XT Primer Research Articles

Characteristics of adhesive bonding with enamel deproteinization.

ABSTRACTObjective: To evaluate the effect of using sodium hypochlorite (NaOCl) on the bond characteristics of orthodontic metal brackets bonded to enamel surface using three adhesive systems. Methods: One hundred twenty premolars were selected and randomly divided into two equal groups of 60 teeth/ each (Groups I and II). The teeth of Group I were left untreated while those of Group II were exposed to 5.25% NaOCl for 1 minute. The teeth in either group were randomly subdivided into three equal subgroups of 20 teeth/ each (A, B and C), according to the type of adhesive system used to bond the brackets. In Subgroup A, phosphoric acid + Transbond XT primer and adhesive were used. In subgroup B, Transbond Plus self-etching primer (SEP) + Transbond XT adhesive were utilized. In subgroup C, phosphoric acid + SmartBond LC adhesive were used. The shear bond strength (SBS) and the degree of adhesive penetration to enamel surface were assessed. Data analyses were performed using ANOVA, post-hoc (LSD), t and chi-square test. Results: Transbond XT had significantly higher SBS than SmartBond LC (p< 0.05). Phosphoric acid provided significantly higher SBS and degree of adhesive penetration than SEP (p< 0.05). NaOCl significantly increased SBS and degree of adhesive penetration in Subgroups B and C (p< 0.05). Conclusion: Adhesion quality of Transbond XT adhesive is better than SmartBond LC. Phosphoric acid is more effective than SEP. NaOCl enhances the bond characteristics.

Bracket bonding to polymethylmethacrylate-based materials for computer-aided design/manufacture of temporary restorations: Influence of mechanical treatment and chemical treatment with universal adhesives.

ObjectiveTo assess shear bond strength and failure mode (Adhesive Remnant Index, ARI) of orthodontic brackets bonded to polymethylmethacrylate (PMMA) blocks for computer-aided design/manufacture (CAD/CAM) fabrication of temporary restorations, following substrate chemical or mechanical treatment.MethodsTwo types of PMMA blocks were tested: CAD-Temp® (VITA) and Telio® CAD (Ivoclar-Vivadent). The substrate was roughened with 320-grit sandpaper, simulating a fine-grit diamond bur. Two universal adhesives, Scotchbond Universal Adhesive (SU) and Assure Plus (AP), and a conventional adhesive, Transbond XT Primer (XTP; control), were used in combination with Transbond XT Paste to bond the brackets. Six experimental groups were formed: (1) CADTemp®/SU; (2) CAD-Temp®/AP; (3) CAD-Temp®/XTP; (4) Telio® CAD/SU; (5) Telio® CAD/AP; (6) Telio® CAD/XTP. Shear bond strength and ARI were assessed. On 1 extra block for each PMMA-based material surfaces were roughened with 180-grit sandpaper, simulating a normal/medium-grit (100 mm) diamond bur, and brackets were bonded. Shear bond strengths and ARI scores were compared with those of groups 3, 6.ResultsOn CAD-Temp® significantly higher bracket bond strengths than on Telio® CAD were recorded. With XTP significantly lower levels of adhesion were reached than using SU or AP. Roughening with a coarser bur resulted in a significant increase in adhesion.ConclusionsBracket bonding to CAD/CAM PMMA can be promoted by grinding the substrate with a normal/medium-grit bur or by coating the intact surface with universal adhesives. With appropriate pretreatments, bracket adhesion to CAD/CAM PMMA temporary restorations can be enhanced to clinically satisfactory levels.

Fourier-transform infrared spectroscopy/attenuated total reflectance analysis for the degree of conversion and shear bond strength of Transbond XT adhesive system.

ObjectiveThe objectives of this study were to evaluate the degree of conversion (DC) for Transbond XT curing light of intensity 1,600 mW/cm2 by using variable curing durations and to determine the effect of the tested curing durations adopted in the current experiment on shear bond strength of Transbond XT resin cement.Materials and methodsA total of 85 orthodontic ceramic brackets (Victory series; 3M Unitek) were utilized in the current experiment. The bonding system used in the current study was Transbond XT Primer followed by Transbond PLUS Color Change Adhesive (3M Unitek) that cured for 3, 6, and 9 seconds. The method was done by polymerization of the adhesive under a ceramic bracket for 40 ceramic brackets. The other 45 brackets were divided into three groups (n=15) according to the curing time duration (3, 6, and 9 seconds). The bonded specimens in each group were debonded using a shear load applied at the bracket bases by the blades of an Instron universal testing machine (ElectroPlus E1000; Instron) and directed in an occlusogingival direction with a crosshead speed of 0.5 mm/min utilizing 50 kg load cell.ResultsOne-way ANOVA revealed that 6 and 9 seconds curing by the Ortholux light cure scored significantly higher values when compared to the 3 seconds curing.ConclusionCuring the Transbond XT for 6 and 9 seconds recorded a significant improvement of bond strength and DC.

Shear bond strength of metal brackets to ceramic surfaces using a universal bonding resin

BackgroundAssure Plus is a recently introduced universal adhesive with the ability to bond to various restorations. This study compared the shear bond strength of brackets bonded to two types of ceramics using conventional bonding agent and Assure Plus. Surface damage caused by debonding was also evaluated.Material and MethodsIn this in vitro study, 40 feldspathic and lithium disilicate ceramic discs were sandblasted, etched with 9.6% hydrofluoric acid and divided into two groups. In group 1, silane was applied and air-dried followed by application of Transbond XT primer, which was light-cured. In group 2, Assure Plus was applied and air-dried. In both groups, maxillary central incisor brackets were bonded. After incubation in distilled water at 37°C for 24 hours and 2000 thermal cycles, bond strength was measured using a universal testing machine, and the adhesive remnant index (ARI) and failure modes were determined. ANOVA and LSD tests were used to compare bond strength values; chi-squared test was used to compare ARI scores.Results Bracket bond to lithium disilicate by Assure Plus was significantly stronger than that to Feldspathic porcelain (P=0.041). Only in the Assure Plus/lithium disilicate group did some adhesive remain on the surface following debonding (40% of samples, P<0.05). Cohesive porcelain fracture had the lowest frequency in the lithium disilicate/Assure Plus group.ConclusionsAssure Plus provided high bond strength between ceramic and brackets and minimized damage to lithium disilicate ceramic during debonding. Assure Plus is recommended for use in orthodontic treatment of adults with ceramic restorations. Key words:Adhesives, ceramics, dental bonding, shear bond strength.

Effects of different primers on indirect orthodontic bonding: Shear bond strength, color change, and enamel roughness.

ObjectiveWe aimed to perform in-vitro evaluation to compare 1) shear bond strength (SBS), adhesive remnant index (ARI), and color change between self-etched and acid-etched primers; 2) the SBS, ARI and color change between direct and indirect bonding; and 3) the enamel roughness (ER) between 12-blade bur and aluminum oxide polisher debonding methods.MethodsSeventy bovine incisors were distributed in seven groups: control (no bonding), direct (DTBX), and 5 indirect bonding (ITBX, IZ350, ISONDHI, ISEP, and ITBXp). Transbond XT Primer was used in the DTBX, ITBX, and ITBXp groups, flow resin Z350 in the IZ350 group, Sondhi in the ISONDHI group, and SEP primer in the ISEP group. SBS, ARI, and ER were evaluated. The adhesive remnant was removed using a low-speed tungsten bur in all groups except the ITBXp, in which an aluminum oxide polisher was used. After coffee staining, color evaluations were performed using a spectrophotometer immediately after staining and prior to bonding.ResultsISONDHI and ISEP showed significantly lower SBS (p < 0.01). DTBX had a greater number of teeth with all the adhesive on the enamel (70%), compared with the indirect bonding groups (0–30%). The ER in the ITBX and ITBXp groups was found to be greater because of both clean-up techniques used.ConclusionsDirect and indirect bonding have similar results and all the primers used show satisfactory adhesion strength. Use of burs and polishers increases the ER, but polishers ensure greater integrity of the initial roughness. Resin tags do not change the color of the teeth.

Evaluation of the effect of moisture and saliva on the shear bond strength of brackets bonded with conventional bonding system and moisture insensitive primer: An in vitro study

Introduction: Bonding of orthodontic attachments with acid etching is the most commonly used orthodontic procedure. However, there are certain limitations with acid etching procedure like/moisture contamination, etching time, the concentration of adhesive, etc., Moisture insensitive primers (MIPs) were introduced to overcome these limitations. Objectives: The aim of this study is to compare the shear bond strength of orthodontic brackets bonded with a MIP (Transbond MIP, 3M Unitek) against a conventional primer (Transbond XT, 3M Unitek) when contaminated with saliva – in vitro study. Methodology: Sixty maxillary premolars extracted for orthodontic purpose or due to periodontal involvement with sound buccal surfaces were collected, cleaned thoroughly, and stored in 0.1% (wt/vol) thymol at room temperature for 2 weeks. Following materials were used: Transbond XT Light cure adhesive (3M unitek), Transbond XT primer (3m unitek), Transbond MIP primer (3M unitek), and Metal brackets (3M unitek). A commercially available artificial saliva (AQWET, CIPLA) was used for contamination purpose. Ivoclarbluephase N LED light curing unit were used for curing purpose. Results: Mean bond strength was well above the clinically acceptable bond strength values indicating the use of these hydrophilic bonding materials in contaminated environments (8.5 Mpa for Transbond XT and 9.25 Mpa for Transbond MIP). On comparison of bond strengths of MIP and XT when contaminated with saliva, statistically significant values were obtained with contamination with saliva after primer application. There was a statistically significant increase in the bond strength after primer application (P = 0.233) and before and after primer application (P = 0.027*). Transbond MIP can be used to achieve adequate bond strength in saliva contaminated condition. Conclusion: Under dry condition, the shear bond strength of conventional primer (TRANSBOND XT) was significantly increased when compared to MIP. Under wet conditions MIP (TRANSBOND MIP) showed the highest shear bond strength and hence can be considered as a material of choice in wet conditions.

Evaluation of Microleakage under Orthodontic Brackets Bonded with Nanocomposites.

Background:The aim of this study was to evaluate the microleakage value under orthodontic brackets bonded with a nano-filled composite and to compare the results with a conventional adhesive using two different bonding systems.Materials and Methods:Forty human premolars were used in this cross-sectional study. The samples were randomly divided into four equal groups of ten: Group I: Acid etch plus Transbond XT primer and Transbond XT adhesive, Group II: Acid etch plus Transbond XT primer and nanocomposite (Filtek Z350), Group III: Scotchbond™ Universal primer plus Transbond XT, and Group IV: Scotchbond™ and nanocomposite. Sections were prepared for microleakage evaluation at the occlusal and gingival margins. Statistical analysis was performed to compare the microleakage values among the groups using analysis of variance (ANOVA).Statistical Analysis:Microleakage values were analyzed with two-way ANOVA test. Intraexaminer error was evaluated by the Kappa statistic. The level of significance was considered at P < 0.05.Results:Gingival side displayed statistically higher microleakage (P < 0.001). The nanocomposite Filtek Z350 generally represented higher microleakage when compared with the Transbond XT at both occlusal and gingival sides of the brackets (P < 0.001). More microleakage values were observed in brackets bonded using acid etch compared with Scotchbond. Comparison of microleakage among all the four groups revealed that Group II and Group III had the most and the least microleakage values, respectively, at the enamel–adhesive interface. Microleakage values for groups bonded with nanocomposite were significantly higher.Conclusion:This investigation clearly reveals the outstanding superiority and efficiency of a Transbond XT adhesive combined with a Scotchbond primer over that obtained using a Filtek Z350 nanocomposite in any combination with the used primers to limit microleakage under bonded brackets.

Comparison of bond strengths of ceramic brackets bonded to zirconia surfaces using different zirconia primers and a universal adhesive.

ObjectivesThe aim of this study is to compare the shear bond strengths of ceramic brackets bonded to zirconia surfaces using different zirconia primers and universal adhesive.Materials and MethodsFifty zirconia blocks (15 × 15 × 10 mm, Zpex, Tosoh Corporation) were polished with 1,000 grit sand paper and air-abraded with 50 µm Al2O3 for 10 seconds (40 psi). They were divided into 5 groups: control (CO), Metal/Zirconia primer (MZ, Ivoclar Vivadent), Z-PRIME Plus (ZP, Bisco), Zirconia Liner (ZL, Sun Medical), and Scotchbond Universal adhesive (SU, 3M ESPE). Transbond XT Primer (used for CO, MZ, ZP, and ZL) and Transbond XT Paste was used for bracket bonding (Gemini clear ceramic brackets, 3M Unitek). After 24 hours at 37°C storage, specimens underwent 2,000 thermocycles, and then, shear bond strengths were measured (1 mm/min). An adhesive remnant index (ARI) score was calculated. The data were analyzed using one-way analysis of variance and the Bonferroni test (p = 0.05).ResultsSurface treatment with primers resulted in increased shear bond strength. The SU group showed the highest shear bond strength followed by the ZP, ZL, MZ, and CO groups, in that order. The median ARI scores were as follows: CO = 0, MZ = 0, ZP = 0, ZL = 0, and SU = 3 (p < 0.05).ConclusionsWithin this experiment, zirconia primer can increase the shear bond strength of bracket bonding. The highest shear bond strength is observed in SU group, even when no primer is used.

Microphotographic Assessment of Enamel Surface using Self-Etching Primer and Conventional Phosphoric Acid: An In vitro Study.

Introduction:Conventional acid-etching method irreversibly removes several microns of enamel surface and also involves many steps. Hence, a simplified technique that minimizes enamel loss, improves adhesion procedures, prevents saliva contamination, and saves chair time, thereby producing clinically useful bond strength, would be valuable.Aim:To assess and compare the bonding mechanism of a self-etching primer (SEP) to that of phosphoric acid on enamel of the human permanent teeth by a scanning electron microscope (SEM).Materials and Methods:Thirty freshly extracted premolars were randomly divided into two groups of fifteen teeth each – the control group I (phosphoric acid) and experimental group II (self-etching primer). Brackets were bonded using Transbond XT adhesive on the buccal surfaces of the teeth after etching and priming according to their respective protocols. The teeth were then sectioned and the samples were subjected to a protocol of demineralization cycles. After complete dissolution of dental tissues, the specimens were gold sputter coated and evaluated under SEM.Results:A characteristically uniform etch pattern was seen in the resin samples of the phosphoric acid/Transbond XT primer group, which revealed increased roughness and resin tags penetrating the demineralized enamel surface, whereas with Transbond Plus SEP, a regular resin tag distribution was observed which showed less magnitude when compared with the control group.Conclusion:From the study, it was concluded that Transbond Plus SEP produced an etch pattern which was more conservative than conventional phosphoric acid system.

The effects of utilizing conventional etching versus self etch primer on the enamel color change after treatment with fixed orthodontic appliances: in vivo study

Objectives: The present study was conducted to evaluate clinically the effect of conventional etching and the self etchprimer on the change in enamel color before and after orthodontic treatment. Materialand Methods: The study was conducted on 24 patients treated with fixed orthodonticappliances. Metal brackets were bonded to the teeth mesial to first molars. The bracketswere bonded utilizing Transbond XT adhesiveafter application of either conventional etching (%37 phosphoric acid etch and Transbond XT primer) or Transbond XT self etch primer (splitmouth design). Teeth which showed bracket bond failure were excluded from the study. Therefore, the final number of teeth which were included in the conventional etch and self etch groups were 164 and 160 respectively. The color of the labial and buccal surfaces of the teeth mesial to the first molars was evaluated before bracket bonding and after orthodontic treatment. This step was done with the aid of spectrophotometer Vita Easyshade (Vita Zahnfabri, Germany). The evaluation of the color depended on the color space system of CIELAB (Commission Internationale de l›Eclairage L*, a* and b*). Three parameters were measured (L*, a*, b*). Also, color change(ΔE) was calculated. Then the collected data was statistically analyzed using Paired t-test.Results: All color measurements (L*, a*, b*) were significantly decreased after orthodontic treatment(P<0.05). Conventional etching provided significantly higher ΔE value than the self etch primer (P<0.05).Conclusion: The utilization of conventional etching or self etch primer have a significant negative effect ontooth color after orthodontic treatment. However, the conventional etching has higher pronounced effects.

Effects of different etching methods and bonding procedures on shear bond strength of orthodontic metal brackets applied to different CAD/CAM ceramic materials.

To investigate the shear bond strength (SBS) of orthodontic metal brackets applied to different types of ceramic surfaces treated with different etching procedures and bonding agents. Monolithic CAD/CAM ceramic specimens (N = 120; n = 40 each group) of feldspathic ceramic Vita Mark II, resin nanoceramic Lava Ultimate, and hybrid ceramic Vita Enamic were fabricated (14 × 12 × 3 mm). Ceramic specimens were separated into four subgroups (n = 10) according to type of surface treatment and bonding onto the ceramic surface. Within each group, four subgroups were prepared by phosphoric acid, hydrofluoric acid, Transbond XT primer, and Clearfill Ceramic primer. Mandibular central incisor metal brackets were bonded with light-cure composite. The SBS data were analyzed using three-way analysis of variance (ANOVA) and Tukey HSD tests. The highest SBS was found in the Vita Enamic group, which is a hybrid ceramic, etched with hydrofluoric acid and applied Transbond XT Adhesive primer (7.28 ± 2.49 MPa). The lowest SBS was found in the Lava Ultimate group, which is a resin nano-ceramic etched with hydrofluoric acid and applied Clearfill ceramic primer (2.20 ± 1.21 MPa). CAD/CAM material types and bonding procedures affected bond strength ( P < .05), but the etching procedure did not ( P > .05). The use of Transbond XT as a primer bonding agent resulted in higher SBS.

INFLUENCE OF PROLONGED CONTINUOUS ORTHODONTIC FORCE ON THE SHEAR BOND STRENGTH OF METALLIC BRACKETS BONDED WITH VARIOUS ADHESIVE SYSTEMS

Purpose: To estimate the effect of prolonged continuous force on the shear bond strength (SBS) of orthodontic brackets bonded with different adhesive systems. Materials and Methods: Eighty premolars were randomly divided into four groups (I, II, III and IV) according to the bonding adhesive used. Orthodontic metal brackets were bonded with one of the succeeding adhesives; Rely-a-bond, Transbond XT primer and adhesive, Transbond Plus self-etch primer (SEP) and Transbond XT adhesive and Smart Bond. Half of the brackets were subjected to 150 g of force for 12 months. All the specimens were thermocycled 1000 times between 5° C and 55° C. A Universal Testing Machine was used to measure SBS. Results: Transbond XT primer and adhesive exhibited the highest significant SBS value (12.8Mpa). Smart bond showed the lowest value (7.7Mpa). Rely-a-bond and Transbond Plus SEP adhesive systems had middle values (8.8 and 7.8Mpa). There was a significant decrease in the SBS of all studied adhesives (P<0.05) accompanied force application (P <0.05). Smart Bond showed the higher reduction in SBS while Transbond XT primer + Transbond XT adhesive revealed the lesser reduction. Conclusion: Application of 150 gram of force for 12 months produced a pronounced negative effect on SBS especially with either SEP or Smart Bond.

Novel evaluation and treatment techniques for white spot lesions. An in vitro study.

White spot lesions (WSLs) are commonly seen during and after orthodontic treatment. Therefore, the objective of this in vitro study was to assess the effect of 45S5-bioglass in remineralizing WSLs using cross-polarization optical coherence tomography (CP-OCT) and confirm the findings by micro-hardness test. Ceramic orthodontic brackets were bonded to the buccal surface of 45 human premolars with Transbond XT primer followed by Transbond PLUS according to the manufacturer's instructions. Then, all specimens were varnished excluding the area of interest (AOI) around the bonded brackets, immersed in demineralizing solution and divided into three groups: BG, REM and CONT. In BG group, 15 specimens were treated with bioglass paste for 24hours. REM group had 15 specimens stored in remineralization solution for 24hours. CONT group had the remaining 15 specimens with no treatment. All specimens were examined under CP-OCT and tested using cross-sectional micro-hardness techniques. CP-OCT analysis showed that the maximum pixel value after bioglass application was significantly increased at AOI when compared to CONT and REM groups (P>.05), which was confirmed by the cross-sectional micro-hardness results (P>.05). Early enamel demineralization and remineralization can be easily and non-invasively monitored with CP-OCT. Bioglass is a potent remineralizing agent.

Enamel shear bond strength of different primers combined with an orthodontic adhesive paste.

The aim of this study was a comparison of shear bond strength (SBS) on tooth enamel of different primers combined with the adhesive paste Transbond XT. Forty bovine teeth were used in order to create 40 test blocks. The blocks were divided into four groups of 10 blocks each: group A - sample primer (SP); group B - Opal Seal (OS); group C - Transbond Plus SEP (TSEP); group D - Transbond XT Primer (TXT). After surface preparation and application of the primer, respectively, two stainless steel brackets were fixed on each tooth by using Transbond XT. Accordingly, 80 brackets were debonded (n=20). Shear bond strength and adhesive remnant index (ARI) scores were evaluated. Statistical analyses were performed by using the Student's t-test and Mann-Whitney U test. All tested groups revealed high shear bond strength in a similar size range. There were no significant differences between the groups concerning shear bond strength. The ARI scores of group C showed significantly lower ARI scores (0 and 1) than that of group D. Apart from that there was no statistical difference. In combination with the adhesive paste Transbond XT, all tested primers were suitable for fixing orthodontic brackets. The primers could be changed according to the clinical situation.

Shear bond strength of orthodontic metal brackets to aged composite using three primers.

BackgroundThis study aimed to assess the effect of surface preparation with sandblasting and diamond bur along with the use of three primers on shear bond strength (SBS) of metal brackets to aged composite.Material and MethodsIn this in vitro, experimental study, 60 Filtek Z250 composite discs were fabricated (10×2mm), immersed in distilled water for 24 hours and subjected to 5000 thermal cycles. They were randomly divided into two groups (n=30) of sandblasting with aluminum oxide particles for 10 seconds and surface roughening with bur. Each group was randomly divided into three subgroups (n=10) for use of Transbond XT, Assure Plus and Composite Primer. Metal brackets were bonded and the samples were stored in distilled water for 24 hours followed by 2000 thermal cycles. The SBS of brackets was measured and the adhesive remnant index (ARI) score was calculated. The data were analyzed by one-way ANOVA, t-test and Chi square test.ResultsThe difference in the mean SBS was not significant among the six subgroups. ConclusionsAll combinations of primers and surface preparation methods provided adequately high SBS between brackets and aged composite surfaces. Considering the ARI scores, surface roughening by bur is superior to sandblasting. Key words:Shear strength, composite resins, orthodontic brackets, aged composite, surface preparation.

Evaluation of the shear bond strength of lingual brackets manufactured by three different processes using two different adhesive primers: An in vitro study

Objective: To compare and evaluate the shear bond strength (SBS) of lingual brackets, manufactured by three different processes, that is, laser sintering, milling, and casting, bonded with two different adhesive primers. Materials and Methods: One hundred and twenty premolars were selected, and three types of lingual brackets were used, namely, STB (milling), 7 th Generation (casting), and lingualmatrix (laser sintering). Forty brackets per system were used half of which were sandblasted while the other half were used as available. Further, these were subdivided and bonded with Transbond XT primer and adhesive and 3M ESPE Primer and Transbond XT adhesive. Customization of STB and 7 th Generation was done by Torque Angulation Reference Guide, Lingualmatrix had bases customized by Computer-aided design/computer-aided manufacturing. SBS was tested with universal testing machine and evaluated for adhesive remnant index (ARI). Results: Statistical analysis showed that surface treatment, use of different primers, method of customization influenced the SBS, and ARI suggested that the fracture occurred between composite and bracket interface. Conclusion: Lingualmatrix bracket showed greater SBS as compared to STB and 7 th Generation, sandblasting increased SBS. 3M ESPE primer group showed increased SBS as that bonded with Transbond XT primer. The fracture was between the composite bracket interface.

Antimicrobial and physical characteristics of orthodontic primers containing antimicrobial agents.

To compare the antimicrobial and physical properties of experimental primers containing chlorhexidine (CHX) or ursolic acid (UA) with a commercial primer. 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. 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. Incorporation of CHX into an orthodontic primer may help prevent enamel demineralization around surfaces without compromising its physical properties.

Effects of two metal primers on the shear bond strength of orthodontic molar tubes bonded to silver amalgam restorations of different dimensions

The aim of this study was to evaluate the shear bond strength (SBS) of orthodontic molar tubes bonded to amalgam restorations and enamel with four different area ratios, with and without the use of various metal primers. One hundred and fifty-six sound lower first molars were divided into five groups; control group (CG;n = 12) then divided into three subgroups: A, B, and C. Class V buccal amalgam restorations consisting of 25%(G1), 50%(G2), 75%(G3), and 100%(G4) of the basal areas of the molar tubes. Transbond XT Primer (TXTP;subgroup A), Alloy Primer (AP;subgroup B) and Reliance Metal Primer (RMP;subgroup C) (n = 12). Transbond XT was used as an adhesive material in all groups. Thermocycling was as 5 –55 °C, 1000 cycles. Data were analysed by one-way ANOVA and post hoc least significant difference tests (p < 0.05). Bond failure sites were classified using a modified Adhesive Remnant Index (ARI) system. SBS did not differ significantly among the three intermediate adhesives in subgroups of groups 1, 2, or 3 (p > 0.05); however, SBS was significantly higher in groups 4B and 4C than in group 4A (p < 0.05). Mean SBSs of groups 1 and 2 were significantly higher than others (p < 0.05). Mean SBS of group 3 was higher than that of group 4, but lower than that of the other groups. For ARI, significant relationships between CG and the intermediate adhesive groups were found (p < 0.05). Application of metal primers, such as AP or RMP, to sandblasted amalgam adjacent to etched enamel (25, 50, and 75%) did not improve bond strength significantly compared with the application of TXTP to amalgam and enamel.

Efficacy of a nAg modified orthodontic primer reducing demineralization around brackets: an in vivo study

Event Abstract Back to Event Efficacy of a nAg modified orthodontic primer reducing demineralization around brackets: an in vivo study Gabriela Moreno-Meraz1, Facundo Ruiz2, Mauricio Pierdant-Pérez3, Antonio A. Gordillo-Moscoso3, Gylmar Mariel-Cárdenas4, Jairo Mariel-Cárdenas5 and Wulfrano Sánchez-Meraz5 1 UASLP, Faculty of Medicine / Faculty of Sciences, Mexico 2 UASLP, Faculty of Sciences, Mexico 3 UASLP, Faculty of Medicine, Mexico 4 UASLP, Faculty of Engineering, Mexico 5 UASLP, Faculty of Stomatology, Mexico Introduction: Tooth enamel, also called enamel tissue or enamel substance way cap covers the dentin in its coronal portion providing protection to the underlying connective tissue. Since enamel composition is based on 95% inorganic matrix it presents a high hardness. Hydroxyapatite crystals are constituted by calcium phosphate, this represents the inorganic component of enamel. Hydroxyapatite crystals are densely packed and are larger than other mineralized tissues. These crystals are susceptible acid substrate, this component is which increases dental demineralization.[1] Dental demineralization is considered to be the most prevalent iatrogenic effect associated with orthodontic treatment and might be jeopardize the longevity and aesthetics of the dental organ associated. It has been documented that the onset and progression of weakness in the enamel surface or dental caries is directly associated with Streptococcus mutans and its prevalence is related to the complexity of itself. It has been clinically proven, that the formation of white opaque spots around braces can occur within the 4 weeks of starting the treatment.[2][3] Silver nanoparticles have demonstrated efficacy as antimicrobials, and some studies have shown that these antimicrobial properties are particularly effective reducing the population of Streptococcus mutans.[4][5][6][7][8] The aim of this study was to compare changes in enamel adjacent to orthodontic brackets using bonding agents enriched with silver nanoparticles (nAg) compared to a conventional primer adhesive with laser fluorescence. Materials and Methods: According with previous studies, Transbond™ XT Primer was doped with silver nanoparticles, A split-mouth design was applied to 20 healthy patients, (40 teeth)[9] who were to begin orthodontic treatment. The brackets were cemented with the nAg doped primer (TX0) randomly allocated to either the right or the left side of the maxilla and it was applied to the incisors following the manufacturer's protocol. The contralateral teeth had the same type of bracket and a conventional primer (TX1) (with no nAg). DIAGNOdent (KaVo Dental Corporation, Lake Zurich, Ill) [10]measurements were used to assess white spot lesions after 8 weeks. This study is registred in the clinical trials page. Results: All analyses were performed with R software version 3.1.0 and R Commander version 2.0-4 package 95% confidence level. [11]There were no missing observations. To determine the effectiveness of treatment, an analysis of the final measurements an ANOVA was performed. The final model (Demineralizatión~Basal + Tx) was significant F (39) = 31.4, p <0.001. It can be explained 63% of the variation in the set of explanatory variables. The mean in FINAL score when TX0 = 3.25 + 1.99 is lower than the mean of FINAL score when TX1 = 9.85 + 6.39. The difference in scores between the two groups is 6.13 (CI 95%, 3.82 - 8.43). Conclusion: Baseline measurements for both treatments showed demineralization degree as the initial score taken with diagnodent. However, the difference in baseline mean was not significant. The teeth, which were primed with nAg doped Transbond XT, had lower final mean score than those primed with conventional Transbond XT, at 8 weeks from baseline measure. This may be attributed to the antimicrobial effect of silver nanoparticles and this effect is not modified after curing the primer. Other studies to evaluate the type of bracket, and to evaluate whether increasing the amount of nanoparticles, the antimicrobial power of the primer is increased without changing its physical properties, and if it persists over time. are needed. UASLP

Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials.

Objective. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond™ and Scotchbond™) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™. Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces, n = 30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120™ testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P ≤ 0.05). Results. Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.