Comparative Evaluation of Fracture Toughness and Flexural Strength of Four Different Core Build-up Materials: An In Vitro Study.

AIM: To evaluate and compare the fracture toughness and flexural strength of four different core build-up materials. MATERIALS AND METHODS: A total of 60 samples were divided into four groups (n = 15) group I: dual cure composite resin reinforced with zirconia particles (Luxacore Z), group II: light cure composite resin (Lumiglass DeepCure), group III: zirconia reinforced glass ionomer cement (GIC) (Zirconomer Improved), and group IV: chemically cure composite resin (Self Comp) respectively. All the core build-up materials were manipulated according to the manufacturer's instructions and poured into the mold. A universal testing machine applied a central load to the specimen in a 3-point bending mode. Fracture of the specimen was identified and the reading was recorded by the universal testing machine. The data were analyzed statistically using one-way analysis of variance (ANOVA) and then compared. RESULTS: Group I showed the highest flexural strength (48.65 MPa) among all the groups while group IV showed the lowest flexural strength (17.90 MPa). Group I showed the highest fracture toughness (99.12 MPa) among all the groups while group IV showed the lowest fracture toughness (36.41 MPa.cm-0.5). When mean flexural strength and fracture toughness values of all four groups were compared by using one-way ANOVA, the compared data was highly significant. CONCLUSION: Based on the findings of this study, dual cure composite resin was the material of choice in terms of flexural strength and fracture toughness for core build-up material followed by light cure composite resin. CLINICAL SIGNIFICANCE: The core buildup material serves to strengthen the tooth structure, allowing it to withstand the forces of chewing and preventing the risk of tooth fractures. This material is essential in restoring damaged or decayed teeth, as it provides a stable foundation for further dental work. By reinforcing the tooth structure, the core buildup material ensures that the tooth can function properly and remain healthy for years to come. How to cite this article: Nakade P, Thaore S, Bangar B, et al. Comparative Evaluation of Fracture Toughness and Flexural Strength of Four Different Core Build-up Materials: An In Vitro Study. J Contemp Dent Pract 2024;25(2):191-195.

Single Nucleotide Polymorphisms of BMP2 Gene Association with Skeletal Class I Crowding: A PCR Study.

AIM AND OBJECTIVE: This study is conducted to find the association of BMP2 (bone morphogenic protein 2) gene variant rs1005464 and rs15705 with skeletal class I crowding cases. MATERIALS AND METHODS: Blood samples from 60 subjects who visited the Department of Orthodontics and Dentofacial Orthopaedics, D.A.P.M.R.V. Dental College, Bengaluru, were taken after written informed consent. These were divided into two groups: group A with 30 subjects having skeletal class I bases with crowding and group B with 30 subjects having skeletal class I bases without visible crowding or spacing (±2 mm). Around 2 mL of venous blood sample was procured from cases and controls after careful examination. All the samples were then subjected to polymerase chain reaction followed by DNA sequencing and capillary electrophoresis. BMP2 rs1005464 and rs15705 gene variants were assessed and Z-Test was used for statistical analysis. RESULT: GG (p = 0.001) and CC (p = 0.0024) genotype of BMP2 gene variant rs1005464 and rs15705, respectively, are significantly associated with skeletal class I crowding cases. CONCLUSION: This study concludes that BMP2 variants rs1005464 and rs15705 can be used as genetic markers for skeletal class I bases having crowding. CLINICAL SIGNIFICANCE: Predisposing genetic markers BMP2 can be identified prior and this would help in predicting the probability of potential crowding in the future and this would help in early prevention and intervention of crowding.

Study of the Role of Salivary Lactate Dehydrogenase in Habitual Tobacco Chewers, Oral Submucous Fibrosis and Oral Cancer as a Biomarker.

AIM: To evaluate the salivary lactate dehydrogenase (LDH) levels in clinico-pathologically confirmed oral submucous fibrosis (OSMF), oral cancer and clinically diagnosed tobacco pouch keratosis patients. MATERIALS AND METHODS: A prospective, comparative study was carried out in a tertiary healthcare centre located in Loni from October 2013 to January 2014. A total of 120 patients were separated into 4 groups depending upon the clinical diagnosis as follows. Group I: healthy control (with no addictions and diseases). Group II: oral cancer. Group III: oral submucous fibrosis. Group IV: habitual tobacco chewers (tobacco addiction without any disease). Substantiation was done using biopsy. The samples were inspected for salivary LDH levels by the technique in line with the recommendations of the International Federation of Clinical Chemistry with the help of Erba Chem semi auto analyser. RESULTS: The mean salivary LDH levels in the control, oral cancer OSMF and habitual tobacco chewer group were 86.12 ± 7.05 IU/L, 592.09 ± 28.57 IU/L, 350.43 ± 5.90 IU/L and 125.19 ± 13.42 IU/L, respectively. Out of 4 groups, LDH activity was increased in saliva of patients with tobacco pouch keratosis, OSMF, and oral cancer consistently. Notable difference was found in the mean salivary levels of the above groups. Results were subjected to appropriate statistical analysis: one-way ANOVA, Student's unpaired t test for group-wise comparison followed by post hoc Tukey's test. CONCLUSION: We observed congruous higher levels of salivary LDH in oral precancer and cancer, and hence it could be a future marker.