The profile of Oral Health Branch of Rafsanjan Cohort Study (OHBRCS) in Rafsanjan City, southeast of Iran

Oral health status can be affected by some factors including drug abuse, systemic conditions and environmental pollutants. The present study was designed to investigate the most important and prevalent dental and oral conditions in adult population of Rafsanjan with the age of 35-70 years. Dental and oral health cohort center as part of the Rafsanjan Cohort Study (RCS) included in the prospective epidemiological research studies in IrAN was established in 2015. Of 9991 subjects enrolled in the RCS, 8682 people participated in the Oral Health Branch of Rafsanjan Cohort Study (OHBRCS). The OHBRCS included 4021 men and 4661 women with the mean age of 49.94 ± 9.51. The most prevalent of oral lesion in total population was candidiasis and the least was aphthous lesion. The prevalence of candidiasis, white and red lesions, periodontal pocket, dental calculus, CAL and the mean of DMFT were higher in the male group than that of female group (p < 0.05). Candidiasis, herpes, oral cancer, white and red lesions were more prevalent in the older age groups (p < 0.05). The mean of DMFT index in total population was 21.30 and was higher among opium users, men and older age (p < 0.05). Also, the opium users had a higher rate of CAL, periodontal pocket, red and white lesions, and candidiasis but a lower rate of BOP (p < 0.05). Younger people had more decayed and filling teeth compared to other age groups, whereas older people had more missing teeth and a higher DMFT index (p < 0.001).

Comparison of the Shear Bond Strength of Orthodontic Composites Containing Silver and Amorphous Tricalcium Phosphate Nanoparticles: an ex vivo Study

Statement of the Problem

It is important to use orthodontic composites with favorable properties, which are easily removed after the end of the treatment but not easily debonded during treatment. Nanoparticles have drawn attention for their antibacterial properties when added to composite resins. However, the effect of addition of nanoparticle on shear bond strength is not broadly discussed.

Purpose

The present study was designed to compare the shear bond strength of orthodontic brackets bonded by orthodontic composite containing silver nanoparticles with orthodontic composite containing amorphous tricalcium phosphate nanoparticles.

Materials and Method

In this ex vivo study, 36 sound extracted human premolars were used and randomly divided into three groups. The brackets were bonded in the first group by composite without nanoparticles, in the second group by composite containing 3% amorphous tricalcium phosphate nanoparticles and in the third group by composite containing 0.3% silver nanoparticles at the buccal surface of the teeth. The shear bond strengths of the samples were measured 24 hours after preparation by a universal testing machine. Data were analyzed using SPSS 21 software through one-way ANOVA and Tamhane's T2 multiple comparison tests. pValues under 0.05 were considered significant.

Results

There was no significant difference between the mean shear bond strength of composite containing amorphous tricalcium phosphate nanoparticles with composite without nanoparticles (p= 0.142). However, the mean shear bond strength in the composite containing silver nanoparticles was significantly lower than the other two groups (p< 0.001).

Conclusion

According to the results of this study, the addition of amorphous tricalcium phosphate nanoparticles to orthodontic composite does not significantly decrease the shear bond strength while silver nanoparticles reduce the shear bond strength of orthodontic composite.