SEM Evaluation of Various Intracanal Irrigation Devices on Smear Layer Removal: A Comparative Study.

AIM: The present study aimed at assessing the effectiveness of different intracanal irrigation devices on the removal of the smear layer. MATERIALS AND METHODS: The recently extracted 80 lower premolars having single canal were chosen for this in vitro study. A round diamond bur was used to gain endodontic access and the root canal was entered with a #15 K-file until the tip was just seen at the apical foramen. Manual instrumentation of root canals of all teeth was done using the step-back method. The samples were later divided randomly into four groups. Later, each sample was exposed to final irrigation by using four different irrigation systems, group 1: conventional needle irrigation, group 2: irrigation with ultrasonic activation, group 3: irrigation with EndoVac system activation, group 4: irrigation with EndoActivator. The samples were next mounted and visualized under scanning electron microscope (SEM) for the absence or presence of the smear layer. RESULTS: Irrigation with EndoVac system activation showed the presence of least smear layer (2.40 ± 0.32), followed next by EndoActivator (3.24 ± 0.46) and ultrasonic activation (4.96 ± 0.54) and conventional needle irrigation (5.20 ± 0.10). No statistically significant difference was found in the apical and coronal thirds of the root canal in removal of the smear layer on an intragroup comparison. However, a statistically significant (p < 0.001) difference was seen between the groups at the apical and coronal thirds on an intergroup comparison. CONCLUSION: This study demonstrated the EndoVac system group to be efficient in removal of the smear layer when compared to the EndoActivator system, ultrasonic activation, and conventional needle irrigation group. CLINICAL SIGNIFICANCE: The definitive objective of endodontic therapy is to transform the affected teeth to a healthy and functional state. The irrigants can reach the working length when delivered by an effective irrigation delivery system. This type of delivery system should deliver adequate volume of irrigants all the way up to the working length and have sufficient flow and be efficient at debridement of complete canal system.

Impact of Surface Treatment with Different Repair Acrylic Resin on the Flexural Strength of Denture Base Resin: An In Vitro Study.

AIM AND OBJECTIVE: The aim and objective of the present study was to assess the flexural strength of denture base resin based on surface treatment with different acrylic resin repair materials. MATERIALS AND METHODS: Totally, 120 heat-polymerized polymethyl methacrylate denture base resin materials which are rectangular shaped with the size of 65 mm × 10 mm × 2.5 mm were fabricated. 150 µm-sized alumina used for surface treatment. All the 120 heat-cured, surface-treated acrylic denture base resin samples were randomly divided into three groups. Group I: glass-fiber-reinforced auto-polymerizing acrylic resin, group II: auto-polymerizing acrylic resin, and group III: light-cured acrylic resin. A universal testing machine was used to test the flexural strength of the repaired specimens. RESULTS: A highest mean flexural strength (88.96 ± 0.31) was demonstrated by group I, followed by group II (72.18 ± 1.86) and group III (66.30 ± 1.02). ANOVA demonstrated a statistically significant inter-group difference. On multiple comparisons, using Tukey's post hoc test a statistically significant difference between groups I and II and between groups I and III was found. CONCLUSION: After considering the limitations, the present study concluded that the highest flexural strength is shown by glass-fiber-reinforced auto-polymerizing acrylic resin than by auto-polymerizing acrylic resin and light-cured acrylic resin. CLINICAL SIGNIFICANCE: Denture repair comprises of joining two fractured parts of a denture with a denture repair material. The success of denture repair depends on the adhesion phenomenon. The treatment of the surface can be accomplished using a suitable material which changes chemically and morphologically and thus promotes better adhesion.

An In Vitro Study of Gutta Percha Removal Commencing from the Root Canal Undergoing Endodontic Retreatment using Different Rotary Instrumentation Systems.

Background: In the root canal, the tenacity of microbial infection in either or both the periradicular area is the utmost communal source of endodontic failure. The majority of the gutta percha is removed using hand and rotational equipment. Aim of Study: To determine gutta percha removal by effectively utilizing three rotary instrumentation devices all through the endodontic retreatment. Objective of Study: To determine amongst the three Nickle-Titanium systems which one is significantly effective in retreatment along with comparison of retreatment efficiency using or avoiding the utilization of solvent. Materials and Methods: On 60 newly extracted, single-rooted mandibular premolars, every root canal was sealed using gutta percha and AH Plus sealer utilizing lateral compaction. After that, the samplings were separated into three investigational groups, each with 20 specimens. After that, individual groups were separated into ten specimens. After that, the groups were withdrawn with or without solvent. ProTaper retreatment files, Mtwo retreatment files, and R-Endo files were utilized to eradicate the gutta percha after two weeks. The extent of root canal filling material left in the coronal, middle, and apical thirds was recorded utilizing a stereomicroscope and a computer image processing program. The data was statistically examined using analysis of variance. Result: The ProTaper group exhibited a smaller amount of remnant filling material than the supplementary groups in the coronal and middle thirds; however a significant difference amid ProTaper and Mtwo, and Mtwo and R-Endo in the nonsolvent groups (P = 0.05) was concluded. In the nonsolvent group, the Mtwo group showed less leftover filling material. Conclusion: The elimination of root canal filling material was found to be equally effective in all systems. However, not a single experimental group could entirely eradicate gutta percha from the root canal.

Anatomical Evaluation of Root and Root Canal Morphology of Permanent Mandibular Dentition among the Saudi Arabian Population: A Systematic Review.

This study aimed to conduct a compendious review of root canal morphology of "permanent mandibular teeth in different regions of Saudi Arabia" to obtain a large sample representing the total population. A detailed search through the databases Web of Science, Scopus, and PubMed was conducted following the PRISMA guidelines. The data were analyzed based on the following inclusion criteria: original full-length original articles that reported the variables of interest "(number of roots, number of canals, Vertucci's classification system and C-shaped canals or mid-mesial canals)" of the mandibular teeth and conducted on Saudi subjects. The retrieved data were presented as frequencies and percentages. The results revealed that 56.6% of mandibular central incisors had one canal and Vertucci type I (56.6%), while 57.4% of the mandibular lateral incisors had one canal, with Vertucci types I and III most frequent. In mandibular canines, 91.8% had one canal and 8.2% had two canals. Most of the mandibular first premolars had one root (86.6%), while almost all mandibular second premolars (91.5%) had one canal, and 96.9% had Vertucci type I configuration. Among the mandibular first molars, three and four canals were prevalent in 58.7% and 40.6%, respectively. The majority of mesial roots had Vertucci type IV (60.6%), and most of distal roots had Vertucci type I (72.2%). Most of the mandibular second molars had three canals (87.3%) and showed Vertucci type IV (39.4%) canals for mesial roots and Vertucci type I (95.6%) for distal roots. The C-shaped canals were seen in 8% of first premolars and 9.8% of second molars. The middle mesial canal was found in 4.2% and 0.4% of first and second molars, respectively. This review could represent "the population of Saudi Arabia as the included samples were combined from different regions of the country." Some variations were noticed within the same group of teeth from different regions. However, the overall results of combined samples were comparable to the other international studies.

Efficacy of Routinely used Analgesics in Management of Pulpal Pain Postoperatively a Clinical Study.

AIM: The aim of this study was to evaluate the efficacy of various routinely used analgesics in the management of pulpal pain preoperatively. MATERIALS AND METHODS: A total of 150 patients were randomly selected and divided into five groups each. At initial visit, a self-administered questionnaire was given, and patients were asked to mark on the Visual Analog Scale (VAS) indicating severity of pain at that moment which is taken as a pretreatment VAS score. Group I patients received aceclofenac + paracetamol, Group II: ketorolac tromethamine, Group III: lornoxicam + paracetamol, Group IV: tramadol + paracetamol, and Group V: paracetamol. All the patients are requested to record their pain levels at 4 h, 6 h, 8 h, 24 h, and 48 h by means of VAS scores before and after treatment. RESULTS: There was no significant decrease in frequency of pain when compared in the first three groups, whereas in Group III and Group IV, the patients experienced an effective reduction in pain because of sustained releasing ability of these drugs. Overall, there was no statistically significant differences among all the groups. CONCLUSION: This study suggests that there was no significant difference in reduction of pain preoperatively. However, lornoxicam + paracetamol and tramadol + paracetamol were effective because of their sustained releasing ability. Ketorolac was effective to reduce the pain for shorter duration. Paracetamol can be advised in compromised patients where safety is concerned.

Influence of Radius of Curvature at Gingival Embrasure in Connector Area on Stress Distribution of Three-Unit Posterior Full-Contour Monolithic Zirconia Fixed Partial Denture on Various Amounts of Load Application: A Finite Element Study.

OBJECTIVES: To test the hypothesis that radius of curvature at gingival embrasure in connector area significantly affects the fracture resistance of full-contour monolithic zirconia three-unit posterior Fixed partial denture (FPD) on various amounts of load application. MATERIALS AND METHODS: In this study, two types of three-dimensional finite element models of a three-unit posterior full-contour monolithic zirconia FPD with two gingival embrasure radii (rGE I, 0.45 mm and rGE II, 0.25 mm) were constructed. The components modeled through finite element modeling were subjected to 400, 600, and 800 N vertical loads at the central fossa of the pontic, and further analysis was carried out. RESULTS: All the results were displayed by post-processor finite element analysis software (ANSYS). The study revealed that with increase in the amount of load application as well as decrease in the gingival embrasure radii, stress concentration values were increasing gradually for both the full-contour monolithic zirconia FPD. CONCLUSION: The fracture resistance of the zirconia posterior FPD was significantly affected by the gingival embrasure radii and the mode of load application. When there is a clinical situation of heavier occlusal forces, the fracture resistance can be increased by designing greater gingival embrasure radii in the connector region.