Assessment of Apical Pressures in Single and Joining Canals - An Ex Vivo Study Based on Computational Fluid Dynamic Analysis.

OBJECTIVE: Computational fluid dynamic analysis (CFD) is claimed to be a reliable tool for analysing the fluid flow and the generated apical pressures in the simulated root canal. The current study aimed to analyse the apical pressures in extracted teeth with single and joining canals. METHODS: Forty-six freshly extracted teeth were collected for the present study. The power was set at 95%, with an effect size of 0.55 (1-ß=95%, α=0.05). Once the root canal anatomy was confirmed with cone-beam computed tomography (CBCT), they were divided into two groups: group I: mandibular second premolars with Vertucci type-I (n=23), and group II: maxillary second premolars with Vertucci type-II (n=23). The instrumentation of the specimens was carried out to a 0.04-taper using rotary instruments. A post-instrumentation CBCT was obtained, and computer-aided design models were obtained. The CFD simulations were then con- ducted with simulated 30-gauge side vented needles at 25, 50, and 75% short of the working length (WL). RESULTS: Group I recorded significantly (p<0.05) higher apical pressures at needle positions 25% short of the WL. However, no significant differences were elicited in the groups at other needle positions. CONCLUSION: Single canal specimens recorded higher apical pressures at needle positions 25% short of the WL. However, no differences were elicited between single and joining canals at higher needle positions.

Comparative Evaluation of the Anesthetic Efficacy of Needle-Free Anesthesia and Conventional Anesthesia in Patients With Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial.

Introduction Pain is the primary reason for which most of the patients seek endodontic treatment. Local anesthesia is considered to be the most important step in the procedure to reduce the pain. However, the majority of the patients do not cooperate due to the fear of syringe anesthesia. The aim of this clinical trial was to compare the anesthetic efficacy of needle-free anesthesia and conventional anesthesia in patients with symptomatic irreversible pulpitis undergoing root canal therapy. Materials and methods A total of 54 patients were enrolled in the study, and the treatment was administered by a single operator. The initial assessment of vitality included cold testing, heat testing, and electric pulp testing. Preoperative pain was assessed using the Visual Analog Scale (VAS) before the administration of anesthesia. Local anesthesia was administered according to the group assigned: Group 1 (conventional anesthesia) and Group 2 (needle-free anesthesia). The pain was assessed during the administration of anesthesia. Following the administration of anesthesia, the vitality of the tooth was evaluated using cold testing, heat testing, and electric pulp testing. Subsequently, the tooth was isolated with a rubber dam, and the access cavity was prepared. The pain was assessed during access cavity preparation and during the first file insertion. Working length was determined using an apex locator (Root ZX Mini, J Morita, Saitama, Japan) and was confirmed using intraoral periapical radiographs. Later on, further treatment was carried out. Results A total of 54 participants were included in this clinical trial. There was no significant difference in mean age distribution between the two groups (p=0.852). Considering the frequency distribution of gender, there was no significant difference; however, Group 1 had more female participants (59.3%) compared to Group 2 (33.3%). There was a significant reduction in the mean pain score in Group 2 compared to Group 1 during the delivery of anesthetic agents (p=0.000). Conclusion Needle-free anesthesia proves to be equally effective as the conventional syringe system in patients experiencing symptomatic irreversible pulpitis undergoing root canal treatment. However, it is noteworthy that patients exhibited greater comfort levels with needle-free anesthesia systems specifically during the administration of the anesthetic solution.

Assessment of Anatomical Dentin Thickness in Mandibular First Molar: An In Vivo Cone-Beam Computed Tomographic Study.

Aim: To determine the minimum dentin thickness in the mesial and distal walls of the mesiobuccal (MB) and mesiolingual (ML) canals of the mandibular first molars using cone-beam computed tomography (CBCT). Materials and Methods: CBCT examinations of 624 mandibular first molars from an Indian subpopulation were analyzed. The mesial and distal minimum dentin thickness was evaluated in 1 mm intervals apical to the furcation area. Independent t-test was used to analyze the data (α = 0.05). Using Cohen's kappa coefficient, the interexaminer and intraexaminer reliability was evaluated. Results: The mesial dentin thickness was significantly higher than the distal dentin thickness for MB and ML canals (P=0.01). The average dentin thickness in the distal and mesial plane of the MB canal was 1.15 ± 0.15 mm and 1.52 ± 0.19 mm at the 1 mm level and 0.83 ± 0.13 and 1.08 ± 0.18 at the 5 mm level, respectively. For the ML canal, the average dentin thickness in the distal plane and the mesial plane was 1.24 ± 0.18 mm and 1.44 ± 0.21 at the 1 mm level and 0.91 ± 0.16 and 1.01 ± 0.17 at the 5 mm level, respectively. Statistical analysis between the MB and ML canals showed significant differences in the dentin thickness at 4 and 5 mm levels in both the distal and the mesial planes (P=0.01). In more than 85% of the cases, the minimum dentin thickness was seen at the 5 mm level in both the distal and mesial planes in MB and ML canals. Conclusion: The distal planes of the mesiolingual and mesiobuccal canals were thinner in most cases, making the distal surface more prone to iatrogenic perforations. Considerably, at 4 and 5 mm from the furcation, the distal wall was significantly thinner than the mesial walls. Understanding the anatomy of the danger zone in the mesial roots of the mandibular first molars may serve to minimize the risk of endodontic mishaps such as strip perforations.

Antimicrobial Efficacy of a Novel Automated Irrigation Device As Compared to Conventional Needle Irrigation Against Enterococcus faecalis: An In Vitro Study.

Aim The present study aims to compare the antibacterial efficacy of a novel automated endodontic irrigation device with that of a manual irrigation technique. Materials and methods The present study considered 45 extracted single-rooted teeth. After sectioning the teeth, the specimens were inoculated with Enterococcus faecalis (E. faecalis) bacteria for three weeks. Instrumentation was done using ProTaper Gold rotary files to size 50 and 5% taper. Based on the irrigation protocol, the experimental samples were divided into Group I: control (normal saline irrigation) (n = 15); Group II: conventional needle irrigation (n = 15); and Group III: automated irrigation (n = 15). The irrigation in Group III was done using the automated irrigation device. After the experimental irrigation, the pre-weighted dentinal shaving was collected in Eppendorf tubes, diluted 10 times, and incubated in the Petri dish with tryptone soy agar (TSA) for 48 hours. Finally, the colony-forming unit (CFU) counts were assessed. IBM SPSS Statistics for Windows version 23.0 (Armonk, NY, USA, IBM Corp.) was used for data analysis. Intergroup comparisons were made using the non-parametric Kruskal-Wallis test. Results The mean CFU count (CFU/ml) for the groups was: Group 1 (normal saline irrigation): 3.67x101; Group 2 (manual irrigation): 2.69× 101; Group 3 (automated irrigation): 1.57× 101. A statistically significant reduction in E. faecalis CFU count was seen among the groups assessed (p<0.01). The automated irrigation group exhibited the most substantial reduction in E. faecalis CFU count. Group 2 showed a significant difference compared to Group 1 (p<0.05). Conclusions The novel automated endodontic irrigation device was superior to manual irrigation in reducing E. faecalis CFU counts. This indicates that the automated irrigation device has the potential to enhance bacterial elimination efficacy during endodontic treatment.

Endodontic retreatment efficacy with and without solvents: A systematic review.

Introduction: This systematic review investigates the crucial need for solvent use in root canal retreatment, as it effectively removes filling materials, reduces apical debris extrusion, and alleviates postoperative pain, ultimately enhancing treatment success. The review aims to assess the success rates, compare outcomes, explore benefits and drawbacks, and identify subgroups where solvent use may be more effective during root canal retreatment. Materials and Methods: The search was performed in PubMed Central, Scopus, Cochrane, LILAC, ScienceDirect, Google Search, Web of Science, and manually using the search items alone and in combination by means of PUBMED search builder. The studies were assessed for eligibility according to the eligibility criteria by two independent reviewers. Groups containing solvent with nonsolvent groups and randomized control trials were included and in vitro studies, retrospective studies, and animal studies were excluded from the study. Quality assessment was performed using the risk of bias (RoB) 2.0 tool. Results: Out of the 596 articles obtained, 14 were shortlisted for full-text reading and finally two articles were included in the study. The studies were assessed for quality, and data were extracted in a tabulated form. Overall RoB is low, but due to the lack of homogeneity, meta-analysis could not be conducted. Conclusion: The use of solvent does not cause any significant difference in the postoperative pain levels or analgesic intake for retrieval of gutta-percha in cases of root canal retreatment. Due to the limited number of studies available and the lack of clinician-related outcomes such as time taken to retrieve the gutta-percha, these results should be taken into consideration with caution.

Comparative Analysis of the Surface Roughness of Class V Composite Restorations Using a Conventional Polishing System and Pre-contoured Cervical Matrices: An In Vitro Study.

BACKGROUND: Rough surfaces of restorations have an impact on the accumulation of plaque, unaesthetic contour, and marginal adaptation, thereby affecting their functional, aesthetic, and clinical performance and the long-term stability of the restoration. Several polishing systems are currently in use for composite restorations, but information on their impact on surface roughness is limited. The present study aimed to determine the surface roughness of class V composite restorations polished using pre-contoured cervical matrices and to compare it with a conventional disc polishing system. MATERIALS AND METHODS: Twenty maxillary anterior teeth were collected and used in the study. Class V cavity preparation was done, and the cavities were restored with two types of composites (microhybrid and nanohybrid) from commercially available brands (Ivoclar and Dentsply) and finished and polished using two polishing systems (super-snap and pre-contoured cervical matrices). The evaluation of surface roughness was done using an atomic force microscope (AFM). RESULTS: The surface roughness parameters (Ra-arithmetic mean/average line roughness and Sa-average surface roughness) of the class V cavities restored using pre-contoured cervical matrices were significantly lower for both the tested resin composites. CONCLUSION: The surface roughness of Class V cavities restored using pre-contoured cervical matrix systems was significantly less for both microhybrid and nanohybrid composites.

Microbial Interactions in Oral Biofilm: Evaluating Therapeutic Interventions and the Emergence of Resistance: A Narrative Review.

The oral cavity comprises numerous anatomical surfaces that are inhabited by a diverse array of bacteria, collectively forming a bacterial biofilm. Within this complex microbial community, certain bacterial species are etiologically linked to the development of common oral pathologies, such as dental caries and periodontitis, which stand as prominent instances of bacterial infections frequently encountered in clinical settings. Most biofilms are believed to be multispecies consortia. While single-species biofilms have been well-researched, mixed-species biofilms and their interactions amongst themselves have not drawn interest. The aim of the current review was to assess the various interactions of dual-species microorganisms in oral biofilm formation. Farnesol given exogenously for the treatment of biofilm can enhance or inhibit the growth of certain organisms, as seen in Candida albicans. In the age of antibiotic resistance, it is imperative to develop and uncover drugs capable of simultaneously targeting multiple species in order to mitigate antimicrobial resistance.

Comparative Study Assessing the Canal Cleanliness Using Automated Device and Conventional Syringe Needle for Root Canal Irrigation-An Ex-Vivo Study.

The success of endodontic treatment relies on both apical and coronal sealing. To achieve a good three-dimensional seal, the removal of the smear layer becomes mandatory. This study aims to assess the difference in debris accumulation and smear layer formation while using automated root canal irrigation and conventional syringe needle irrigation. Single-rooted human mandibular premolar teeth (n = 30) which were indicated for orthodontic extractions were selected. An endodontic access cavity was prepared, and a glide path was created. Based on the irrigation protocol decided upon for the study, the teeth were randomly allocated into three study groups, namely Group 1, where the manual syringe needle irrigation method was adopted; Group 2, in which automated root canal irrigation was undertaken; and Group 3, in which teeth remained un-instrumented as it was considered the Control group. The teeth were decoronated at the cement-enamel junction (CEJ) and were subjected for scanning electron microscopy (SEM) examination. Debris and smear layers were viewed in 1000× magnification and scored. A statistically significant (p < 0.05) lower mean debris and smear layer score (p < 0.05) was observed in both study groups when compared with the control group. However, no significant difference (p > 0.05) in the debris and smear layer was observed between the manual syringe needle irrigation and automated irrigation, although automated irrigation devices can be a potential alternative. The present study concluded that the efficacy of smear layer removal remained the same with both automated irrigation and manual syringe irrigation.

Children's perspective on color, smell and flavor of toothpaste.

INTRODUCTION: The foundation for healthy permanent teeth in children and teenagers is laid during the first years of life. Poor diet, poor habits of food intake, and inadequate toothbrushing habits during the first 2 years of life have been shown in several studies to be related to tooth decay in children. The development of caries in primary teeth further increases the risk of developing caries in permanent teeth. MATERIALS AND METHODS: A survey was conducted with 787 school children aged between 5 years and 12 years in Chennai city on their perspective of toothpaste color, smell, and flavor. RESULTS: Of 787 children, 222 chose red as the color they want in their toothpaste whereas only 61 children preferred white as their toothpaste color. The survey showed that 50% of the children wanted their toothpaste to taste sweet, followed by minty (20%), sour (14%), and spicy (11%). When asked about what they would like their toothpaste to smell like, majority (41%) of children opted for fruity, followed by sweet (23%), minty (18%), and fragrant (16%). CONCLUSION: Based on the responses made by 787 children aged between 5 and 12 years, it can be concluded that children prefer red color, fruity smell, and sweet flavor.

Assessment of apical pressures at different automated irrigant flow rates: an ex vivo study based on computational fluid dynamic analysis / Avaliação de pressões apicais em diferentes taxas de fluxo irrigante automatizadas: um estudo ex vivo baseado em análise dinâmica de fluidos computacionais

Objective: The current study aimed at assessing the induced apical pressure at various simulated irrigant flow rates. Materials and Methods: Forty eight freshly extracted single-rooted premolars were decoronated and prepared to size 30 0.04 taper using HY-Flex CM rotary file system and were scanned using cone-beam computed tomography (CBCT). The scanned images were reconstructed to three-dimensional Computer-aided design models (CAD) and the 3D needle was also reconstructed. Finally, simulations were done by placing the 30 gauge open-ended needle 3 mm short of the working length. Results: There was a statistically significant difference (p<0.05) among the different groups compared. 1 ml/min flow rate induced the least apical pressures (p<0.05) as compared to the other types. Conclusion: 1 ml/min flow rates induced the least apical pressures when open-ended needles are used for irrigation.(AU)

Objetivo: O presente estudo teve como objetivo avaliar a indução de pressão apical em várias taxas de fluxo irrigante simuladas. Material e Métodos: Quarenta e oito raízes de pré-molares unirradiculares recém extraídos tiveram suas coroas removidas, foram preparados para uma conicidade de tamanho 30 0.04 através de um sistema rotatório de limas HYFlex CM e foram escaneados via tomografia computadorizada cone-beam (CBCT). As imagens escaneadas e as agulhas para irrigação foram reconstruídas em modelos tridimensionais de design assistido por computador (CAD). Ao final, foram feitas simulações através de agulhas de calibre 30 e 3 mm a menos que o comprimento de trabalho. Resultados: Houve diferença estatisticamente significativa (p<0.05) entre os diferentes grupos. A taxa de fluxo de 1 ml/min induziu as menores pressões apicais (p<0.05) quando comparada às demais taxas. Conclusão: Taxas de fluxo de 1 ml/min induziram as menores pressões apicais quando agulhas de ponta aberta foram utilizadas para irrigação (AU)