Color Alterations, Flexural Strength, and Microhardness of 3DPrinted Resins Treated in Different Coloring Agents.

Purpose This study evaluated the color alterations, flexural strength and microhardness properties of two different 3D-printed permanent crown resins. Materials and Methods Samples were produced from two different 3D Print permanent crown resins: Group 1 (Saremco Crowntec; Saremco, Switzerland), Group 2 (P-crown Version 2; Senertek, Turkey). Color changes (ΔE values), flexural strenght and vickers hardness number of the samples were calculated. Data were analyzed with Shapiro-Wilk normality test, Independent-t test, and Mann Whitney-U tests. Significance level was accepted as P<0.05. Results ΔE values for red wine were found to be significantly higher in Group 1 (6.43Å}2.26; P<0.001). The flexural strength values (MPa) of Group 1 were significantly higher than Group 2 in all three solutions (P<0.001). There was no significant difference between the VHN values of the samples kept in wine and coffee solutions (P= 0.271; 0.827). Conclusion 3D printing resins are affected at different levels by coloring solutions. Microhardness and flexural strength of 3D print samples kept in different coloring agents are different.In the use of 3D printing resins, product selection should be made by taking into account the individual factors such as the eating and drinking habits of the patients and the physical properties expected from the sample.

Accuracy of 3 Soft Tissue Prediction Methods After Double-Jaw Orthognathic Surgery in Class III Patients.

PURPOSE: We aimed to evaluate the accuracy and validity of conventional manual prediction method (CM) and 2-dimensional and 3-dimensional (3D) soft tissue prediction methods for Class III bimaxillary orthognathic surgery patients. METHODS: Twenty skeletal Class III patients were included in this study. Soft tissue prediction was achieved with a traditional manual technique, 2-dimensional software (Dolphin Imaging, version 11.5), and 3-dimensional software (SimPlant Master, version 16.0) on preoperative lateral cephalometric radiographs and cone beam computurized tomography (CBCT) images and then compared with postoperative lateral cephalometric radiographs obtained at least 6 months after surgery (mean, 11.5 ± 6.77 months). Forty-eight measurements were done to determine the reliability of the methods. RESULTS: All prediction methods have limited postsurgery prediction accuracy for the subnasal upper lip area. Most of the differences were not more than 3 mm for all study groups, except the 3D software, which predicted the upper lip area to be, on average, 3.08 ± 1.38 mm further back (P < 0.001). Although the conventional method predicted 20 of 48 measurements similar to the final results, the poorest predictions were found at the nasal and labiomental areas (P < 0.001). Two-dimensional software predicted 23 of 48 measurements very close to the final results but made significantly different predictions for the nasolabial and labiomental angles, labrale superius point, and the chin area. CONCLUSIONS: The 3D method predicted, especially the upper lip area, to be significantly and clinically incorrect, and its soft tissue prediction was insufficient compared with the other 2 methods. The 3D software needs to be updated, especially in evaluating soft tissue A point and upper lip changes after surgery.

Use of Laser Systems in Orthodontics.

Laser systems have been used in the practice of dentistry for >35 years. Laser systems have so many advantages, such as increase patient cooperation, reduce the duration of treatment time, and help the orthodontists to enhance the design of a patient's smile to improve treatment efficacy, and the success of orthodontic treatments can also be improved by diminishing the orthodontic pain and the discomfort of the patients. Laser systems also have some disadvantages, such as cost, large space requirements for some types, and high-risk potential for physician and patient if not used at the appropriate wavelength and power density, that is why before incorporating lasers into clinical practice, the physician must fully understand the basic science, safety protocol, and risks associated with them. Lasers have many applications in orthodontics, including accelerating tooth movement, bonding and debonding processes, pain reduction, bone regeneration, etching procedures, increase mini-implant stability, soft tissue procedures (gingivectomy, frenectomy, operculectomy, papilla flattening, uncovering temporary anchorage devices, ablation of aphthous ulcerations, and exposure of impacted teeth), fiberotomy, scanning systems, and welding procedures. In reviewing the literature on the use of laser in orthodontics, many studies have been conducted. The purpose of the present study was to give information about the use of laser in the field of orthodontics, the effects of laser during the postoperative period, and its advantages and disadvantages and to provide general information about the requirements to be considered during the use of laser.

Do total or partial etching procedures effect the rate of white spot lesion formation? A single-center, randomized, controlled clinical trial.

OBJECTIVE: To determine whether total or partial etching procedures influence the appearance of white spot lesions (WSLs). MATERIALS AND METHODS: This split-mouth, double-blind, controlled, randomized study included 20 patients (mean age 16.75 years), who had class I malocclusion, mild crowding, and satisfactory oral hygiene. A total of 40 maxillary quadrants were randomly allocated to be treated using a total etching (TE) or partial etching (PE) protocol. Quantitative light fluorescence images were captured at the beginning and at 3 (T1) and 6 (T2) months after beginning orthodontic treatmen, as well as when the debonding phase of orthodontic treatment was complete (T3). The presence of pre- and posttreatment WSLs was assessed with quantitative light fluorescence software and analyzed with Student's t-test. RESULTS: The analyses showed that, at T2, the total etching group had significantly higher ΔQ and A scores than the partial etching group ( P < .05). The ΔF scores increased significantly at all timepoints in the TE group, but only at T1 and T3 in the PE group. However, no differences were noted at T3 between the TE and PE groups ( P > .05). The inclusion of only right-handed people may have limited the generalizability of the findings. The absence of analyses of the plaque and gingivitis scores of patients was another limitation of this study. CONCLUSIONS: WSL formation was observed mostly in maxillary lateral incisor teeth irrespective of the etching technique. Although PE seems to be more successful in the first 6 months, no difference was observed between PE and TE in the long term for WSL formation.

Relationship between odontogenic bacteremia and orthodontic stripping.

INTRODUCTION: The aim of this study was to evaluate the prevalence of bacteremia associated with an orthodontic stripping procedure. METHODS: The study included 29 orthodontic patients (mean age, 18.2 ± 3.4 years). We used a standardized stripping procedure: a perforated stripping disk with a contra-angle hand piece was used at a low speed (<15,000 rpm; 10 seconds) on the mandibular anterior teeth. Blood samples were collected by inserting a cannula into the left antecubital fossa. A baseline sample was taken before treatment, and a second sample was taken after the stripping procedure. These samples were inoculated into aerobic and anaerobic blood culture bottles and incubated, and the bacterial cultures were identified; the samples collected before and after the stripping procedure were statistically analyzed. RESULTS: Transient bacteremia was not detected in any pretreatment blood sample, but it was found in 1 postoperative blood sample; this sample tested positive for Streptococcussanguis. CONCLUSIONS: The bacterial species in the positive postoperative blood sample was S sanguis, which might be associated with infective endocarditis. Clinicians should explain the level of risk to the patient and consult a concerned medical specialist.