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Abstract This study evaluated the biocompatibility of mineral trioxide aggregate (MTA) and Biodentine (BD) as root-end filling materials. Six mongrel dogs were divided into two equal groups according to the evaluation period; group A: one month and group B: three months. Three premolars of the same quadrant in each arch were used, summing up 36 teeth (6 teeth/dog). These teeth were randomly subdivided into three subgroups according to the root-end filling material used: MTA, BD and no root-end filling material (control). Endodontic access cavities were performed for induction of periapical pathosis. After the infection period, root canal instrumentation and obturation were accomplished. One day after root canal procedures, root-end surgery was performed. Surgical access was achieved and the root-end was resected approximately 3 mm above the apex. Root-end cavity was prepared ultrasonically and filled with the tested materials. All samples were evaluated by radiography and histopathology (Inflammation and new hard tissue formation). Data were collected and subjected to statistical analysis. In group A, MTA subgroup exhibited significant higher mean inflammatory score than BD subgroup (P 0.05). Regarding mean mineralization score, there was no significant difference between all subgroups in both groups A and B (P > 0.05). Biodentine exhibited favorable biocompatibility in the initial stage of healing than MTA and comparable biomineralization. Clinical relevance: Biodentine could be considered as an acceptable alternative to MTA in peri-radicular surgeries.

BackgroundsInter-individual variability in response to statin was mainly due to genetic differences. This study aimed to investigate the association of CYP3A4*22 (rs35599367), CYP3A5*3 (rs776746) single nucleotide polymorphism (SNP) with response to simvastatin in hypercholesterolemia patients conducted at King Abdulaziz University hospital (KAUH) in Jeddah, Saudi Arabia.Patients and methodsA total of 274 participants were registered in the current study. Hypercholesterolemic patients taking simvastatin 20 mg (n = 148) and control subjects (n = 126) were tested for rs35599367 and rs776746 genotypes using Custom Taqman ® Assay Probes. Response to simvastatin in these patients was assessed by determination of low density lipoprotein (LDL-C), total cholesterol (TC) and by measuring statin plasma levels using Liquid Chromatography-Mass Spectrometry (LC-MS).ResultsNone of the participants carried a homozygous CYP3A4*22 mutant genotype, while 12 (4.4%) individuals had a heterozygous genotype and 262 (95.6%) had a wild homozygous genotype. The CYP3A5*3 allele was detected in the homozygous mutant form in 16 (5.8%) individuals, while 74 (27.0%) individuals carried the heterozygous genotype and 184 (67.2%) carried the wildtype homozygous genotype. Of the patient group, 15 (11%) were classified as intermediate metabolizers (IMs) and 133 (89%) as extensive metabolizers (EMs). Plasma simvastatin concentrations for the combined CYP3A4/5 genotypes were significantly (PConclusionThe present study showed associations between CYP3A4*22 (rs35599367) and CYP3A5*3 (rs776746) SNP combination genotypes with response to statins in hypercholesterolemia. Patients who had either a mutant homozygous allele for CYP3A5*3 or mutant homozygous and heterozygous alleles for CYP3A4*22 showed increased response to lower TC and LDL-C levels.

Aim: This study evaluated the sealing ability of ProRoot MTA and Biodentine as root-end filling materials. Method: In total, twenty (N = 20) extracted human maxillary central incisor teeth were decontaminated, cleaned and decoronated. Instrumentation was performed according to the step back technique using #50 Flex-o-file. Then the canals were flared to #70 Flex-o-file. Obturation was performed with conventional gutta percha and a resinous sealer (AH26) using the lateral condensation technique. Resection of 3 mm of apical end of each root was achieved perpendicular to the long axis of the root. Root-end cavity was prepared in each sample ultrasonically then filled with tested materials (N = 10). Fluid filtration method was used to assess the sealing ability of each tested material at three different experimental periods; one day, one week and one month after setting. All data were tabulated and statistically analyzed with a level of significance set at P ≤ .05. Results: At each specific time interval, the leakage mean values were not consistent among the tested materials. At one day interval, ProRoot MTA samples had a higher leakage mean value than Biodentine samples. However, this difference in leakage was not statistically significant (P > .05). At one week interval, both materials showed an increased degree of leakage mean value with no significant difference (P > .05). At one month interval, ProRoot MTA samples showed a decrease in leakage mean value, while the Biodentine samples showed a further increase in leakage mean value. This difference was statistically significant (P

Aim: The aim of this study is to compare the retention force of three different types of overdenture attachment systems used in implant-retained mandibular complete overdentures. Materials and Methods: Twenty-one similar acrylic resin blocks were prepared and divided into three study groups: Group A (snap attachment) - 10 specimens, Group B (locator attachment) - 1 specimen, and Group C (syncone attachment) - 10 specimens. A single rectangular heat cure acrylic resin block with two implant analogs 22 mm apart was used with all specimens. Each specimen was subjected to 5500 cycles of insertion and removal in the presence of artificial saliva, representing 5 years of usage. Retention was measured three times for each specimen using universal testing machine. Data were analyzed using one-way and two-way analysis of variance at 95% level of confidence. Results: Locator attachment group (Group B) showed the greatest retention level throughout the study, followed by snap attachment (Group A), and syncone attachment (Group C) showed the lowest retention level. Conclusion: Regardless of the initial retention level of overdenture attachment, gradual loss of retention values is inevitable. However, the rate of retention loss in overdenture attachments is higher in types which comprised plastic parts within their components, rather than those totally made up of noble metals.

Aim of the work: The purpose of this study was to compare stress induced by the conventional design of lower unilateral free-end saddle and side plate with extra-coronal attachment (OT Cap attachment) and record the micro-strains induced by this stress. Materials and methods: Strain gauge technology was used for strain analysis. A two-layer epoxy resin model with a unilateral distal extension base was used in this study with the second premolar as the last standing abutment. Model A: A lower metallic partial denture was made with an RPI clasp as a direct retainer on the second premolar and a double Aker clasp for cross-arch stabilization on the 1st and 2nd molars of the dentulous side, and the lingual plate served as a major connector. Model B: Lower metallic partial denture was made with the extra-coronal attachment (OT Cap attachment) as a direct retainer on the second premolar splinted with the first premolar by crowns. Stresses were measured vertically and obliquely at the buccal and lingual sides of the lower 2nd premolar, the edentulous ridge in the lower 2nd molar, and the double Aker in the dentulous side of model A. However, stresses were measured vertically and obliquely at the buccal and lingual side of the lower 2nd premolar and the edentulous ridge in the lower 2nd molar of model B. Data were collected, tabulated, and statistically analyzed using the SPSS software program. Results: The present study revealed that stresses recorded at the abutment teeth and the ridge in the area of the lower second molar were higher in the case of conventional RPD than in OT attachment and the micro strains recorded around the abutment tooth were much more than micro-strains recorded around the residual ridge. Conclusions: Mandibular partial denture using OT attachment can be considered as a prosthetic option for the management of class II Kennedy classification as it can improve the integrity of the alveolar bone of the abutment tooth and the residual ridge. Splinting of abutments reduces the stresses located in the buccal and lingual aspects of the abutment connection between the abutment and the OT attachment allowing better distribution of the stresses between the abutment tooth and the ridge vertically and obliquely. [ABSTRACT FROM AUTHOR]