Effect of ovarian activity on orthodontic tooth movement and gingival crevicular fluid levels of interleukin-1β and prostaglandin E2 in cats

Objective:To evaluate whether there is any correlation between ovarian activity and two potent bone-resorbing mediators (prostaglandin E₂ [PGE₂], interleukin-1β [IL-1β]) secreted from the gingival crevicular fluid (GCF) during orthodontic tooth movement.Materials and Methods:Eighteen female cats were included in this study. Animals were randomly divided into three groups (estrous, anestrous, and ovariectomized groups), each having six queens. Estrous was induced by administration of 150 IU equine chorionic gonadotropin (eCG) to queens of the estrous group. A closed-coil spring, applied with 80 g of tipping force to the canine, was attached between the maxillary canine and mini-implant. GCF was collected on days 0, 6, and 12 from each cat to examine PGE₂ and IL-1β during orthodontic tooth movement in cats. The PGE₂ and IL-1β levels were determined with enzyme-linked immunosorbent assay.Results:There was no significant difference (P > .05) between anestrous and the ovariectomized groups in terms of tooth movement on days 6 and 12 of distalization. In contrast, tooth movement in the estrous group was lower (P < .05) than in the remaining two groups (anestrous and ovariectomized). The mean PGE₂ and IL-1β levels of the canine teeth of the estrous groups were significantly lower than the remaining two groups on days 6 and 12 (P < .05) of coil spring applications.Conclusions:These results indicate that ovarian activity can affect orthodontic tooth movement and GCF levels of IL-1β and PGE₂ in cats.     

Effect of bracket type on halitosis,periodontal status,and microbial colonization

Objective: To determine the effect of bracket type on halitosis, periodontal status, and microbial colonization.Materials and Methods:Forty-six patients scheduled for fixed orthodontic treatment (age 11–16 years) were selected from the orthodontic department of Suleyman Demirel University. Patients were divided into two groups with random distribution of brackets; 23 patients were treated with self-ligating brackets (group SLBs), the others with conventional brackets (group CBs). Halitosis measurements and periodontal and microbial records were obtained before the placement of brackets (T0), 1 week later (T1), and 5 weeks after bonding (T2). Periodontal parameters, including plaque index (PI), gingival index (GI), and bleeding on probing index (BOP), were obtained from all the bonded teeth. Halitosis measurements were performed at the same time. Microbial samples were obtained from the buccal surfaces of all the bonded teeth. Data were analyzed by using a repeated-measurement analysis of variance test for the comparison of parameters between groups and times.Results:Periodontal parameters and halitosis results were higher in the CBs group than in the SLBs group (P < .05). In the SLBs group, halitosis and BOP values revealed no pronounced changes between T1 and T2 (P > .05). Intra- and intergroup comparisons showed that there were no statistically significant differences for microbial colonization between all the time intervals (P > .05).Conclusion:Bracket type has an effect on halitosis and periodontal status. Therefore, self-ligating brackets may be advised in order to prevent patients from developing halitosis and to increase the likelihood of good oral hygiene during orthodontic treatment.     

Temporary deterioration of oral health–related quality of life (OHRQoL) in nonextraction and extraction modalities of comprehensive orthodontic treatment in adolescents

ObjectiveTo evaluate the effects of nonextraction and all first premolar extraction modalities of orthodontic treatment on oral health–related quality of life (OHRQoL) among adolescents.Materials and MethodsSixty-eight adolescents of aged 12–18 years were chosen. Subjects who required nonextraction orthodontic treatment were included in group I, and those who required all first premolar extractions for orthodontic treatment were included in group II. Baseline OHRQoL data (T₀) were recorded before the start of treatment. To evaluate the impact of orthodontic treatment on OHRQoL, the Oral Health Impact Profile-14 (OHIP-14) questionnaire was presented to all subjects for retrospective evaluation at 1 month (T₁), 3 months (T₂), 6 months (T₃) and 1 year (T₄) after the start of orthodontic treatment and 1 week after completion of orthodontic treatment (T₅).ResultsAt T₁ and T₂, the physical pain and physical disability domains of OHIP-14 were impacted significantly by comprehensive orthodontic treatment in both groups (P < .001). The negative impact of orthodontic treatment on OHRQoL was maximum at T₁ and then slowly recovered to the pretreatment level at T₃ in both groups. Recovery of OHIP-14 scores was relatively faster in group I subjects compared to group II subjects. At T₁ and T₂, social disability and handicap domains were deteriorated significantly in group II subjects compared to group I subjects (P < .01).ConclusionsThe severity of OHRQoL deterioration was similar in both modalities of orthodontic treatment, but recovery from negative impacts was relatively slower in the first premolar extraction subjects.     

Flowable Composites for Bonding Orthodontic Retainers

Objective:To test the null hypothesis that there are no statistically significant differences between flowables and an orthodontic adhesive tested in terms of shear bond strength (SBS) and pullout resistance.Materials and Methods:To test the SBS of Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were applied to the enamel surfaces of 15 teeth. Using matrices for application, each composite material was cured for 40 seconds and subjected to SBS testing. To test pullout resistance, 15 samples were prepared for each composite in which a wire was embedded; then the composite was cured for 40 seconds. Later, the ends of the wire were drawn up and tensile stress was applied until the resin failed. Findings were analyzed using an ANOVA and a Tukey HSD test.Results:The SBS values for Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were 19.0 ± 10.9, 14.7 ± 9.3, 22.4 ± 16.3, and 16.8 ± 11.8 MPa, respectively, and mean pullout values were 42.2 ± 13.0, 24.0 ± 6.9, 26.3 ± 9.4, and 33.8 ± 18.0 N, respectively. No statistically significant differences were found among the groups in terms of SBS (P > .05). On the other hand, Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and Flow-Tain (P < .01). However, there were no significant differences among the pullout values of flowables, nor between Light Bond and Tetric Flow (P > .05).Conclusions:The hypothesis is rejected. Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and FlowTain. However, flowable composites provided satisfactory SBS and wire pullout values, comparable to a standard orthodontic resin, and therefore can be used as an alternative for direct bonding of lingual retainers.     

Expression of substance P,calcitonin gene-related peptide, β-endorphin and methionine-enkephalin in human dental pulp tissue after orthodontic intrusion: A pilot study

Objective:To determine the levels of two sensory neuropeptides (substance P [SP] and calcitonin gene-related peptide [CGRP]) and two endogenous opioids (methionine-enkephalin [Met-Enk] and β-endorphin [β-End]) in dental pulp tissue samples subjected to controlled orthodontic intrusive forces.Materials and Methods:Sixteen healthy premolars were selected from eight patients who were undergoing extraction for orthodontic purposes. Eight were randomly used as controls, and the other eight were assigned to an experimental group (controlled orthodontic intrusive forces applied for 24 hours). After this period, teeth were extracted, and pulp samples were obtained. All samples were processed to quantify the expression levels of SP, CGRP, Met-Enk, and β-End using commercial radioimmunoassay kits.Results:All samples exhibited basal levels of both neuropeptides and endogenous opioids. After 24 hours of the intrusive stimulus, all patients reported a tolerable discomfort localized at the involved premolar. Only SP was significantly increased (P < .05). For the other molecules, no statistically significant differences were observed (P > .05); however, they expressed important increasing trends.Conclusions:The expression levels of SP and CGRP in dental pulp samples from the experimental group support the positive correlation between the symptomatic clinical scenario and increased expression levels of neuropeptides, clarifying the role of neurogenic inflammation in early injury response.     

Biochemical markers of bone metabolism during early orthodontic tooth movement with aligners

Objective:To evaluate the expression of receptor activator of nuclear factor-kappa ligand (RANKL), osteoprotegerin (OPG), osteopontin (OPN), interleukin 1β (IL-1β), and transforming growth factor ß1 (TGF-ß1) in the gingival crevicular fluid (GCF) of teeth subjected to orthodontic forces released by aligners.Materials and Methods:A total of 10 healthy, adult patients were selected to participate in this split-mouth study. The treatment plan was designed to obtain only one movement with the first aligner: distalization of a second molar. GCF samples were obtained from pressure and tension sites of the test tooth and from the mesiobuccal and distobuccal sites of the control tooth. The GCF sample volumes were measured using a Periotron 8000. Levels of TGF-β, IL-1β, RANKL, OPG, and OPN were measured by enzyme-linked immunosorbent assay.Results:IL-1β showed a significant increase at the pressure sites after 1 week and 3 weeks with respect to baseline (P < .05) compared with control sites. The kinetics of TGF-1β and OPN were characterized by a significant increase at the tension sites of the test teeth (P < .05) after 3 weeks from the application of orthodontic force. The RANKL level was significantly increased at pressure and tension sites after 1 hour and after 1 week from the application of the orthodontic forces (P = .023 and P = .043, respectively).Conclusions:An increased concentration of bone modeling and remodeling mediators at the pressure sites (IL-1β, RANKL) and tension sites (TGF-1β, OPN) was observed. These scenarios are compatible with previous in vivo and in vitro studies investigating the biological effects of orthodontic tooth movement.     

Comparative short-term in vitro analysis of mutans streptococci adhesion on esthetic,nickel-titanium,and stainless-steel arch wires

Objective: To test the hypothesis that there are no differences in mutans streptococci (MS) adhesion between esthetic and metallic orthodontic arch wires based on their surface characteristics.Materials and Methods:Surface roughness (R_a) and apparent surface free energy (SFE) were measured for six wires—four esthetic, one nickel-titanium (NiTi), and one stainless-steel (SS)—using profilometry and dynamic contact angle analysis, respectively. The amount of MS (Streptococcus mutans and Streptococcus sobrinus) adhering to the wires was quantified using the colony-counting method. The surfaces, coating layers, and MS adhesion were also observed by scanning electron microscopy. Statistical significance was set at P < .05.Results:The R_a values of the esthetic wires were significantly different from one another depending on the coating method (P < .05). The NiTi wire showed the highest SFE, followed by the SS wire and then the four esthetic wires. The NiTi wires produced a significantly higher MS adhesion than did the SS wires (P < .05). The esthetic wires showed significantly lower MS adhesions than did the NiTi wire (P < .05). Pearson correlation analyses found moderate significant positive correlations between the SFE and the S mutans and S sobrinus adhesions (r  =  .636/.427, P < .001/P  =  .001, respectively).Conclusions:The hypothesis is rejected. This study indicates that some esthetic coatings on NiTi alloy might reduce MS adhesion in vitro in the short term.     

Levels of gingival crevicular fluid matrix metalloproteinases in periodontally compromised teeth under orthodontic forces

Objective:To examine levels of matrix metalloproteinases (MMPs)-1, -2, -3, -7, -8, -12, and -13 in the gingival crevicular fluid (GCF) of periodontally compromised teeth at different time points during orthodontic movement.Materials and Methods:Ten controlled periodontitis subjects were submitted to orthodontic treatment. One dental arch was subjected to orthodontic movement, and teeth in the opposite arch were used as controls. GCF samples were collected from the lingual sites of two movement and two control incisors 1 week before orthodontic activation (−7 d), immediately after orthodontic activation, and after 1 hour, 24 hours, and 7, 14, and 21 days. Multiplexed bead immunoassay was used to measure MMPs in GCF. Data were analyzed using Friedman and Wilcoxon statistical tests.Results:The only significant change found over time was in the levels of MMP-1 in the movement group (P < .05). When the two groups were compared after activation, the only statistically significant difference found was in levels of MMP-12 24 hours after activation (P < .05).Conclusions:Our findings suggested that the orthodontic movement of periodontally compromised teeth without active pockets did not result in significant changes in the GCF levels of MMPs.     

Cytotoxic effects of orthodontic composites

Objectives:To evaluate the cytotoxic effects of five different light-cured orthodontic bonding composites.Materials and Methods:The orthodontic composites Heliosit Orthodontic (Ivoclar), Transbond XT (3M Unitek), Bisco ORTHO (Bisco), Light Bond (Reliance), and Quick Cure (Reliance) were prepared, and the samples were extracted in 3 mL of BME (Basal Medium Eagle) with 10% newborn calf serum for 24 hours. The L929 cells were plated (25,000 cells/mL) in a 96-well dish and maintained in a humidified incubator for 24 hours at 37°C, 5% CO₂, and 95% air. After 24 hours of incubation of the cells, the incubation medium was replaced by the immersed medium in which the samples were stored. Then, L929 cells were incubated in contact with eluates for 24 hours. The cell mitochondrial activity was evaluated by the methyl tetrazolium (MTT) test. Twelve wells were used for each specimen, and the MTT tests were applied two times. The data were statistically analyzed by one-way analysis of variance (ANOVA) and Tukey HSD tests.Results:Results with L929 fibroblasts demonstrated that except for Transbond XT, freshly prepared composite materials did not reduce vital cell numbers (P > .05) compared with the control group. Our data demonstrate that Transbond XT showed significant cytotoxicity compared with the control group.Conclusion:Results indicate that tested orthodontic bonding composites are suitable for clinical application, but that further studies using different test methods are needed for Transbond XT.     

The effect of N-acetylcysteine on the antibacterial capability and biocompatibility of nano silver–containing orthodontic cement

ObjectivesTo determine whether the incorporation of N-acetylcysteine (NAC) improves the antibacterial ability and biocompatibility of nano silver (NAg)–containing orthodontic cement.Materials and MethodsNAg was synthesized using a sodium citrate reduction method. NAg particles were characterized using transmission electron microscopy and ultraviolet-visible absorption spectra. NAg and NAC were incorporated into a resin-modified glass ionomer cement. Enamel shear bond strength (SBS), antibacterial capability, and cytotoxicity were evaluated.ResultsIncorporating 0.15% NAg and 20% NAC had no adverse effect on the SBS of orthodontic cement (P > .1). Adding NAC into NAg-containing cement greatly reduced the biofilm metabolic activity and lactic acid production (P < .05) and lowered the colony unit–forming counts by approximately 1 log (P < .05). The cell viability against NAg-containing cement was improved by NAC (P < .05).ConclusionsThe incorporation of NAC into NAg-containing cement achieved stronger antibacterial capability and better biocompatibility, without compromising the enamel SBS. The combined use of NAC and NAg is promising to combat caries in orthodontic practice.     

Fixed Orthodontic Appliance Therapy and Its Impact on Oral Health-Related Quality of Life in Chinese Patients

Objective:To determine changes in oral health-related quality of life (OHRQoL) during fixed orthodontic appliance therapy in Chinese patients.Materials and Methods:Two-hundred fifty Chinese orthodontic patients completed six distinct intervals of the 14-item Oral Health Impact Profile (OHIP-14, Chinese version): before treatment (T0); after the placement of the fixed appliance at 1 week (T1), 1 month (T2), 3 months (T3), and 6 months (T4); and posttreatment (T5).Results:The overall response rate was 88.8% (222 of 250). Significant differences of overall OHIP-14 scores could be found between any two time points (P < .001), except for between T0 and T2 (P > .05) and between T3 and T4 (P > .05). Overall scores at T1 were significantly higher than the scores at the other intervals (P < .001), with a significant change in the scores on physical pain (P < .001), psychological discomfort (P < .001), and physical disability (P < .001). Scores at T5 were lowest among the six time points (P < .001).Conclusions:Fixed orthodontic appliance therapy did affect Chinese patients'' OHRQoL. Patients were considerably compromised in terms of their overall OHRQoL until approximately 1 month after insertion. The severity of the compromised condition in terms of overall OHRQoL was greatest at 1 week with the reported impact on physical pain, psychological discomfort, and physical disability. Patients'' OHRQoL was better after they completed the orthodontic treatment than before or during treatment.     

Debris,Roughness and Friction of Stainless Steel Archwires Following Clinical Use

Objective:To investigate the degree of debris, roughness, and friction of stainless steel orthodontic archwires before and after clinical use.Materials and Methods:For eight individuals, two sets of three brackets (n  =  16) each were bonded from the first molar to the first premolar. A passive segment of 0.019- × 0.025-inch stainless steel archwire was inserted into the brackets and tied by elastomeric ligature. Debris level (via scanning electron microscopy), roughness, and frictional force were evaluated as-received and after 8 weeks of intraoral exposure. Mann-Whitney, Wilcoxon signed-rank, and Spearman correlation tests were used for statistical analysis at the .05 level of significance.Results:There were significant increases in the level of debris (P  =  .0004), roughness of orthodontic wires (P  =  .002), and friction (P  =  .0001) after intraoral exposure. Significant positive correlations (P < .05) were observed between these three variables.Conclusion:Stainless steel rectangular wires, when exposed to the intraoral environment for 8 weeks, showed a significant increase in the degree of debris and surface roughness, causing an increase in friction between the wire and bracket during the mechanics of sliding.     

Mandibular vertical asymmetry in adult orthodontic patients with different vertical growth patterns: A cone beam computed tomography study

Objective:To evaluate condylar and ramal vertical asymmetry in adult orthodontic patients with different vertical growth patterns and a clinically normal sagittal skeletal pattern using cone-beam computed tomography (CBCT).Materials and Methods:The study sample consisted of 101 adult orthodontic patients (48 men and 53 women) divided into three groups according to their vertical growth patterns: high- (33 patients; mean age, 25.06 ± 6.05 years), low- (34 patients; mean age, 24.88 ± 5.22 years), and normal-angle (34 patients; mean age, 24.14 ± 4.26 years) groups. Condylar, ramal, condylar plus ramal height, and index measurements were performed using CBCT images and analyzed using one-way analysis of variance and post hoc Tukey tests.Results:There was no statistically significant difference in height measurements between right and left sides in each group, except a slight difference of approximately 0.5 mm for condylar height (CH) in the low-angle group (P < .05). No statistically significant gender differences were found for the values (P > .05). In the high-angle group, the ramal height (RH) and condylar plus ramal height (CH + RH) on both sides were found to be less than those of the low- (P < .001) and normal-angle groups (P < .017 and P > .017, respectively), and the asymmetry index values were slightly higher than those of the low- and normal-angle groups (P > .05).Conclusions:The high-angle group showed statistically significantly smaller values of RH and CH + RH on both sides and statistically insignificantly higher asymmetry index values than the low- and normal-angle groups.     

Effectiveness of twin-block and Mandibular Protraction Appliance-IV in the improvement of pharyngeal airway passage dimensions in Class II malocclusion subjects with a retrognathic mandible

Objective:To test the hypothesis that twin-block and Mandibular Protraction Appliance-IV (MPA-IV) are not effective in improving the pharyngeal airway passage (PAP) dimensions among Class II malocclusion subjects with a retrognathic mandible.Materials and Methods:Eighty-three subjects ranging in age from 8 to 14 years were divided into four groups. Group I included 30 Class I malocclusion subjects (healthy controls); group II consisted of 16 Class II malocclusion subjects (Class II controls); group III had 16 subjects in whom Class II malocclusion was treated by MPA-IV; and the remaining 21 subjects formed group IV, whose Class II malocclusions were corrected by twin-block appliance. Lateral cephalograms recorded at the beginning of orthodontic treatment in group I subjects and at the beginning and end of follow-up/treatment with functional appliance in group II, III, and IV subjects were analyzed to determine the PAP dimensions. Paired t-test, one-way analysis of variance, and Tukey tests were applied for statistical analysis, and a P-value .05 was considered statistically significant.Results:Soft palate length was decreased significantly in group III (P < .05) and group IV (P < .001) subjects. Soft palate thickness in group IV subjects was increased significantly as compared to group II (P < .05) and group III (P < .01) subjects. The improvement in soft palate inclination in group III and group IV subjects was significant (P < .01). The oropharynx depth was increased significantly in group III (P < .05) and group IV (P < .001) subjects. The depth of the hypopharynx was increased significantly (P < .01) in group IV subjects.Conclusions:The twin-block appliance was more efficient than the MPA-IV in the improvement of PAP dimensions among Class II malocclusion subjects with retrognathic mandible.     

Parents' preferences regarding appearance and attire of orthodontists

Objective:To evaluate parents'' preferences regarding the appearance and attire of orthodontists.Materials and Methods:Parents attending their child''s first orthodontic appointment were asked to choose from among sets of photographs of potential orthodontic providers. Selected factors were varied within the sets, including sex and age of the provider as well as attire (casual, formal, white coat, or scrubs), hairstyle (loose or tied back for women, facial hair or clean shaven for men), and presence of a nametag.Results:A total of 77 parents participated. There were significant differences in choice of provider in terms of the provider''s sex (P < .0001), age (P  =  .0013), dress (P < .0001), hair (P < .0001), and nametag (P  =  .0065). There were no significant differences in preference attributable to parent characteristics (P > .05).Conclusion:Parents of orthodontic patients demonstrated clear preferences for choosing a provider related to factors that are not within the control of the practitioner (sex and age) as well as factors that can be changed by the practitioner (attire, hairstyle, and wearing a nametag).     

Effectiveness of metronidazole gel and mobile telephone short-message service reminders on gingivitis in orthodontic patients:: A double-blind randomized controlled trial

ObjectivesTo compare the effectiveness of metronidazole gel and mobile telephone short-message service (SMS) reminders on gingivitis in patients undergoing fixed orthodontic treatment.Materials and MethodsThe trial was double blinded (patient and investigator), and only the clinical trial unit pharmacist was unblinded. Data were collected from patients undergoing fixed orthodontic treatment for at least 6 months. A total of 66 patients were randomly assigned to either 0.8% metronidazole gel (n = 22), SMS reminder and placebo gel (n = 22), or placebo (control) group only (n = 22). Gingival index (GI), bleeding index (BI), and orthodontic plaque index (OPI) were evaluated on several teeth at baseline (T₀) and after 4 weeks (T₁). Paired-sample t-tests were used to compare mean differences of indexes at T₀ and T₁ in the groups, and independent-sample t-tests were used to determine the effects of interventions compared with the controls.ResultsData from 64 patients were analyzed; there were 2 dropouts. There were statistically significant (P < .05) reductions in GI, BI, and OPI scores from T₀ to T₁ for each intervention. However, there were no significant differences between each intervention and the control group. There were no adverse effects.ConclusionsThe null hypothesis could not be rejected. There is no difference between interventions (application of 0.8% metronidazole gel and SMS reminder for reinforcing oral hygiene) in reducing gingival inflammation in orthodontic patients.     

The adjunct effectiveness of diode laser gingivectomy in maintaining periodontal health during orthodontic treatment: A randomized controlled clinical trial

Objective:To evaluate the effectiveness of diode laser gingivectomy as an adjunct to nonsurgical periodontal treatment in the management of periodontal health among patients receiving fixed orthodontic appliance therapy (FOAT).Materials and Methods:Thirty patients undergoing FOAT with gingival enlargement were block randomized into two treatment groups. The test group received diode laser gingivectomy (940-nm diode laser, ezlase, Biolase Technology Inc) as an adjunct to nonsurgical periodontal treatment. The control group received nonsurgical periodontal treatment only. For both groups, five periodontal parameters were assessed at baseline, 1 month, 3 months, and 6 months: Plaque Index, Gingival Index, bleeding on probing, probing pocket depth, and Gingival Overgrowth Index. Intra- and intergroup variations in the periodontal parameters were determined over time.Results:Both groups showed statistically significant improvements in periodontal health over the study period (P < .05). However, significant improvements in periodontal health were evident earlier among the test group subjects (P < .05). The magnitude of improvement in periodontal health compared to baseline was greater in the test group than in the control group for Gingival Overgrowth Index at 1 month (P < .001) and 3 months (P < .05), Gingival Index at 3 months (P < .05) and 6 months (P < .05), and probing pocket depth at 1 month (P < .05).Conclusions:Nonsurgical periodontal management with or without the adjunct use of lasers can be effective in the management of gingival health problems among patients receiving FOAT. The adjunctive use of lasers can produce an earlier and greater improvement in gingival health.     

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

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

Effect of the bracket types on microbial colonization and periodontal status

Objective:To evaluate the effect of different bracket types on the levels of Streptococcus mutans (SM) and Lactobacillus (LB) in saliva, in plaque, and on the periodontal condition.Materials and Methods:Forty patients aged 14 to 16 years, who had Angle Class I malocclusion with minimal crowding, were nonsmokers, were without systematic disease, and did not use antibiotics or oral mouth rinses during the 3-month period before the study were randomly selected. The patients were subdivided into two groups with random allocation of bracket type: conventional brackets (CB; Avex Mx, OPAL orth.) with steel wire ligature or self-ligating brackets (SLB; F1000, Leone S.p.A.). Microbial and periodontal records were obtained before bonding (T₁) and 1 month after bonding (T₂). Microbial samples were collected from the stimulated saliva and the plaque from the labial surfaces of the upper and lower lateral incisors. To estimate the number of colony-forming units of SM and LB, Dentocult SM and LB kits were used. The plaque index (PI), gingival index (GI), and pocket depth (PD) values were recorded to evaluate the periodontal condition. Paired t-test and Mann-Whitney U-test were used to compare the groups statistically.Results:No significant differences occurred in SM or LB colonization between the groups. In the SLB group, PI, GI, and PD values increased significantly (P < .05). A greater increase was found in PD value in the SLB group (0.98 mm) compared with the CB group (0.04 mm; P < .05).Conclusions:The F1000 SLB do not have an advantage over Avex Mx CB with respect to periodontal status and colonization of SM and LB.