Effects of Rinsing Water Temperature and Preheated Composites on Microleakage of Composite Restorations with Two Bonding Agents

Objectives: The aim of this study was to evaluate the effects of rinsing water temperature and preheated composites on microleakage of class V restorations with two different bonding agents. Materials and Methods: Eighty class V cavities were prepared in the buccal and lingual surfaces of 40 molars. Single Bond and Prime and Bond NT bonding agents were used. The teeth were divided into four groups of 10. G1: After acid etching, cavities were rinsed with 23˚C water and filled with 23˚C composite resin. G2: Rinsing water and composite resin had 55˚C temperature. G3: Rinsing water had 55˚C and composite resin had 23˚C temperature. G4: Rinsing water had 23˚C and composite resin had 55˚C temperature. The specimens were immersed in 0.5% basic fuchsine dye. Microleakage scores were analysed with the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests. Results: There were significant differences in microleakage of specimens prepared with Single Bond and Prime and Bond NT only in group 1 (P<0.05). There were no significant differences between the microleakage of groups rinsed with different water temperatures (P>0.05). There were significant differences between the unheated and preheated composite groups (P<0.05). Conclusion: Preheating of composite is a valuable method to increase its adaptability and decrease microleakage of composite restorations.

Influence of the endodontic access cavity design and restorative technique on hard tissue removal and fracture resistance of mandibular premolars

This study assessed the influence of traditional (TradAC) and conservative access (ConsAC) with different restorative techniques on the percentage of hard tissue removed (%HTR) and on the fracture resistance of mandibular premolars. 45 premolars were scanned in a micro-computed tomography and assigned into four groups according to access (TradAC or ConsAC) and restorative technique: composite resin (CR) or fiber post (FP) + CR. After post preparation, the teeth were rescanned to determine the volume enlargement and %HTR from the crown and root canal. After restoration, the load at fracture was recorded. Data were analyzed statistically by one-way ANOVA and Tukey’s post-hoc test, ANOVA repeated measure, and chi-square tests (P<0.05). TradAC (RC or FP) resulted in the increase (Δ%) of root canal volume and hard tissue removed up to 14 mm (%) in comparison with ConsAC (RC or FP). TradAC + FP removed a greater percentage of hard tissue from the crown when compared to TradAC + CR. The percentage of hard tissue removed in the crown in the ConsAC groups was statistically lower than in the TradAC groups. The control group showed higher fracture resistance than all experimental groups, with no differences among the latter. Restorable fracture patterns were more prevalent. Traditional endodontic access cavities removed a higher percentage of dentine than conservative endodontic access cavities. However, no differences in fracture resistance were observed. Restorations using composite resin or fiber post associated with composite resin showed similar results of fracture resistance.

Evaluation of Different Beverages’ Effect on Microhardness and Surface Roughness of Different Artificial Teeth

Purpose: This study evaluated the microhardness and surface roughness of four artificial teeth type against various beverages. Materials and Methods: Conventional acrylic resin, reinforced acrylic resin, microfiller composite resin, and nanofiller composite resin teeth were used. From each group, 10 maxillary first and second molars were immersed in 5 beverages (tea, filtered coffee, cola, cherry juice, and distilled water. The test period of 24 hours appears comparable to approximately 1 month of normal beverage consumption. The test periods used in this study were arranged according to this protocol and 1 week, 1 month, 3 months and 6 months of normal beverage consumptions were simulated. Vickers microhardness and surface roughness of denture teeth were measured for each test period. Results: The microhardness values significantly decreased in all beverages especially in 6th month. The surface roughness values significantly increased in all beverages especially in 3th month. There were no statistically significant differences between the beverages. Microfiller composite resin denture teeth had the highest microhardness values and the lowest surface roughness values. Conclusions: Different types of beverages consumed daily negatively affect the microhardness and surface roughness of artificial teeth. Microfiller composite resin teeth could have the ideal surface properties

Evaluation of the Sealing Ability of Direct versus Direct-Indirect Veneer Techniques: An In Vitro Study

Backgrounds. Marginal discoloration, microleakage, wear, and marginal fractures are all prevalent problems with composite veneers, and this scenario leads the esthetic outcome to deteriorate with time, resulting in patient discontent. Aim of the Study. The study’s goal was to determine the marginal sealing ability of composite laminate veneers when employing two types of veneer techniques: direct and direct-indirect veneers, as well as two types of composite resin: nanohybrid and microfilled composite resin restorations, using dye penetration method. Materials and Methods. In this study, forty extracted human teeth were utilized. Following a standardized veneer preparation on the labial surface of the teeth, they were separated into two groups of 20 teeth each, using the following composite application techniques: group A: direct veneers and group B: direct-indirect veneers. Following that, each major group was separated into two subgroups of ten teeth each, based on the type of composite employed: subgroup 1 used nanohybrid composite resin, while subgroup 2 used microfilled composite resin. All of the samples were kept in distilled water, thermocycled, and soaked in 2% basic fuchsine dye. These specimens were sectioned and examined under a stereomicroscope for dye penetration at the gingival margin. The data was analyzed using independent T -tests using SPSS 22. Result. Using direct-indirect veneer technique with nanohybrid composite resin material resulted in the most negligible dye penetration at the gingival margin, while using direct veneer technique with microfilled composite resin material resulted in the maximum dye penetration. For both composite materials, gingival microleakage was lower when using the direct-indirect veneer technique than when using the direct technique, and the difference was statistically significant ( P < 0.05 ). In both techniques, gingival microleakage was lower with nanohybrid composite than with microfilled composite, and the difference was statistically highly significant ( P = 0.001 ). Conclusion. The sealing ability of the gingival margin of tooth/composite interface is better when applying direct-indirect veneer technique with nanohybrid composite resin than that of direct veneer technique with microfilled composite resin material.

Fracture Resistance of Primary Canines Restorations Reinforced with a Flowable or a Packable Composite Resin Posts; In- Vitro

Aim and Background: Restoration of severely damaged primary anterior teeth are deemed as serious challenges for pediatric dentists. The aim of this study was to evaluate the fracture resistance of primary canines restored with flowable or packable composite resin posts. Material and Methods This study was conducted on a group of extracted primary canines. After cutting the coronal section, standard pulpectomy was performed and root canals were filled with ZOE paste leaving 3 mm coronal root space. A liner was placed above the root canal filling as a barrier. Samples were then randomly divided into two groups of fifteen. Both groups, received etch, bond, then in group I Core Flo Composite resin placement into canal, in group II, post shaping using designated packable composite resin and inserted into the canal. Followed by Core buildup and Crown reconstruction using Z250 composite resin. Samples were mounted at 148 ° angle on the acrylic blocks and stored in de-ionized water for 72 hours. Fracture resistance was measured using Universal Testing Machine. Data analysis were performed using independent t-test. Chi- square test were also employed to assess the type of fracture within groups. Results The mean fracture resistance in the group I was 830.31(+/-328.69N) and 803.09(+/-326.45N) in group II. Moreover, statistical analyses of the results showed no significant difference between the mean values of the fracture resistance (p-value=0.822) of groups as well as the type of fracture (p-value=0.79) between groups. Conclusion The ease of use and proper adhesion of the Core Flo composite resin, seems to help its use in the reconstruction of severely destructed anterior primary teeth.

RETRIEVING BROKEN INSTRUMENT IN HALF OF THE APIKAL ON CANINES TEETH WITH H-FILE BRAIDING TECHNIQUE

ABSTRACTBackground: Broken instruments affect the outcome and prognosis. A broken instrument will prevent the procedure of cleaning and shaping, irrigation and obturation of the root canal on the obstructed root section causing failure in endodontic treatment. There are some treatments for broken instrument including retrieving a broken fragment file and bypassing it on the root canal. the aim of the case report aims to provide an alternative for retrieving broken instruments using the H-file braiding technique. Method: A 38-year-old female patient came to the Dental Conservation Clinic RSGM Prof. Soedomo FKG UGM. A patient got a history of initial root canal treatment in a clinic, which ended with a separated file on canine teeth left upper. No complain pain, from the investigation radiographic there is an instrument broken in half apical. The teeth 23 seen temporary restoration cavity class I is still in good. Retrieving broken instruments using the H-file braiding technique, preparation with step back techniques, obturation with warm vertical condensation technique and class I composite resin restorations with fiber-reinforced retention. Result: No complain pain after 2 weeks retrieving broken instrument.Conclusion: The technique of the H-file braiding technique is one technique to retrieve a broken instrument, this procedure is simple, cost-effective, harmless to the teeth and gives root canal sealing.