Color changes of nanocomposites used for clear aligner attachments: an in vitro study.

PURPOSE: The purpose of this study was to compare the color changes of two different nanocomposites used for two different designs of clear aligner attachments. METHODS: In all, 120 human premolars were embedded in 12 upper dental models with 10 premolars in each model. Models were scanned and attachments were digitally designed. Conventional attachments (CA) were prepared for the first six models and optimized multiplane attachments (OA) were prepared for the other six models with packable composite (PC) on the right quadrant and flowable composite (FC) on the left quadrant of each model. The models were subjected to 2000 thermal cycles at 5 °C/55 °C and then consecutively immersed in the five different staining solutions each for 48 h to simulate external discoloration. Color measurements were taken with a spectrophotometer. Color changes (∆E*ab) of the attachments before and after immersion were compared with the Commission Internationale de l'Éclairage L*a*b* (CIELAB) color space approach. RESULTS: When ∆E*ab values were examined, no significant difference was observed between the groups according to the attachment type (P > 0.05). After the coloration process, the flowable composite group showed less coloration than the packable composite group for both attachment designs (P < 0.05). Color difference values after the staining procedure were significantly higher in the CA-PC and OA-PC groups compared to the CA-FC and OA-FC groups (P < 0.05). CONCLUSION: Color change of the packable nanocomposite was more pronounced than that of the flowable nanocomposite for both attachment designs. Therefore, clear aligner attachments created using flowable nanocomposite can be recommended, especially in the anterior region where esthetics are important for the patient.

Comparative evaluation of periodontal effects and survival rates of Memotain and five-stranded bonded retainers : A prospective short-term study.

PURPOSE: To prospectively compare the short-term periodontal effects and survival rates of mandibular lingual canine-to-canine Memotain (CA-Digital, Mettmann, Germany) and five-stranded bonded retainers. METHODS: In all, 52 patients requiring retention after orthodontic treatment were assigned to 2 study groups (n = 26 in each group). Retention was provided by Memotain retainers which were fabricated digitally using CAD-CAM (computer-aided design and computer-aided manufacturing) technology in the first group and by five-stranded retainers which were fabricated manually using a conventional bending method in the second group. The patients were examined at the following time points: 1 week, 1 month, 3 months and 6 months. Plaque index, gingival index, probing depth, marginal recession, bleeding on probing, failure rate per tooth, and survival rate of retainer wires were analyzed by Mann-Whitney U, Friedman, Wilcoxon signed-rank, and χ2 tests. RESULTS: The differences between the groups were nonsignificant for plaque index, gingival index, probing depth, marginal recession, bleeding on probing, failure rate per tooth and survival rate of retainer wires. Significant differences were observed within the groups throughout the follow-up period for plaque index and probing depth. The survival rates of retainer wires were 77% for the Memotain retainers and 73% for the five-stranded retainers for the 6­month follow-up period. CONCLUSIONS: Periodontal outcomes and survival rates of Memotain and five-stranded mandibular lingual bonded retainers were similar. Furthermore, periodontal health was maintained and considerably high survival rates were achieved with both retainer types.

External apical root resorption after nonextraction orthodontic treatment with labial vs. lingual fixed appliances.

OBJECTIVES: The aim of this retrospective study is to compare external apical root resorption (EARR) after labial and lingual fixed orthodontic treatment, as detected with panoramic radiographs. MATERIALS AND METHODS: Sixty subjects were divided into two groups according to the treatment type: lingual (30 patients) and labial (30 patients) fixed orthodontic treatment. Panoramic radiographs which were obtained at the beginning of treatment (T0) and at the end of the treatment (T1) were evaluated. The maxillary and mandibular central and lateral incisors, as well as canine crown and root lengths were measured for T0 and T1. Crown to root ratios were used to determine EARR. Data were evaluated using analysis of variance and χ2 analysis. RESULTS: In all, 5 patients (16.7%) in the lingual group and 7 patients (23.3%) in the labial group had a minimum of one tooth with severe EARR, while 9 patients (30%) in the lingual group and 14 patients (46.7%) in the labial group had no EARR. A total of 26 teeth (7.2%) in the lingual group and 34 teeth (9.4%) in the labial group developed severe EARR; however, 184 teeth (51.1%) in the lingual group and 202 teeth (56.1%) in the labial group did not reveal any EARR. No statistically significant difference was found for the resorption rates between the treatment groups (p > 0.05). Although not statistically significant, there was a higher percentage of severe EARR in the mandible within the labial group. CONCLUSIONS: Both lingual and labial orthodontic techniques showed statistically similar root resorption rates. EARR is a multifactorial issue and individual predispositions must also be taken into consideration.

Comparison of short-term effects of mini-implant-supported maxillary expansion appliance with two conventional expansion protocols.

OBJECTIVE: This study evaluates the dentoskeletal effects of a mini-implant-supported maxillary expansion (MISME) appliance in comparison with two types of conventional expansion methods. METHODS: Records of 42 patients with bilateral or unilateral posterior crossbite were included in this study. The patients were divided into three groups. In group 1, four miniscrews were placed to the palatal region and an acrylic expansion device was bonded on these screws. A bonded maxillary expansion appliance was used in group 2, while a banded expansion appliance was used in group 3. Measurements from cephalometric, postero-anterior radiographs, and dental casts taken before and after expansion were evaluated statistically. RESULTS: ANB angle increased significantly in group 1 and 3. MISME group also showed an increase of SNA angle. Measurements regarding the vertical dimension did not change with MISME but significant posterior rotation was found in group 2 and 3. Overbite value showed a significant decrease in group 2 and 3, but remained stable in group 1. The nasal, maxillary, maxillary intermolar widths showed significant increases in all groups. The difference between MISME group and other groups in maxillary width was significant indicating more skeletal expansion in MISME group. The maxillary molars showed significant buccal tipping in group 2 and 3, while lingual tipping of molars was found in MISME group. CONCLUSIONS: MISME can be a better alternative to bonded expansion particularly in patients with vertical growth patterns and lack of anchorage teeth.

Effects of different orthodontic adhesives and resin removal techniques on enamel color alteration.

OBJECTIVE: To investigate the color alterations in enamel following the use of different orthodontic bonding resins and adhesive residue-removal burs. MATERIALS AND METHODS: Metal brackets were bonded to extracted human premolars (n  =  175) by using an etch-and-rinse adhesive system, a self-etch adhesive system (SEP), or a resin-modified glass ionomer cement (RMGIC). After 24 hours of photoaging, the brackets were removed and the adhesive residue on the tooth surfaces was cleaned with either a tungsten carbide bur or a Stainbuster bur. Tooth colors were measured with a spectrophotometer at baseline, after adhesive removal, and after additional photoaging. Color evaluation was made, and color differences induced by photoaging were calculated. Statistical evaluation was made using the Kruskal-Wallis test and the Mann-Whitney U-test, with Bonferroni correction. RESULTS: All specimens showed discoloration at varying levels. The highest color change was observed in the etch-and-rinse adhesive/tungsten carbide bur group. When the etch-and-rinse and self-etch adhesives were used, adhesive-remnant removal with Stainbuster burs resulted in significantly lower discoloration. The type of bur did not affect the extent of enamel discoloration in the RMGIC group. CONCLUSIONS: Orthodontic treatment alters the original color of enamel, and both the adhesive system and the resin-removal methods are responsible for this change. When brackets are bonded with the etch-and-rinse system or the SEP, cleaning the adhesive residuals with Stainbuster burs is recommended for minimal change. RMGIC can be safely cleaned with tungsten carbide burs.

Effects of various analgesics on the level of prostaglandin E2 during orthodontic tooth movement.

AIM: The aim of this double-blind, randomized, placebo-controlled clinical study was to evaluate the analgesic effects of preoperative/postoperative ibuprofen and acetaminophen use after bonding and to find a relation between the pain level and the amount of prostaglandin released. MATERIALS AND METHODS: Forty-eight patients were included and randomly divided to three equal groups that received either ibuprofen, acetaminophen or placebo for pain relief. The pain levels were measured before bonding, after bonding, at first, second, third, and seventh days on a 100 mm visual analogue scale (VAS) and gingival crevicular fluid (GCF) samples were collected at the same time intervals to measure the amount of prostaglandin E2 (PGE2) released. PGE2 levels were determined with ELISA test. The results were evaluated with Wilcoxon and Kruskal­Wallis tests with Bonferroni correction. RESULTS: Acetaminophen and placebo groups showed similar pain levels during the first 2 days, whereas ibuprofen group showed lower pain levels during the first day after bonding. PGE2 levels did not show statistically significant difference in time within the analgesic groups. No significant relation between the pain perceived and PGE2 released was found. LIMITATIONS: The biggest limitation of this study is the subjective nature of pain and its method of evaluation. CONCLUSIONS: The perception of pain by patients taking ibuprofen and acetaminophen at pre/post appliance placement was not different from patients taking placebo. No time-related differences in PGE2 level were found between the groups and no significant correlation was found between the perception of pain and PGE2 levels.

Palatal implant versus zygoma plate anchorage for distalization of maxillary posterior teeth.

This study aimed to examine the skeletal, dental, and soft tissue effects of the implant-supported pendulum (ISP) and the zygoma anchorage system (ZAS) used for the distalization of maxillary posterior teeth. Among 30 patients showing Angle class II malocclusion, 15 patients with a mean age of 14.3±1.6 years and treated with ISP were included in the first group; 15 patients with a mean age of 14.7±2.5 years and treated with ZAS were included in the second group. The predistalization and postdistalization lateral cephalograms were analysed. Statistical evaluation was carried out using SPSS. Point A and upper incisors protruded in the ISP group, retruded in the ZAS group. Upper posterior teeth were distalized in both groups, but more in the ZAS group. Significant differences were observed between the groups for the sagittal movements of Point A, incisors, and posterior teeth. Overbite decreased in the ISP group, overjet decreased in the ZAS group, upper and lower lips retruded only in the ZAS group. Both methods provided absolute anchorage for distalization of posterior teeth, but the skeletal and soft tissue outcome and distalization obtained was greater in the ZAS group. Both methods can be used as alternatives to extraoral traction and conventional molar distalization appliances with different patient requirements.

A comparative study of qualitative and quantitative methods for the assessment of adhesive remnant after bracket debonding.

The amount of the residual adhesive after bracket debonding is frequently assessed in a qualitative manner, utilizing the adhesive remnant index (ARI). This study aimed to investigate whether quantitative assessment of the adhesive remnant yields more precise results compared to qualitative methods utilizing the 4- and 5-point ARI scales. Twenty debonded brackets were selected. Evaluation and scoring of the adhesive remnant on bracket bases were made consecutively using: 1. qualitative assessment (visual scoring) and 2. quantitative measurement (image analysis) on digital photographs. Image analysis was made on scanning electron micrographs (SEM) and high-precision elemental maps of the adhesive remnant as determined by energy dispersed X-ray spectrometry. Evaluations were made in accordance with the original 4-point and the modified 5-point ARI scales. Intra-class correlation coefficients (ICCs) were calculated, and the data were evaluated using Friedman test followed by Wilcoxon signed ranks test with Bonferroni correction. ICC statistics indicated high levels of agreement for qualitative visual scoring among examiners. The 4-point ARI scale was compliant with the SEM assessments but indicated significantly less adhesive remnant compared to the results of quantitative elemental mapping. When the 5-point scale was used, both quantitative techniques yielded similar results with those obtained qualitatively. These results indicate that qualitative visual scoring using the ARI is capable of generating similar results with those assessed by quantitative image analysis techniques. In particular, visual scoring with the 5-point ARI scale can yield similar results with both the SEM analysis and elemental mapping.

Effects of a fluoride-containing casein phosphopeptide-amorphous calcium phosphate complex on the shear bond strength of orthodontic brackets.

The purpose of this study was to investigate the effects of enamel pre-treatment with a new fluoride-containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) complex on the shear bond strength (SBS) of brackets bonded with etch-and-rinse or self-etching adhesive systems. The material comprised 66 extracted human premolars randomly divided into six equal groups with respect to the enamel pre-treatment and adhesive system employed: 1. No pre-treatment and brackets bonded with the etch-and-rinse adhesive system (Transbond XT). 2. Pre-treatment with fluoride-containing CPP-ACP paste (MI Paste Plus) and Transbond XT. 3. Pre-treatment with non-fluoride CPP-ACP paste (MI Paste) and Transbond XT.4. No pre-treatment and brackets bonded with the self-etching adhesive system (Transbond Plus). 5 and 6. Enamel pre-treated as for groups 2 and 3, respectively, and the Transbond Plus. Bonded specimens were subjected to thermal cycling (×1000) before SBS testing. The residual adhesive on the enamel surface was evaluated after debonding with the adhesive remnant index (ARI). Data evaluation was made using one-way analysis of variance and Tukey test for SBS results, and Kruskal-Wallis test for ARI results. The results showed that enamel pre-treatment with either fluoride or non-fluoride CPP-ACP paste had no significant effect on the SBS of the self-etching adhesive system (P > 0.05). Enamel pre-treatment with non-fluoride CPP-ACP in group 3 significantly reduced the SBS of the etch-and-rinse adhesive (P < 0.001), while pre-treatment with fluoride-containing CPP-ACP paste (groups 2 and 5) did not affect debonding values (P > 0.05). The fluoride-containing CPP-ACP did not compromise the SBS of brackets bonded with the tested etch-and-rinse and self-etching systems, but its non-fluoride version significantly decreased the SBS of the etch-and-rinse adhesive system.

Comparison of the intrusive effects of miniscrews and utility arches.

INTRODUCTION: The aim of this prospective study was to compare the effects of incisor intrusion obtained with the aid of miniscrews and utility arches. METHODS: Twenty-four patients (10 male, 14 female) with a deepbite of at least 4 mm were divided to 2 groups. In group 1, 13 patients (3 male, 10 female; mean age, 20.90 ± 7.12 years) in the postpubertal growth period were treated by using miniscrews; in group 2, 11 patients (7 male, 4 female; mean age, 15.25 ± 3.93 years) were treated with utility arches. Lateral cephalometric headfilms were taken at the beginning of treatment and after intrusion for the evaluation of the treatment changes. Statistical analyses of the data were performed with a significance level of P <0.05. RESULTS: Intrusion lasted 6.61 ± 2.95 months for group 1 and 6.61 ± 2.46 months for group 2. The changes in the center of resistance of the incisors were 1.75 ± 0.4 mm (P <0.05) for group 1 and 0.86 ± 0.5 mm (P >0.05) for group 2; the difference between the groups was significant (P <0.05). In the miniscrew group, the incisors were protruded 0.79 ± 1.4 mm (P >0.05) relative to pterygoid vertical and 3.85° ± 2.4° (P >0.05) relative to the palatal plane. In group 2, the incisors showed 3.91 ± 0.7 mm (P <0.05) of protrusion relative to pterygoid vertical and 13.55° ± 2.4° (P <0.05) relative to the palatal plane. The maxillary first molars showed significant distal tipping in group 2 (P <0.05). CONCLUSIONS: Unlike with utility arches, true maxillary incisor intrusion can be achieved by application of intrusive forces close to the center of resistance by using miniscrews with no counteractive movements in the molars.

Self-reported pain associated with the use of intermaxillary elastics compared to pain experienced after initial archwire placement.

OBJECTIVE: To evaluate the pain during the use of intermaxillary elastics and to compare it with that of initial archwire placement. MATERIALS AND METHODS: Sixteen orthodontic patients who underwent initial bonding (7 girls, 13 boys; mean age 16.75 ± 2.61 years) and 19 patients who would be using intermaxillary elastics for the first time (13 girls, 7 boys; mean age 16.21 ± 3.01 years) were enrolled in this prospective study. A visual analog scale form was given to each patient to measure the pain levels, and these were measured by the same investigator using a digital caliper. Data were evaluated using Mann Whitney U-test. RESULTS: The pain started to increase 2 hours after the application of elastics. The highest levels were achieved at the sixth hour and the same night. The pain levels started to decrease at day 2. Although the pain levels of the elastic group started to decrease after the second day, the pain levels of the initial bonding group were still significantly high. CONCLUSIONS: Intermaxillary elastics cause similar amounts of pain compared with initial archwire placement, but the pain of the elastics did not last as long as the pain felt after initial bonding.

Differences in cephalometric measurements: a comparison of digital versus hand-tracing methods.

The aim of this study was to evaluate the accuracy of cephalometric measurements using computerized tracing of direct digital radiographs in comparison with hand tracing of digital radiographic printouts. Comparisons were made between methods in terms of accuracy of individual measurements as well as evaluation of treatment outcomes. Pre- (T1) and post- (T2) treatment cephalometric digital radiographs of 30 patients were traced using the Vistadent OC 1.1 computer software program (group 1) and manually (group 2) by the same investigator. A total of 26 anatomical landmarks were located and measured. Measurement reproducibility was evaluated by calculating intraclass correlation coefficients, and paired t-tests were used to compare differences in individual measurements and treatment outcomes between methods. Differences greater than 0.05 were considered to be statistically significant. Significant differences were found between the two methods for SNB, Wits appraisal, Cd-A, Cd-Gn, FMA, SN-PP, U1-NA (mm), U1-FH, L1-NB (mm), and Li-E plane. No significant differences were found between the two methods in the measurement of treatment changes. Cephalometric measurements of most parameters were reproducible for both methods. Despite some discrepancies in measured values between hand-tracing and the computerized method, any differences were minimal and clinically acceptable.

Miniscrews for upper incisor intrusion.

The aim of this study was to investigate if true incisor intrusion can be achieved using miniscrews. Eleven patients (three males and eight females; mean age: 19.8 +/- 4.8 years) with normal vertical dimension showing a pre-treatment deep bite of 5.9 +/- 0.9 mm and a 'gummy' smile were enrolled in the study. After levelling of the maxillary central and lateral incisors with a segmental arch, an intrusive force of 80 g using closed coil springs was applied from two miniscrews placed between the roots of the lateral and canine teeth. The amount of incisor intrusion was evaluated on lateral cephalometric headfilms taken at the end of levelling (T1) and at the end of intrusion (T2). Statistical analysis of the data was performed using a paired t and Wilcoxon signed rank tests. A significance level of P < 0.05 was predetermined. The mean upper incisor intrusion was 1.92 mm and the mean overbite decrease 2.25 +/- 1.73 mm in 4.55 months. Upper incisor angulation resulted in a 1.81 +/- 3.84 degree change in U1-PP angle and a 1.22 +/- 3.64 degree change in U1-NA angle. However, these were not statistically significant (P > 0.05). True intrusion can be achieved by application of intrusive forces close to the centre of resistance using miniscrews. However, studies with a larger number of subjects and long-term follow-up are necessary.

Comparison of cephalometric measurements with digital versus conventional cephalometric analysis.

The aim of this study was to evaluate the accuracy and reliability of angular and linear cephalometric measurements using a computerized method of direct digital radiographs. This was then compared with the measurements obtained with a computerized method that uses a digitizing pad and hand tracing of printout radiographs. Pre-treatment digital cephalometric radiographs of 125 patients were traced using Vistadent 2.1 AT and Jiffy Orthodontic Evaluation (JOE) software programs and by hand tracing of the printouts. Twenty-six anatomical landmarks were defined on each radiograph by a single investigator and 28 variables were calculated. Statistical analysis was undertaken using one-way analysis of variance and multiple group comparisons using Duncan's test at a significance level of 0.05. Low correlation coefficients indicated poor reproducibility for nasolabial angle for each of the three methods (P > 0.05). Most of the variables showed consistency between the three methods except for nasolabial angle, ANS-Me, APFH, L1-NB, Nperp-Pg, Go-Me, and U1-NA measurements. The findings indicated that most of the cephalometric measurements were highly reproducible with direct digital radiographs using Vistadent 2.1 AT as well as with printouts using both JOE software and hand tracing. Despite the low correlation for some measurements between the Vistadent 2.1 AT, JOE, and hand-tracing methods, most of the commonly used measurements were accurate. The user-friendly and time-saving nature of the computerized method using digital radiographs makes it the preferred option.

Treatment of horizontal root-fractured maxillary incisors--a case report.

Traumatic dental injuries often occur to the teeth and their supporting tissues and they are the main reasons for emergency visit to a dental clinic. Management of a fracture depends on its position and the extent of root involvement. Horizontal root fractures are not seen frequently and the treatment consists of reduction and long-term rigid fixation of the coronal segment. The present case demonstrates the successful management of two horizontally fractured maxillary central incisors with a follow-up period of 9 months.

Pendulum appliances with 2 anchorage designs: conventional anchorage vs bone anchorage.

INTRODUCTION: The aim of this retrospective study was to compare the dentoalveolar and skeletal effects obtained with 2 types of pendulum appliance with different anchorage designs: bone-anchored pendulum appliance (BAPA) and conventional pendulum appliance (CPA). METHODS: The sample consisted of 39 patients (25 girls, 14 boys) with Angle Class II molar relationships. Correction of the molar relationship was achieved with the BAPA with palatal intermaxillary fixation screws for anchorage in the first group (n = 22) and with the CPA in the second group (n = 17). Lateral cephalograms before treatment and at the end of distalization were measured, and changes in the groups and the differences between the groups were analyzed statistically. RESULTS: The average distalization times were 6.8 months for the BAPA group and 5.1 months for the CPA group. The maxillary first molars were tipped 9.1 degrees in the BAPA group and 5.3 degrees in the CPA group; the molars moved distally 4.8 mm in the BAPA group and 2.7 mm in the CPA group. Despite mesialization of the premolars and proclination of the incisors with the CPA, both premolars were spontaneously distalized, and the incisors were retruded with the BAPA. CONCLUSIONS: The amount of distal molar movement was similar between the BAPA and the CPA. No anchorage loss or spontaneous distal premolar and incisor movement, which might decrease total treatment time, was seen with the BAPA.

Soft tissue profile after distal molar movement with a pendulum K-loop appliance versus cervical headgear.

OBJECTIVE: To evaluate the soft tissue changes associated with the pendulum appliance that was supported with a K-loop buccally and to compare these treatment changes with a cervical headgear group. MATERIALS AND METHODS: The records of 30 patients having skeletal Class I, dental Class II malocclusions were divided to two groups. Group 1 consisted of 7 girls, 8 boys (mean age, 15.0 +/- 3.4 years), and Group 2 consisted of 10 girls, 5 boys (mean age 14.2 +/- 2.9 years). The first group was treated with a pendulum appliance that was supported with a K-loop buccally, and the second group was treated with cervical headgear. Lateral cephalograms were taken at the beginning of treatment and at the end of distal molar movement. Treatment changes within the groups were analyzed using the paired t-test, and between group changes were analyzed with the independent t-test. RESULTS: The results showed that the pendulum/K-loop appliance had no significant effect on skeletal and dental variables and soft tissue A point, upper lip thickness, and sagittal upper lip position relative to the E plane. A significant difference for the change in Vp-Ls distance was found in patients in the pendulum/K-loop group (P < .05). Patients in the cervical headgear group showed significant retrusion in skeletal, dental, and soft tissue measurements (P < .05). CONCLUSIONS: The pendulum/K-loop appliance produces distal molar movement without causing any significant changes in the sagittal or vertical positions of either the jaw or the soft tissue profile.

The use of intraosseous screw for upper molar distalization: a case report.

The use of implants has made a major change in orthodontic treatment mechanics. They have replaced conventional unaesthetic and compliance dependent extraoral appliances with well accepted intraoral mechanics. Implants can be used in molar and canine distalization, intrusion and in extraoral force applications. In the present case report, treatment of a case using an intermaxillary fixation screw (IMF) will be presented. The treatment results will be evaluated using pretreatment, post distalization and post treatment cephalometric radiographs and dental casts.