Effectiveness of vibrational forces on orthodontic treatment : A randomized, controlled clinical trial.

AIM: AcceleDent® Aura (OrthoAccel® Technologies, Bellaire, TX, USA) is a class II medical device with U.S. Food and Drug Administration approval that uses SoftPulse Technology™ to increase the speed of tooth movement. The aim of this study was to evaluate the application of vibrational forces on the rate of canine distalization. METHODS: A total of 20 patients (10 boys and 10 girls) who had class II division 1 malocclusion or severe crowding and indicated first premolar extractions for treatment were included in the study. The patients were divided into two groups: 8 in the control group and 12 in the study group. Three-dimensional digital models were taken just before canine distalization and after space closure using the 3Shape TRIOS® R700 (3Shape Inc., Copenhagen, Denmark) device. Linear measurements between molars and canines were evaluated. The results were assessed with SPSS 23.0 program (IBM, Armonk, NY, USA). RESULTS: One subject was excluded from the study group due to insufficient oral hygiene and poor patient compliance. Tooth movement rates were 1.06 mm/month for mandibular and maxillary canine teeth in the control group. In the study group, tooth movement rates were 1.24 mm/month for maxillary canines and 1.09 mm/month for mandibular canines. These differences were not statistically significant (p > 0.05). CONCLUSION: AcceleDent® Aura is an easy-to-use device; however, in our study its application did not have any positive effects on canine retraction rates.

Effects of skeletally anchored Class II elastics: A pilot study and new approach for treating Class II malocclusion.

OBJECTIVE: To evaluate the skeletal, dentoalveolar, and soft tissue effects of skeletally anchored Class II elastics and compare them with a matched control group treated by a monobloc appliance for the correction of skeletal Class II malocclusion due to mandibular retrusion. MATERIALS AND METHODS: Twelve patients (6 girls, 6 boys) were randomly divided into two groups. In the elastics group, six patients (12.9 ± 1.5 years of age; 3 boys, 3 girls) were treated with skeletally anchored Class II elastics. Two miniplates were placed bilaterally at the ramus of the mandible and the other two miniplates were placed at the aperture piriformis area of the maxilla. In the monobloc group (3 boys and 3 girls; mean age, 12.3 ± 1.6 years), patients used the monobloc appliance. The changes observed in each phase of treatment were evaluated using the Wilcoxon matched-pair sign test. Intergroup comparisons at the initial phase of treatment were analyzed by the Mann-Whitney U test. RESULTS: There were statistically significant group differences in Co-Gn, B-VRL, U1-PP, U1-VRL, Ls-VRL, with significant increases in these parameters in the elastics group (P < .05). The mandibular incisors were protruded in the monobloc group (5.45 ± 1.23°), whereas they were retruded in the elastics group (-3.01 ± 1.66°; P < .01). CONCLUSIONS: The undesirable dentoalveolar effects of the monobloc appliance were eliminated by using miniplate anchorage. Favorable skeletal outcomes can be achieved by skeletal anchorage therapies which could be an alternative to treat skeletal Class II patients with mandibular deficiency.

Shear bond strengths of brackets bonded with a new self-adhering resin composite.

PURPOSE: To determine the shear bond strength (SBS) of orthodontic brackets bonded with a self-adhering resin composite. METHODS: 45 freshly extracted mandibular incisors were randomly divided into 3 groups (n = 15 per group). Brackets were bonded with 3 bonding systems and cured with an LED light. Brackets were bonded with a new self-adhering resin cement in the study group. A conventional etch-and-rinse adhesive system and a self-etching adhesive system were used for comparison. After bonding, the SBS of the brackets were tested with a universal testing machine. RESULTS: Analysis of variance indicated a significant difference between groups (p<0.001). The highest values for SBS were measured in group I (21.80 ± 2.57 MPa). The SBS was significantly lower in groups II and III than in group I (P<.001). The lowest values for SBS were measured in group III (5.90 ± 0.90 MPa). SBS was significantly higher in group II than in group III (p<0.001). CONCLUSIONS: The self-adhering adhesive system showed a clinically insufficient SBS, whereas the SBS of conventional etch-and-rinse adhesive system and the self-etching adhesive system were significantly higher and clinically sufficient.

In vitro evaluation of microleakage of class V cavities restored with new flowable compomers on the primary teeth.

INTRODUCTION: The aim of the study was to evaluate the in vitro microleakage of new flowable compomers in the class V cavities of primary teeth. METHODS: Thirty freshly extracted, non-carious, primary molars without visible defects were used in this study. Class V cavities (n = 60), with the occlusal and cervical margins located in the enamel, were prepared on the buccal and lingual surfaces. The samples were randomly divided into 3 groups of 20 each. Group 1: restored with Twinky Star Flow (Voco, Cuxhaven, Germany), Group 2: restored with Dyract Flow (Dentsply, Konstanz, Germany) and Group 3: restored with R&D Series Nova Compomer Flow (Imicryl, Konya, Turkey) according to the manufacturer's instructions. After a thermocycling regimen of 1000 cycles between 5°C and 55°C, the samples were isolated, immersed in 0.5% basic fuchsine solution for 24 h at 37°C and sectioned longitudinally in a buccolingual direction. The sections were evaluated for values of microleakage with a stereomicroscope. RESULTS: All materials showed microleakage but no statistically significant difference was observed among the groups (p>0.05). The highest microleakage score was observed in group II (1.65 ± 0.49) and group I (1.75 ± 0.44) at occlusal and gingival margins, respectively. CONCLUSIONS: Flowable compomers showed insignificantly least amount of microleakage in class V cavities prepared on primary molars.

Can brackets be bonded with a composite resin after expiration date?

INTRODUCTION: The aim of the study was to compare shear bond strengths of brackets bonded with a composite resin before and after expiration dates. METHODS: Forty-five freshly extracted premolar teeth were randomly divided into 3 groups of 15. Ormco Mini 2000 (Ormco Corp, Glendora, Calif) bicuspid metal brackets were used in the study. Group I: the brackets were bonded with Blugloo (Ormco Corp, Glendora, Calif) adhesive paste before the expiration date. Groups II and III: the brackets were bonded with same light cure composite resin 1 and 2 years after the expiration date. All of the groups were cured with a LED light. After bonding, the shear bond strengths of the brackets were tested with a universal testing machine. One-way ANOVA with post-hoc Tukey tests were used to compare shear bond strengths of the groups. The chi-square test was used to determine significant differences in the adhesive remnant index (ARI) scores between the groups. Significance for all statistical tests was predetermined at p<0.05. RESULTS: No statistically significant difference was found in shear bond strengths and ARI scores between three groups (p<0.05). There was a greater frequency of ARI scores of 2 and 3 and 4 in all groups. CONCLUSIONS: Expiration dates do not have a significant effect on the shear bond strength of the composite material. Further studies are needed to investigate in other ways such as cytotoxicity of the composite resins after expiration date.

The reliability of the Greulich and Pyle atlas when applied to a Southern Turkish population.

OBJECTIVE: The aim of this study was to evaluate the applicability of Greulich and Pyle (GP) method for Southern Turkish population. MATERIALS AND METHODS: Hand and wrist radiographs of 535 patients (276 females, 259 males aged from 10 to 18 years) selected retrospectively from the archive. Skeletal age (SA) estimation was performed according to GP atlas. The chronological age (CA) and SA were compared using the Paired t-test. RESULTS: The mean difference between the CA and SA ranged from 0.07 to 1.11 years. These differences between the CA and estimated SA were statistically significant in group I (10-10.90 years) (P < 0.001), group II (11-11.90 years) (P < 0.050), group III (12-12.90 years) (P < 0.001), group IV (13-13.90 years) (P < 0.010), and group V (14-14.90 years) (P < 0.001) for females. The mean difference between the CA and SA ranged from -0.41 to -1.79 years for females. These differences between the CA and estimated SA were statistically significant in all age groups. CONCLUSIONS: Statistically significant differences were found in the CA and SA assessed by GP method for the Southern Turkish sample. SA was significantly over-predicted in the 10-15 year ages in males and for 10-18 year ages for females. It is appropriate to use GP method in Southern Turkish children; however, a revision is needed for better results and to minimize the mistakes.

Effects of contamination by either blood or a hemostatic agent on the shear bond strength of orthodontic buttons.

OBJECTIVE: To evaluate the effects of contamination by either blood or a hemostatic agent on the shear bond strength (SBS) of orthodontic buttons. METHODS: We used 45 freshly extracted, non-carious, impacted third molars that were divided into 3 groups of 15. Each tooth was etched with 37% phosphoric acid gel for 30 s. Human blood or the blood stopper agent was applied to the tooth surface in groups I and II, respectively. Group III teeth were untreated (controls). Orthodontic buttons were bonded to the teeth using light-curing composite resin. After bonding, the SBS of the button was determined using a Universal testing machine. Any adhesive remaining after debonding was assessed and scored according to the modified adhesive remnant index (ARI). ANOVA with post-hoc Tukey's test was used to determine significant differences in SBS and Fisher's exact test, to determine significant differences in ARI scores among groups. RESULTS: ANOVA indicated a significant difference between groups (p < 0.001). The highest SBS values were measured in group III (10.73 ± 0.96 MPa). The SBS values for teeth in groups I and II were significantly lower than that of group III (p < 0.001). The lowest SBS values were observed in group I teeth (4.17 ± 1.11 MPa) (p < 0.001). CONCLUSIONS: Contamination of tooth surfaces with either blood or hemostatic agent significantly decreased the SBS of orthodontic buttons. When the contamination risk is high, it is recommended to use the blood stopper agent when bonding orthodontic buttons on impacted teeth.

Cephalometric comparison of obstructive sleep apnea patients and healthy controls.

OBJECTIVE: This study aimed to compare the cephalometric characteristics of obstructive sleep apnea (OSA) patients with those of healthy subjects and to determine possible relationships between cephalometric measurements of OSA patients and control subjects. METHODS: Standardized lateral cephalograms of 16 OSA patients and 16 healthy controls were obtained. Airway dimensions and dentofacial parameters were measured using a cephalometric analysis program (Dolphin Imaging Cephalometric and Tracing Software, Chatsworth, CA, USA). All statistical analyses were conducted using SPSS version 17.0.0 (SPSS Inc., Chicago, IL, USA). Descriptive statistics were calculated for all measurements, and the Mann-Whitney U test was used to evaluate intergroup differences. RESULTS: Midface length was significantly shorter and upper lip E-plane length was significantly longer in the OSA group than in the controls (P<.05). SNA, SNB, and mandibular plane angles (GoGn-SN), anterior and posterior facial heights, and posteroanterior face height ratio were similar in both groups. Maxillary length was slightly longer in the OSA group, whereas the mandibular length showed a slight increase in the control group (P<.05). The axial inclination of the lower incisor to its respective plane was normal, whereas the upper incisor was significantly protrusive (P<.05) in the OSA group. Distance between the hyoid and mandible was significantly greater in the OSA group than in the controls, indicating that the hyoid bone was positioned more downward in the OSA group (P<.05). CONCLUSIONS: In this study, the patients with OSA demonstrated significant differences in several craniofacial measurements. OSA patients showed reduced midface length and inferiorly placed hyoid bone and tended to have smaller airway dimensions.

Effects of severity and location of nonsyndromic hypodontia on craniofacial morphology.

OBJECTIVE: To evaluate the effects of severity and location of nonsyndromic hypodontia on craniofacial morphology. MATERIALS AND METHODS: A total of 154 patients with at least two or more congenitally missing teeth were selected and divided into two groups (group I [mild]: patients with two to five missing teeth; group II [severe]: patients with six or more missing teeth). The patients with hypodontia were divided into three groups according to the location of missing teeth in the dental arches (anterior, posterior, and both anterior and posterior) and location of missing teeth between the jaws (maxilla, mandible, and both maxilla and mandible). Fifty Class I patients without any missing teeth served as the control group. Twenty-one measurements were performed on lateral cephalograms. Intergroup differences for the severity and location of hypodontia were analyzed using analysis of variance (ANOVA) and post-hoc Tukey tests. RESULTS: Significant decreases were found in mandibular plane angles (P < .05), upper and lower incisor measurements (P < .05), anterior (P < .001) and posterior (P < .05) face heights, and ramus height (P < .01), as well as a significant increase in the soft tissue convexity angle (P < .05) among the hypodontia groups and control group. These differences were more excessive in the severe hypodontia group. Upper lip-E plane measurements were significantly longer in the mandible group than in the maxilla group (P < .01). CONCLUSIONS: Patients with congenitally missing teeth have different craniofacial morphologies. The severity and location of missing teeth have a significant effect.

Tooth sizes in nonsyndromic hypodontia patients.

OBJECTIVE: To evaluate and compare the sizes of teeth in mild and severe hypodontia patients with those of healthy controls. MATERIALS AND METHODS: Dental casts of 154 patients with two or more congenitally missing teeth were obtained. Patients were divided into two groups according to severity of hypodontia. Group I (mild) consisted of 118 patients with two to five missing teeth. Group II (severe) consisted of 36 patients with six or more missing teeth. In addition, a control group was included, which consisted of 50 patients who had an Angle Class I jaw relationship and no missing teeth. Mesiodistal and labiolingual dimensions of the teeth were measured with a digital caliper on dental casts. The independent-samples t-test was used to evaluate the effect of gender on measurements. Intergroup differences for mesiodistal and labiolingual dimensions were evaluated with analysis of variance and post hoc Tukey tests. RESULTS: Statistically significant differences were found between girls and boys with hypodontia in the mesiodistal dimension of the mandibular first premolar and the labiolingual dimension of the mandibular lateral incisor (P < .01). Mesiodistal and labiolingual width measurements of the teeth of hypodontia patients showed statistically significant differences compared with the control group (P < .05). Most teeth showed significant dimensional reductions in severe hypodontia compared with mild hypodontia (P < .05). CONCLUSIONS: The mesiodistal and labiolingual dimensions of teeth in both mild and severe hypodontia groups were smaller than those in control subjects. The reduction in size was more excessive in the severe hypodontia group. The teeth showing the greatest difference in tooth dimensions were the maxillary lateral incisor (in mesiodistal dimension) and the mandibular canine (labiolingual dimension).

Dentofacial characteristics of patients with rheumatoid arthritis.

OBJECTIVES: The aims of this study are to evaluate the dentofacial morphology of patients with rheumatoid arthritis (RA) and to compare the morphological data with those of healthy age- and sex-matched control subjects. METHODS: Twenty-seven RA patients (mean age, 45.77 ± 8.64 years) and 25 healthy subjects (mean age, 44.80 ± 8.24 years) participated in this prospective study. Clinical and functional evaluations of the RA patients were assessed. The erythrocyte sedimentation rate, C-reactive protein level, rheumatoid factor level, and anti-citrullinated peptide antibodies (ACPA) titers of RA patients were determined, and DAS28 scores were calculated. Linear and angular measurements were performed on cephalometric tracings and condylar erosion was evaluated on lateral panoramic radiographs. Statistical comparison of the two groups was performed with an independent samples t test. Pearson correlation analysis was used to assess the relationship between the clinical and laboratory parameters. RESULTS: Based on DAS28 scores, no patient with RA was in the remission period, 3 patients had low, 23 had medium, and 1 had high disease activity. Sixteen (59.26 %) patients with RA had positive ACPA titers. Lateral cephalometric radiographs revealed statistically significant difference between the two groups for the measurement of U1-NA (millimeter; p = 0.047), U1-NA (degrees; p = 0.031), L1-NB (degrees; p = 0.030), IMPA (L1-MP; p = 0.001), interincisal angle (U1-L1; degrees; p = 0.022) and midface length (Co-A; millimeter; p = 0.033). A significant positive linear correlation was found between disease duration time and DAS28 scores (r = 0.066, p = 0.040). CONCLUSIONS: Dentoalveolar effects of RA on dentofacial morphology are more significant than the skeletal effects. Future studies with larger sample sizes are required to evaluate the exact effects of RA on dentofacial morphology. CLINICAL RELEVANCE: Clinicians should consider the fact that RA-associated dentoalveolar changes can be observed and may affect the orthodontic treatment process.

Effects of different bleaching methods on shear bond strengths of orthodontic brackets.

OBJECTIVE: To evaluate the effects of different bleaching methods on the shear bond strength (SBS) of orthodontic brackets. MATERIALS AND METHODS: Forty-five freshly extracted premolars were randomly divided into three groups (n = 15 per group). In group I, bleaching was performed with the office bleaching method. In group II, bleaching was performed with the home bleaching method. Group III served as the control. Orthodontic brackets were bonded with a light cure composite resin and cured with an LED light. After bonding, the SBS of the brackets were tested with a Universal testing machine. RESULTS: Analysis of variance indicated a significant difference between groups (P < .001). The highest values for SBS were measured in group III (20.99 ± 2.32 MPa). The SBS was significantly lower in groups I and II than in group III (P < .001). The lowest values for SBS were measured in group II (6.42 ± 0.81 MPa). SBS was significantly higher in group I than in group II (P < .001). CONCLUSIONS: Both of the bleaching methods significantly affected the SBS of orthodontic brackets on human enamel. Bleaching with the home bleaching method affected SBS more adversely than did bleaching with the office bleaching method.

Effects of different intracoronal bleaching methods on shear bond strengths of orthodontic brackets.

OBJECTIVE: To evaluate the effects of different intracoronal bleaching methods on the shear bond strengths (SBS) of orthodontic brackets. MATERIALS AND METHODS: Sixty freshly extracted mandibular incisors were randomly divided into four groups (n = 15 per group). After filling the root canals, root fillings were removed 2 mm apical to the cementoenamel junction, and a 2-mm-thick layer of zinc-phosphate cement base was applied. Group 1 served as the control. Intracoronal bleaching was performed with hydrogen peroxide (Opalacence Endo, Ultradent products Inc, South Jordan, Utah) in group 2, sodium perborate (Sultan Healthcare, Englewood, NJ) in group 3, and 37% carbamide peroxide (Whiteness Super Endo, Dentscare, ltda, Joinville, Brazil) in group 4. Orthodontic brackets were bonded with a light cure composite resin and cured with an LED light. After bonding, the SBS of the brackets was tested with a Universal testing machine. RESULTS: Analysis of variance indicated a significant difference between groups (P < .001). The highest values for SBS were measured in group 1 (10.15 ± 1.15 MPa). The SBS was significantly lower in groups 2, 3, and 4 than in group 1 (P < .001). The lowest values for SBS were measured in group 3 (6.17 ± 0.85 MPa). SBS was significantly higher in group 4 than in group 3 (P < .05). CONCLUSIONS: Intracoronal bleaching significantly affected the SBS of orthodontic brackets on human enamel. Bleaching with sodium perborate affects SBS more adversely than does bleaching with other agents.

Comparison of the effects of rapid maxillary expansion and surgically assisted rapid maxillary expansion in the sagittal, vertical and transverse planes

Objective: The aim of this study was to evaluate and compare the effects of rapid maxillary expansion (RME) and surgically assisted RME (SARME) in the sagittal, vertical, and transverse planes. Study design: Orthodontic records of 28 patients were selected retrospectively and divided into two treatment groups. Group 1 comprised 14 patients (4 boys, 10 girls, mean age 14.2 ± 0.74 years) who had been treated with RME. Group 2 comprised 14 patients (4 boys, 10 girls, mean age 19.6 ± 2.73 years) who had been treated with SARME. Measurements were performed on lateral and posteroanterior cephalograms and dental casts obtained before (T0) and after (T1) expansion. Results: Statistically significant differences were found in soft tissue convexity angle, anterior face height, and upper nasal width in group 1, and in U1-NA length and posterior face height measurements in group 2 (P<.05). In both groups significant increases were found in interpremolar, intermolar, maxillary, and lower nasal widths and in anterior lower face height (P<.01). Statistically significant intergroup differences were found in the ANB angle(P<.05) and maxillary intercanine (P<.01) measurements. Conclusion: With both RME and SARME, successful expansion of maxillary dentoalveolar structures and nasalcavity and palatal widening were achieved. Sagittal plane effects of SARME were similar to those of RME on dental skeletal and airway measurements (AU)

Cephalometric evaluation of children with familial Mediterranean fever.

OBJECTIVE: To test the null hypothesis that no differences exist in craniofacial morphology between patients with familial Mediterranean fever (FMF) and the healthy population. MATERIALS AND METHODS: Standardized lateral cephalograms of 32 FMF patients (mean age, 11.50 ± 2.72 years) and 32 healthy controls (mean age, 11.86 ± 2.19 years) were obtained. Cranial and dentofacial parameters were measured using a cephalometric analysis program (Nemoceph Imaging Cephalometric and Tracing Software S.L., Spain). All statistical analyses were conducted using SPSS version 17.0.0 (SPSS Inc., Chicago, Ill). Descriptive statistics were calculated for all measurements, and the independent t-test was used to evaluate intergroup differences. RESULTS: The ANB angle was significantly greater in the FMF group (P < .05). Differences in SNA and SNB angles were insignificant. Anterior (P < .001) and posterior (P < .05) face heights were significantly shorter in the FMF group. Mandibular body length (P < .001) and condylion to gnathion (P < .05) measurements were significantly shorter in the FMF group. The upper lip was more protrusive in the FMF group (P < .05). U1-NA (mm; P < .001) and L1-NB (mm; P < .05) measurements were significantly shorter in the FMF group. CONCLUSION: The hypothesis is rejected. Significant differences exist between the craniofacial morphology of patients with FMF and the healthy population.

Effects of fluorosis and self etching primers on shear bond strengths of orthodontic brackets.

OBJECTIVES: To evaluate the effects fluorosis and self etching primers (SEP) on shear bond strengths (SBS) of orthodontic brackets. METHODS: A total of 48 (24 fluorosed and 24 non-fluorosed) non-carious freshly extracted human permanent premolar teeth were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. Fluorosed and non-fluorosed teeth were randomly assigned to 4 groups of 12 each. In groups I (non-fluorosed teeth) and II (fluorosed teeth), standard etching protocol was used and brackets were bonded with Light Bond. In groups III (non-fluorosed teeth) and IV (fluorosed teeth), Transbond Plus SEP was used and brackets were bonded with Transbond XT Light Cure Adhesive. All specimens were cured with a halogen light. After bonding, SBS of the brackets were tested with Universal testing machine. After debonding, all teeth and brackets in the test groups were examined under 10x magnifications. Any adhesive remained after debonding was assessed and scored according to the modified Adhesive Remnant Index (ARI). RESULTS: ANOVA indicated a significant difference between groups (P<.001). SBS in group II (Light Bond+Fluorosis) were significantly lower than other groups. ARI scores of the groups were also significantly different (P<.001). There was a greater frequency of ARI scores of 1,2 and 3 in group II (Light Bond+Fluorosis). CONCLUSIONS: When standard etching protocol was used enamel fluorosis significantly decreased the bond strength of orthodontic brackets. Satisfactory bond strengths were obtained when SEP was used for bonding brackets to the fluorosed teeth.

Effects of airway problems on maxillary growth: a review.

The volume of air passing through the nose and nasopharinx is limited by its shape and diameter. Continuous airflow through the nasal passage during breathing induces a constant stimulus for the lateral growth of maxilla and for lowering of the palatal vault. Maxillary morphological differences exist between patients with airway problems and control groups, identifying a potential etiological role in these patients. The purpose of this article was to review the literature on the interaction between airway problems and expressed maxillary morphology including specific dental and skeletal malocclusions. Statistically significant differences were found between patients with airway problems and control groups, in maxillary skeletal morphology including shorter maxillary length, more proclined maxillary incisors, thicker and longer soft palate, narrower maxillary arch and higher palatal vault.

Effects of fluorosis and bleaching on shear bond strengths of orthodontic brackets.

OBJECTIVES: To evaluate the effects of fluorosis and bleaching on shear bond strengths of orthodontic brackets. METHODS: A total of 45 (30 fluorosed and 15 non-fluorosed) non-carious freshly extracted human permanent premolar teeth which were extracted for orthodontic reasons and without any caries or visible defects were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. First group consisted of 15 fluorosed teeth. Second group of fluorosed teeth were bleached with a 35% hydrogen peroxide office bleaching agent. Third group served as control. No bleaching procedure was applied. Orthodontic brackets were bonded with a light cure composite resin and cured with a halogen light. After bonding, shear bond strengths of the brackets were tested with Universal testing machine. RESULTS: The results showed that fluorosis only and bleaching of fluorosed teeth significantly reduced the bond strengths of the orthodontic brackets (P < .001). Although bleaching of fluorosed teeth decreased the values more, no statistically significant difference was found between fluorosis group and fluorosis+bleaching group (P > .05). CONCLUSIONS: Fluorosis and bleaching of fluorosed teeth reduce bracket bond strength to enamel, but the bond strength with these still exceed the minimum 6 to 8 MPa required to expect adequate clinical performance.