Shear bond strength and adhesive remnant index of orthodontic brackets bonded to enamel using adhesive systems mixed with TiO2 nanoparticles

Abstract

Introduction: It is recently suggested that titanium dioxide (TiO2) nanoparticles can be added to bracket luting agents in order to reduce bacterial activity and protect the enamel. However, it is not known if this addition can affect the shear bond strength (SBS) below clinically acceptable levels. Therefore, this study examined this matter within a comprehensive setup. Methods: This in vitro experimental study was conducted on 120 extracted human premolars randomly divided into four groups (n=30): in groups 1 and 2, Transbond XT light-cured composite with or without TiO2 was applied on bracket base; in groups 3 and 4, Resilience light-cured composite with or without TiO2 was used. Brackets were bonded to teeth. Specimens in each group (n=30) were divided into three subgroups of 10 each; then incubated at 37°C for one day, one month, or three months. The SBS and adhesive remnant index (ARI) were calculated and compared statistically within groups. Results: The SBS was not significantly different at one day, one month or three months (p>0.05) but composites without TiO2 had a significantly higher mean SBS than composites containing TiO2 (p<0.001). The SBS of Transbond XT was significantly higher than that of Resilience (p<0.001). No significant differences were noted in ARI scores based on the type of composite or addition of TiO2 (p>0.05). Conclusions: Addition of TiO2 nanoparticles to Transbond XT decreased its SBS to the level of SBS of Resilience without TiO2; thus, TiO2 nanoparticles may be added to Transbond XT composite for use in the clinical setting.

Shear Strength of Brackets Bonded with Universal Adhesive Containing 10-MDP after 20,000 Thermal Cycles

“…When considering the ARI, even if methods of measurement could influence score assignment results [27], ARI score is nowadays widely used in bonding studies to assess and discuss adhesive left on tooth surface after debonding. Generally, a score of "0" is often related to contaminants over enamel.…”

Comparison of antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times

“…Decalcification of enamel surfaces adjacent to the orthodontic appliances is an important complication associated with orthodontic treatment. 1 Despite many attempts made in line with patient health education, white spot lesions (WSL) accompanied by fixed orthodontic appliances are still a major clinical problem, and WSLs have been increasing since the advent of bonding brackets. 2 These spots can apparently lead to patient dissatisfaction after orthodontic treatment.…”

“…That is why new studies have drawn a special attention to the antibacterial properties of resin composites to reduce the risk of recurrent caries around direct composite restorations. 1,2,4 Various approaches have been adopted to add antibacterial properties to resin composites and adhesives. The first approach is adding antibacterial materials to the resin matrix that are released over time and inhibit bacterial growth.…”

“…12,13 In addition to silver, many other nanoparticles like hydroxyapatite, chitosan, copper acids, titanium, zinc and silicone dioxide (SiO 2 ) have been added to composites and have been investigated. 1,2,[14][15][16] This study was conducted to compare the antibacterial effects of adding different nanoparticles to orthodontic composites on the growth of Streptococcus mutans at different times.…”

Nanomaterials Application in Orthodontics

“…Its development is generally associated with the activity of cariogenous bacteria due to prolonged dental plaque accumulation on teeth surfaces, deficiencies, avitaminosis, and diet. The demineralization process that starts the caries is called a white spot lesion (WSL), meaning, that decalcification of enamel surfaces adjacent to the orthodontic appliances is directly associated with orthodontic treatment [ 4 ]. Several studies confirm the accelerated accumulation of WLS in orthodontic treatments.…”