Effects of teriparatide on bone formation in rats with experimentally induced premaxillary expansion.

OBJECTIVE: This study aimed to evaluate the effects of systemic teriparatide on sutural bone formation after premaxillary suture expansion in rats. MATERIAL AND METHODS: Twenty Wistar male rats (8-10 weeks old) were randomly divided into two groups, namely, control (C, n=10) and teriparatide (T, n=10). An expansion force was applied to the maxillary incisors using helical spring for a seven-day expansion period, for both groups. On the eighth day, the rats were kept for a seven-day consolidation period, and then 60 µg/kg teriparatide (once a day) was administered to group T subcutaneously for seven days. Then, all the rats were sacrificed, and histological sections were stained with hemotoxylin-eosin for examination. Anti-osteonectin, anti-osteocalcin, anti-Vascular endothelial growth factor (VEGF) and anti-transforming growth factor beta (TGF-ß) were evaluated by immunohistochemical analysis in the midpalatal suture area. RESULTS: Histologically, the newly formed bone tissue was observed to be larger in group T than in group C. The number of immunoreactive osteoblasts for osteonectin, osteocalcin and VEGF antibodies was significantly higher in group T than in group C (p = 0.0001). The TGF-ß antibody showed a mild reaction in group T, but did not reach significance in comparison with group C (p ˃ 0.05). CONCLUSION: Systemic teriparatide application following the premaxillary expansion of the suture area may stimulate bone formation and add to the consolidation of the expansion in rats by regulating osteonectin, osteocalcin and VEGF.

Does mini-implant-supported rapid maxillary expansion cause less root resorption than traditional approaches? A micro-computed tomography study.

OBJECTIVE: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. METHODS: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: miniimplant- supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. RESULTS: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). CONCLUSIONS: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

Borate and boric acid supplementation of drinking water alters teeth and bone mineral density and composition differently in rabbits fed a high protein and energy diet.

The reported beneficial effects of boron on mineralized tissues in animals and humans vary. Thus, a study was performed to assess whether the variability was the result of different forms of boron supplementation, method of supplementation, and increased adiposity of the rabbit experimental model. Thirty-one female New Zealand White rabbits, (aged 8 months, 2-2.5 kg weight) were fed a grain-based high energy diet containing 11.76 MJ/kg (2850 kcal/kg) and 3.88 mg boron/kg. The rabbits were randomly divided into four treatment groups: Control group was not supplemented with boron (n:7; C), and three groups supplemented with 30 mg boron/L in drinking water in the forms of borax decahydrate (Na2O4B7 10H2O, n:10; BD), borax anhydrous (Na2O4B7, n:7; Bah) or boric acid (H2BO3, n:7; BA). Cone beam micro computed tomographic (micro-CT), histological and elemental analysis was used to evaluate the bones/teeth. Results of the experiments demonstrated that boron supplementation had beneficial effects on mineralized tissue but varied with the type of treatment. Mineral density of the femur was increased by the Bah and BA treatments (p < 0.001), but only BA increased mineral density in the tibia (p = 0.015). In incisor teeth, mineral density of dentin was increased by all boron treatments (p < 0.001), and mineral density of enamel was increased by the BD and Bah treatments. Mineral analysis found that all boron treatments increased the boron concentration in tibia and femur. In the tibia, both the BD and Bah treatments decreased the iron concentration, and the BD treatment decreased the magnesium concentration. Sodium and zinc concentrations in the tibia were decreased by the Bah and BA treatments. The boron treatments did not significantly affect the calcium, copper, molybdenum, potassium phosphorus, and sulfur concentrations. The findings show that boron supplementation can have beneficial effects on mineralized tissues in an animal model with increased adiposity, which is a model of increased inflammatory stress. However, this effect varies with the form of boron supplemented, the method of supplementation, and the mineralized tissue examined.

Three-dimensional soft tissue evaluation after rapid maxillary expansion and mandibular midline distraction osteogenesis.

OBJECTIVES: To evaluate the effects of rapid maxillary expansion (RME) and mandibular midline distraction osteogenesis (MMDO) on facial soft tissues using three-dimensional (3D) images. MATERIALS AND METHODS: A total of 20 patients (average age 15.86 ± 2.17 years) were treated with RME and MMDO using tooth-borne distractors. Three-dimensional photographs of each patient were taken with a stereophotogrammetry system at baseline (T0), at the end of the distraction period (T1), and at the end of the consolidation period (T2). All data were analyzed using a dependent-samples t-test at a significance level of 5%. RESULTS: Total and lower face height increased after MMDO (P < .05). Nasal and mouth width increased after RME as compared with baseline (P < .05). The labiomental angle increased at T1 and decreased at T2 (P < .05). After MMDO, the convexity angle increased while the mandibular angle decreased (P < .05). Upper and lower lip angles increased after RME (P < .05). The distance from the lower lip to the E plane increased after MMDO and decreased after RME (P < .05). CONCLUSIONS: The MMDO and RME procedures provide an efficient nonextraction treatment alternative for transverse maxillomandibular deficiency. MMDO may improve the facial soft tissue profile in the transverse and vertical axis of the mandibular region.

Does the rhythm and appliance type of rapid maxillary expansion have an effect on root resorption?

OBJECTIVES: To evaluate the volume, amount, and localization of root resorption in the upper first premolars by micro-computed tomography (micro-CT) after three different rapid maxillary expansion appliances and two different activation rhythms. MATERIALS AND METHODS: The patients were divided into three groups; Hyrax, acrylic cap splint (ACS), and full coverage acrylic bonded (FCAB) appliances. Each group was then divided into the following two subgroups: rapid maxillary expansion (RME) and semirapid maxillary expansion (SRME). After expansion was completed, the appliances were stabilized for 12 weeks during the retention period. For each group, 10 premolars (for a total of 60 premolars) were scanned with the micro-CT (SkyScan). The reconstructed 3D images of each root sample were divided into six regions. The resorption craters on these six different root surfaces were analyzed by special CTAn (SkyScan) software for direct volumetric measurements. Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests were used for statistical analysis. RESULTS: The total volume of root resorption was less with FCAB than with ACS and Hyrax (P < .001). In all groups, a greater volume of resorption was found on the buccal surface than on the lingual surface (P < .001). No significant differences were found between the RME and SRME groups (P > .05). CONCLUSIONS: All expansion appliances caused root resorption in the upper first premolar teeth, but FCAB may be safer in terms of root resorption. The resorption craters were generally concentrated on the buccal surface. There was no effect of activation rhythm on root resorption.

Comparison of facial soft tissue changes after treatment with 3 different functional appliances.

INTRODUCTION: This study aimed to evaluate the effects of 3 different fixed or removable functional appliances on the soft tissue changes in patients with Class II Division 1 malocclusion using 3-dimensional images. METHODS: A total of 60 patients with Class II Division 1 malocclusion (38 girls and 22 boys; mean age, 12.35 ± 1.01 years) were treated with 3 different functional appliances, namely, Twin-block (TB) (group TB, n = 20), mono-block (MB) (group MB, n = 20), or Herbst (H) (group H, n = 20) for 9.55 ± 1.46 months. Three-dimensional photographs of each patient were taken at the baseline and the end of the therapy with a 3dMD Face system (3dMD, Atlanta, Ga). Statistical analyses were performed using the dependent samples t test, 1-way analysis of variance, Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests. RESULTS: No statistically significant differences were detected for soft tissue changes except for the lower facial width found, at least in group H (P <0.05). Volumetric differences in the mandible were similar between the groups (P >0.05). A statistically significant decrease in total facial height and an increase in convexity angle and facial depth were detected in all groups after treatment compared with the baseline (P <0.05). The upper and lower facial height, lower lip height, and nasal width were statistically significantly increased in the TB and MB groups after treatment compared with the baseline (P <0.05) and similar to those in group H (P >0.05). CONCLUSIONS: TB, MB, and H appliances may promote the facial soft tissue profile, including volumetric improvement, in the mandibular region.

Effects of orthodontic force on root surface damage caused by contact with temporary anchorage devices and on the repair process.

OBJECTIVE: This study aimed to evaluate the effects of force loading on root damage caused by contact with temporary anchorage devices (TADs) during orthodontic treatment and to examine the repair process 4, 8, and 12 weeks after TAD contact by micro-computed tomography (CT). METHODS: We enrolled 42 volunteers who required bilateral upper first premolar extractions. The experimental study design was as follows. For both first premolars, cantilever springs were placed, and then TADs were immediately inserted between the premolars of all volunteers. According to the removal order of the appliances, the participants were divided into the TAD group (Group T: n = 21, only TAD removal) and the spring group (Group S: n = 21, only spring removal). A split-mouth design was adopted in both groups as follows. For each volunteer, the left premolars were extracted 4, 8, or 12 weeks after TAD-root contact. The right premolars were extracted immediately after contact in both groups (Groups T-C and S-C) and used as positive controls. Resorption volumes and numbers of craters were determined by micro-CT. RESULTS: The numbers of resorption craters were higher in Group T than in Group S at 8 and 12 weeks (p < 0.01). Crater volumes were higher in Group T than in Group S at 4 and 12 weeks (p < 0.01, both). CONCLUSIONS: Root injury was not completely repaired 12 weeks after root-TAD contact, even when the TADs were removed in cases of continuous force application.

Treatment of post-orthodontic white spot lesions with CPP-ACP paste: A three year follow up study.

To determine the efficacy of topical applications of 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste in reverting white spot lesions (WSLs) after fixed orthodontic treatment. Forty one participants were randomly assigned to either the test group (CPP-ACP) or the control group (only fluoride toothpaste). All patients used regular fluoride-containing toothpaste. CPPACP paste or fluoridated toothpaste was applied on to tooth surfaces with WSLs twice a day during 36-month after de-bonding. The labial/buccal surfaces of teeth were assessed by use of DIAGNOdent pen (DD), Gorelick Index and ICDAS II criteria at baseline (T1) and 36-month (T2) follow-up visits. The total counts of Streptococcus mutans and Lactobacillus were obtained at T1 and T2. DMFT, DMFS, stimulated flow rate and buffer capacity were calculated in two appointments. Daily usage of CPP-ACP paste was not better than normal care for improving the appearance of WSLs after 36 months.

Treatment of Class II malocclusion with mandibular skeletal anchorage.

INTRODUCTION: The aim of this case report was to present the dentofacial changes obtained with bone anchorage in a Class II patient with moderate to severe crowding. METHODS: A boy, aged 14.5 years, with a dolichofacial type, convex profile, and skeletal and dental Class II relationships was examined. After evaluation, functional treatment with bone anchorage and 4 first premolar extractions was decided as the treatment approach. Miniplates were placed on the buccal shelves of the mandibular third molars. The hook of the anchor was revealed from the first molar level. After surgery, the 4 first premolars were extracted to retract the protrusive mandibular incisors. The maxillary and mandibular first molars were banded, and a lip bumper was inserted to apply elastics and to help distalize the maxillary first molars. Orthodontic forces of 300 to 500 g were applied immediately after placement, originating from the miniscrews to the hooks of the appliance to advance the mandible. RESULTS: After 20 months of treatment, the patient had a dental and skeletal Class I relationship, the mandible was advanced, the maxilla was restrained, and overjet was decreased. CONCLUSIONS: The combination of a bone anchor, Class II elastics, and an inner bow is a promising alternative to functional treatment, along with extractions, in Class II patients.

Dietary arginine silicate inositol complex inhibits periodontal tissue loss in rats with ligature-induced periodontitis.

The purpose of this study was to induce experimental periodontitis in rats previously fed diets containing arginine silicate inositol (ASI) complex and examine the biochemical, immunological, and radiological effects. Fifty two 8-week-old female Sprague Dawley rats were equally divided into four groups. The control group included those fed a standard rat diet with no operation performed during the experiment. The periodontitis, ASI I, and ASI II groups were subjected to experimental periodontitis induction for 11 days after being fed a standard rat diet alone, a diet containing 1.81 g/kg ASI complex, or a diet containing 3.62 g/kg ASI complex, respectively, for 8 weeks. Throughout the 11-day duration of periodontitis induction, all rats were fed standard feed. The rats were euthanized on the eleventh day, and their tissue and blood samples were collected. In the periodontitis group, elevated tissue destruction parameters and reduced tissue formation parameters were found, as compared to the ASI groups. Levels of enzymes, cytokines, and mediators associated with periodontal tissue destruction were lower in rats fed a diet containing ASI complex after experimental periodontitis. These results indicate that ASI complex could be an alternative agent for host modulation.

Microcomputed tomography evaluation of white spot lesion remineralization with various procedures.

INTRODUCTION: The aim of this study was to use microcomputed tomography to evaluate the effects on white spot lesions of 3 remineralizing agents compared with artificial saliva (Inonu University, Malatya, Turkey). The agents were GC Tooth Mousse (GC International, Itabashi-ku, Tokyo, Japan), 50-ppm sodium fluoride solution (Inonu University, Malatya, Turkey), and Clinpro 5000 (3M ESPE Dental Products (St Paul, Minn). The experimental and control teeth were stored in artificial saliva. METHODS: Forty-four extracted premolars were divided into 4 groups of 11 teeth each (3 experimental groups and 1 control group). After white spot lesions were created on the teeth, a remineralizing agent was applied. Microcomputed tomography scanning was performed at the following times: T0 (sound enamel), T1 (day 0, when the white spot lesion was formed), T2 (day 15), and T3 (day 30). Volume, depth, surface area, and mineral density changes of the white spot lesions were evaluated at different time points using CTAn software (SkyScan; Bruker, Kontich, Belgium). RESULTS: GC Tooth Mousse and Clinpro 5000 improved all measurements after 30 days. However, Clinpro 5000 was not as effective in reducing lesion depth as it was in the other parameters. The artificial saliva group and the 50-ppm sodium fluoride solution did not show significant effects in the regression of the white spot lesions at the end of the 30-day experiment. CONCLUSIONS: GC Tooth Mousse and Clinpro 5000 were more effective in remineralization of white spot lesions than sodium fluoride solution and artificial saliva. They can be preferred for use clinically. Microcomputed tomography is a novel and effective method that shows promise in accurately evaluating white spot lesions and remineralization.

Evaluation of the effects of the low-level laser therapy on swelling, pain, and trismus after removal of impacted lower third molar.

BACKGROUND: In current study we aimed to examine the effect of a low-level laser therapy on the pain, mouth opening and swelling of patients whose impacted 3rd molar tooth was extracted in addition measurement volumetrically to the edema with 3dMD face system. METHODS: It was surveyed 15 patients who had bilateral symmetric lower 3rd molars. Surgical sides of patients were randomly separated into two groups: the study group and the control group. It was applied extra oral low-level laser therapy (LLLT, 0.3 W, 40 s, 4 J/cm(2)) to the study group (n = 15) after the surgical operation and on the 2nd day. Only routine postoperative recommendation (ice application) was made in the control (n = 15) group. The maximum mouth opening, pain level and facial swelling evaluated. 3dMD Face® (3dMD, Atlanta, GA) Photogrammetric System was used to evaluate volumetric changes of the swelling. RESULTS: There was no statistically significant difference in the edema and interincisal opening between the groups and the pain level in the laser group was significantly lower than in the control group on the 7(th) postoperative day. CONCLUSIONS: Although there were decreasing trismus, swelling, and pain level, with this LLLT, there was significant difference only in the 7th day pain level in the laser group compared with the control group.

Effects of Different Combinations of Er:YAG Laser-Adhesives on Enamel Demineralization and Bracket Bond Strength.

OBJECTIVE: The purpose of this study was to investigate the demineralization around brackets and shear bond strength (SBS) of brackets bonded to Er:YAG laser-irradiated enamel at different power settings with various adhesive systems combinations. METHODS: A total of 108 premolar teeth were used in this study. Teeth were assigned into three groups according to the etching procedure, then each group divided into three subgroups based on the application of different adhesive systems. There were a total of nine groups as follows. Group 1: Acid + Transbond XT Primer; group 2: Er:YAG (100 mJ, 10 Hz) etching + Transbond XT Primer; group 3: Er:YAG (200 mJ, 10 Hz) etching + Transbond XT Primer; group 4: Transbond Plus self-etching primer (SEP); group 5: Er:YAG (100 mJ, 10 Hz) etching + Transbond Plus SEP; group 6: Er:YAG (200 mJ, 10 Hz) etching + Transbond Plus SEP; group 7: Clearfil Protect Bond; group 8: Er:YAG (100 mJ, 10 Hz) etching + Clearfil Protect Bond; group 9: Er:YAG (200 mJ, 10 Hz) etching + Clearfil Protect Bond. Brackets were bonded with Transbond XT Adhesive Paste in all groups. Teeth to be evaluated for demineralization and SBS were exposed to pH and thermal cyclings, respectively. Then, demineralization samples were scanned with micro-CT to determine lesion depth values. For SBS test, a universal testing machine was used and adhesive remnant was index scored after debonding. Data were analyzed statistically. RESULTS: No significant differences were found among the lesion depth values of the various groups, except for G7 and G8, in which the lowest values were recorded. The lowest SBS values were in G7, whereas the highest were in G9. The differences between the other groups were not significant. CONCLUSIONS: Er:YAG laser did not have a positive effect on prevention of enamel demineralization. When two step self-etch adhesive is preferred for bonding brackets, laser etching at 1 W (100 mJ, 10 Hz) is suggested to improve SBS of brackets.

A Patient- and Family-Centered Care Approach to Orthodontics: Assessment of Feedbacks from Orthodontic Patients and Their Families.

OBJECTIVE: This study aimed to evaluate orthodontic patients and their families' clinical satisfaction and their perception of dentists in the framework of the Patient and Family Centered Care (PFCC) concept. METHODS: The study population comprised patients treated at the Orthodontics clinic and their families. A mixed method research with quantitative and qualitative components was employed by conducting questionnaires with 62 patients and 65 parents. Collected data were recorded on the computer, and analyses were performed. RESULTS: A majority of the patients who received treatment at our clinic were high school graduates, while their parents were university graduates. The patient's and their parents' overall satisfaction were similar. We also found that the patients and their parents expected doctors to have ethical perception and professional behavior in the treatment process. CONCLUSION: According to the results obtained from the survey questionnaires, the patients and their parents expect a dentist to have the following qualities: courtesy, friendliness, respect, punctuality, communication skills, and knowledgeableness. Dentists can optimize clinical and patient satisfaction by providing care and attention based on the principles of patient centered care (PCC) and PFCC and shaped in accordance with the expectations of the patients and their parents.

Micro-CT evaluation of microleakage under orthodontic ceramic brackets bonded with different bonding techniques and adhesives.

AIM: The aim of this study was to evaluate microleakage under orthodontic ceramic brackets bonded with direct and different indirect bonding techniques and adhesives using micro-computed tomography. MATERIALS AND METHODS: A total of 30 human maxillary premolars were randomly separated into five groups with six teeth in each group. In group I, teeth were bonded directly with Transbond XT (3M Unitek). In group II, group III, group IV, and group V, teeth were bonded through an indirect technique with Custom I.Q. (Reliance Orthodontic Products), Sondhi Rapid-Set (3M Unitek), RMbond (RMO), and Transbond IDB (3M Unitek), respectively, following the manufacturer's instructions. Micro-CT system model 1172 of Skyscan (Kontich, Belgium) was used to scan all samples. NRecon (Skyscan) version 1.6, CT-Analyser V.1.11 (Skyscan), and TView (SkyScan, Bvba) software programs were used for microleakage evaluation. Microleakage values between the test groups were assessed using the Kruskal-Wallis test, while the Wilcoxon signed rank test was used for within-group comparisons. The level of significance was set at P < 0.05. RESULTS: According to the Kruskal-Wallis analysis of variance test, there were no significant differences among the tested groups, with regard to volume and percentage (microleakage/region of interest × 100) of microleakage values (P < 0.05). The Wilcoxon signed rank test showed that coronal microleakage volume and percentage values significantly differed for RMbond and Transbond IDB groups. LIMITATIONS: In the study, only ceramic brackets were used and microleakage into mini gaps did not show up on the micro-CT image because 50% silver nitrate solution could not penetrate into mini gaps which are smaller than silver nitrate particles. CONCLUSION: Use of direct and indirect bonding techniques with different adhesives did not significantly affect the amount of microleakage.

The Role of Ideal Angles, Ratios, and Divine Proportions in Aesthetic Evaluation of Adolescents.

OBJECTIVES: The aim of our study was to investigate whether the parameters of ideal angles, ratios, and divine proportions that have been previously mentioned in the literature influence the aesthetic evaluation of Turkish adolescents. MATERIALS AND METHODS: A total of sixty patients (30 males and 30 females) were enrolled in this study. Ages of the subjects ranged from 9 to 17. Pre-treatment extra-oral photographs were taken to evaluate facial aesthetics. Two distinct panels consisting of 50 orthodontists and 50 laypersons were created for scoring the photographs of the patients. Scoring was performed using the VAS scale. Twenty-seven ratios and 19 divine proportions were measured in frontal photographs, and 26 angles were measured in profile photographs. RESULTS: Pearson correlation was used to determine the relationship between the photograph analysis measurements and VAS scores, and then regression analyses were performed to disclose to what extent significant values may warrant the term beauty. CONCLUSION: As a result of our investigations, none of the golden proportions was associated with facial aesthetics according to both orthodontists and laypersons. According to other angles and ratios that were measured, it was determined that orthodontists noticed the sagittal position of the lower jaw, the distance between the eyes and length of the face, whereas laypersons noticed only the distance between the eyes and length of the face. LEVEL OF EVIDENCE V: This journal requires that the authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Bone regeneration by low-level laser therapy and low-intensity pulsed ultrasound therapy in the rabbit calvarium.

OBJECTIVE: We evaluated the efficacy of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS), alone and in combination, in triggering new bone formation. STUDY DESIGN: Sixteen New Zealand white rabbits were given two calvarial defects by using a 6-mm trephine bur, then divided into four treatment groups: control, LLLT, LIPUS, and LLLT+LIPUS. The LLLT and LIPUS groups were treated three times a week for two weeks. The LLLT+LIPUS group received each treatment on the same day, 12h apart, three days a week for two weeks. The animals were sacrificed after three weeks. RESULTS: LLLT and LIPUS, alone and in combination, enhanced new bone formation in comparison to the untreated controls after three weeks (P<0.05); the combined therapy did not produce an additive effect. CONCLUSIONS: Our results demonstrate the efficacy of LLLT or LIPUS in triggering bone regeneration. Therapeutic dose and duration requires further study.

Physical properties of different orthodontic cements.

INTRODUCTION: We evaluated the water absorption, solubility, and compressive strength of different cements and resin-modified glass ionomer cements (RMGICs), namely Adhesor®, Ketac(™) Cem, Ortho Band Paste LC(™), Glass Ionomer Band Cement, and Transbond(™) Plus. Our aims were to compare the mechanical and physical properties of the cements widely used in orthodontics and to define the most suitable cements in an oral environment in terms of those characteristics. MATERIALS AND METHODS: To assess compressive strength, the cements were subjected to compression tests done on a universal testing machine. To test water absorption and solubility, the weight changes in cement specimens were determined after immersion in distilled water for 1, 7, and 30 days. RESULTS: Adhesor® and Ketac(™) Cem presented significantly higher solubility values than other cements after water immersion for 1, 7, and 30 days (p < 0.001). CONCLUSION: Our results revealed that the traditional orthodontic cements have higher water solubility and water absorption values as well as lower compressive strength values than the RMGICs used in this study. Furthermore, Transbond(™) Plus revealed the highest compressive strength, whereas Adhesor® showed the lowest.

Cytotoxicity Evaluation of Bioresorbable Fixation Screws on Human Gingival Fibroblasts and Mouse Osteoblasts by Real-Time Cell Analysis.

PURPOSE: To evaluate the effects of bioresorbable fixation screws (BFSs) on human gingival fibroblast (HGF) and mouse osteoblast (MC3T3-E1) cell viability. MATERIALS AND METHODS: The KLS Martin SonicPins Rx, Synthes RapidSorb Cortex Screws, and Inion CPS Bioabsorbable Fixation System each were incubated in Dulbecco's Modified Eagle Medium for 72 hours according to ISO 10993-5 standards. A real-time cell analyzer was used to evaluate cell survival. After seeding 200-µL cell suspensions in the wells of an E-plate View 96, HGF and MC3T3-E1 cells were treated with the bioactive components released by the bioresorbable materials and monitored every 15 minutes for 96 hours. Statistical significance was determined using 1-way analysis of variance and Tukey-Kramer tests. RESULTS: There were significant differences in the HGF responses to the untreated control conditions and the Synthes (P < .01), Inion (P < .05), and KLS Martin (P < .05) treatments over 48 hours. The Synthes (P < .01) and Inion (P < .01) treatments produced lower HGF cell index values than the untreated control at 72 hours, whereas the KLS Martin treatment did not. When left to elute for 96 hours, there were no significant differences in values among the control and study groups for HGFs (P > .05). All tested BFSs decreased cell survival rates of M3T3C1 cells for 48 hours (P < .01), 72 hours (P < .001), and 96 hours (P < .001). CONCLUSION: Differences in the sensitivities of the 2 tested cell lines to the different BFSs might be the result of the different materials used to manufacture the screws. These results provide fundamental knowledge and new insights for the future design and development of new biocompatible BFSs for oral and maxillofacial surgery.

Effects of contemporary orthodontic composites on tooth color following short-term fixed orthodontic treatment: a controlled clinical study.

BACKGROUND/AIM: To determine the color alterations of natural teeth associated with different orthodontic composites used in comprehensive short-term treatment. MATERIALS AND METHODS: Twenty-two patients were treated with fixed appliances and 22 untreated subjects were also evaluated. Lower incisors were bonded with different orthodontic composites: 42 with Grengloo, 41 with Light Bond, 31 with Kurasper F, and 32 with Transbond XT. The color parameters of the Commission Internationale de l'Eclairage (CIE) were measured for each tooth with a spectrophotometer. Color assessment in relation to time, adhesive material, and their interaction was made with 2-way mixed analysis of variance (ANOVA) and 1-way ANOVA for the color differences (ΔE*). Further analyses were done using Tukey's honestly significant difference tests and paired-samples t-tests. RESULTS: The color of teeth was affected by treatment. The mean L* and a* values increased, whereas the mean b* values decreased. Total color differences of teeth demonstrated visible color changes clinically after treatment, ranging from 1.12 to 3.34 ΔE units. However, there were no significant differences for color of enamel. CONCLUSION: Teeth may be discolored with fixed appliances during treatment. Moreover, contemporary orthodontic composites have similar effects of enamel discoloration.