can be used as an alternative material for pulpotomy of primary teeth instead of MTA.

Does Bleaching Affect the Microleakage of Class II Restoration with Bulk-Fill Composite?

INTRODUCTION: The use of technology in bulk-fill composites (BCs) has reduced the stresses caused by polymerization shrinkage, debonding, microleakage, or posttreatment sensitivity in them. This study was conducted to determine whether bleaching affects the microleakage of class II restoration with bulk-fill material. MATERIALS AND METHODS: This laboratory study was performed on 40 normal human premolars in 4 groups (n = 20). Class II cavities were prepared in mesial and distal surfaces of the teeth with dimensions of 2 × 2 × 4 mm. Then, based on the bleaching process by 20% carbamide peroxide gel and using two types of composites, the restored cavities were randomly divided into 4 groups: (1) CC without bleaching (CC group), (2) BC without bleaching (BC group), (3) CC with bleaching (CCB group), and (4) BC with bleaching (BCB group). Then, the samples were thermocycled for 1000 cycles at a temperature range of 5-55°C, and they were immersed in 0.6% alkaline fuchsine in order to penetrate into the pigment for 24 h. After cutting, the samples were placed under a stereomicroscope (40%) to determine microleakage. The data were analyzed using one-way analysis of variance (ANOVA), and a p value <0.05 was considered as statistically significant. RESULTS: Microleakage was determined in the CC group (0.97 ± 0.42), BC group (1.08 ± 0.54), CCB group (1.19 ± 0.37), and BCB group (0.30 ± 0.47). There were also no significant differences in the mean microleakage between the groups. No cases with zero microleakage (no microleakage) and grade 3 of microleakage (pigment penetration into the axial wall) were observed in the samples. Also, a two-by-two comparison of significant differences between CC and BC groups (p=0.89), CC and CCB groups (p=0.45), CC and BCB groups (p=0.11), BC and CCB groups (p=0.87), BC and BCB groups (p=0.41), and CCB and BCB groups (p=0.86) showed that the difference was not statistically significant. CONCLUSION: Results showed no difference between microleakage of BC and CC with and without bleaching, and bleaching had the same effect on microleakage of these two types of composites.

Comparison of the accuracy of fixture-level implant impressions using two different materials for splinting.

Background. Various materials are used for splinting impression copings, the most common of which are auto-polymerizing resins. In this study, a new light-curing pattern resin (Jig-Gel) was investigated and compared with auto-polymerizing resins using two different splinting methods. Methods. After taking impressions with two different materials, a digital caliper with an accuracy of 0.01 mm was used for splinting and measuring the distances between the external parts of the analogs inside the plaster cast. The accuracy was also compared in five groups as follows; group 1: splinting of impression copings by auto-polymerizing acrylic resin, group 2: cutting the splinting of impres-sion copings with self-polymerizing acrylic resin, group 3: splinting of impression copings with a light-cured resin pattern (Jig-Gel), group 4: splinting of impression copings cut by a light-cured resin pattern, and group 5: impression with no splint. All statistical analyses were performed with SPSS 17. Statistical significance was set at P<0.05. Results. The highest impression accuracy was obtained in the group without cutting the splint of the impression copings using auto-polymerizing acrylic resin. Compared with the impression methods, impression making of non-splint samples in an impression coping was the least accurate, and the results for the two used methods were similar. Conclusion. The results of this study showed that the combination of the impression coping method and auto-polymerizing acrylic resin had the highest accuracy.

Factors Affecting the Duration of Fixed Orthodontic Treatment in Patients Treated in a University Department between 2016 and 2020.

Objective:The aim of this study was to assess the effect of possible influential factors on duration of fixed orthodontic treatment. Methods:This cross-sectional retrospective study included 505 female and 183 male orthodontic patients (a total of 688 persons) referring to a university department of orthodontics during 2016-2020. The study population included only those who had undergone fixed orthodontic treatment of both maxillary and mandibular arches. Information including age, gender, total treatment duration, number of missed treatment sessions, incidences of bracket debonding, and type of treatment plan were collected from patient records. Data were analyzed using SPSS software version 21 at 0.05 significance level. Results:The mean duration of orthodontic treatment was significantly longer in men than women (19.09±5.6 versus 18.22±4.56 months, respectively; P=0.040). The treatment duration was also longer in patients with a treatment plan including teeth extraction compared to non-extraction treatment plans (19.85±4.30 versus 17.56±5.02 months, respectively; P<0.001). Duration of treatment in patients with more than one missed treatment appointment was significantly longer than those who had . one missed session (P<0.001). Duration of treatment in patients with bracket debonding was significantly longer (P=0.030). Also, the duration of treatment had a significant correlation with the frequency of both missed sessions (r=0.365, P<0.001) and bracket debonding (r=0.098, P=0.01). Conclusion:Based on the results of the present study, missed sessions, treatment plan, and bracket debonding have the greatest effect on the duration of fixed orthodontic treatment.

Dental Radiographic/Digital Radiography Technology along with Biological Agents in Human Identification.

The heavy casualties associated with mass disasters necessitate substantial resources to be managed. The unexpectedly violent nature of such occurrences usually remains a problematic amount of victims that urgently require to be identified by a reliable and economical method. Conventional identification methods are inefficient in many cases such as plane crashes and fire accidents that have damaged the macrobiometric features such as fingerprints or faces. An appropriate recognition method for such cases should use features more resistant to destruction. Forensic dentistry provides the most appropriate available method for the successful identification of victims using careful techniques and precise data interpretation. Since bones and teeth are the most persistent parts of the demolished bodies in sudden mass disasters, scanning and radiographs are unrepeatable parts of forensic dentistry. Forensic dentistry as a scientific method of human remain identification has been considerably referred to be efficient in disasters. Forensic dentistry can be used for either "sex and age estimation," "Medical biotechnology techniques," or "identification with dental records," etc. The present review is aimed at discussing the development and implementation of forensic dentistry methods for human identification. For this object, the literature from the last decade has been searched for the innovations in forensic dentistry for human identification based on the PubMed database.

Synthetic materials in craniofacial regenerative medicine: A comprehensive overview.

The state-of-the-art approach to regenerating different tissues and organs is tissue engineering which includes the three parts of stem cells (SCs), scaffolds, and growth factors. Cellular behaviors such as propagation, differentiation, and assembling the extracellular matrix (ECM) are influenced by the cell's microenvironment. Imitating the cell's natural environment, such as scaffolds, is vital to create appropriate tissue. Craniofacial tissue engineering refers to regenerating tissues found in the brain and the face parts such as bone, muscle, and artery. More biocompatible and biodegradable scaffolds are more commensurate with tissue remodeling and more appropriate for cell culture, signaling, and adhesion. Synthetic materials play significant roles and have become more prevalent in medical applications. They have also been used in different forms for producing a microenvironment as ECM for cells. Synthetic scaffolds may be comprised of polymers, bioceramics, or hybrids of natural/synthetic materials. Synthetic scaffolds have produced ECM-like materials that can properly mimic and regulate the tissue microenvironment's physical, mechanical, chemical, and biological properties, manage adherence of biomolecules and adjust the material's degradability. The present review article is focused on synthetic materials used in craniofacial tissue engineering in recent decades.

The Potential Application of Green-Synthesized Metal Nanoparticles in Dentistry: A Comprehensive Review.

Orodental problems have long been managed using herbal medicine. The development of nanoparticle formulations with herbal medicine has now become a breakthrough in dentistry because the synthesis of biogenic metal nanoparticles (MNPs) using plant extracts can address the drawbacks of herbal treatments. Green production of MNPs such as Ag, Au, and Fe nanoparticles enhanced by plant extracts has been proven to be beneficial in managing numerous orodental disorders, even outperforming traditional materials. Nanostructures are utilized in dental advances and diagnostics. Oral disease prevention medicines, prostheses, and tooth implantation all employ nanoparticles. Nanomaterials can also deliver oral fluid or pharmaceuticals, treating oral cancers and providing a high level of oral healthcare. These are also found in toothpaste, mouthwash, and other dental care products. However, there is a lack of understanding about the safety of nanomaterials, necessitating additional study. Many problems, including medication resistance, might be addressed using nanoparticles produced by green synthesis. This study reviews the green synthesis of MNPs applied in dentistry in recent studies (2010-2021).

Comparing the Dimensional Accuracy of Casts Obtained from Two Types of Silicone Impression Materials in Different Impression Techniques and Frequent Times of Cast Preparation.

INTRODUCTION: The dimensional accuracy of casts is essential in the quality of fixed prosthesis treatment, whereby the impression method is a very crucial factor affecting it. The aim of this in vitro study is to compare the dimensional accuracy of casts resulting from two types of silicone impression materials in different impression techniques and frequent times of cast preparation. MATERIALS AND METHODS: A metal model was made from two prepared abutments, and 10 casts were prepared from each material technique (n = 40). The impressions were made by condensation and addition silicone (one-stage and two-stage impressions). The casts were made from same impressions 1 h, 24 h, and 14 days. The diameter, height, and the distance between two dies were recorded. Data were analyzed by repeated measure ANOVA (P value <0.05). RESULTS: The dimensional accuracy of all four materials techniques of impression (diameter, height, and the distance between dies) was the same in different times of impression. Dimensional accuracy of the die diameter and distance between dies in one-stage (Speedex) condensation silicon and one-stage (Panasil) addition silicone did not differ significantly, and their one-stage method developed more accurate casts compared to the two-stage method of the same impression material. The height of the casts prepared from the one-stage method through Speedex and Panasil did not differ significantly from the two-stage method of the same impression material. CONCLUSION: One-stage condensation silicone and one-stage addition silicone material techniques offered the maximum dimensional accuracy in the obtained casts. The time of impression did not have any significant effect in the accuracy of any of the four impression material techniques.

Ability of Calcium Silicate and Epoxy Resin-based Sealers to Fill the Artificial Lateral Canals in the Presence or Absence of Smear Layer.

Background:The lateral canals are pathways for bacteria and their products to pass between the root canal and the periradicular tissue. Objectives: The present study aims to compare the filling ability of the lateral canals with three calcium silicate based sealers, including MTA Fillapex, Endoseal MTA and Sure-Seal Root, and AH26 epoxy resin sealer in the presence and absence of the smear layer. Materials and methods:Six lateral canals were prepared using an engine reamer in 80 single-rooted human teeth. The root canals were cleaned, then the teeth were randomly divided into two groups. In group A, the smearlayer was removed using 17% EDTA and 5.25% NaOCl, and in group B, the canals were irrigated with normal saline. Groups A and B were divided into four subgroups each, according to the sealer used: A1, B1 (MTA Fillapex sealer), A2, B2 (Endoseal MTA sealer), A3, B3 (Sure-Seal Root sealer), and A4, B4 (AH26 sealer). Obturation of canals was conducted by the warm vertical technique and then teeth were incubated for 72 hours. Teeth were made clear and the filling of lateral canals were evaluated under stereomicroscope. Results:In group A, the highest lateral canals filling rate was in subgroup A2 and the lowest in subgroup A1, and the difference was statistically significant. However, in both groups, the highest lateral canals filling rate was in subgroups B2 and B3 and the lowest in subgroup B1. However, the difference was not statistically significant. In addition, no significant difference was observed in the lateral canals filling rate considering their position in the root. Conclusion:Providing the removal of the smear layer, calcium silicate-based sealers, Endoseal MTA and Sure-Seal Root had a higher ability to fill the lateral canals than AH26 and MTA fillapex sealers.

A Novel Developed Bioactive Composite Resin Containing Silver/Zinc Oxide (Ag/ZnO) Nanoparticles as an Antimicrobial Material against Streptococcus mutans, Lactobacillus, and Candida albicans.

AIM: The objectives of this study were to develop a new bioactive composite resin containing silver/zinc oxide (Ag/ZnO) nanoparticles and investigate the effects on mechanical, cytotoxic, biocompatibility, and antimicrobial properties. MATERIALS AND METHODS: Disc-shaped specimens were prepared from composite with and without nanoparticles in separate culture media containing Streptococcus mutans, Lactobacillus, and Candida albicans. Bracket bonding evaluation was performed on composite without nanoparticles (O), composite containing ZnO (Z) nanoparticles, composite containing ZnO nanoparticles and silver ions (A&Z), and composite containing Ag/ZnO nanoparticles (AZ) synthesized using optical precipitation. RESULTS: Composite resin with nanoparticles (AZ, A&Z, and Z) showed significant antimicrobial properties (P < 0.05). The mean shear bond strength of A&Z composite resin (13.61 ± 0.73 MPa) was significantly less than that of conventional composite resin (19.03 ± 4.12 MPa) (P < 0.05). In addition, the mean shear bond strength of AZ composite resin (20.49 ± 1.03 MPa) was significantly higher than that of Z (16.35 ± 1.03 MPa) and A&Z composite resins. CONCLUSIONS: Incorporation of ZnO nanoparticles and their compounds into orthodontic composite resins induced antibacterial properties against oral pathogens, and of all these nanoparticles, the AZ group exhibited the best antimicrobial activity and highest shear bond strength.

Effect of Light Emitting Diode Photobiomodulation on the Stability of Dental Implants in Bone Grafted Cases: a Split-Mouth Randomized Clinical Trial.

Introduction: The high success rate of implants has made implant-based prostheses attractive to edentulous patients. Osseointegration lasts 4-6 months, increasing to 6-8 months in cases requiring bone grafts and guided bone regeneration. Many efforts have been made to accelerate osseointegration, including low level laser (LLL) and light emitting diode (LED) photobiomodulation. Material and methods:Twelve patients underwent bimaxillary immediate implant surgery with particulate bone grafts between the socket wall and the implant, and the transmucosal abutment was attached on implants at the same time. The intervention side was exposed to LED radiation for 20 minutes a day one day preoperatively and 10 consecutive sessions, starting from the day of surgery. A trained operator measured and recorded the implant stability quotient (ISQ) value on both sides immediately after surgery as well as one month and three months postoperatively. Results: The ISQ value was 37.54 on the non-irradiated side immediately after surgery; it decreased to 35.09 one month postoperatively and increased to 46.45 at three months after the operation. The ISQ value was 36.73 on the irradiated side immediately after surgery and it increased to 47.36 and 71.18 at one month and three months postoperatively, respectively. There were significant differences between the ISQ values on the irradiated side at all the three time intervals, but also a significant difference on the non-irradiated side, except for two other two time intervals of immediately and one month after surgery. Although there was no significant difference between the two sides in terms of the ISQ value immediately after surgery, the ISQ value was significantly higher on the irradiated versus non-irradiated side at one month and three months postoperatively. Conclusion:Low level laser radiation resulted in a favorable increase in the ISQ value in three months. Light emitting diode has lso led to a clinically significant increase in the ISQ value after three months because implants with ISQ values >54 could be loaded.

The Effect of Mechanical and Chemical Surface Preparation Methods on the Bond Strength in Repairing the Surface of Metal-Ceramic Crowns with Composite Resin: a Systematic Review and Meta-Analysis.

The aim of this study was to find the most effective surface preparation methods to enhance the bond strength between the composite resin and surface remaining from ceramic fracture. In this systematic review and meta-analysis, 39 studies were examined. The information related to the studies was extracted and categorized based on the type of the substrate material and applying or not applying thermal cycles (p<0.05). In the meta-analysis of substrate metal-ceramic samples without aging, application of air abrasion resulted in a significant increase of the bond strength to composite resin when using chemical compounds of the group without the mentioned functional monomers. Application of mechanical and chemical surface preparation methods can result in enhanced bond strength of the composite to the substrate material, which depends on the type of substrate material.

Comparison of marginal adaptation of Class II cavities restored with bulk-fill and conventional composite resins using different universal bonding agent application strategies.

BACKGROUND: This in vitro study was conducted to compare the effect of universal bonding application strategy (i.e., self-etch and etch-and-rinse) on marginal adaptation of bulk-fill and conventional composite resins in Class II restorations. MATERIALS AND METHODS: In this in vitro study sixty sound premolars extracted for orthodontic reasons were selected. The samples were allocated to four groups based on the universal bonding application strategy (self-etch and etch and rinse) and type of composite (bulk-fill and conventional). In each group, boxes were prepared with a depth of 4 mm on the mesial surfaces. Finally, the marginal adaptation of the samples was evaluated under a stereomicroscope. Two-way ANOVA was used to compare the marginal adaptation data in the study. Statistical significance was set at P < 0.05. RESULTS: Considering the type of universal bonding application strategy, there was a statistically significant difference in marginal adaptation. Etch-and-rinse strategy showed better marginal adaptation compared to self-etch strategy (P < 0.001). However, there was no statistically significant difference in marginal adaptation between the two composite resins (P = 0.829). Furthermore, the interaction between the two factors (type of universal bonding application strategy and type of composite resin) was not statistically significant (P = 0.629). CONCLUSION: Etch-and-rinse bonding application strategy in both the bulk-fill and conventional composite resins exhibited better marginal adaptation compared to self-etch bonding application strategy. However, the difference of marginal adaptation between the two types of composite resins (bulk and conventional) was not significant.

Ergonomic Evaluation of Senior Undergraduate Students and Effect of Instruction Regarding Ergonomic Principles on It.

Background and objective: Musculoskeletal disorders in dentists due to abnormal postures may result in economic and health problems. To prevent these problems, the working posture of dental students should be assessed and corrected in dental procedures. This study was undertaken to assess the effect of instruction regarding ergonomic principles on them by using the Rapid Entire Body Assessment (REBA) method. Material and methods: The posture of 117 students was assessed by REBA before and after of the "Ergonomic principles in dentistry" course. The sample size was selected based on previous studies on this issue. REBA scores were assessed by SPSS software using Friedman-test. Results: The statistical analysis of data gathered from this study showed that the ergonomic structure had a significant effect only in the group of right-handed females (P=0.046). In other groups, no significant change was observed (P>0.05). There was no significant change before and after instruction in REBA classifications (negligible, low risk, medium risk, high risk, very high risk) (P>0.05). There was no relation between the types of positions and REBA score (P>0.05). Conclusion: Ergonomic instruction can significantly decrease musculoskeletal disorders in female dentists who use their right-hand to work. In the other groups, however, the absolute amount of danger became better, but this change was not statistically significant.

Comparison of Effects Exerted by 4% Articaine Buccal Infiltration and 2% Lidocaine Inferior Alveolar Nerve Block on Pain Perception and Behavioral Feedback of Children during Pulp Treatment of Mandibular Second Primary Molars.

Background: One of the most impressive factors discouraging many people from seeking dental treatment is the fear of experiencing pain during dental procedures. Thus, the use of an effective method for pain control is vital in this regard. Articaine, which has an additional ester and thiophene groups that increase its biosolubility and permeability compared to older anesthetic agents, can be more effective on inducing anesthesia during dental treatment. Given the inconsistent currently available information on this concept, the present study was designed to compare the efficacy of articaine with that of lidocaine on pain control during pulp treatment of deciduous molar. Methods and materials: In this cross-sectional study, 38 patients who needed pulpotomy in both mandibular second molar of primary teeth were randomly divided into two groups, using the Randlist software. In the first meeting, infiltration with articaine 4% (epinephrine 1/100 000) was performed for all patients in group 1 on the left side of the mandible. At the next appointment, inferior alveolar nerve block was done with lidocaine 2% on the right side of the mandible (epinephrine 1/80 000). Notably, for all patients in the second group, the first injection was performed on the right second primary molar with articaine 4% (epinephrine 1/100 000), and inferior alveolar nerve block was also done with lidocaine 2% on the left side of the mandible (epinephrine 1/80 000). Results:Of the 38 patients included in the current study, 10 (26.3%) subjects in the lidocaine group and nine (23.6%) in the articaine group complained of pain during their dental treatment procedures, but this difference was not statistically significant. Conclusion: According to the findings of this study, buccal infiltration of 4% articaine had a comparable anesthetic outcome to that of 2% lidocaine for inferior alveolar nerve block in pulp treatment of the second primary mandibular molars.