Comparison of the Effects of Various Methods Used to Remove Adhesive from Tooth Surfaces on Surface Roughness and Temperature Changes in the Pulp Chamber.

OBJECTIVE: The purpose of the present study was to compare the effects of three methods of removing adhesive on enamel surface roughness and dental pulp temperature. METHODS: Ninety human maxillary premolars were randomly divided into three groups (n=30) according to the type of adhesive clean-up procedure: aluminum oxide-based burs, erbium-doped yttrium aluminum garnet (Er:YAG) laser, and tungsten carbide bur. The surface roughness of enamel was measured using a non-contact optical profilometer. After the first readings of surface roughness were measured (T1), orthodontic brackets were attached to the enamel surface with composite. The brackets on the teeth were debonded using bracket removal pliers. The residue of adhesive was eliminated from the enamel surface of the teeth by different procedures in each group. While removing adhesive from the tooth surface, the intrapulpal temperature rise was simultaneously measured using a thermocouple. One-way ANOVA and post-hoc Tukey HSD tests were used to analyze data with a significance level set at 0.05. RESULTS: The highest roughness average (Ra) values were observed for the Er:YAG laser group, with a significant difference with the aluminum oxide bur group and tungsten carbide bur group (p<0.001). Ra values for the aluminum oxide bur group were significantly lower than those for the other groups (p<0.001). Comparing the thermal changes in each group showed a significant decrease in the Er:YAG laser group, but a significant increase in two other groups. CONCLUSION: Within the limitations of the present study, one-step finisher and polisher bur created the smoothest enamel surface, whereas Er:YAG laser the roughest. Tungsten carbide and aluminum oxide-based burs generated more heat than Er:YAG laser.

Comparison of the Effects of Two Different Analgesics on Bone Regeneration During Mandibular Distraction Osteogenesis.

INTRODUCTION: Mandibular distraction osteogenesis (DO) is frequently used in the management of bone defects and craniofacial deformities, with analgesics commonly administered to relieve acute postoperative pain. This experimental animal study investigated the effects of 2 analgesics, acetaminophen and acemetacin, on bone regeneration after DO. MATERIALS AND METHODS: This study was conducted with 14 mature male New Zealand rabbits (2.8-3.2 kg) randomized into 2 groups of 7. Mandibular osteotomies were performed under optimal operating conditions, and a custom-made distractor was applied to the mandible of each subject, with distraction initiated after a 5-day latency period at a rate of 1.0 mm/d (2 × 0.5 mm/d) for 10 days. Analgesics were administered via oral gavage during the latency period and for the first 5 days of the distraction period for 10 days in total, with group I receiving acetaminophen (200 mg/kg/d) and group II receiving acemetacin (5 mg/kg/d). Subjects were sacrificed and their mandibles dissected at the end of 4 weeks postoperatively. Bone mineral density (BMD) and bone mineral content (BMC) were measured using dual-energy X-ray absorptiometry (DEXA), and histomorphometric analysis was performed to evaluate the quality of newly formed bone. Paired group comparisons of non-normally distributed numerical variables were made using the Mann-Whitney U test, with a P value of <0.05 considered statistically significant. RESULTS: No significant differences in BMC and BMD values of intact bone, newly formed bone, or bone around the pin site were observed between the 2 groups. Histometric analysis also indicated acetaminophen and acemetacin to have similar effects on bone regeneration during distraction. CONCLUSION: Acemetacin may be an alternative to acetaminophen for treating pain associated with DO, given the similarities in the effects of the 2 analgesics on bone regeneration. However, this finding should be supported by further experimental and human studies.

Combined Use of Retraction and Torque Arch with Mini-Screws: A Cephalometric Study.

OBJECTIVE: Our objective was to investigate and quantify the treatment of micro-implant-aided retraction and torque (R&T) arch on dentofacial structures. METHODS: Twelve patients (mean age 21.2 years) who required orthodontic camouflage treatment were included in the study. Following the canine distalization, mini-screws were placed between maxillary first molars and second premolars, and R&T arch was applied for the retraction of incisors. The vertical retraction arms of the arch were adjusted between the apex of the lateral incisor and the alveolar bone so that the retraction force passed through the center of resistance of four incisors and forced the incisors to bodily retraction. Closed coil-springs applying 150 gr of force were used to retract the incisors. The retraction period lasted for 217±34 days. RESULTS: SNA and NV-A decreased (p<0.05), indicating alveolar bone remodeling around Point A. The reduction in the SNA caused a statistically significant decrease in the ANB (p<0.01). SN/1, NA/1, NA-1, and overjet decreased significantly (p<0.01), depending on the retrusion of the incisors. The distances from the apex and incisal point of the central incisor to the SV reference plane also decreased significantly (p<0.01), revealing a nearly parallel movement of the incisors. Anchorage loss of the molars and decrease in nasolabial angle were not significant (p>0.05). CONCLUSION: A combined use of R&T arch with mini-screws is an effective method to retract the incisors without anchorage loss. The type of movement is nearly parallel.

Intraoral Molar Distalization with Intraosseous Mini Screw.

The aim of the present study was to evaluate the effects of the miniscrew-supported, modified Hyrax appliance on bilateral distalization of posterior teeth. A 15-year-old girl with Class II malocclusion (end-to-end molar relationships, space deficiency for maxillary canine) underwent orthodontic treatment. The patient rejected tooth extraction. Then, she was treated with the miniscrew-supported, modified Hyrax appliance. An activation of 1 mm per month was planned. Lateral cephalometric views were used to evaluate distal movement. Distalization was successfully achieved at 4 months. No anchorage loss and incisor protrusion were noted. It would be beneficial to choose this appliance for the distalization of maxillary molars in patients with maxillary incisor protrusion, as this appliance does not cause anchorage loss in the upper jaw.

Level of Social Appearance Anxiety in Individuals with and without Alignment of Teeth.

OBJECTIVE: The aim of this study is to determine the level of social appearance anxiety in individuals with and without alignment of teeth and to demonstrate that orthodontic treatment is effective in reintegrating the individual into society, as well as in improving self-confidence communication skills, and self-esteem. METHODS: The present study included 50 patients (24 males and 26 females) with dental alignment and 50 patients (28 males and 22 females) without dental alignment. The study was performed as an interview study using the Social Appearance Anxiety Scale, which measures emotional, cognitive, and behavioral anxiety felt by the individual due to his/her appearance. Hypotheses were proven by t-test and one-way analysis of variance using the Statistical Package for the Social Sciences program. RESULTS: The mean level of social appearance anxiety was higher in patients with dental misalignment (p<0.05). The result of t-test analysis revealed no significant difference between the scores of male and female participants (p>0.05). CONCLUSION: The level of social appearance anxiety increases in individuals with dental misalignment. However, it is independent from gender.

Effect of a self-etching adhesive containing an antibacterial monomer on clinical periodontal parameters and subgingival microbiologic composition in orthodontic patients.

INTRODUCTION: The aims of this study were to evaluate the effect of a self-etching adhesive system containing an antibacterial monomer on periodontal health and subgingival microbiologic composition in orthodontic patients and to compare it with a conventional adhesive system. METHODS: A split-mouth design was chosen, and 15 patients were included in the study. Brackets in contralateral quadrants were bonded with either a conventional adhesive system (control) or a self-etching adhesive system that contained an antibacterial monomer. Clinical periodontal parameters including plaque index, gingival index, probing depths, and bleeding on probing were determined. Subgingival plaque samples were collected before bracket placement (T0) and at the 6-month follow-up (T1). The real-time TaqMan polymerase chain reaction assay was used to determine the subgingival counts of Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Campylobacter rectus. For clinical periodontal parameters, analysis of covariance (ANCOVA) and, for bacterial counts, Wilcoxon tests were used for statistical comparisons at the P <0.05 level. RESULTS: Clinical periodontal parameters were not changed, and they were not different between the groups from T0 to T1. T forsythensis and F nucleatum increased during the treatment period in both groups (P <0.05). The majority of the bacteria were T nucleatum at T0 and T1 in both groups. Changes in bacterial load from T0 to T1 were not different between groups except for T forsythensis and F nucleatum (P <0.05). CONCLUSIONS: The use of an antibacterial monomer did not have an additional positive effect on clinical periodontal parameters. When used in bonding orthodontic brackets, the antibacterial monomer failed to reduce periodontopathogenic bacteria when compared with the conventional adhesive system during a 6-month treatment period.

Effect of vitamin C on bone formation in the expanded inter-premaxillary suture. Early bone changes.

AIM: The aim of this experimental study was to histomorphometrically evaluate the effects of vitamin C administration on bone formation in response to expansion of the rat inter-premaxillary suture. MATERIALS AND METHODS: A total of 30 50- to 60-day old Wistar male rats were divided into three groups of equal number. The inter-premaxillary suture in each animal was expanded with a 0.49 N force applied to the upper incisors. At 24 h after appliance placement, control animals received saline solution (group I) and two groups were given a single dose of vitamin C using two different methods [locally into the suture (group II) and systemically via intramuscular injection (group III)]. The area of new bone (µm(2)), the perimeter around the new bone (µm), Feret's diameter (µm), and the percentage of new bone to non-ossified tissue (%) were measured and compared. Kruskal-Wallis and Tukey tests were used for statistical evaluation at the p<0.05 level. RESULTS: We observed significant differences among the groups in all histomorphometric parameters. New bone area, bone perimeter, Feret's diameter, and percentage of new bone dimensions were significantly higher in group III than the others (p<0.001). Histomorphometric measurements of bone architecture revealed that this improved in the group administered with vitamin C systemically, while local injection revealed significantly less bone growth than the control group. CONCLUSION: The systemic administration of vitamin C during the early stages of inter-premaxillary suture expansion may stimulate bone growth. However, local injection of this antioxidant into an orthopedically-expanded suture area has negative effects on bone formation.

Effect of antibacterial monomer-containing adhesive on enamel demineralization around orthodontic brackets: an in-vivo study.

INTRODUCTION: The aims of this study were to evaluate the effect of an antibacterial monomer-containing self-etching adhesive in reducing enamel demineralization around orthodontic brackets in vivo and to compare it with the conventional adhesive system quantitatively. METHODS: Fourteen orthodontic patients were randomly divided into 2 equal groups; they received brackets fitted to all their teeth, bonded with either Clearfil Protect Bond (Kuraray Medical, Okayama, Japan) (experimental group) or Transbond XT (3M Unitek, Monrovia, Calif) (control group). Block randomization to obtain equal numbers in each group was used. After 30 days, all first premolars were extracted with orthodontic indications and longitudinally sectioned. Demineralization was assessed by cross-sectional microhardness. Determinations were made at the bracket edge cementing limits and at occlusal and cervical points 100 and 200 µm away from the edge. In all of these positions, 6 indentations were made at depths of 10 to 90 µm from the enamel surface. Analysis of variance (ANOVA) and the Tukey post-hoc test were used. The statistical significance level was set at P <0.05. RESULTS: ANOVA showed statistically significant differences for adhesive type, position, depth, and their interactions (P <0.05). The multiple comparison test showed that the antibacterial monomer-containing adhesive was significantly more efficient than the conventional adhesive system, reducing enamel demineralization in almost all evaluations (P <0.05). CONCLUSIONS: The results indicated that using antibacterial monomer-containing adhesive for bonding orthodontic brackets successfully inhibited caries in vivo. This cariostatic effect was localized at the area around the brackets and was significant after 30 days.

Does a chitosan-containing dentifrice prevent demineralization around orthodontic brackets?

OBJECTIVE: To test the null hypothesis that there is no significant difference between the chitosan-containing and conventional nonfluoridated dentifrices in inhibition of enamel demineralization around orthodontic brackets. MATERIALS AND METHODS: Sixteen orthodontic patients who were scheduled to have extraction of four first premolars for orthodontic reasons were divided into two groups after the power of the study was estimated. Patients in the experimental group were instructed to use chitosan-containing dentifrice (AloeDent), and patients in the control group were instructed to use nonfluoridated dentifrice (Sensodyne Mint). After 60 days, the teeth were extracted and longitudinally sectioned. The demineralization was assessed by cross-sectional microhardness. The determinations were made at the bracket edge cementing limits and at occlusal and cervical points, 100 µm and 200 µm away from the edge. In all these positions, indentations were made at depths of 10, 20, 30, 50, 70, and 90 µm from the enamel surface. Analysis of variance (ANOVA) and Tukey test were used for statistical evaluation at P < .05 level. RESULTS: ANOVA showed statistically significant differences for the factors of dentifrice type, position, and depth (P  =  .000). Statistically significant differences for microhardness values between two tested dentifrices were observed up to 20 µm of depth from the enamel surface (P < .05). Lower microhardness values were found for nonfluoridated dentifrice. Significant microhardness differences were also determined between materials at occlusal and cervical 0 µm positions (P < .05). At these positions, chitosan-containing dentifrice showed lower demineralization than the control. CONCLUSION: Chitosan-containing dentifrice may reduce the enamel decalcification found in patients with poor oral hygiene. The null hypothesis is rejected.

Amorphous calcium phosphate-containing orthodontic composites. Do they prevent demineralisation around orthodontic brackets?

BACKGROUND: A preliminary study using laser fluorescence suggested that amorphous phosphate-containing orthodontic composites may prevent demineralisation around bonded orthodontic brackets. OBJECTIVE: To compare the microhardness of the enamel around brackets bonded with an amorphous calcium phosphate-containing orthodontic composite (ACP-containing) with the microhardness of the enamel around brackets bonded with a conventional composite resin. METHODS: Forty extracted upper premolars were used. Orthodontic brackets were bonded to the teeth with either an ACP-containing composite resin (N = 20) or a conventional composite resin (N = 20). The latter were used as the control. The crowns of all teeth were painted with an acid resistant varnish, leaving a 2 mm ring of exposed enamel around the brackets. The teeth were then subjected to a daily cycle of demineralisation for 6 hours and remineralisation for 18 hours for 21 days. Each tooth was sectioned and the microhardness of the enamel determined 25, 50, 75, 100 and 150 microm from the surface. RESULTS: The enamel was significantly harder 25 microm (p = 0.000) and 50 microm (p = 0.001) from the enamel surface in the teeth with brackets bonded with the ACP-containing composite resin as compared with the control teeth. CONCLUSION: ACP-containing orthodontic composite resins may reduce the enamel decalcification found in patients with poor oral hygiene.

Response of the expanded inter-premaxillary suture to intermittent compression. Early bone changes.

OBJECTIVE: To determine the response of the expanded premaxillary suture in the rat to an externally applied force. Specifically, to investigate early bone changes in the expanded suture to intermittent loading and unloading. METHODS: Twenty-four 50 to 60 day-old Wistar rats were assigned to three groups. The inter-premaxillary sutures in all animals were expanded with a 50 g force applied to the upper incisors. Group I served as the control, whereas in Groups II and III the incisors were subjected to intermittent loading and unloading after five days of expansion. The intermittent forces were produced by a cam (0.416 mm, 100 cycles per minute) applied to the disto-gingival margins of the upper incisors. The mechanical stimuli were applied daily over nine days for six seconds in Group II (30 grams force, 10 cycles/day) and 10 minutes in Group III (30 grams force, 1000 cycles/day). Bone regeneration in the suture was evaluated histomorphometrically. The area of new bone (microm2), the perimeter around the new bone (microm), Feret's diameter (microm) and the percentage of new bone to non-ossified tissue (%) were measured and compared. RESULTS: Statistically significant differences were found between the groups for all histomorphometric parameters. New bone area (p < 0.001), bone perimeter (p < 0.001), Feret's diameter (p < 0.001) and percentage of new bone (p < 0.001) were significantly larger in the experimental groups as compared with the Control group. The histomorphometric measurements confirmed that more new bone was deposited in the sutures subjected to intermittent loading and unloading. CONCLUSION: The application of cyclic loading and unloading to the orthopaedically expanded inter-premaxillary suture during the early retention phase stimulated the formation of new bone.

Demineralization properties of newly erupted and mature premolars around orthodontic brackets: an in-vivo study.

INTRODUCTION: The aims of this study were to evaluate the in-vivo reaction of newly erupted enamel to demineralization around orthodontic brackets and to compare it with that of mature enamel. METHODS: Thirteen orthodontic patients scheduled to have 4 first premolars extracted for orthodontic reasons were divided into 2 groups. Group 1 included 7 younger patients with newly erupted teeth (4 boys, 3 girls; mean age, 11.21 +/- 1.12 years; range, 11-13 years). Group 2 contained 6 adults with mature teeth (5 men, 1 woman; mean age, 34.64 +/- 4.01 years; range, 25-41 years). Brackets were placed, and, 30 days later, the teeth were extracted. These teeth were longitudinally sectioned, and demineralization was assessed by cross-sectional microhardness. Determinations were made at the bracket-edge composite limits and at occlusal and cervical points 100 mum away. Evaluations under the brackets and at the lingual surfaces were made as controls. In all these positions, 6 indentations were made at depths from 10 to 90 mum from the enamel surface. Analysis of variance (ANOVA) and Tukey tests were used for statistical evaluation at the P <0.05 level. RESULTS: ANOVA showed statistically significant differences for tooth type, position, depth, and their interactions (P <0.05), except the tooth type and position interaction. The multiple comparison test showed less demineralization in the enamel around orthodontic brackets bonded to mature teeth campared with newly erupted teeth (P <0.05). CONCLUSIONS: During the 30-day study period, the tooth enamel in the adult orthodontic patients was more resistant to demineralization than that of the younger patients.

Effect of ED-71, a New Active Vitamin D Analog, on Bone Formation in an Orthopedically Expanded Suture in Rats. A Histomorphometric Study.

OBJECTIVES: The aim of this experimental study was to evaluate the effects of ED-71, a new active vitamin D analog, on bone regeneration in response to expansion of the mid-palatal suture, in rats, histomorphometrically. METHODS: Sixteen male 50-60 days old Wistar rats were separated into two equal groups (control and experimental). Both groups were subjected to expansion, and 30 grams of force was applied to the maxillary incisors with a helical-spring. Experimental group was treated with single-dose ED-71 (0.8 mug/kg body weight) in the mid-palatal suture locally and eight control animals received vehicle solution. Bone regeneration in the mid-palatal suture was evaluated by bone histomorphometric method and mineralized area (Md.Ar), fibrosis area (Fb.Ar), mineralized area/fibrosis area (Md.Ar/Fb.Ar), bone area (B.Ar) and osteoblast number (N.Ob) parameters were evaluated. Mann Whitney-U test was used for statistical evaluation at P<.05 level. RESULTS: Statistical analysis showed significant differences between groups for all investigated histomorphometric parameters. Md.Ar (P<.001), Md.Ar/Fb.Ar (P<.001), B.Ar (P<.01) and N.Ob (P<.001) parameters were significantly increased and Fb.Ar (P<.001) measurement was significantly decreased in experimental group. ED-71 group with a mean of 24.55+/-6.47 showed statistically higher N.Ob than the control group (mean N.Ob: 12.82+/-5.81). CONCLUSIONS: ED-71 has positive effects on early phase of bone regeneration in the mid-palatal suture in response to expansion and may be beneficial in routine maxillary expansion procedures.

Efficiency of amorphous calcium phosphate-containing orthodontic composite and resin modified glass ionomer on demineralization evaluated by a new laser fluorescence device.

OBJECTIVES: The aim of this in vitro study was to compare the efficacy of Amorphous Calcium Phosphate (ACP)-containing orthodontic composite and resin-modified glass ionomer cement (RMGIC) on enamel demineralization adjacent to orthodontic brackets evaluated by a new laser fluorescence device. METHODS: Sixty extracted maxillary premolars were used in the present study. Twenty orthodontic brackets were bonded with ACP-containing orthodontic adhesive (Aegis-Ortho), 20 were bonded with RMGIC (Fuji Ortho LC) and 20 were bonded with Transbond XT composite as the control. All samples were then cycled for 21 days through a daily procedure of demineralization for 6 hours and remineralization for 17 hours. After this procedure, demineralization evaluations were undertaken by a pen-type laser fluorescence device (DIAGNO-dent Pen). Analysis of variance (ANOVA) and Tukey test was used for statistical evaluation, at P<.05 level. RESULTS: According to ANOVA, significant demineralization variations (DeltaD) were determined among groups (F=6.650; P<.01). The ACP-containing composite showed the lowest (mean: 8.98+/-2.38) and the control composite showed the highest (mean:12.15+/-3.83) DeltaD, during 21 days demineralization process (P<.01). Significant difference was also observed between the DeltaD scores of the RMGIC (mean: 9.24+/-2.73) and control (P<.05). No significant differences was found in preventive effects of ACP-containing composite and RMGIC (P<.05) against demineralization. CONCLUSIONS: The use of both ACP-containing orthodontic composite and RMGIC should be recommended for any at-risk orthodontic patient to provide preventive actions and potentially remineralize subclinical enamel demineralization.