Maxillary Expansion Via Palatal Mini-Implants: A Preliminary Study

Objective: This study evaluates the skeletal and dental effects of a mini-implant supported maxillary expansion (MISME) appliance that applied forces directly to the maxilla

Mechanical properties of bulk-fill versus nanohybrid composites: effect of layer thickness and application protocols

Objective: The objective of this study was to evaluate the compressive strength, flexural strength and flexural modulus of high-viscosity, low-viscosity bulk-fill, and conventional nano-hybrid resin composite materials alone and when covered with nano-hybrid resin composite at different incremental thicknesses on the bulk-fill composites. Materials and Methods: Specimens (N=60) were fabricated from the following materials or their combinations (n=10 per group): a) conventional nano-hybrid composite Z550 (FK), b) high-viscosity bulk-fill composite (Tetric N Ceram-TBF), c) low-viscosity bulk-fill composite SDR (SDR), d) Sonicfill (SF), e) SDR (2 mm)+FK (2 mm), f) SDR (4 mm)+FK (4 mm). After 24 h water storage, compressive strength was measured in a universal testing machine (1 mm/min). Additional specimens (N=40) (25x2x2 mm3) were made from FK, TBF, SDR and SF in order to determine the flexural strength and the flexural modulus, (n=10) and subjected to three-point bending test (0.5 mm/min). Data were analyzed using one-way ANOVA and Tamhane’s T2 post-hoc tests (p<0.05). Results: The mean compressive strength (MPa) of the nano-hybrid composite (FK) was significantly higher (223.8±41.3) than those of the other groups (123±27 - 170±24) (p<0.001). SDR (4 mm)+FK (2 mm) showed significantly higher compressive strength than when covered with 4 mm (143±30) or when used alone (146±11) (p<0.05). The mean flexural strength (159±31) and the flexural modulus of FK (34±7) was significantly higher than that of the high- or low-viscosity bulk-fill composites (p<0.001). The mean flexural strength of SF (132±20) was significantly higher compared to TBF (95±25) (p<0.05). Conclusion: Bulk-fill resin composites demonstrated poorer mechanical properties compared to nano-hybrid composite but similar to that of SF. Increasing the thickness of low-viscosity bulk-fill composite (SDR) from 2 to 4 mm underneath the nano-hybrid composite (FK) can improve the mechanical properties of the bulk-fill composites. KeywordsBulk-fill composites; Compressive strength; Flexural modulus; Flexural strength; Mechanical properties

Effects of cavity disinfectants on bond strength of an etch-and-rinse adhesive to water- or ethanol-saturated sound and caries-affected dentin

Objective: To evaluate the effect of cavity disinfectants on the immediate microtensile bond strength (TBS) of an etch-and-rinse adhesive to water- and ethanol-saturated sound and caries-affected dentin (CAD). Material and Methods: Thirty-six human molars were sectioned to expose 1/3 of the mid-coronal dentin surface. Sound (n=18) and CAD (n=18) specimens were divided into six groups each (n=3): one positive control (sound), one negative control (CAD), and five experimental groups each. In the control group, dentin surfaces were bonded using an etch-and-rinse adhesive with a traditional water-wet bonding technique. In the experimental groups, ozone was applied before etching and chlorhexidine after etching. In the ethanol-wet bonding groups, acid-etched dentin surfaces were treated with ethanol. Following adhesive application and composite buildups, bonded specimens were sectioned to form sticks. Failure modes were analyzed using a stereomicroscope. Results: The water-wet bonded sound control group yielded the highest TBS among all groups (p0.05). Conclusions: The TBS values of CAD were lower than those of sound dentin. Ethanol-wet bonding improved the TBS of CAD. Ozone application reduced the TBS in both sound and CAD; chlorhexidine improved the immediate TBS after etching in CAD

Short-Term Evaluation of Nasal Changes After Maxillary Surgery

Objective: To determine the nasal soft-tissue profile changes in skeletal Class III patients who underwent maxillary or bimaxillary orthognathic surgery

Microleakage of high viscosity glass-ionomer and glass-carbomer with and without coating before and after hydrothermal aging

Objective: The objective of this study was to evaluate the microleakage patterns of GIC and GGC with and without their protective surface coatings on enamel and dentin margins before and after aging. Material and Methods: Two rectangular cavities (height: 2 mm; width: 3 mm; depth: 1.5 mm) were prepared on each tooth at the cemento-enamel junction were prepared on human permanent molars (N=56) and the teeth were randomly assigned to be restored with one of the following: a) high viscosity glass-ionomer cement (GIC) (EQUIA Fil, C Corp., Tokyo, Japan) (n=28), b) glass-carbomer cement (GCC) (Glass Carbomer Products, Leiden, The Netherlands) (n=28). Half of the teeth were further divided into two groups where one group received protective surface coating (SC) (G-Coat Plus, GC Corp) (n=14) and the other group did not (n=14). Half of the teeth were stored for 24 hours (n=7), and the other half was thermocycled (5000 cycles, 5-55°C) (n=7). For microleakage analysis, the teeth were immersed in 5% methylene blue dye for 24 hours, sectioned into two equal halves. Microleakage patterns were evaluated using stereomicroscope and scored on a scale of 0-3 (0: No dye penetration, 1: Dye penetration less than half of the axial wall, 2: Dye penetration more than half the axial wall, 3: Dye penetration spreading along the axial wall). Data were analyzed using Kruskal-Wallis tests at the significance level of 0.05. Results: Compared to 24 h storage, after thermocycling, surface coating on GIC decreased microleakage significantly compared to GCC (p=0.046) but not for GCC. In the thermocycled groups, coated GIC showed significantly less leakage at the enamel margin but no significant difference was found with both GIC and GCC in the dentin margins. Conclusion: The application of surface coating significantly reduced the microleakage scores of GIC but not GCC, within the enamel margins only.KeywordsGlass-carbomer; Glass-ionomer; Microleakage

Comparison of short-term effects of mini-implant-supported maxillary expansion appliance with two conventional expansion protocols

Objective: This study evaluates the dentoskeletal effects of a mini-implant-supported maxillary expansion (MISME) appliance in comparison with two types of conventional expansion methods. Methods: Records of 42 patients with bilateral or unilateral posterior crossbite were included in this study. The patients were divided into three groups. In group 1, four miniscrews were placed to the palatal region and an acrylic expansion device was bonded on these screws. A bonded maxillary expansion appliance was used in group 2, while a banded expansion appliance was used in group 3. Measurements from cephalometric, postero-anterior radiographs, and dental casts taken before and after expansion were evaluated statistically. Results: ANB angle increased significantly in group 1 and 3. MISME group also showed an increase of SNA angle. Measurements regarding the vertical dimension did not change with MISME but significant posterior rotation was found in group 2 and 3. Overbite value showed a significant decrease in group 2 and 3, but remained stable in group 1. The nasal, maxillary, maxillary intermolar widths showed significant increases in all groups. The difference between MISME group and other groups in maxillary width was significant indicating more skeletal expansion in MISME group. The maxillary molars showed significant buccal tipping in group 2 and 3, while lingual tipping of molars was found in MISME group. Conclusions: MISME can be a better alternative to bonded expansion particularly in patients with vertical growth patterns and lack of anchorage teeth

Can Simple Tests Prior to Endoscopy Predict the OLGA Stage of Gastritis?

Gastritis is a progressive disease that evolves from a non-atrophic to atrophic state and progresses through intestinal metaplasia, with some cases leading eventually to gastric cancer. Since gastritis by definition is an inflammatory process of the mucosal lining of the stomach and is usually associated with pain, we aimed to identify any association between the severity of gastritis and pain and a simple inflammatory marker derived from a complete blood count (CBC). This was a prospective cross-sectional study which enrolled 155 consecutive adult patients who underwent an upper endoscopy. Prior to the endoscopy, all patients were given a questionnaire, numerical rating scale (NRS) and complete blood count evaluation. The biopsy was obtained from the gastric mucosa according to the modified Sydney classification and scored with the Operative Link for Gastritis Assessment (OLGA) scoring system. The results showed a significant correlation between NRS and intestinal metaplasia (p < 0.01); moreover, a correlation was also found between the NRS and OLGA stage (r = 0.469, p < 0.001). A nonlinear curve was constructed for OLGA stage estimation according to NRS scores (r2 was found to be 0.442, with p < 0.001). The results also showed a correlation between the neutrophil to the lymphocyte ratio (NLR) and OLGA stage (p < 0.01). No correlation was found between the other gastric parameters and NLR (p > 0.05). Helicobacter pylori positivity did not correlate with NRS and NLR. As a conclusion, pain measured by NRS and NLR, which are simply calculated from the CBC prior to endoscopy, may be used to predict OLGA stages and estimate the severity of gastritis in endoscopy patients