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To compare bracket survival and adhesive removal time between a flash-free and a conventional adhesive for orthodontic bracket bonding. Forty-five consecutive patients had their maxillary incisors, canines, and premolars bonded with ceramic brackets using a flash-free adhesive (APC Flash-Free Adhesive, 3M Unitek, Monrovia, Calif) on one side and a conventional adhesive (APCII Adhesive, 3M Unitek) on the other side. The side allocation was randomized. Bracket failure was recorded at 4-week intervals. The adhesive remnant index (ARI) was scored on debond and adhesive removal timed to the nearest second. The primary outcome was adhesive removal time per quadrant. Secondary outcomes were bracket failure rate, time to first-time failure of a bracket, and ARI score on debond. Paired t-tests were used to compare adhesive removal times and ARI scores between the adhesives with P <.05 considered statistically significant. Bracket failure rates were 4.3% for the flash-free adhesive and 1.9% for the conventional adhesive, with mean times to first-time failure of 31 weeks for the flash-free adhesive and 42 weeks for the conventional adhesive; neither failure rates nor times to first failure were significantly different. Although the flash-free adhesive left significantly more adhesive on the tooth surface after debonding, the adhesive removal times were 22.2% shorter than with the conventional adhesive. Bracket survival with the flash-free adhesive was equivalent to the conventional adhesive when ceramic brackets were bonded. Adhesive removal was significantly faster when using the flash-free adhesive, which may result in time savings of more than 20% compared with the conventional adhesive. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this in vivo study was to investigate the preventive effect of two different adhesives on enamel demineralization and compare these adhesives with a conventional one. Materials and Methods: Fifteen patients requiring the extraction of their first four premolars for orthodontic treatment were included in the study. One premolar was randomly selected, and an antibacterial monomer-containing and fluoride-releasing adhesive (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan) was used for orthodontic bracket bonding. Another premolar was randomly selected, and a fluoride-releasing and recharging orthodontic adhesive (Opal Seal, Ultradent Products, South Jordan, Utah) was used. One premolar was assigned as a control, and a conventional adhesive (Transbond XT, 3M Unitek, Monrovia, Calif) was used. The teeth were extracted after 8 weeks, and the demineralization areas of the 45 extracted teeth were analyzed using microcomputed tomography with software. Results: There was no significant difference between the white spot lesion (WSL) rates of the adhesives (P . .05). The volumes of the WSLs varied from 0 to 0.019349 mm3. Although Opal Seal showed the smallest lesion volumes, there was no significant difference in volumetric measurements of the lesions among the groups (P . .05). Conclusions: The findings indicated no significant differences between the preventive effects of the adhesives used in this in vivo study over 8 weeks. [ABSTRACT FROM AUTHOR]

Objective: To compare the antimicrobial and physical properties of experimental primers containing chlorhexidine (CHX) or ursolic acid (UA) with a commercial primer. Materials and Methods: Two antibacterial agents, 3 mg each of CHX and UA were incorporated respectively into 1 ml of Transbond XT primer (TX) to form antibacterial primers, TX-CHX and TX-UA. The antimicrobial activity of the three primers (TX, TX-CHX, and TX-UA) against Streptococcus mutans in both planktonic and biofilm phases was analyzed by determining minimum inhibitory and bactericidal concentrations and by performing growth and biofilm assays. Growth and biofilm assays were performed in both the absence and presence of thermocycling in a water tank to analyze the effects of water aging on the antimicrobial activities of primers. After bonding brackets onto bovine incisors using the primers, shear bond strength and mode of fracture were analyzed to compare physical properties. Results: TX-CHX had stronger antimicrobial activity against S. mutans in the planktonic and biofilm phases than did TX or TX-UA. When applied, TX-CHX completely inhibited the growth and biofilm formation of S. mutans. In addition, the antimicrobial activity of TX-CHX was maintained after thermocycling. However, TX-UA did not show significant antimicrobial activity compared with TX. There was no significant difference in either shear bond strength or bond failure interface among the primers. Conclusion: Incorporation of CHX into an orthodontic primer may help prevent enamel demineralization around surfaces without compromising its physical properties. [ABSTRACT FROM AUTHOR]

Objective: To determine pain during debonding and the effects of different pain control methods, gender, and personal traits on the pain experience. Materials and Methods: Patients who had fixed orthodontic treatment with metal brackets, but no surgical treatment or craniofacial deformity, were included. Sixty-three patients (32 female, aged 17.2 ± 2.9 years; 31 male aged, 17.2 ± 2.5 years) were allocated to three groups (n = 21) according to the pain control method: finger pressure, elastomeric wafer, or stress relief. Pain experience for each tooth was scored on a visual analogue scale (VAS), and general responses of participants to pain were evaluated by Pain Catastrophizing Scale (PCS). Multiple linear regression analysis, the Mann Whitney U-test, and Spearman's rank correlation coefficient analysis were used to analyze the data. Results: When the VAS scores were adjusted, finger pressure caused a 47% reduction overall, 56% in lower elastomer wafer total, 59% in lower right arch, 62% in lower left, and 62% in lower anterior compared with the elastomeric wafer. In the elastomer wafer group, upper and lower anterior scores were higher than posterior scores, respectively. Females had higher VAS (lower left and anterior) and total PCS scores than males. Regardless of the pain control method, total PCS scores were correlated with total ( r = .254), upper total ( r = .290), right ( r = .258), left ( r = .244), and posterior ( r = .278) VAS scores. Conclusions: The stress relief method showed no difference when compared with the other groups. Finger pressure was more effective than the elastomeric wafer in the lower jaw. Higher pain levels were recorded for the anterior regions with the elastomeric wafer. Females and pain catastrophizers gave higher VAS scores. [ABSTRACT FROM AUTHOR]

Objective: To investigate the shear bond strength (SBS) of orthodontic brackets bonded to eroded enamel treated with preventive approaches and to examine the enamel/bracket interfaces. Materials and Methods: Ninety-one brackets were bonded to seven groups of enamel samples: sound; eroded; eroded+treated with calcium silicate-sodium phosphate salts (CSP); eroded+infiltrated by ICON®; eroded+infiltrated by ICON® and brackets bonded with 1-month delay; eroded+infiltrated by an experimental resin; and eroded+infiltrated by an experimental resin and brackets bonded with 1-month delay. For each group, 12 samples were tested in SBS and bond failure was assessed with the adhesive remnant index (ARI); one sample was examined using scanning electron microscopy (SEM). Results: Samples treated with CSP or infiltration showed no significant differences in SBS values with sound samples. Infiltrated samples followed by a delayed bonding showed lower SBS values. All of the values remained acceptable. The ARI scores were significantly higher for sound enamel, eroded, and treated with CSP groups than for all infiltrated samples. SEM examinations corroborated the findings. Conclusions: Using CSP or resin infiltration before orthodontic bonding does not jeopardize the bonding quality. The orthodontic bonding should be performed shortly after the resin infiltration. [ABSTRACT FROM AUTHOR]

Objective: To determine if there is a significantly different effect on vertical changes during phase I palatal expansion treatment using a quad helix and a bonded rapid maxillary expander in growing skeletal Class I and Class II patients. Materials and Methods: This retrospective study looked at 2 treatment groups, a quad helix group and a bonded rapid maxillary expander group, before treatment (T1) and at the completion of phase I treatment (T2). Each treatment group was compared to an untreated predicted growth model. Lateral cephalograms at T1 and T2 were traced and analyzed for changes in vertical dimension. Results: No differences were found between the treatment groups at T1, but significant differences at T2 were found for convexity, lower facial height, total facial height, facial axis, and Frankfort Mandibular Plane Angle (FMA) variables. A comparison of treatment groups at T2 to their respective untreated predicted growth models found a significant difference for the lower facial height variable in the quad helix group and for the upper first molar to palatal plane (U6-PP) variable in the bonded expander group. Conclusion: Overall, both the quad helix expander and the bonded rapid maxillary expander showed minimal vertical changes during palatal expansion treatment. The differences at T2 suggested that the quad helix expander had more control over skeletal vertical measurements. When comparing treatment results to untreated predicted growth values, the quad helix expander appeared to better maintain lower facial height and the bonded rapid maxillary expander appeared to better maintain the maxillary first molar vertical height. [ABSTRACT FROM AUTHOR]

The article discusses the initial changes in salivary levels of periodontal pathogens after orthodontic treatment with fixed appliances. It mentions that the Simplified Oral Hygiene Index, Plaque Index, and Gingival Index were measured as periodontal parameters. It notes that the all periodontal parameters were significantly decreased immediately after debonding.

Objective: To evaluate the bonding time, shear bond strength (SBS), and adhesive residue index (ARI) of APC(TM) Flash-Free bonding system. Materials and Methods: Thirty-six extracted human maxillary premolars were randomly divided into three groups (12 per group) and used for this in vitro study: group 1, APC Flash-Free Adhesive Coated Appliance System; group 2, Clarity ADVANCED Ceramic Bracket pasted manually; group 3 (control group), 3M APC PLUS Adhesive prepasted brackets bonded with the extruded flash removed. Bonding time was measured using a stopwatch. Bond strength was measured using an Instron at a cross-head speed of 1 mm/min. The ARI was graded on a scale from 1 to 5. Repeatedmeasures analysis of variance and post hoc Tukey tests were used for statistical analysis. Results: It took significantly (P < .001) less time to bond in the APC Flash-Free Adhesive group (30.7 ± 3.3 seconds) compared with the control group (41.8 ± 4.0 seconds) and the manual group (39.2 ± 2.8 seconds). The APC Flash-Free Adhesive coated bracket had significantly (P < .001) greater SBS (13.7 ± 2.2 MPa) compared with the control group (10.8 ± 2.0 MPa) and the manual group (10.4 ± 1.4 MPa). The ARI was significantly (P < .001) greater with the APC Flash-Free Adhesive coated bracket compared with that of the other two groups. Conclusions: Compared with other methods of bonding, the APC Flash-Free Adhesive Coated System can potentially reduce bonding time while increasing SBS. [ABSTRACT FROM AUTHOR]

Objective: To analyze the clinical and laboratory properties of the recently introduced APC flashfree orthodontic adhesive. Material and Methods: After bonding of 80 brackets on human teeth (group A: APC flash-free adhesive n = 40, group B: APC Plus adhesive n = 40), the following measurements were recorded: time for bonding, stereomicroscopic evaluation of excess adhesive, color penetration (methylene blue, 0.5%/24 h), and Adhesive Remnant Index (ARI) score after debonding. Results: The time needed for bonding differed significantly between the two groups (A: 19.5 s/tooth vs B: 33.8 s/tooth). The adhesive excess, which was metrically measured from the bracket edge, ranged from 166.27 µm to 81.66 µm (group A) and 988.53 µm to 690.81 µm (group B). After methylene coloration in group A, 52 of 80 measurements showed discoloration on the bracket-adhesive and/or adhesive-enamel interface, while for group B, 78 of 80 were coloration positive. The ARI scores did not differ, with an average ARI score of 2.0 for group A and 2.8 for group B. Conclusion: The flash-free adhesive significantly reduced the time needed for the bonding process. The excess resin expanded 0.16 to 0.08 mm over the bracket margin. The new technology seems to facilitate a smooth and sufficient marginal surface of the adhesive, which clinically might improve reduction of plaque accumulation. [ABSTRACT FROM AUTHOR]

Objective: To evaluate adhesive performance in terms of debonding forces of precoated metal and ceramic brackets 4 years after expiration. Materials and Methods: Buccal and lingual surfaces of embedded extracted maxillary premolars were etched with 34% Tooth Conditioner Gel (Dentsply Caulk, Milford, Del), rinsed, and dried. Transbond MIP (3M Unitek, Monrovia, Calif) was applied prior to placing adhesive precoated brackets (APC II Victory stainless steel and APC Plus Clarity ceramic brackets, 3M Unitek). The preexpiration brackets had 29-35 months before, and the postexpiration brackets were 45-52 months past, their expiration dates. Sample size was 17-21 per group. Debonding forces were determined by subjecting the bonded brackets to a shear force in a universal testing machine. Debonding forces were compared using two-way ANOVA. Debonded surfaces were examined under a stereomicroscope to determine failure modes, which were compared using the chi-square test. Results: No statistically significant difference was found in debonding forces (P ?=? .8581) or failure modes (P ?=? .4538) between expired and unexpired brackets. Metal brackets required statistically significantly higher debonding forces than did ceramic brackets (P ?=? .0001). For both expired and unexpired brackets, failure modes were mostly cohesive in the adhesive layer for ceramic brackets, and mixed between adhesive and cohesive failure in the adhesive layer for metal brackets. Conclusions: Adhesive precoated brackets did not have any reduction in enamel-adhesion properties up to 4 years after their expiration date. Extended shelf life testing for precoated dental brackets may be worth considering. [ABSTRACT FROM AUTHOR]

Objective: To examine differences in the shear bond strength of orthodontic brackets on differently mineralized enamel surfaces after applying a caries infiltrant or conventional adhesive. Materials and Methods: A total of 320 bovine incisors were assigned to eight pretreated groups, and the shear force required for debonding was recorded. Residual adhesive was evaluated by light microscopy using the adhesive remnant index. Statistical analysis included Kolmogorov-Smirnov, analysis of variance (ANOVA), and Scheffé tests. Results: The highest bond strength (18.8 ± 4.4 MPa) was obtained after use of the caries infiltrant. More residual adhesive and fewer enamel defects were observed on infiltrated enamel surfaces. Brackets on demineralized enamel produced multiple enamel defects. Conclusions: Acceptable bond strengths were obtained with all material combinations. A cariesinfiltrant applied before bracket fixation has a protective effect, especially on demineralized enamel. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the combined effects of material type, surface treatment, and thermocycling on the bond strength of orthodontic brackets to materials used for the fabrication of provisional crowns. Materials and Methods: Four materials were included in this study (ProTemp, Trim Plus, Trim II, and Superpont C+B). Sixty cylindrical specimens (1x3 cm) were prepared from each material and equally divided into three groups. The first group was ground with silica carbide paper, the second was polished with pumice, and the last group was sandblasted with 50-(jm aluminum oxide particles. Stainless-steel maxillary central incisor brackets (Victory Series, 3M) were bonded to the provisional material specimens with Transbond XT light-cured composite resin, and half of the specimens from each group were thermocycled 500 times in 5°C and 55°C water baths. Then the brackets were debonded with shear testing, and the results were statistically analyzed by three-way analysis of variance and Tukey's multiple-comparison tests at α = 0.05. Adhesive Remnant Index (ARI) was also identified. Results: Before and after thermocycling, ProTemp materials showed the highest shear bond strength with orthodontic brackets (10.3 and 13.1 MPa, respectively). The statistical analysis indicated an interaction among the three independent variables (P < .05) and statistically significant differences in bond strength among provisional materials (P < .001), surface treatments (P < .001), and thermocycling (P < .05). According to the ARI, most groups demonstrated adhesive failure. Conclusions: The provisional material type, surface treatment, and artificial aging have a significant effect on bond strength. Sandblasting treatment exerts a beneficial effect on shear bond strength [ABSTRACT FROM AUTHOR]

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 Otest, 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. [ABSTRACT FROM AUTHOR]

Objective: To determine the influence of two adhesion boosters on shear bond strength and on the bond failure location of indirectly bonded brackets. Materials and Methods: Sixty bovine incisors were randomly divided into three groups (n =20), and their buccal faces were etched using 37% phosphoric acid. In group 1 (control),brackets were indirectly bonded using only Sondhi adhesive. In groups 2 and 3, the adhesion boosters Enhance Adhesion Booster and Assure Universal Bonding Resin, respectively, were applied before bonding with Sondhi. Maximum bond strength was measured with a universal testing machine, and the location of bond failure was evaluated using the Adhesive Remnant Index (ARI). One-way analysis of variance followed by the Tukey test (P < .05) was used to compare the shear bond strength among groups, and the differences in ARI scores were evaluated using the Kruskal-Wallis test (P < .05). The Pearson correlation coefficientwas calculated to determine whether there was any correlation between bond strength and ARI scores. Results: The mean shear bond strength in group 3 was significantly higher (P < .01) than in the other groups. Evaluation of the locations of bond failure revealed differences (P < .05) among the three groups. There was a moderate correlation between bond strength and ARI scores within group 3 (r = 0.5860, P < .01). Conclusion: In vitro shear bond strength was acceptable in all groups. The use of the Assure adhesion booster significantly increased both the shear bond strength of indirectly bonded brackets and the amount of adhesive that remained on the enamel after bracket debonding. [ABSTRACT FROM AUTHOR]

Objective: To comparatively assess the failure rate of adhesive precoated (APC) self-ligating metal brackets bonded with two different enamel surface preparation techniques: self-etching primer (SEP) and conventional two-step etch and primer method (CM). Materials and Methods: Fifty-seven patients with complete permanent dentition were included in this study. A total of 1140 APC self-ligating brackets (3M Unitek, Monrovia, Calif) were bonded using a split-mouth design. For each patient, SEP (Transbond Plus SEP, 3M Unitek) and CM (37% phosphoric acid) were used in alternate quadrants. All brackets were bonded by the same investigator after pumicing and rinsing of all of the teeth. The number, site, and date of first-time bracket failures were monitored throughout orthodontic treatment (mean, 22 months). The survival rates of the brackets were estimated by Kaplan-Meier and log-rank tests (P < .05). The adhesive remnant index was used to determine the bond failure interface. Results: The bond failure rates were 2.97% and 2.18% for the CM and SEP, respectively. No statistically significant difference in failure rates was found between the groups. The bond failure sites were predominantly at the enamel-adhesive interface in both groups. Conclusion: This long-term in vivo study showed that the combined use of SEP and the APC bracket system can be used effectively for bonding brackets after pumicing the enamel surfaces in clinical orthodontics. [ABSTRACT FROM AUTHOR]

Objective: To compare the effect of laser irradiation at two different pulse settings and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. Materials and Methods: Thirty-six premolars were allocated to three groups (n = 12): (1) 37% phosphoric acid etching, (2) erbium-doped yttrium aluminum garnet (Er:YAG) laser etching with medium-short pulse mode (MSP; 100 |is, 120 mj, 10 Hz, 1.2 W), and (3) Er:YAG laser etching with quantum-square pulse mode (QSP; 120 mj, 10 Hz, 1.2 W). Metallic brackets were bonded with Transbond XT. After photopolymerization, the samples were subjected to 5000 thermal cycles and debonded with a universal testing machine, and the SBS values were recorded. Surface morphology was evaluated with profilometric examination, scanning electron microscopy, and atomic force microscopy Results: The results of SBS testing were analyzed by one-way analysis of variance and Tukey honestly significant diffference tests. The mean SBS values of QSP and MSP laser groups were 11.80 ± 2.7 MPa and 10.10 ± 4.5 MPa, respectively, and the QSP group demonstrated significantly higher SBS (P < .01) than that of the acid-etched group (6.6 ± 2.4 MPa). No significant difference was observed between the SBS values of the two laser groups (P< .05). The difference between the ARI scores of the laser groups and the acid-etched group was statistically significant (P < .05). Conclusion: Laser etching at MSP and QSP modes present successful alternatives to acid etching; however, long-term clinical studies are required to verify clinical success. [ABSTRACT FROM AUTHOR]

Objective: To test the null hypothesis that combining low-viscosity caries infiltrant with conventional adhesive resins would not improve sealing of sound enamel against demineralization in vitro. Materials and Methods: Bovine enamel discs (N = 60) with diameter of 3 mm were randomly assigned to six groups (n = 10). The discs were etched with 37% phosphoric acid for 30 seconds and treated with resins of different monomer content forming the following groups: (1) Icon (DMG), (2) Transbond XT Primer (3M ESPE), (3) Heliobond (Ivoclar Vivadent), (4) Icon + Transbond XT Primer, and (5) Icon + Heliobond. Untreated etched samples served as the negative control. Specimens were subjected to demineralization by immersion in hydrochloric acid (pH 2.6) for 80 hours. Calcium dissolution into the acid was assessed by colorimetric analysis using Arsenazo III method at 16-hour intervals. Groups presenting high protection against demineralization were subjected to further acidic challenge for 15 days with calcium measurements repeated at 24-hour intervals. Data were analyzed by Kruskal-WaIIis test and Mann-Whitney U-test. Results: Untreated specimens showed the highest amount of demineralization. Icon and Transbond XT primer decreased the mineral loss significantly compared to the control. Heliobond performed significantly better than both Icon and Transbond XT primer. Combination of Icon both with Transbond XT primer or Heliobond served as the best protective measures and maintained the protective effect for the additional 15-day acidic challenge. Conclusions: Within the limitations of this in vitro study, it could be concluded that the use of low- viscosity caries infiltrant prior to application of the tested conventional adhesives increases their protective effect against demineralization. [ABSTRACT FROM AUTHOR]

Objective: To determine the influence of the type of orthodontic adhesive system, such as conventional acid-etching (CE) and self-etching primers (SEPs), on the stain susceptibility of enamel surface after debonding. Effects of clean-up procedures on the enamel surface were also determined. Materials and Methods: Two types and four brands of adhesive systems were investigated using 135 human premolars. Unbonded teeth were used as controls. Three-dimensional scanning of the enamel surface was performed before bracket bonding, after debonding, and after clean-up procedures. The color of each tooth was measured before bracket bonding and again after debonding and clean-up procedures. This was followed by methylene blue staining. The stain susceptibility of the enamel surface was measured after finishing only (F-condition) and after finishing/polishing (FP-condition). Results: After debonding, the amount of residual adhesive resins in CE materials was greater than that in SEP materials. For the F-condition, staining color change in SEP materials was significantly higher than that in CE materials. For the FP-condition, staining color change in both CE and SEP materials was not different from those of the control. Conclusions: The SEP system would show less stain susceptibility if the thin residual adhesive resin layer after debonding is removed by polishing. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that orthodontic bonding has no effect on the initial adhesion of mutans streptococci (MS) in the presence of saliva. Materials and Methods: Hydroxyapatite (HA) and orthodontic adhesive (AD) disks were prepared to a uniform size. HA disks were etched with 37% phosphoric acid (HE, etched group). Some of the HE disks were coated with Transbond XT primer and light cured (HP, primed group). Transbond Plus SEP was applied to a third set of HA disks, dried, and light cured (SEP, self-etching primer group). Adhesion assays were performed using two MS strains in the presence of fluid-phase or surface-adsorbed unstimulated whole saliva (UWS). The MS adhesion patterns were examined by scanning electron microscopy. Results: MS adhesion was influenced by the bonding steps and the presence of UWS. UWS treatment decreased MS adhesion. However, surface-adsorbed UWS resulted in slightly less inhibition of MS adhesion than fluid-phase UWS. MS adhesion was significantly greater for HE than for the other groups. There were interaction effects between the UWS treatment and surface groups. MS adhesion to HP and AD was significantly diminished in the presence of surface-adsorbed or fluid-phase UWS compared with adhesion to HA, HE, or SEP. Conclusion: The hypothesis is rejected. Our results suggest that MS adhesion is significantly influenced by the bonding procedure used, and the application of conventional primers for the bracket bonding can inhibit MS adhesion to tooth surfaces in the presence of UWS. [ABSTRACT FROM AUTHOR]

Objective: To determine if a new unfilled experimental self-etching primer (SEP) adhesive system (SBP-40TX + C&B Metabond) that incorporates a methyl methacrylate-based 4-META/TBB (4- methacryloxyethyl trimellitate anhydride tri-n-butyl borane) resin can provide adequate shear bond strength (SBS) when used for bonding orthodontic brackets. Methods and Materials: Forty-eight human maxillary premolars were randomly divided into three groups of 16 specimens each. Brackets were bonded with three bonding systems. A filled Bis- GMA/TEGDM (triethylene glycol dimethacrylate)-based SEP adhesive system (Transbond Plus) and an unfilled conventional etch-and-rinse adhesive system (C&B Metabond) were used for comparison. The SBS for each sample was examined with a universal testing machine, and the Adhesive Remnant Index score was calculated. Enamel surfaces after conditioning were examined using a scanning electron microscope. Data were compared by one-way analysis of variance and a χ² test. Results: The experimental SEP showed a milder etching pattern than Transbond Plus SEP. No statistically significant differences in the mean SBS were found between the specimens bonded with the unfilled experimental SEP adhesive system (10.0 MPa) and the filled SEP adhesive system (8.7 MPa). The unfilled experimental SEP adhesive system showed less residual adhesive than the filled SEP adhesive system. Conclusions: The unfilled experimental SEP adhesive system showed a clinically sufficient SBS that was equivalent to the filled SEP adhesive system. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship between the forces applied by the operator and the amount of adhesive used in the direct and indirect bonding methods. Materials and Methods: A system for measuring the force applied by operator was used to test specimens prepared by 12 orthodontic specialists. To determine the proper amount of adhesive, metal brackets were bonded to transparent resin teeth using composite resin paste and different forces (100, 200, and 300 g); the area of the composite resin paste was then measured using image-analysis software. The mean forces applied in direct and indirect bonding were compared by Student's t-test. Results: Various values for force were obtained for the direct bonding (53-940 g) and indirect bonding (150-870 g) techniques. Although in all cases the area of composite resin paste after the application of constant force was greater than the area of the metal brackets, an insufficient amount of composite resin paste on the bracket base was observed with forces of 100 and 200 g. Conclusions: A force of greater than 200 g might be preferable for obtaining a thin composite resin layer and for achieving sufficient spreading of the composite resin paste. [ABSTRACT FROM AUTHOR]

Objective: To evaluate impulse debonding compared to three conventional methods for bracket removal in relation to the damage caused to the enamel surface. Materials and Methods: Ninety-six osteotomed third molars were randomly assigned to two study groups (n 5 48) for bracket bonding with either a composite adhesive system (CAS) or a glassionomeric cement (GIC). These two groups were then each randomly divided into four subgroups (n 5 12) according to the method of debonding using (1) bracket removal pliers, (2) a side-cutter, (3) a lift-off debracketing instrument, or (4) an air pressure pulse device. Following debonding and corresponding postprocessing with either a finishing bur (CAS) or ultrasound (GIC), the enamel surfaces were assessed for damage, adhesive residues, and the need for postprocessing using scanning electron microscopy and the Adhesive Remnant Index, and the surfaces were compared in terms of mode of removal and type of adhesive using Fisher's exact test (α 5 5%). Results: No significant differences were found between the two different types of adhesives (CAS, GIC) in terms of the amount of damage to the enamel. Portions of enamel damage were found for impulse debonding/0%

Objective: To compare, in vitro, the shear bond strength (SBS) of two bond systems: Transbond XT/XT primer (TXT/XT) and Transbond Plus Color Change/Transbond Self Etching Primer (TPCC/TSEP). Materials and Methods: Each system was examined under four enamel surface conditions (dry, water, saliva, and blood), and 160 bovine teeth were divided into eight groups of 20 according to enamel surface condition. Group 1 used TPCC/TSEP and Group 2 used TXT/XT under dry conditions; Group 3 used TPCC/TSEP and Group 4 used TXT/XT with water; Group 5 used TPCC/TSEP and Group 6 used TXT/XT under saliva; and Group 7 used TPCC/TSEP and Group 8 used TXT/XT with blood. Brackets were bonded, and the samples were thermocycled 500 times between 5°C and 55°C; they were then submitted to a shear bond test with a universal testing machine with a 50 kgf load cell at 5 mm/min. Results: Although water and saliva affected TXT/XT more than they affected TPCC/TSEP, there were no significant differences among the groups (Groups 3 and 4: P = .940; Groups 3 and 5 and Groups 4 and 6: P = 1.000; Groups 3 and 6: P = .988; Groups 4 and 5: P = .690; and Groups 5 and 6: P = .861). Conclusions: The presence of blood resulted in the lowest SBS from both bond systems, but especially from TXT/XT. TPCC/TSEP resulted in a higher SBS than TXT/XT under all conditions except the dry enamel surface. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the cytotoxic effects of three different resin-modified orthodontic band adhesives. Materials and Methods: Three resin-modified orthodontic band adhesives (Bisco Ortho Band Paste LC™, Multi-Cure Glass Ionomer Band Cement™, and Transbond Plus Light Cure Band Adhesive™) were prepared and the samples were extracted in 3 mL of Basal Medium Eagle with 10% newborn calf serum for 24 hours. The L929 cells were plated (25,000 cells/mL) in wells of 96-well dishes and maintained in a humidified incubator for 24 hours at 37°C, 5% CO2, and 95% air. After 24-hour 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 methyltetrazolium test. Twelve wells were used for each specimen, and methyltetrazolium tests were applied two times. The data were statistically analyzed using one-way analysis of variance and Tukey Honestly Significantly Different tests. Results: Results with L929 fibroblasts demonstrated that all freshly prepared resin-modified orthodontic band adhesive materials reduced vital cell numbers (P > .05), in comparison to the control group. Our data demonstrate that all materials showed significant cytotoxicity compared to the control group. Conclusions: The results indicate that all materials showed significant cytotoxicity compared to the control group, and further studies using different test methods are needed for all resin-modified orthodontic band adhesives. [ABSTRACT FROM AUTHOR]

Objective: To determine the shear bond strength (SBS) and microleakage of metal brackets bonded with two different adhesives when a resin coat and the adhesive were light-cured separately or simultaneously. Materials and Methods: Eighty stainless steel brackets were bonded to the enamel of extracted premolars, 40 with Transbond Plus adhesive (group 1) and 40 with Transbond XT (group 2). Each group was subdivided into tour equal subgroups; a, b, c, and d. Brackets in subgroups a and b were bonded with the adhesive without coating. For brackets in subgroup c, Ortho-Choice Ortho-Coat was applied and cured after curing of the adhesive, while the coat was applied and cured with the adhesive for brackets in subgroup d. The specimens were immersed in a 2% methylene blue dye. After debonding, the teeth and brackets were examined with a stereomicroscope. The data were subjected to a two-way analysis of variance (ANOVA), Duncan multiple range test, and Pearsoncorrelation. Results: Both adhesives had comparable SBS. Curing of the coat after curing of the adhesive showed significantly higher SBS than other protocols. There was no significant difference in SBS of the adhesives without coating and with curing of the coat and adhesive simultaneously. Application of the coat significantly reduced microleakage. There was a significant negative relationship between SBS and microleakage. Conclusions: SBS was significantly improved with curing of the coat and adhesive separately, while it was not adversely affected when the coat and adhesive were cured simultaneously. Using the coat with either protocol significantly reduced the microleakage. [ABSTRACT FROM AUTHOR]

Objectives: To test the hypothesis that there is no difference in the cytotoxicity related to the modes of polymerization of five commercially available orthodontic bonding resins, with and without an oxygen-inhibited layer (OIL), and to evaluate the degree of conversion (DC) of these resins and correlate this to cytotoxicity. Materials and Methods: Five commercially available orthodontic bonding resins were tested for cytotoxicity and DC. Thirty-six disks of standardized dimensions, for each resin, were used for cytotoxicity assessment. Half of them were washed with 99% acetone to remove the OIL (washed resins), and the remaining disks were left intact (intact resins). Glass disks were used as a control. Vero cells were exposed to intact and washed resins on day 1. Cell viability was determined by tetrazolium bromide reduction assay 1, 3, and 6 days after exposure. The DC of the adhesive specimens of each resin, prepared with a procedure identical to the clinical bonding process, was assessed by Fourier transform infrared spectroscopy. Results: Single-cured systems were comparatively less cytotoxic than dual-cured systems. With removal of the OIL, increased cell viability was noted only with two resins on all three days. Resins tested showed differences in DC. A positive correlation was demonstrated by two resins. Conclusion: The hypothesis is rejected. Single-cured systems are superior to dual-cured systems in exhibiting comparatively less toxicity and higher DC. A significant positive correlation was not established between cytotoxicity and DC. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that adhesive remnant index (ARI) scores show no differences when examined under different magnifications. Materials and Methods: The study included 80 upper human premolars. Stainless steel brackets were bonded to the specimens with Transbond XT light cure adhesive and Transbond Plus Self Etch Primer (3M Unitek, Monrovia, Calif, USA). The brackets were debonded 24 hours after bonding with a universal testing machine (LLOYD Instruments, Segensworth, Fareham, England) at a cross head speed of 2.00 mm/mm. The adhesive remnant was evaluated after debonding with the naked eye and under lox and 20× magnification (Mag) using the 4-point scale described by Artun and Bergland. Results: ARI scores were significantly different at different magnifications (P = .018). Scores were not significantly different when evaluated with the naked eye and under lox Mag (P = .102). Scores were significantly different under 20× Mag and with the naked eye (P = .014); under 20× Mag, score 0 decreased from 12 to 6 and score 2 increased from 14 to 20 and also under 20× Mag and under 10× Mag (P = .046); the under 20× Mag score 1 decreased from 40 to 38 and score 3 increased from 14 to 16. Conclusion: ARI scores were significantly different under 20× Mag, where score 0 decreased and score 2 increased compared with the naked eye, while score 1 decreased and score 3 increased compared with lox Mag. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there is no difference in the degree of conversion (DC%) of orthodontic composites during the light-curing process with or without the use of a glass-fiber reinforcement. Materials and Methods: Two light-curing orthodontic adhesives, Transbond XT (TB) and Beauty Ortho Bond (BO), were used with woven preimpregnated glass fibers. The degree of monomer conversion was determined for both adhesives in three settings (n = 5 per group): in the first group, the adhesive was cured without a bracket (control); in the second group, the bracket was bonded using adhesive without fiber reinforcement; and in the third group, a layer of glass-fiber net was added between the bracket and resin. The adhesive resin was light cured, and the DC% was determined by Fourier transform infrared spectroscopy. Results: A two-way analysis of variance revealed significant differences in the DC% (P < .001) between adhesives and between the fiber-reinforced and nonreinforced groups. When the nonreinforced adhesives were light cured under the brackets, the DC% was significantly lower (TB: 37.0%, SD 3.4; BO: 36.9%, SD 1.9) compared with the control (TB: 54.7%, SD 0.6; BO: 65.9%, SD 0.5). A higher DC% was found when the resin was light cured in the presence of a glass-fiber net (TB: 44.1%, SD 0.3; BO: 55.3%, SD 1.7). Conclusion: The hypothesis is rejected. The degree of monomer conversion of the light-curing adhesive resin under stainless steel bracket can be improved by adding a thin layer of glass-fiber-reinforced composite between the bracket and adhesive resin. [ABSTRACT FROM AUTHOR]

Objective: To determine if a new premixed self-etch adhesive can be used to successfully bond orthodontic brackets to enamel. Materials and Methods: Forty human molars were cleaned, mounted, and randomly divided into two groups. In group 1, 20 teeth were conditioned using the self-etching primer Transbond Plus (3M Unitek, Monrovia, Calif). In group 2, 20 teeth were conditioned using a new premixed self-etching adhesive, AdheSE One (Ivoclar Vivadent Inc, Amherst, NY). Both groups were bonded using brackets precoated with a composite adhesive. The teeth were debonded within half an hour following initial bonding using a universal testing machine. After debonding, the enamel surface was examined under 10x magnifications to determine the amount of residual adhesive remaining on the tooth. A Student's t-test was used to compare the shear bond strength (SBS) of the two groups, and the Chi-square test was used to compare the adhesive remnant index (ARI) scores for the two adhesive systems. Results: The mean SBS of the brackets bonded to the teeth using AdhesSE One was 3.6 ± 1.3 MPa and was significantly lower (t = 2.80, P = .01) than the SBS of the brackets bonded using Transbond Plus (x̄ = 5.9 ± 3.2 MPa). The comparisons of the ARI scores between the two groups (χ² = 19.26) indicated that bracket failure mode was also significantly different (P < .001), with more adhesive remaining on the teeth bonded using Transbond Plus. Conclusions: The SBS of the new premixed self-etching adhesive needs to be increased for it to be successfully used for bonding orthodontic brackets. [ABSTRACT FROM AUTHOR]

Objective: To compare the clinical performance of a self-etching primer (SEP) with a conventional two-step etch and primer method (CM). Materials and Methods: Study subjects were 39 patients with a mean age of 15 years 7 months. Six hundred and eighty-eight brackets were bonded by one operator with a split-mouth design, using Transbond Plus Self-Etching Primer or a conventional two-step etch and primer (Transbond XT). The survival rate of the brackets was estimated by the Kaplan-Meier analysis. Bracket survival distributions with respect to bonding procedure, dental arch, type of tooth (incisor, canine, and premolar) and patients' gender were compared using the log-rank test. Bond failure interface was determined using the Adhesive Remnant Index (ARI). Results: The bond failure rates of SEP and CM were 4.7% and 1.7%, respectively. A significant difference was found between the bonding procedures using the log-rank test (P < .05). Furthermore, canine and premolar teeth displayed a lower survival rate than incisor teeth (P < .05). Survival rates did not show significant differences between the upper and lower dental arches and patients' gender (P > .05). No significant difference was observed for ARI scores (P > .05). Conclusion: These findings indicate that the SEP (Transbond Plus) can be effectively used to bond orthodontic brackets. [ABSTRACT FROM AUTHOR]

Objective: To compare the in vitro microleakage of orthodontic brackets (metal and ceramic) between enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival sides produced by self-etching primer system with that of conventional acid etching and bonding. Materials and Method: Sixty freshly extracted human mandibular premolar teeth were used in this study. The teeth were separated into four groups of 15 teeth each and received the following treatments: Group 1, 37% phosphoric acid gel + Transbond XT liquid primer + stainless steel bracket; Group 2, Transbond Plus Self-Etching Primer (TSEP) + stainless steel bracket; Group 3, 37% phosphoric acid gel + Transbond XT liquid primer + ceramic bracket; Group 4, TSEP + ceramic bracket. After curing, specimens were further sealed with nail varnish, stained with 0.5% basic fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage for the enamel-adhesive and bracket-adhesive interfaces from both occlusal and gingival margins. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U tests. Results: The gingival sides in all groups exhibited higher microleakage scores compared with those observed in occlusal sides for both adhesive interfaces. Enamel-adhesive interfaces exhibited more microleakage than did the adhesive-bracket interfaces. Brackets bonded with self-etching primer system showed significantly higher microleakage at the enamel-adhesive interface of the gingival side. Conclusions: TSEP causes more microleakage between enamel-adhesive interfaces, which may lead to lower bond strength and/or white-spot lesions. [ABSTRACT FROM AUTHOR]

Objective: To compare the effects of two polishing systems on the surface roughness of three types of porcelain after orthodontic debonding. Materials and Methods: A total of 90 porcelain discs were fabricated from feldspathic (n = 30), leucite-based (n = 30) or lithia disilicate-based (n = 30) ceramics. Ten samples in each group served as the control and received no surface treatment. The remaining 60 samples in three of the porcelain groups were bonded with lower incisor brackets and debonded using a testing machine in shear mode at a rate of 1 mm/minute crosshead speed. After debonding, the remaining adhesive resin was removed with a tungsten carbide bur. Then, two experimental subgroups (10 each) in each porcelain group were treated as follows: in the first subgroup, porcelain polishing wheel and polishing paste were applied, whereas in the second, polishing was performed using a series of Sof-Lex discs. The average surface roughness (Ra) of the all samples was evaluated using SPM/AFM (surface probe microscope/atomic force microscope). Data were statistically analyzed by analysis of variance for each porcelain material and polishing method. Results: The polishing techniques affected surface roughness significantly. There were significant differences between the groups; higher Ra values were obtained with the use of porcelain polishing wheel and polishing paste (P < .001). Conclusion: The application of Sof-Lex discs can produce smoother porcelain surfaces than porcelain polishing wheel and polishing paste. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that bonding with a blue light-emitting diode (LED) curing unit produces no more failures in adhesive-precoated (APC) orthodontic brackets than bonding carried out by a conventional halogen lamp. Materials and Methods: Sixty-five patients were selected for this randomized clinical trial, in which a total of 1152 stainless steel APC brackets were employed. In order to carry out a valid comparison of the bracket failure rate following use of each type of curing unit, each patient's mouth was divided into four quadrants. In 34 of the randomly selected patients, designated group A, the APC brackets of the right maxillary and left mandibular quadrants were bonded using a halogen light, while the remaining quadrants were treated with an LED curing unit. In the other 31 patients, designated group B, halogen light was used to cure the left maxillary and right mandibular quadrants, whereas the APC brackets in the remaining quadrants were bonded using an LED dental curing light. The bonding date, the type of light used for curing, and the date of any bracket failures over a mean period of 8.9 months were recorded for each bracket and, subsequently, the chi-square test, the Yates-corrected chi-square test, the Fisher exact test, Kaplan-Meier survival estimates, and the log-rank test were employed in statistical analyses of the results. Results: No statistically significant difference in bond failure rate was found between APC brackets bonded with the halogen light-curing unit and those cured with LED light. However, significantly fewer bonding failures were noted in the maxillary arch (1.67%) than in the mandibular arch (4.35%) after each light-curing technique. Conclusions: The hypothesis cannot be rejected since use of an LED curing unit produces similar APC bracket failure rates to use of conventional halogen light, with the advantage of a far shorter curing time (10 seconds). [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there is no difference in the bond strength with or without contamination with artificial saliva when using two different self-etching primers (Transbond Plus and iBond) in comparison with a conventional acid-etching method (37% phosphoric acid and Transbond XT) for bonding of orthodontic brackets. Materials and Methods: One hundred fifty extracted human premolars were randomly allocated to six different groups, with 25 teeth in each group. Orthodontic metal brackets (APC II, Victory Twin 22 UNIV) were used. For contamination, a saliva replacement (Ptyalin) was applied. After contamination the surface was air-dried for 5 seconds and the bonding procedure continued. The bonded teeth were stored in deionized water at 37°C for 30 days and then thermocycled for 24 hours before debonding with a universal testing machine. The load was recorded at bond failure. The location of adhesive failure was determined under magnification using the adhesive remnant index (ARI). Results: Clinically acceptable bond strengths were found for all primers used in this study. The contamination by saliva significantly decreased the bond strength when using the conventional acid-etching method (t = 0.0001). Self-etching primers were less influenced by saliva contamination. There was no significant difference in the ARI score among the groups (P > .05). Conclusions: Saliva contamination significantly decreased the bond strength when the conventional acid-etching method was used. The self-etching primers were influenced the least. The bond strengths achieved for the self-etching primers and the conventional etching method after saliva contamination were not significantly different. [ABSTRACT FROM AUTHOR]

Objective: To examine the ultrastructure of six light-cure orthodontic adhesives with scanning electron microscope (SEM) and transmission electron microscope (TEM), microhardness tester, and energy dispersive X-ray microanalyzer (EDX). Materials and Methods: The orthodontic adhesives evaluated were Transbond XT, Light Bond, BeautyOrtho Bond, Kurasper F, Heliosit Orthodontic, and Salivatect. Specimens of each adhesive were carefully prepared for observation under SEM and TEM. Furthermore, the Vickers hardness was tested, and the adhesives were evaluated with EDX. Results: SEM and TEM images illustrated great diversity of the adhesives ultrastructure. The Vickers hardness test showed significant differences among all the adhesives (except Transbond XT and Salivatect). Although some similar elements were detected with EDX, the concentration was different in each adhesive. Conclusion: Orthodontic brackets can be bonded to the enamel surface with the adhesives available on the market. However, orthodontists might achieve better results identifying their properties and compositions. [ABSTRACT FROM AUTHOR]

Objective: To determine the degree of cure of a light-cured resin-modified glass ionomer (RMGI) under molar bands compared with a light-cured resin and a dual-cured resin. Materials and Methods: The 3 cements used were Fuji Ortho LC, Eagle Spectrum resin, and Variolink II dual-cure. Each sample was indirectly light cured for 20 seconds (10 seconds occlusally, 10 seconds cervically) under sections of molar bands, and the degree of cure was evaluated with micro-MIR FTIR spectroscopy. Results: The RMGI exhibited a significantly higher mean degree of cure (55.31%) than both of the resins (Eagle 19.23%; Variolink It, 25.42%), which did not differ significantly at α = .05 level of significance. Conclusion: Higher degree of conversion can be obtained from RMGIs under molar bands compared with composite resin adhesives provided the proper curing technique is used. [ABSTRACT FROM AUTHOR]

Objective: To determine the bond failure pattern and time to first bond failure at an orthodontic clinic. Materials and Methods: The study included 63 subjects meeting the study criteria. A total of 1074 brackets (Roth prescription 0.022 slot) were bonded to incisors, canines, and premolars using a no-mix adhesive (Unite, 3M Unitek). The survival and failure rates of the brackets were evaluated by tooth position in the dental arch, sagittal occlusal relationship, and gender of the patients. Overall bracket survival rates were estimated using the Kaplan-Meier test. Results: The total percentage of bond failure was 17.87%. The mean survival time for the sample was 235 days (SE = 32.27 days). Significantly higher failure rates were observed for posterior than anterior teeth (P < .05) and in the Class II division 2 malocclusion group than other malocclusion groups (P < .05). No difference was observed between dental arches or genders. However, in terms of survival time, the difference was marginally significant for gender (P = .051) Conclusion: For 1074 brackets bonded with a no-mix adhesive system in 63 patients, the mean time until first bracket failure was 235 days. The overall failure rate of brackets was 17.87%. [ABSTRACT FROM AUTHOR]

Objective: The hypothesis of this two-part study is that adhesive systems for bonding orthodontic brackets (ie, two self-etch primers [Transbond and M-Bond] and a conventional phosphoric acid etch [Rely-a-Bond]) would show a difference with respect to rebonded enamel surface morphology and chemical composition. Materials and Methods: This study examined the enamel surface before and after debonding with scanning electron microscopy and the enamel surface chemical composition for the elements Ca, P, O, F, Si, and C using x-ray photoelectron spectroscopy. Results: The etching of the two self-etch groups is less aggressive and less uniform than that of phosphoric acid. The change in the concentration of C indicated that the separation of the bracket from the enamel surface is at the resin-enamel interface for the phosphoric acid-etched adhesive and a mixed mode involving the enamel-resin-bracket interfaces for the self-etching systems. F release appears to occur for Transbond but not for M-Bond. Conclusions: The results confirm the original hypothesis that differences in adhesive systems are manifested in less aggressive etches and less adhesive left on the enamel surface for the self-etching adhesive systems. [ABSTRACT FROM AUTHOR]

Objective: To test the null hypothesis that the resin base and the resin hybrid glass ionomer base adhesives do not cause inflammation after contacting primary human gingival fibroblasts in vitro. Materials and Methods: The resin base and resin hybrid glass ionomer base adhesives were used to treat human gingival fibroblasts to evaluate the survival rate using MTT colorimetric assay to detect the level of cyclooxygenase-2 (COX-2) mRNA by reverse transcription polymerase chain reaction (RT-PCR) technique and COX-2 protein expression using Western blot analysis. The results were analyzed using one-way analysis of variance (ANOVA). Tests of differences of the treatments were analyzed using the Tukey test and a value of P < .05 was considered statistically significant. Results: The paste and primer of the resin base adhesive and the liquid of glass ionomer adhesive showed decreasing survival rates after 24 hours of treatment (P < .05). All orthodontic adhesives induced COX-2 protein expression in human gingival fibroblasts. The exposure of quiescent human gingival fibroblasts to adhesives resulted in the induction of COX-2 mRNA expression. The investigations of the time-dependent COX-2 mRNA expression in adhesive-treated human gingival fibroblasts revealed different patterns. Conclusions: The hypothesis is rejected. For orthodontic patients with gingival inflammation, except for those with oral hygiene problems, the activation of COX-2 expression by orthodontic adhesive may be one of the potential mechanisms. [ABSTRACT FROM AUTHOR]

Objective: To determine the effects of thermocycling on shear bond strengths (SBSs) of a self-etching primer (SEP) after 0, 2000, and 5000 thermal cycles. Materials and Methods: Brackets were bonded to bovine incisors with two etching protocols. In the control group (conventional method) teeth were etched with 37% phosphoric acid. In the experimental group, an SEP (Transbond Plus) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT) and light cured for 20 seconds in both groups. The SBSs were measured after water storage at 37°C for 24 hours, after 2000 and 5000 cycles of thermocycling between 5°C and 55°C. Bond failure location was determined with the Adhesive Remnant Index (ARI). Results: In the control group, SBSs did not show any significant differences among 0, 2000, and 5000 thermal cycles. However, in group SEP, SBSs decreased with 2000 and 5000 thermal cycles, and these decreases were significantly different from no thermocyling (P < .001). A significant difference was observed between ARI scores of the control group with 5000 thermal cycles and group SEP with no thermal cycles (P < .003). In addition, a significant difference was found between group SEP with no thermocycling and with 5000 thermal cycles (P < .003). Conclusion: The results of this study indicate that the SEP (Transbond Plus) provides clinically acceptable bond strength values compared with the conventional method after thermocycling. [ABSTRACT FROM AUTHOR]

Objective: To determine whether an amorphous calcium phosphate (ACP)-containing adhesive has an acceptable level of shear bond strength to be used as an orthodontic adhesive. Materials and Methods: Sixty extracted premolars were randomly divided into three groups for orthodontic bonding. Group 1 used a composite resin adhesive (Transbond XT), group 2 was bonded with an ACP-containing adhesive (Aegis Ortho), and group 3 used a resin-modified glass ionomer (Fuji Ortho LC). All bonded teeth were stored in distilled water at 37°C for 40 ± 2 hours prior to debonding. Shear bond strength and adhesive remnant index (ARI) were recorded for each specimen. Results: The mean shear bond strengths for the three test groups were: group 1 (15.2 ± 3.6 MPa), group 2 (6.6 ± 1.5 MPa), and group 3 (8.3 ± 2.8 MPa). A one-way analysis of variance showed a significant difference in bond strengths between the groups. A post hoc Tukey test showed group 1 to be significantly (P < .001) greater than groups 2 and 3. A Kruskal-Wallis test and a Mann-Whitney U-test showed groups 1 and 3 exhibited lower ARI scores than group 2, but a majority of specimens in each group had greater than 50% of the cement removed along with the bracket during debonding. Conclusions: The ACP-containing adhesive demonstrated a low, but satisfactory bond strength needed to function as an orthodontic adhesive. [ABSTRACT FROM AUTHOR]

Objective: To determine if there is any significant difference in excess adhesive flash (EAF) with the use of APC PLUS adhesive coated appliance system and Transbond XT and if other variables such as side of the mouth, time taken to bond the brackets, the age of the orthodontic specialist, or the years of clinical experience affected the amount of EAF. Materials and Methods: Twenty orthodontic specialists bonded 20 preadjusted straight wire brackets (Victory, 3M Unitek) on a typodont with a Class I crowded malocclusion in a split-mouth design, with one-half of the brackets bonded with APC PLUS adhesive system and the other half with Transbond XT. The teeth were sputter coated with gold and an image was taken at 32x magnification in a scanning electron microscope (Philips XL30). The resultant tagged image file (TIF) was opened in AnalySIS Pro 3.1 (Soft Imaging System, Munich, Germany) and the area of EAF was measured. Results: t-Tests demonstrated that: (1) there was no statistically significant difference in EAF between two adhesives when bonding in different quadrants of dentition; and (2) there was no statistically significant difference in EAF between two adhesives overall. Analysis of variance models demonstrated there were no statistically significant differences found regarding the age of the orthodontic specialists, years of clinical experience, and time in performing the bonding. Conclusions: The addition of a coloring agent to assist in the visualization of the excess adhesive does not reduce the amount of excessive adhesive around orthodontic brackets. [ABSTRACT FROM AUTHOR]

Objective: To evaluate shear bond strengths (SBSs) of a self-etching primer (SEP) following saliva contamination at different stages of bonding at debond times of 5, 15, and 30 minutes and 24 hours. Materials and Methods: Two-hundred forty human premolars were divided into four groups: group 1, uncontaminated; group 2, saliva contamination after priming; group 3, saliva contamination before priming; and group 4, saliva contamination before and after priming. Four subgroups according to debond times of 5, 15, 30 minutes and 24 hours were composed. Metal brackets were bonded with an SEP (Transbond Plus) and light-cure adhesives paste (Transbond XT). SBS values and the adhesive remnants were determined. Results: The highest SBS was obtained at a debond time of 24 hours for the control group. This was significantly different from the other groups. SBSs at 5, 15, and 30 minutes showed no significant difference from each other in the control group (P > .05). Lowest SBSs were obtained at a debond time of 5 minutes for groups 1, 2, 3, and 4 (8.38, 7.10, 7.06, and 6.26 MPa, respectively) and were not significantly different from each other (P > .05). SBSs at 24 hours were not significantly different from each other for groups 2, 3, and 4 (P > .05). Significant differences were found in the adhesive remnant (P < .001). Conclusions: SEP (Transbond Plus) may produce clinically acceptable bracket bonding after 5, 15, and 30 minutes from time of placement on the teeth, even with light and heavy saliva contamination. [ABSTRACT FROM AUTHOR]

Objective: To determine the influence of self-etching primer (SEP) application time on the shear bond strength of orthodontic brackets. Materials and Methods: Forty human molars were cleaned, mounted, and randomly divided into two groups. The same SEP, adhesive, and brackets were used in both groups. Twenty teeth were conditioned following the manufacturers' recommendations by rubbing the SEP on the enamel surface for 3 to 5 seconds. The remaining 20 teeth were conditioned using the same SEP, but the application time was increased to 15 seconds. The teeth were debonded within half an hour following initial bonding using a universal testing machine. After debonding, the amount of residual adhesive remaining on the tooth was determined. Student's t-test was used to compare the shear bond strength (SBS) of the two groups, and the χ² test was used to compare the Adhesive Remnant Index (ARI) scores for the two adhesive systems. Results: The mean SBS of the brackets bonded to the teeth subjected to the SEP for 3 to 5 seconds was 8.0 ± 4.6 MPa and was not significantly different (t = -0.69, P = .494) from the SBS of the brackets bonded using a 15-second SEP application time (x̄ = 8.9 ± 3.4 MPa). The comparisons of the ARI scores between the two groups (χ² = 2.16) indicated that bracket failure mode was not significantly different (P = .340) for both groups, and most failures were at the bracket-adhesive interface. Conclusion: The present findings indicate that increasing the SEP application from 3 to 5 seconds to 15 seconds does not result in a significant increase in SBS. [ABSTRACT FROM AUTHOR]

Objective: To determine the toxicity of orthodontic adhesives assessed on in vitro three-dimensional reconstructed human oral epithelium (RHOE). Materials and Methods: Two adhesive primers, Transbond XT (3M, Monrovia, Calif) and Excite (Vivadent, Schaan, Liechtenstein), were tested. After topical exposure, the cell cultures were fixed, cut, and stained for light microscopy (LM) and transmission electron microscopy (TEM). Detection of cytotoxicity by measuring lactate dehydrogenase (LDH) activity was performed. Toxicity was assessed by evaluating the morphological changes with LM and TEM. Copper wires and Triton X-100 served as positive controls, and native cell cultures as negative control. Results: Morphological evaluation of the native cell cultures revealed no toxic reactions. The LDH assay revealed the following mean values for viability: native cell line (negative control), 1.51; Triton X-100 (positive control), 3.06; Transbond XT polymerized, 1.15; Excite polymerized, 1.11; Transbond XT primer, 2.67; and Excite primer, 0.04. Acute toxicity was observed for Triton X-100 and Transbond XT primer (P < .001). Histological evaluation of the RHOE showed toxicity for both primers and mild changes after topical application of polymerized adhesives. The biocompatibility ranking of the adhesive primers was the same after histological analysis and LDH assay except for Excite™ noncured. Conclusions: RHOE proved to be a valuable model for topical exposure. The toxicity of both uncured primers was demonstrated. [ABSTRACT FROM AUTHOR]

Objective: To evaluate a new self-etch conditioner used with resin-modified glass ionomers (RMGIs) in bonding orthodontic brackets. Materials and Methods: Sixty human molars were cleaned, mounted, and randomly divided into three groups. In group 1 (control), 20 orthodontic brackets were bonded to teeth using Transbond Plus Self-etching Primer; in group 2, 20 brackets were bonded using an RMGI with a 10% polyacrylic acid conditioner. In group 3, 20 brackets were bonded using Fuji Ortho LC with a new no-rinse self-conditioner for RMGIs. The same bracket type was used on all groups. The teeth were debonded in shear mode using a universal testing machine, and the amount of residual adhesive remaining on each tooth was evaluated. Analysis of variance was used to compare the shear bond strength (SBS), and the χ² test was used to compare the Adhesive Remnant Index (ARI) scores. Results: There were no significant differences in the SBS (P = .556) between the groups. The mean SBS for Transbond Plus was 8.6 ± 2.6 MPa, for Fuji Ortho LC using 10% polyacrylic acid 9.1 ± 4.6 MPa, and for Fuji Ortho LC using GC Self-conditioner 9.9 ± 4.1 MPa. The comparisons of the ARI scores between the three groups (χ² = 35.5) indicated that bracket failure mode was significantly different (P < .001), with more adhesive remaining on the teeth bonded using Transbond. Conclusions: The new self-etch conditioner can be used with an RMGI to successfully bond brackets. In addition, brackets bonded with Fuji Ortho LC resulted in less residual adhesive remaining on the teeth. [ABSTRACT FROM AUTHOR]

Objective: To evaluate and compare the shear bond strengths of two adhesives using two types of brackets: a conventional and a self-ligating bracket system. Materials and Methods: Sixty extracted human premolars were collected. The premolars were randomly divided into three groups of 20 teeth. All three groups were direct bonded. Groups 1 and 2 used light-cured adhesive and primer (Transbond XT) with a conventional (Orthos) and a self-ligating bracket (Damon 2), respectively. Group 3 used a light-cured primer (Orthosolo) and a light-cured adhesive (Blūgloo) with a self-ligating bracket (Damon 2). The specimens were stored in distilled water at 37°C for 40 ± 2 hours, after which they were debonded and inspected for Adhesive Remnant Index (ARI) scoring. Results: The mean shear bond strength was 15.2 MPa for group 1, 23.2 MPa for group 2, and 24.8 MPa for group 3. A one-way analysis of variance and post hoc Tukey test showed significant differences in bond strength (P < .001) between group 1 and groups 2 and 3 but no significant difference (P > .05) between groups 2 and 3. A Weibull analysis demonstrated that all three groups provided sufficient bond strength with over 90% survival rate at normal masticatory and orthodontic force levels. A Kruskal-Wallis test showed no significant difference (P > .05) in ARI scores among all three groups. Conclusions: All three groups demonstrated clinically acceptable bond strength. The Damon 2 self-ligating bracket exhibited satisfactory in vitro bond strength with both adhesive systems used. [ABSTRACT FROM AUTHOR]

Objective: To produce an antibacterial adhesive for orthodontic bonding without compromising the mechanical property. Materials and Methods: We added benzalkonium chloride (BAC) to the Superbond C&B (4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane [4-META/MMA- TBB]), a resin that exhibits a strong bonding strength between enamel and bracket. BAC concentrations in the BAC composites were 0.25%, 0.75%, 1.25%, 1.75%, 2.5%, and 5% (wt/wt). Antibacterial activity of the BAC composite was measured by the disk diffusion method. BAC-composite discs were placed on the surface of the agar inoculated with Streptococcus mutans and Streptococcus sobrinus, and the plates were incubated at 37°C. After 48 hours of incubation, the inhibition zone around each sample was measured and recorded. The BAC-modified composite was used to bond metal brackets to the phosphoric acid-etched enamel surface of human premolars. The shear bond strengths were measured after immersion in water at 37°C for 24 hours. Results: The BAC-composite samples showed significant (P < .0001) antibacterial activity compared with the control. Measurable zones of bacterial inhibition increased as the BAC content in test samples increased. The shear bond strength declined with the increase in BAG concentration in the composite. A significant difference was found between the control composite and composites containing 1.25%, 1.75%, 2.5%, and 5% BAC (P < .05). No significant difference was found between the control composite and composites containing 0.25% and 0.75% BAG. However, shear bond strengths of the modified composites ranged from 10.12 MPa to 20.94 MPa. Conclusions: These results confirmed that BAG-modified 4-META/MMA-TBB resin has a possibility for clinical application as an orthodontic bonding adhesive. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there are no significant differences in the shear bond strength or the adhesive remaining on the tooth after debonding between precoated and uncoated brackets using a self-etching primer. Materials and Methods: APC Plus precoated brackets and uncoated brackets were bonded with Transbond XT adhesive using the self-etching primer Transbond Plus Self-Etching Primer (TPSEP). The brackets were bonded to extracted human premolars and categorized into two groups: (1) TPSEP/Transbond XT and (2) TPSEP/APC Plus. Shear bond strength was measured with a universal testing machine. The adhesive remnant on each tooth after debonding was quantified with image analysis equipment. Scanning electron microscope (SEM) observations of enamel surfaces treated with TPSEP were also carried out. Results: No significant differences were observed in the shear bond strengths for the two groups evaluated (P < .05). TPSEP/APC Plus left significantly less adhesive on the tooth after debonding than did TPSEP/Transbond XT (P < .05). It was observed that SEM left a porous and potentially retentive surface. Conclusions: There was no significant difference in the bond strength of the two systems tested, but there was a significant difference in the percentage of area of adhesive remaining on the tooth. [ABSTRACT FROM AUTHOR]

Objective: To assess and compare the effects of one- and two-step self-etching primer and adhesive with conventional acid-etching and bonding system on the shear bond strength of orthodontic brackets. Materials and Methods: The one-step self-etching primer and adhesive used was Clearfil tri-S bond, the two-step fluoride-releasing antibacterial self-etching primer and adhesive was Clearfil Protect Bond, and the fluoride-releasing conventional acid-etching and bonding system was Kurasper F Bond. Brackets were bonded to defect-free human premolars (n = 14 per group) according to each manufacturer's recommendations by using light-cured bracket adhesive Kurasper F Paste with a light-emitting diode of a light-curing unit. The specimens were stored in deionized water at 37°C for 48 hours and then tested in shear with a universal testing machine at a cross-head speed of 5 mm/min until the brackets debonded. The mode of failure of the brackets was determined by a modified adhesive remnant index. Results: Mean shear bond strength values were 9.00 MPa for Kurasper F Bond, 9.55 MPa for Clearfil Protect Bond, and 9.48 MPa for Clearfil tri-S Bond. One-way analysis of variance detected no statistically significant difference among groups (P = .98, P > .05). The predominant failure for the three groups was at the bracket-adhesive interface leaving less than 25% of the adhesive on the bracket base. Conclusions: One-step self-etching adhesive and two-step fluoride-releasing antibacterial self- etching adhesive have sufficient mechanical properties for the bonding of orthodontic brackets. [ABSTRACT FROM AUTHOR]