Comparison of mechanical stability of mini-screws with resorbable blasting media and micro-arc oxidation surface treatments under orthodontic forces: An in vitro biomechanical study.

INTRODUCTION: The aim of this study was to compare the primary stability of mini-screws with different surface treatments such as resorbable blasting media (RBM) and micro-arc oxidation (MAO) under in vitro orthodontic forces. MATERIAL AND METHODS: Thirty-six self-drilling TiAl6V4-ELI grade 23 titanium alloy 1.6×8mm mini-screws were inserted into polyurethane foam blocks and divided into three groups according to surface properties: machine surface (MS), RBM-treated, and MAO-treated. An orthodontic force of 150g was applied to the mini-screws using NiTi coils. Maximum insertion torque (MIT) and maximum removal torque (MRT) were measured with a digital torque screwdriver during insertion and removal. For each mini-screw, stability measurements were made with the Periotest M device at day 0 and weeks 1, 2, 4, 8, and 12. RESULTS: Significant differences in MIT were observed between all groups in pairwise comparisons (P<0.001) with the highest value in the MAO-treated group and the lowest in the MS group. The mean MRT values differed in all three groups (P=0.001). In pairwise comparisons of MRT, only the difference between MS group and RBM-treated group was significant. The highest value was observed in the RBM-treated group, while the lowest value was observed in the MS group. Periotest values were significantly higher in the MAO-treated group than the RBM-treated group at weeks 8 and 12. A positive significant correlation was found between MIT and MRT in all groups. No significant correlation was found between MIT, MRT and Periotest values in all groups. CONCLUSION: RBM-treated group was significantly higher than the MS group in MIT and MRT values. According to Periotest values, RBM-treated group was found to be significantly more stable than the MAO-treated group at weeks 8 and 12. Therefore, RBM surface treatment was found to be more favourable than other surfaces to increase success rate in clinical applications.

Does audiovisual information affect anxiety and perceived pain levels in miniscrew application? - a within-person randomized controlled trial.

BACKGROUND: Anxiety can cause difficulties during surgical procedures. The main objective of this study was to evaluate changes in patients' anxiety and perceived pain levels after receiving audiovisual and verbal information about miniscrew application. MATERIALS AND METHODS: Eighty-eight patients (30 males and 58 females) with a mean age of 18.18 ± 5.39 years who had fixed orthodontic treatment and required miniscrew anchorage took part in this questionnaire-based randomized controlled trial. The participants were randomly allocated to two groups and either watched a video depicting miniscrew application (study group, 44 patients) or were informed verbally about the procedure (control group, 44 patients) before miniscrew placement. The audiovisual information was given via a video containing footage of local anesthesia injection, topical antiseptic application, and miniscrew insertion. The Spielberger State-Trait Anxiety Inventory (STAI) was used to measure anxiety immediately before miniscrew application. Self-drilling miniscrews (8 mm length, 1.5 mm diameter; Aarhus System Miniscrews, American Orthodontics, Washington, USA) were placed in posterior buccal interdental region. Each patient received only one miniscrew. Postoperative pain (PP) was determined using a 100-mm horizontal visual analog scale (VAS). RESULTS: State and total anxiety scores were significantly higher in the study group than in the control group (p = 0.009 and p = 0.011 respectively). The mean PP scores (SD) for control and study groups were 12.86 (14.22) and 12.8 (16.22), respectively. The results of Mann-Whitney U test showed no significant difference (p > 0.05). Participants' PP scores did not have a significant effect on state, trait, or total anxiety scores. There was a weak but significant positive correlation between trait anxiety and state anxiety scores in both groups. CONCLUSION: Using an audiovisual method to inform patients about miniscrew placement increased anxiety levels but did not affect pain perception.

Can We Improve the Laser Etching with the Digitally Controlled Laser Handpiece-Xrunner?

OBJECTIVE: The aim of this study was to compare the shear bond strength (SBS), enamel surface characteristics, and the adhesive remnant index (ARI) scores of different etching methods. BACKGROUND DATA: Laser etching changes the physical characteristics of the enamel surface and these alterations hold promise for the conditioning of enamel for bonding procedures. A new Er:YAG laser handpiece is unique in its ability to digitally control size, shape, and depth of irradiated enamel area. MATERIALS AND METHODS: Ninety-eight premolar teeth were used in this study. Eighty of 98 teeth were divided into four experimental groups of 20 teeth each for SBS testing: (1) 37% phosphoric acid, (2) manual Er:YAG laser (120 mJ, 10 Hz, and 1.2 W), (3) manual Er,Cr:YSGG laser (45 mJ, 50 Hz, and 2.25 W), and (4) digitally controlled Er:YAG laser (Xrunner; 100 mJ, 10 Hz, 1 W). The SBS values and ARI scores were recorded. Eighteen teeth were used to evaluate the surface morphology with scanning electron microscopy and atomic force microscopy after etching and following debonding and restoration. RESULTS: Mean SBS value was 7.75 ± 2.5 MPa for Xrunner and 8.11 ± 3.5, 9.47 ± 3.3, and 7.11 ± 3.7 MPa for the acid, Er,Cr:YSGG, and Er:YAG groups, respectively (p = 0.148). However, the acid etching group demonstrated significantly higher ARI scores (p < 0.001). CONCLUSIONS: All etching methods caused enamel surface irregularities and were effectively restored to its original gloss. Laser etching was found to be an alternative to acid etching; however, the clinical success should be evaluated with further studies.

Intrapulpal Temperature Increase During Er:YAG Laser-Aided Debonding of Ceramic Brackets.

OBJECTIVE: The purpose of this study was to evaluate the temperature changes in the pulp chamber while using a newly introduced application of Er:YAG laser to debond ceramic brackets in a study model with a pulpal circulation with and without thermocycled samples. BACKGROUND DATA: An esthetic alternative to stainless steel brackets, ceramic brackets have been proposed. However, because of their low fracture resistance and high bond strengths, ceramic brackets can cause a problem when they are being removed using conventional techniques. MATERIALS AND METHODS: Experimental Groups A and B were established for samples with or without thermocycling. The same 20 maxillary central incisor and 20 premolar teeth were used in both groups. Pulpal blood microcirculation was simulated using an apparatus described in a previous study. Monocrystalline brackets were bonded by using Transbond XT. In Group A, brackets were debonded using the Er:YAG laser (600 mJ, 2 Hz, long pulse, and no air or water spray) after being stored in distilled water for 24 h. In Group B, brackets were debonded using the same laser system as that used in Group A after being stored in distilled water for 24 h and then thermocycled for a total of 5000 cycles between 5°C and 55°C. The laser irradiation duration and intrapulpal temperature changes were measured. RESULTS: In Group B, the intrapulpal temperature increase of the central incisors was significantly higher than that of the premolar teeth. In the central incisor and premolar teeth groups, there were no statistically significant difference between Groups A and B (p > 0.05). A positive correlation was found between laser irradiation duration and temperature increase (p < 0.01). CONCLUSIONS: The use of Er:YAG laser is an effective method for debonding the monocrystalline ceramic brackets. This method can be used safely under the consideration of intrapulpal temperature changes.

Reliability Assessment of Orthodontic Apps for Cephalometrics.

OBJECTIVE: The aim of this study was to evaluate the accuracy and reliability of cephalometric measurements using iPad apps called CephNinja and SmartCeph Pro. The measurements were compared with the measurements obtained using Dolphin Imaging computer software. METHODS: Twenty digital cephalometric radiographs were randomly selected from the archives and traced using the CephNinja app, SmartCeph Pro app, and Dolphin Imaging software. Twenty-one landmarks and 16 measurements were performed in each program. The statistical analysis was conducted using the Bland-Altman analysis at a significance level of 0.05. RESULTS: For the CephNinja app, there were seven measurements that were in accordance with Dolphin Imaging software. For the SmartCeph Pro app, six measurements were in accordance with Dolphin software. Both apps gave better results for angular measurements than linear ones. CONCLUSION: These findings indicate that, although they are user-friendly, orthodontic apps for cephalometrics are not equal with Dolphin software now and need to be developed to be more reliable for most of the measurements.