EFFECT OF DIFFERENT NUMBER OF THERMAL CYCLING ON MARGINAL LEAKAGE OF CLASS V RESTORATION USING NANO TOOTH COLOURED MATERIALS: EFEK SUHU YANG BERBEDA TERHADAP KEBOCORAN MARGIN TAMBALAN KELAS V DARI BAHAN PEWARNA GIGI NANO TOOTH COLOURED MATERIALS

Nano tooth coloured materials may have been produced as an ideal restorative material, however, thermally induced stresses may lead to microleakage between restorative material and tooth structure which may cause unwanted complications. Thermocycling has been an important method to emulate the thermal changes of the oral cavity. This study was aimed to investigate the effect of increasing number of thermal cycles on marginal leakage of nano tooth coloured materials. A total of 56 Class V cavities was prepared on the buccal surface of the extracted single rooted human premolars and restored with either Filtek Z350 (3M-ESPE, USA) or Ceram X (Dentsply, Germany). The samples were then divided into four groups with (n=7): 1) 0 thermocycle, 2) 500 cycles, 3) 5,000 cycles and 4)10,000 cycles. All samples were immersed in 2% methylene blue dye for 4 hours at room temperature, sectioned and viewed under stereomicroscope for dye penetration. Data were analyzed using T-test and One-way ANOVA and Post-hoc Scheffe with p<0.05 considered to be significant. Microleakage was only evident in both materials at 5,000 cycles above. The results showed that there was a significant difference in microleakage between 5,000 and 10,000 cycles for both materials (Filtek Z350: p<0.001; Ceram X: p<0.001). However, there was no significant difference in microleakage between Filtek Z350 and Ceram X at 5000 cycles (p=0.194) and at 10,000 cycles (p=0.499). As conclusion, microleakage increases with the duration of thermal cycling in both nano-tooth coloured materials. Both materials showed similar pattern of microleakage when challenged to a higher number of thermal cycles

Surface Roughness Evaluation Of Experimental Dental Nanocomposite After Bleaching

Bleaching or tooth whitening is getting more popular in this world that concerns esthetic [1]

Safety Comparison of Over the Counter Bleaching with Professionally Prescribed Home Bleaching Agent

Aims: This aimed to compare the colour changes, microhardness, and surface roughness of the human natural tooth after bleaching treatment with a professional home bleaching agent and over-the-counter (OTC) bleaching agent. Settings and Design: This was an in vitro study using extracted human teeth stained with human blood as specimens. Materials and Methods: Fifty-seven human natural teeth were embedded in acrylic of 2.5 mm thickness and 14 mm × 8 mm surface area. The samples were stained with human blood before they were divided into three groups (n = 19 per group) of control (C), Professional Bleaching Opalescence PF 15% (PB), and OTC Whitelight Tooth Whitening set (WL) before being treated with the respective bleaching agents for 10 days. Color changes were measured as colorimetric measurements (L*, a*, and b* values) were recorded during prestaining, poststaining, and postbleaching, while microhardness and surface roughness measurements were recorded for pre- and postbleaching. Statistical Analysis: Statistical analysis was done with SPSS (IBM Statistic, California, USA) version 22.0. Paired t-test and nonparametric analysis (Wilcoxon Signed-Rank Test) were used to analyze the data. P value was set as significant at P < 0.05. Results: The color changes in PB group was not significantly better compared with WL group (PB: 12.2 [4.07] and WL: 12.2 [4.32]). Whereas significant difference was noticed in microhardness after bleaching in PB group with a higher VHN number (500.4 [121.10]) compared with WL group (471.0 [114.47]) . The surface roughness (Ra) remain the same for all experimental groups. Conclusions: Both professional home bleaching agent and OTC bleaching agents showed similar efficacy, with no effect on surface roughness, and both caused an increase in microhardness

Effects of polishing techniques on the staining of two nano-tooth coloured materials

Surface polishing affect the staining of nano-tooth coloured materials. Here we studied the effect of tea and coffee staining on polished nano-composite resin and nano-ormocers. Eighty-four discs (5 × 2 mm) of Filtek Z350 and Ceram X were fabricated using acrylic molds and polished with either: (1) Sof-lex (2) Enhance/Pogo (3) control (no polishing-Mylar). After polishing, the tests materials were immersed in either tea or coffee (n=7), for 48, 96 and 168 h at 37°C. The colour difference (ΔE) values were assessed with a spectrophotometer (Cecil CE 2021 UV/VIS), the data were analysed using Kruskal-Wallis Test. The results showed that polishing significantly affected the ΔE values of both materials (p<0.05). In all groups, Ceram X showed less staining than Filtek Z350. Both Filtek Z350 and Ceram X also reacted differently in coffee and tea. Significant ΔE values for Filtek Z350 obtained with different polishing techniques exposed to coffee in ascending order: Sof-lex < Enhance/Pogo < Mylar strip. For Ceram X, significant ΔE values obtained in exposure to tea in ascending order: Pogo < Mylar < Sof-lex. Mylar caused more staining in Filtek Z350 whilst Sof-Lex caused the least staining. However, in Ceram X, Enhance/Pogo caused the least staining. In conclusion, Ceram X is more colour stable than Filtek Z350. It may be suggested to always use the polishing system produced by the same company that produces the restorative material for better staining resistant

Comparison of composite resin and porcelain inlays for restoration of noncarious cervical lesions: An In vitro study

Background: Composite resin (CR) currently is one of the most commonly used material in restoring noncarious cervical lesions (NCCL) due to its strength and esthetics color but has microleakage problem. The aim of this study is to compare in vitro the microleakage depth between CR and porcelain in restoring NCCL. Materials and Methods: This an in vitro study was done by preparing cavities on the buccocervical surface of 62 extracted premolar teeth which randomly assigned to two groups (n = 31) where Group 1 was restored with nanocomposite and Group 2 was cemented with porcelain cervical inlays. They were then subjected to thermocycling before immersion in 2% methylene blue dye for 24 h. Dye penetration depths were measured using Leica imaging system For statistical analysis, independent t-test was used to analyze the results (P < 0.05). Results: Porcelain cervical inlay restorations demonstrated statistically lesser microleakage depth for the cervical margins (P = 0.018) when compared to CR. Deeper microleakage depth at the cervical compared to coronal margins of CR (P = 0.006) but no significant difference of both margins for porcelain cervical inlays (P = 0.600). Conclusion: Porcelain cervical inlays show lesser microleakage than CR which could be alternative treatment option in restoring NCCL with better marginal seal and esthetics

Synthesis and Properties of Novel Calcia-Stabilized Zirconia (Ca-SZ) with Nano Calcium Oxide Derived from Cockle Shells and Commercial Source for Dental Application

Various oxides are used to stabilize zirconium oxide (ZrO2), but their superior hardness causes wear of the machining tool. Calcia-doped zirconia has been studied but reports on properties suitable for dental application are lacking. Therefore, this study aimed to fabricate and characterize zirconia stabilized by calcium oxide (CaO) derived from cockle shells and compare it with zirconia stabilized by commercial CaO, sintered at different temperatures. In this study, 176 pressed pellets of zirconia mixed with CaO either derived from cockle shells or commercial CaO were sintered between 1200 and 1500 &deg;C to produce calcia-doped zirconia. Characterizations were made with SEM and XRD. Specimens were subjected to density, compressive and flexural strength, and Vickers hardness testing. Data were analyzed using the independent t-test and one-way ANOVA. XRD revealed the zirconia was stabilized into tetragonal and cubic phases (Ca-SZ). Ca-SZ cockle shells (CS) and Ca-SZ commercial (CC) have average particle sizes of 267 nm and 272 nm, respectively, with similar surface roughness. At 1400 &deg;C sintering temperature, flexural strengths were 1165 and 1152 MPa, compressive strengths were 4914 and 4913 MPa, and Vickers hardness were 977 and 960 MPa for Ca-SZ(CS) and Ca-SZ(CC), respectively. Both Ca-SZ materials showed no significant difference in most properties (p &lt; 0.05) when sintered at different temperatures. The fully sintered Ca-SZ is less hard compared to the ceria-stabilized tetragonal zirconia polycrystal (Ce-TZP) available on the market. Thus, Ca-SZ may be used as an alternative to the current zirconia available on the market for dental application

A 2D Photographic and 3D Digital Dental Model Analysis of Golden Percentage in Maxillary Anterior Teeth

The objective of this paper was to evaluate the existence of golden percentage in natural maxillary anterior teeth with the aid of 3D digital dental models and 2D photographs. And to propose regional values of golden percentage for restoration of maxillary anterior teeth. For this purpose, one hundred and ninety dentate subjects with sound maxillary anterior teeth were selected. Standardized frontal images were captured with DSLR, and the apparent width of maxillary anterior teeth was measured utilizing a software on a personal laptop computer. Once the dimensions were recorded, the calculations were made according to the golden percentage theory (GPT). The data were analyzed by independent and paired T-test. The level of significance was set at p<0.05. The golden percentage values were not found in this study. The values obtained were 16%, 15%, 20%, 20%, 15%, and 16% moving from the right canine to the left canine teeth. There was no significant gender difference in the golden percentage values. Thus, golden percentage should not be used solely for the correction of anterior teeth or for determining dental attractiveness. Emphasis should be given to a range of dental proportion on regional basis

Effects of calcium hydroxide intracanal medicament on push-out bond strength of endodontic sealers: A systematic review and meta-analysis

Objective: To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers. Methods: A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value <0.05. Results: A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD = 0.03; 95% CI = −0.55, 0.60; p = 0.93), and calcium silicate-based group (SMD = 0.02; 95% CI = −0.31, 0.35; p = 0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias. Conclusion: The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers. Clinical significance: The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.The authors would like to acknowledge the Ministry of Higher Education Malaysia for Fundamental Research Grant Scheme with project code: FRGS/1/2021/SKK0/USM/02/31. The authors would also like to acknowledge the support of University Sains Malaysia (USM) Fellowship. The authors declare no conflict of interest