سال:1399 | دوره: | شماره: |تعداد مقالات:9

Background. The disinfection of orthodontic acrylic resins might change the physical and mechanical properties of these materials. We aimed to investigate the impact of four different commercially available disinfectants on the surface roughness of acrylic resins used for orthodontic appliances. Methods. Four disinfectant solutions (BirexSE, Opti-Cide3, COEfect MinuteSpray, and CaviCide Spray) were used to disinfect orthodontic acrylic resins using the spraying method. The resins were subjected to repeated disinfection protocols. Distilled water, also applied via spraying method, was used as a control. Surface roughness was scrutinized to examine the extent of surface topography changes by stylus profilometry. Data normality was evaluated via the Shapiro– Wilk test, followed by the Wilcoxon Signed-Rank test for non-parametric data or paired Student’ s t-test for parametric data to compare intra-group differences in roughness before and after the use of the disinfectant solutions. Results. Some of the disinfectants (BirexSE and CaviCide) resulted in significant changes in surface roughness values before and after the disinfection compared to the controls (P<0. 05). The groups that were in contact with distilled water, Opti-Cide, and Coeffect did not exhibit significant differences in surface roughness before and after the intervention (P>0. 05). However, from a clinical perspective, the resulting variations in surface roughness (<%0. 15) induced by these solutions might not reflect clinically significant differences. Conclusion. The use of disinfectant solutions is unlikely to harm the surface of orthodontic acrylic resins. Oral care providers need to be attentive to the interpretation and implementation of clinically significant changes in their evidence-based approach regarding potential material damages by disinfection sprays.

Background. Various treatment modalities, such as leucocyte platelet-rich fibrin (L-PRF), bone grafts, and membranes, have been used for the restoration of lost periodontal tissues. Titanium-prepared platelet-rich fibrin (T-PRF) has attracted attention for its proper haemocompatibility, thick fibrin meshwork, and long resorption time. The present study aimed to evaluate the effectiveness of T-PRF and L-PRF in the management of intra-bony defects based on clinical and radiographic criteria. Methods. Twenty-six subjects with 34 intra-bony 3-walled defects were divided into two groups (n=17) and treated with T-PRF or L-PRF. Clinical and radiographic measurements were recorded at baseline and 6-, 3-and 9-month intervals and tabulated on Microsoft Excel spreadsheets. For intra-and intergroup comparisons, paired and unpaired t-tests were performed. P<0. 05 was set as statistically significant Results. Intra-group comparisons revealed statistically significant differences (P<0. 05) from baseline in both groups regarding clinical measurements. On intergroup comparison, the T-PRF group exhibited a significantly higher defect fill compared to the L-PRF group (P<0. 05). Conclusion. Within the limits of the present study, T-PRF seems to be a better alternative to L-PRF in the treatment of intra-bony defects.

Background. Cleft lip and palate (CLP) is a common congenital anomaly. Many genes, like MAPK4 and SOX-1OT, are associated with its etiology in different populations. High-risk markers on these genes reported in other populations were not studied in our population. Hence, the study aimed to determine the association of MAPK4 and SOX-1OT polymorphisms in CLP in multiplex families. Methods. Based on inclusion and exclusion criteria, we selected 20 multiplex CLP families for this case‒ control study, in which the affected individuals and healthy controls selected from these families were compared. Fifty subjects affected with cleft and 38 unaffected subjects were included in the study. The polymorphisms studied for the association consisted of rs726455 and rs2969972 in the genes SOX-1 OT and MAPK4, respectively. DNA was isolated and sent for genotyping using the MassArray method. Plink, a whole-genome association analysis toolset, was used for statistical analysis. Results. Both polymorphisms followed Hardy– Weinberg equilibrium. The rs726455 of SOX-1OT yielded a P-value of 0. 983 and an allelic odds ratio (OR) of 0. 983. For rs2969972 of MAPK4, the P-value was 0. 04 (significant), and the allelic OR was 0. 51. Minor allele frequency (MAF) in the unaffected subjects was more than the MAF in the affected subjects for rs2969972. Conclusion. The results suggested that polymorphism rs726455 on SOX-1OT was not associated with familial cases of CLP. Since MAF in the unaffected subjects was more than the MAF-affected subjects, rs2969972 on MAPK4 is protective in the multiplex families.

Background. The use of bleaching agents might result in microstructural changes in tooth structure and in restorative materials. This study compared the effects of bleaching with %15 carbamide peroxide and %35 hydrogen peroxide on the flexural strength of Cention N restorative material using the self-cured and dual-cured polymerization modes. Methods. Sixty bar-shaped samples of Cention N restorative material were included in this in vitro study and assigned to three groups (n=20) randomly: control, bleaching with %15 carbamide peroxide and bleaching with %35 hydrogen peroxide. Each group was divided into two subgroups: samples polymerized in the self-cured mode and samples polymerized in the dual-cured mode. Then the flexural strengths of the samples were determined. Two-way ANOVA was used to compare flexural strengths between the three groups in two polymerization modes, followed by post hoc Tukey test. Statistical significance was defined at P<0. 05. Results. The difference in the mean flexural strength was significant in terms of the bleaching regimen (P<0. 001), with significantly lower flexural strength in the two bleaching groups compared to the control group. However, the mean flexural strengths were not significantly different in terms of the polymerization mode applied (P=0. 14). Conclusion. The application of %15 carbamide peroxide and %35 hydrogen peroxide bleaching agents decreased the flexural strength of Cention N restorative material. Irrespective of the bleaching regimen, there was no significant difference in the flexural strength of Cention N between the self-curing and dual-curing polymerization modes.

Background. This study was conducted to compare the cyclic fatigue resistance of VDW. ROTATE, TruNatomy Prime, HyFlex CM, and 2Shape nickel-titanium (NiTi) rotary instruments in doublecurved canals in a simulated clinical environment. Methods. Eighty NiTi files were used for the fatigue testing in stainless steel canals compatible with instrument sizes until fracture occurred (n=20): VDW. ROTATE (04. /25#), TruNatomy Prime (04. /26#), HyFlex CM (04. /25#) and 2Shape TS04. /25#( 1). For each instrument, the number of cycles to fracture (NCF) was calculated, and the fractured fragment length (FL) was measured. To verify that the files were fractured due to cyclic fatigue, the fractured surfaces of the files were evaluated under a scanning electron microscope. Data were statistically analyzed using the Kruskal– Wallis and Student’ s t-tests at the %95 confidence level. Results. The failure of the files due to cyclic fatigue was first seen in the apical curvature before the coronal curvature (P<0. 05). The highest fatigue resistance was observed in VDW. ROTATE and HyFlex CM files in both curvatures (P<0. 05). There were no significant differences in the fatigue resistance between the HyFlex CM and VDW. ROTATE files or between the 2Shape and the TruNatomy files (P>0. 05). There was no difference in the fractured lengths of the files between the apical and coronal curvatures (P>0. 05). Conclusion. In artificial S-shaped root canals, VDW. ROTATE and HyFlex CM files exhibited higher fatigue resistance compared to 2Shape and TruNatomy files.

Background. Bioceramics need to interact chemically with dentin to exhibit adequate bioactivity. Proper bonding of bioceramics with dentin is of considerable importance. This study aimed to evaluate the wettability and marginal adaptation of bioceramics after the use of surface-active agents on dentin: %0. 5 cetrimide and %1 alkylbenzene sulfonate. Methods. Of ninety maxillary central incisors, 45 teeth were sectioned longitudinally with 45 root halves randomly assigned to three groups (n=15): group I: no pre-treatment; group II: %0. 5 cetrimide; group III: %1 alkylbenzene sulfonate. Then, the samples were subdivided into three subgroups (n=5): subgroup I: MTA; subgroup II: Biodentine, and subgroup III: BioRoot. A controlled-volume droplet of bioceramic material was placed on each root half, which was positioned in a dynamic contact angle analyzer to record the static contact angle for wettability. The remaining 45 samples were decoronated; the root canals were prepared and randomly categorized, as mentioned above. The root canal surfaces were treated, filled with the bioceramic material, transversely sectioned, and then each middle section was analyzed microscopically for marginal adaptation. Statistical tests used included post hoc Tukey tests and one-way ANOVA. The level of statistical significance set at %95 (P<0. 05). Results. The contact angle values and interfacial gap width values after surface pre-treatment were significantly lower when compared to no pre-treatment group (P<0. 05). The values were significant for %0. 5 cetrimide in the case of Biodentine and %1 alkylbenzene sulfonate in the case of BioRoot (P<0. 05). Conclusion. The two surfactants yielded promising results for enhancing the wettability and marginal adaptation of materials to the root dentin, which is required for obtaining an adequate seal, penetration, and bond strength of bioceramics.

Background. This study aimed to assess the accuracy of three electronic apex locators (EALs) (Dentaport ZX [J Morita, Tokyo, Japan], Propex Pixi [Dentsply Maillefer, Ballaigues, Switzerland], and iPex II [NSK, Tokyo, Japan]) during root canal retreatment. Methods. The root canal lengths of 90 extracted single-rooted human teeth were determined under a dental operating microscope at ×10 magnification. The actual working length (AWL) was 0. 5 mm less than the root length. Electronic measurements were performed with the three EALs. The root canals were instrumented and filled to the actual working length using the lateral compaction technique. After seven days, the teeth were retreated until the retreatment file was applied to the root canal at the working length determined by EALs, and then, the three EALs were used for determining the retreatment working length. Data were analyzed using chi-squared and Kruskal– Wallis tests. Results. In the retreatment, the accuracy of EALs was reported at %83. 3 for Dentaport ZX, %83. 4 for Propex Pixi, and %80 for iPex II within a tolerance of 0. 5± mm of the AWL. Conclusion. Under the limitations of this study, Dentaport ZX, Propex Pixi, and iPex II can be a useful adjunct during retreatment. Clinicians should be aware that residual materials in the root canal during retreatment can affect the accuracy of EALs.

Background. This experimental study aimed to assess the effects of Vitamins C and E on orthodontic tooth movement. Methods. Fifty-one male Wistar albino rats were divided into six groups: five appliance groups and one control group. The appliance groups had an orthodontic appliance consisting of a closed-coil spring ligated between the maxillary incisor and maxillary first molar (50 g). Vitamin E and C (150 mg/kg) were injected intraperitoneally per day in the first and second groups, respectively. Vitamins E and C (20 μ L) were locally injected into the periodontal gap of the moving teeth in the third and fourth groups, respectively, once every three days. No vitamin was injected in the last (fifth) appliance group. The experimental period was 18 days. Histological and biochemical (alkaline phosphatase, osteocalcin, and NTx levels) evaluations of the samples were performed, and maxillary incisor‒ molar distance was measured before and after the experiment. Results. The amount of tooth movement was similar in the appliance groups. All the vitamin groups showed significantly increased osteoblastic activity, while those treated with systemic vitamins exhibited significantly increased numbers of collagen fibers on the tension side compared to the appliance control group (P<0. 05). Conclusion. Vitamin C and E supplements positively affected bone formation on the tension side of the teeth during experimental orthodontic tooth movement.

Background. Alveolar bone remodeling after tooth loss results in reduced ridge dimensions in horizontal and vertical planes. To prevent this, various authors have proposed different ridge preservation techniques. A collagen plug is a novel material that has shown promising results in preserving the alveolar bone. PRP has also yielded favorable outcomes in wound healing and promoted osteoinduction and osteoconduction Methods. Thirty patients of both sexes with an age range of 30– 18 years requiring bilateral extraction of teeth with similar tooth root anatomy in the maxilla or mandible were included in the study. The extraction of teeth was carried out atraumatically. The patients’ arches were randomly divided and labeled as the test or control sides. Bone width was measured on both sides. A collagen plug, with PRP, was placed, and the extraction socket was sutured on the test side. The control side was just sutured. A baseline RVG was taken to record the apico-coronal height. The patients were recalled after 10 days for suture removal and evaluation of wound healing. Parameters were re-evaluated at three and six months postoperatively. The data were subjected to t-test and one-way ANOVA. Results. The height of the crestal bone on the grafted side was more when compared to the non-grafted side three and six months after tooth extractions, and the difference was statically significant (P<0. 001). No statistically significant difference was seen in the width of the alveolar bone three and six months after tooth extraction (P>0. 05). Conclusion. Collagen and PRP provided reasonable socket preservation as simple and inexpensive options as compared to other materials.