Effect of Ti:Sapphire-femtosecond laser on the surface roughness of ceramics.

BACKGROUND AND OBJECTIVES: Some of these adult patients have ceramic crowns, to which orthodontists have concerns about bonding brackets. The aim of the present study was to evaluate the effect of a Ti:Sapphire femtosecond (fs) laser (Integra-C-3.5, Quantronix, NY) on the surface roughness of two ceramic surfaces (feldspathic and IPS Empress e-Max) and to compare results with those of two other lasers (Er:YAG and Nd:YAG) and conventional techniques, i.e., sandblasting (50 µm) and hydrofluoric (HF) acid. MATERIALS AND METHODS: Ceramic discs were fabricated (n = 150) and divided into two groups, each of which was then divided into five subgroups prepared with Ti:Sapphire fs, Nd:YAG, or Er:YAG lasers, sandblasting, or HF acid (n = 15). The surface roughness of the ceramic discs was evaluated using a profilometer (Mitotoyo Surf Test SJ 201 P/M; Mitutoyo Corp, Japan) before and after each surface treatment. Three traces were recorded for each specimen at three different locations in each direction, providing nine measurements per sample, which were then averaged to obtain the surface roughness value. Data were analyzed using the Wilcoxon signed-rank test (P < <0.05), two-way ANOVA, and Tukey's HSD test (P < 0.05). Additional samples were prepared for each group and evaluated using atomic force microscopy (AFM; NTEGRA Solaris, NTMDT, Russia). RESULTS: No significant difference was found between the feldspathic and IPS Empress e-Max ceramics. The Ti:Sapphire fs laser was associated with the highest mean roughness value. AFM images of the ceramic surfaces treated confirmed that the fs-laser-treated surfaces had the highest degree of irregularity. CONCLUSION: Within the limitations of this in vitro study, the Ti:Sapphire fs laser yielded the highest surface roughness and could be an alternative ceramic surface treatment to increase bond strength.

Effect of Ti:sapphire laser on shear bond strength of orthodontic brackets to ceramic surfaces.

BACKGROUND AND OBJECTIVES: With increasing demand for orthodontic treatments in adults, orthodontists continue to debate the optimal way to prepare ceramic surfaces for bonding. This study evaluated the effects of a Ti:sapphire laser on the shear bond strength (SBS) of orthodontic brackets bonded to two ceramic surfaces (feldspathic and IPS Empress e-Max) and the results were compared with those using two other lasers (Er:YAG and Nd:YAG) and 'conventional' techniques, i.e., sandblasting (50 µm) and hydrofluoric (HF) acid. MATERIALS AND METHODS: In total, 150 ceramic discs were prepared and divided into two groups. In each group, the following five subgroups were prepared: Ti:sapphire laser, Nd:YAG laser, Er:YAG laser, sandblasting, and HF acid. Mandibular incisor brackets were bonded using a light-cured adhesive. The samples were stored in distilled water for 24 hours at 37°C and then thermocycled. Extra samples were prepared and examined using scanning electron microscopy (SEM). SBS testing was performed and failure modes were classified. ANOVA and Tukey's HSD tests were used to compare SBS among the five subgroups (P < 0.05). RESULTS: Feldspathic and IPS Empress e-Max ceramics had similar SBS values. The Ti:sapphire femtosecond laser (16.76 ± 1.37 MPa) produced the highest mean bond strength, followed by sandblasting (12.79 ± 1.42 MPa) and HF acid (11.28 ± 1.26 MPa). The Er:YAG (5.43 ± 1.21 MPa) and Nd:YAG laser (5.36 ± 1.04 MPa) groups were similar and had the lowest SBS values. More homogeneous and regular surfaces were observed in the ablation pattern with the Ti:sapphire laser than with the other treatments by SEM analysis. CONCLUSIONS: Within the limitations of this in vitro study, Ti:sapphire laser- treated surfaces had the highest SBS values. Therefore, this technique may be useful for the pretreatment of ceramic surfaces as an alternative to 'conventional' techniques.

Attention-deficit/hyperactivity disorder symptoms in children with traumatic dental injuries.

AIM: The aim of this study was to compare the symptoms of attention-deficit/hyperactivity disorder (ADHD) in children with TDIs with to non-injured children. MATERIAL AND METHODS: Children between 7 and 16 years old who were admitted to the Selcuk University, Faculty of Dentistry, for treatment of dental trauma were included in the study group (SG). As a control group (CG), children with no reported history of dental trauma were recruited. The Conners' Parent Rating Scale-Revised: Short Form (CPRS-R: S) was used to assess ADHD symptoms. RESULTS: Both groups, SG and CG, composed of 55 children. There were no significant differences in age, gender, and duration of education between SG and CG. Children with TDIs had significantly higher CPRS-R: S Hyperactivity scores. Hyperactivity level was positively correlated with the history of previous dental trauma. There were no associations between number of injured teeth, type of injury, and ADHD symptoms. CONCLUSIONS: These findings suggest that children with TDIs have more hyperactive symptoms than children without dental trauma. Clinicians should screen ADHD symptoms in children with TDIs and refer them for treatment when necessary.

Can demineralized enamel surfaces be bonded safely?

OBJECTIVE: To evaluate and compare the effects of enamel demineralization, microabrasion therapy and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application on the shear bond strength (SBS) of orthodontic brackets bonded to enamel surfaces and enamel color. MATERIALS AND METHODS: Eighty freshly extracted human maxillary premolar teeth were allocated to one of the four groups. Brackets were bonded directly to non-demineralized enamel surfaces in Group I (control group), directly to the demineralized enamel surfaces in Group II, to demineralized enamel surfaces after CPP-ACP application in Group III and to demineralized enamel surfaces after microabrasion therapy in Group IV. The samples were stored in water for 24 h at 37°C and then underwent thermocycling. The SBS in megapascals (MPa) was determined by a shear test with 0.5 mm/min crosshead speed and failure types were classified with modified adhesive remnant index scores. The data were analyzed with one-way analyses of variance (ANOVA), Tukey and chi-square tests at the α = 0.05 level. RESULTS: Significant differences were found among the four groups (F = 21.57, p < 0.01). No significant difference was found between Group I and III (17.12 ± 2.84 and 15.08 ± 3.42 MPa, respectively) or between Group III and IV (12.82 ± 2.64 MPa). The lowest SBS value was determined in Group II (5.88 ± 2.12 MPa). Enamel demineralization, microabrasion therapy and CPP-ACP application affected enamel color significantly. CONCLUSION: CPP-ACP application and microabrasion therapy are able to increase the decreased SBS of orthodontic brackets because of enamel demineralization.

Effects of 2 bracket and ligation types on plaque retention: a quantitative microbiologic analysis with real-time polymerase chain reaction.

INTRODUCTION: The aim of this study was to evaluate the effects of self-ligating brackets and conventional brackets ligated with stainless steel ligatures on dental plaque retention and microbial flora. METHODS: Twenty boys (mean age, 14.2 ± 1.5 years) underwent bonding with self-ligating bracket systems and conventional standard edgewise bracket systems ligated with stainless steel ligatures with a split-mouth design. Clinical measurements, including plaque index, probing pocket depth, and bleeding on probing, were obtained before bonding, 1 week after bonding, and 3 months after bonding. Supragingival plaque samples were obtained at baseline and 3 months after bonding for the detection of bacteria. A quantitative analysis for Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Lactobacillus acidophilus was performed using real-time polymerase chain reaction. The Mann-Whitney U test and the Hotelling T(2) multivariate test were used for statistical comparisons of the groups. RESULTS: The numbers of S mutans, S sobrinus, L casei, and L acidophilus were not statistically different between self-ligating brackets and conventional brackets ligated with stainless steel ligatures (P >0.05). The 2 archwire ligation techniques showed no statistically significant differences in plaque index, bleeding on probing, and probing pocket depth values of the bonded teeth (P >0.05). All clinical parameters and the numbers of all microorganisms showed statistically significant increases from baseline to 3 months after bonding in both groups (P <0.001). CONCLUSIONS: Self-ligating brackets and conventional brackets ligated with stainless steel ligatures do not differ with regard to dental plaque retention.

Comparison of the outcomes of the lower incisor extraction, premolar extraction and non-extraction treatments.

The aim of this retrospective study was to evaluate the treatment outcome of lower incisor extraction and to compare it with premolar extraction and non-extraction treatment. The sample consisted of 60 subjects with Class I malocclusion and moderate crowding. The sample was separated into three groups: extraction of a lower incisor group, extraction of a four first premolar group and a non-extraction group. All groups involved 13 girls and 7 boys with a total of 20 patients. The Peer assessment rating (PAR) index was applied to a patient's pre-treatment (T1) and post-treatment (T2) dental casts. T1 dental casts were also used for determining Bolton discrepancy. One-way analysis of variance and post hoc Tukey HSD tests were used for statistical analysis. For the mean percentage PAR score reduction for each group, there was one significant difference seen between the lower incisor extraction group and the non-extraction group (P = 0.047). For the mean anterior ratios, there were significant differences among premolar extraction group versus non-extraction group (P = 0.042) and non-extraction group versus lower incisor extraction group (P = 0.000). For the mean overall ratios, there were significant differences among the premolar extraction group versus lower incisor extraction group (P = 0.048) and the non-extraction group versus lower incisor extraction group (P = 0.001). Orthodontic treatment without extraction has a better treatment outcome than the four-first premolar extraction and single lower incisor extraction protocols in Class I cases with moderate to severe mandibular anterior crowding.

Maxillary and mandibular mesiodistal tooth sizes among different malocclusions in a sample of the Turkish population.

The purpose of this study was to establish normative data for mesiodistal tooth crown dimensions with respect to malocclusions and gender differences in Turkish sample. The subjects were randomly selected and assigned to three malocclusion groups according to Angle's classification. Each group consisted of 100 individuals between the ages of 13 and 18 years with the following distribution: Class I, 42 males and 58 females; Class II, 52 males and 48 females; and Class III, 51 males and 49 females. An electronic digital calliper was used to measure the mesiodistal tooth width from the right second permanent molar to the left second permanent molar on both upper and lower study casts. For statistical evaluation, one- and two-way analyses of variance and post hoc Tukey's honestly significant difference (HSD) tests were performed. There were statistically significant differences for the maxillary canine (P < 0.001), first premolar (P < 0.05), second molar (P < 0.05), and mandibular canine (P < 0.01) for males, and for all maxillary teeth and the mandibular central (P < 0.05), canine (P < 0.001), and first premolar (P < 0.05) teeth in females among the malocclusion groups. When Angle's classification was evaluated, significant differences were determined, except for the first and second mandibular molars. All mesiodistal widths were also found to be statistically different according to gender dimorphism. A significant relationship was found between mesiodistal tooth size, Angle's classification, and gender. Therefore, tooth dimensions may play a crucial role in treatment planning and in achieving satisfactory interdigitation of the upper and lower dentition following the completion of orthodontic treatment.

New regression equations for mixed-dentition arch analysis in a Turkish sample with no Bolton tooth-size discrepancy.

INTRODUCTION: Our objectives were to establish new regression equations derived from 228 Turkish patients (100 boys, 128 girls) with no intermaxillary tooth-size discrepancy that would give the greatest correlation coefficient for the sum of permanent tooth widths of the canines and the premolars of both jaws, according to sex, and to compare our new data with those from other studies. METHODS: Mesiodistal tooth widths were measured from dental casts. Student t tests were carried out to compare tooth sizes between the sexes and the right and left sides of the arches. The constants a and b in the standard linear regression equation (y = a + bx), the correlation coefficients (r), the coefficients of determination (r2), and the standard errors of the estimates (SEE) were calculated. RESULTS: Statistically significant differences were found between the widths of teeth between the sexes in both the maxillary (P <0.01) and mandibular (P <0.001) arches. The r value was 0.956 to 0.989, with the higher coefficients in the girls. The r2 values were 91% in boys and 98% in girls, and the SEE was better in the maxilla and the mandible (0.013 mm) for the girls. The regression equations produced predictions of mesiodistal width summations for the maxillary and mandibular canine and premolar segments that were much different from other reported studies. CONCLUSIONS: New regression equations were derived for Turkish people. The prediction equations and probability tables should be revised by using subjects with no tooth-size discrepancy.

Transient bacteremia after removal of a bonded maxillary expansion appliance.

INTRODUCTION: The aim of this study was to investigate the presence of transient bacteremia after the removal of a modified bonded rapid maxillary expansion appliance. METHODS: The sample consisted of 25 subjects (15 girls, 10 boys; mean age, 14.4 years; range, 12.2-16.6 years). All subjects underwent rapid maxillary expansion at the start of the orthodontic treatment with the same type of appliance. Two 10-mL blood samples were taken, the first as a baseline and the second 3 minutes after removal of the appliance. All blood samples were incubated in an automated blood culture system, and bacteria were identified by using conventional biochemical methods and API kits (bioMérieux, Marcy l'Etoile, France). RESULTS: Overt soft-tissue bleeding was observed in 11 of the 25 patients during appliance removal, and 8 of 25 patients showed bacteremia after appliance removal. The data were analyzed with the Fisher exact test. No statistically significant relationship was found between overt bleeding and bacteremia incidence (P = 0.054). CONCLUSIONS: Because transient bacteremia is caused by trauma from the removal of the modified bonded rapid maxillary expansion appliance, orthodontists should consider the possibility of bacterial endocarditis in at-risk patients when using splint-type tooth-and-tissue-borne rapid maxillary expansion appliances.

Occlusal contact changes with removable and bonded retainers in a 1-year retention period.

OBJECTIVE: To test the hypothesis that there is no difference in the number of occlusal contacts in centric occlusion in patients treated with bonded and removable retention procedures and a control group during a 1-year retention period. MATERIALS AND METHODS: Twenty-five patients received a removable Hawley retainer, and 25 patients received maxillary and mandibular bonded retainers. The retainer patients were compared with 20 control subjects with normal occlusions. Silicone-based impression bites were used to record occlusal contacts. Paired-sample t-test, analysis of variance (ANOVA), and Tukey tests were used to evaluate intragroup and intergroup differences. RESULTS: An increased number of occlusal contacts were recorded in total-arch and posterior combined (actual/near) teeth during the retention period as compared with the control group. In the Hawley group, actual and total contacts on the first and second molar and actual contacts on the premolar and canine showed statistically significant increases. In the bonded retainer group, near and total contacts on the first and second molars and premolars showed statistically significant increases. Slight occlusal changes were seen in the control sample during the observation period, presumably from growth and development. ANOVA comparisons of total contacts of anterior and posterior teeth indicated statistically significant differences in the three groups on posterior segments. CONCLUSIONS: The hypothesis is rejected. Both retention procedures allowed relative vertical movement of the posterior teeth, but the number of contacts on the posterior segment was increased more in the bonded retainer group than in the Hawley and control groups at the end of retention.

Standards of soft tissue Arnett analysis for surgical planning in Turkish adults.

The aims of this study were (1) to establish standards for Arnett soft tissue cephalometric analysis of Anatolian Turkish young adults and (2) to identify possible gender differences between males and females. After analysing the cephalometric radiographs of 350 individuals, 133 subjects (67 males, mean age 22.6 +/- 2.2 years, and 66 females, mean age 22.1 +/- 2.6 years) with normal antero-posterior and vertical skeletal relationships were selected. The true vertical line was established. The landmarks were marked and soft tissue facial analysis was performed. For statistical evaluation, an independent-samples t-test was used. The lower lip thickness of the Turkish population was lower and menton thickness was greater than Arnett's norms. Turkish subjects have depressed orbital rims, cheek bones, subpupils, upright and thin upper and lower lips, retruded incisors, and pogonion and point B. Most of the Turkish mean harmony values were within the range of Arnett's harmony standards. Soft tissue thicknesses were greater and facial lengths, except upper incisor exposure, were longer in Turkish males than females. These differences between ethnic groups should be taken into consideration when formulating orthodontic/orthognathic treatment plans for patients with dentofacial deformity.

Biomechanical evaluation of chincup treatment with various force vectors.

INTRODUCTION: The aim of this study was to evaluate the biomechanical effects of chincup treatment by using a 3-dimensional finite element model. METHODS: Three-dimensional models of the mandible and the temporomandibular joint were modeled and analyzed. The final mesh consisted of 1572 solid elements with 5432 nodes. The chincup with 500 g of force was applied in a direction from the chin toward the mandibular condyle, the coronoid process, and a point anterior to the coronoid process. Then, the mechanical responses in terms of displacement and von Mises stresses are evaluated. RESULTS: The mandible was displaced backward and downward with the vector passing through the condyle. Forward and upward displacement was recorded with the force vector passing through or anterior to the coronoid process. The mandibular condyle and the coronoid process showed minimal displacement for all force vectors. The highest stress levels were observed in the condylar and posterior ramus regions and increased as the force vector was transferred away from the condyle. CONCLUSIONS: With the limitations of modeling, boundary conditions, and solution assumptions, chincups applied in various directions produce different force vectors, which induce different stress locations and displacements. The force vector is an important determinant of the orthopedic effects of the chincup and therefore should be carefully considered.

Conventional and high intensity halogen light effects on water sorption and microhardness of orthodontic adhesives.

OBJECTIVE: To test the null hypothesis that when the equivalent total light energy is irradiated to three orthodontic adhesive resins, there is no difference between the microhardness and water sorption values regardless of the curing light sources. MATERIALS AND METHODS: Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light-Bond, Transbond XT) and two light intensities (quartz tungsten halogen [QTH] and high intensity quartz tungsten halogen [HQTH]). One half of each of the 40 samples of three adhesive pastes was polymerized for 20 seconds by a QTH light source, and the other half was polymerized for 10 seconds by a HQTH light source. Water sorption was determined and Vickers hardness was established with three measurements per sample at the top, center, and bottom. Statistical analysis was performed using two-way analysis of variance (ANOVA) with multiple comparisons (Tukey-HSD). RESULTS: Statistically significant differences were found among all adhesives for water sorption and hardness values cured with QTH and HQTH. The HQTH curing unit resulted in higher values than did the QTH. The highest water sorption values were observed for Kurasper F cured with HQTH and the lowest value was observed for Transbond XT cured with QTH. For microhardness Light-Bond cured with HQTH produced the highest values, and Transbond XT cured with QTH produced the lowest. CONCLUSIONS: When the equivalent total light energy is irradiated to three orthodontic adhesive resins, there are significant differences between the microhardness and water sorption values cured with the QTH and HQTH light source. The null hypothesis is rejected.

Occlusal contacts with different retention procedures in 1-year follow-up period.

INTRODUCTION: The aim of this follow-up study was to evaluate the number of contacts in centric occlusion during a 1-year retention period in patients treated with 2 retention procedures and in a control sample. METHODS: Twenty patients received modified wraparound Hawley retainers, and 20 received maxillary Jensen plates with mandibular fixed retainers. These retention patients were compared with a control group of 20 subjects with normal occlusions. Silicone-based impression bites were used to record occlusal contacts. Paired and independent-sample t tests were used to evaluate intragroup and intergroup differences. RESULTS: Contacts increased in the total arch and the posterior combined (actual/near) during the retention period compared with the control group. In the Hawley retainer group, actual contacts on the second molars (P <.05), near contacts on the premolars (P <.05), and total contacts on the first molars (P <.05) and premolars (P <.01) had statistically significant increases. In the maxillary Jensen plate and mandibular fixed lingual retainer group, the number of actual contacts on the posterior segment increased. Actual contacts on the first molars (P <.01), second molars (P <.01), premolars (P <.05), and canines (P <.05), and total contacts on the first (P <.05) and second (P <.05) molars had statistically significant increases. During the observation period, some slight occlusal changes were seen in the control sample, presumably from growth and development. At the end of the study, during the 1-year follow-up period, no statistically significant occlusal contact differences were observed in the 3 groups. CONCLUSIONS: Retention procedures carried out in this study allowed relative vertical movement of the posterior teeth.

The effects of rapid maxillary expansion on voice function.

OBJECTIVE: To evaluate the effects of rapid maxillary expansion (RME) on vocal function in patients with bilateral maxillary crossbite. MATERIALS AND METHODS: We designed our research as a prospective, controlled, clinical study. The treatment group and the control group each had 20 subjects for a total of 40 subjects. Acoustic voice samples were recorded from all patients at T1 and T2 by the Multi-Dimensional Voice Program (MDVP Model 5105) for acoustic analysis in Computerized Speech Lab (CSL). RESULTS: No statistically significant differences were found between the treatment and control groups in the means of any parameters. CONCLUSIONS: RME does not change vocal quality or resonance, so it can be safely used with patients.

Chronologic age and skeletal maturation of the cervical vertebrae and hand-wrist: is there a relationship?

INTRODUCTION: The aims of this study were (1) to investigate the relationship between chronologic age and maturation of cervical vertebrae, (2) to identify the relationship between chronologic age and maturation stage evaluated by hand-wrist radiographs, and (3) to determine whether the maturation of cervical vertebrae correlates with maturation indicated by hand-wrist radiographs in a Turkish population. METHODS: The samples were derived from lateral cephalometric and hand-wrist radiographs of 503 subjects (213 male, 290 female; ages, 5.3-24.1 years). Cervical vertebral development was evaluated by the method of Hassel and Farman. Skeletal maturation of each hand-wrist radiograph was determined according to the method described by Björk and Grave, and Brown's system. The Spearman rank-order correlation coefficients were estimated separately for males and females to measure the relationships among chronologic age, cervical vertebral maturation, and the skeletal maturation measured at the hand-wrist. RESULTS: The Spearman correlation coefficients were 0.72 (P <.001) between chronologic age and cervical vertebrae skeletal maturation, and 0.79 (P < .001) between chronologic age and maturation via hand-wrist radiographs. The correlation coefficient between hand-wrist and cervical-vertebrae maturation was 0.86 (P <.001). CONCLUSIONS: The cervical-vertebrae maturation stages are clinically useful maturity indicators of the pubertal growth period Turkish subjects.

Conventional and high-intensity halogen light effects on polymerization shrinkage of orthodontic adhesives.

The objectives of this study were to compare the polymerization shrinkage of three orthodontic adhesives. In addition we wanted to determine the effectiveness of the high-intensity quartz tungsten halogen (HQTH) in curing orthodontic adhesives on polymerization shrinkage with that of the quartz tungsten halogen (QTH). A total of 120 glass ring molds were prepared using a low-speed saw. The internal surface of the glass rings were roughened and etched. Adhesive pastes were placed into the glass molds, which were sandwiched between two glass slides. Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light Bond, and Transbond XT) and two light intensities. One half of each 40 samples of three adhesive pastes was polymerized for 20 seconds by a QTH (Hilux 350), and the other half was polymerized for 10 seconds by a HQTH (Optilux 501). The volumetric polymerization shrinkage for each system was measured through the specific density method modified by Puckett and Smith. Statistical analysis was performed using two-way analysis of variance for intergroup comparisons. The HQTH-curing unit resulted in a more polymerization shrinkage than did the QTH for all investigated adhesives. However, no statistically significant differences were found. The highest shrinkage was observed for Light Bond cured with HQTH (1.59 +/- 0.82%), and the lowest value was observed for Transbond XT cured with QTH (1.23 +/- 0.60%). There are no significant differences in polymerization shrinkage of the three investigated orthodontic adhesives when polymerized with a QTH or a HQTH.

Effects of different rapid maxillary expansion appliances on facial soft tissues using three-dimensional imaging.

OBJECTIVE: To determine three-dimensional (3D) effects of three different rapid maxillary expansion (RME) appliances on facial soft tissues. MATERIALS AND METHODS: Forty-two children (18 boys, 24 girls) who required RME treatment were included in this study. Patients were randomly divided into three equal groups: banded RME, acrylic splint RME, and modified acrylic splint RME. For each patient, 3D images were obtained before treatment (T1) and at the end of the 3-month retention (T2) with the 3dMD system. RESULTS: When three RME appliances were compared in terms of the effects on the facial soft tissues, there were no significant differences among them. The mouth and nasal width showed a significant increase in all groups. Although the effect of the acrylic splint RME appliances on total face height was less than that of the banded RME, there was no significant difference between the appliances. The effect of the modified acrylic splint appliance on the upper lip was significant according to the volumetric measurements (P < .01). CONCLUSIONS: There were no significant differences among three RME appliances on the facial soft tissues. The modified acrylic splint RME produced a more protrusive effect on the upper lip.

Three-dimensional evaluation of hybrid expander appliances: A pilot study.

OBJECTIVE: To evaluate transverse dimensional changes in dentoalveolar and skeletal structures caused by hybrid expander, using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The CBCT records of nine patients (five boys and four girls) (mean age 13.61 ± 0.72 years) treated with hybrid expander were examined. CBCT images were taken at pretreatment and after the expansion. ELSA (point equidistant to both foramina spinosa) was determined as a reference point to compare the distances in all three dimensions. Nineteen transversal dimensions and four angles were measured for both right and left sides. Wilcoxon signed rank test was used for statistical comparison at P < .05 levels. RESULTS: A V-shaped expansion of suture was successfully achieved in all patients without teeth support. The amount of opening was greater in anterior than posterior and in inferior than superior. An 8.75-mm screw expansion was achieved for all patients. Expansion effects reverberated to maxillary central incisor, canine, first premolar, and first molar at 70%, 75%, 92%, and 89%, respectively. The molar teeth tipped buccally (right 3.06° and left 3.24°) as did premolars (right 2.88° and left 3.02°). CONCLUSION: The hybrid expander, minimally invasive expansion appliance that protects teeth by including bone support, can be used easily for rapid maxillary expansion treatment.

Effects of remineralization procedures on shear bond strengths of brackets bonded to demineralized enamel surfaces with self-etch systems.

OBJECTIVE: To compare the effects of different remineralization procedures on the surface roughness of teeth, shear bond strengths (SBSs), and Adhesive Remnant Index scores of self-etching primer (SEP) used to bond orthodontic brackets to previously treated demineralized enamel surfaces. MATERIALS AND METHODS: A total of 140 extracted human premolar teeth were randomly divided into seven equal groups. Group I was the control group. A demineralization procedure was performed in the other six groups. A remineralization procedure was performed before bonding by using casein phosphopeptide-amorphous calcium phosphate, fluoride, a microabrasion mixture (18% hydrochloric acid-fine pumice), a microabrasion agent, and resin infiltration in groups III to VII. Brackets were bonded using a self-etching primer/adhesive system. The specimens were tested for SBS. The roughness and morphology of the enamel surfaces were analyzed using profilometer and scanning electron microscopy. Data were analyzed with analysis of variance, Tukey, and G-tests at the α  =  .05 level. RESULTS: Significant differences were found in the SBS values among the seven groups (F  =  32.69, P  =  .003). The lowest SBS value was found in group II (2.62 ± 1.46 MPa). No significant differences were found between groups I, III, and VII, between groups III and IV, or between groups V and VI. The differences in the roughness values were statistically significant among the groups (P  =  .002). CONCLUSIONS: Remineralization procedures restore the decreased SBS of orthodontic brackets and decrease surface roughness caused by enamel demineralization. SEPs provide clinically acceptable SBS values for bonding orthodontic brackets to previously treated demineralized enamel surfaces.