ABSTRACT
PURPOSE: Fixed orthodontic appliances induce biofilm deposition, which harbors a microbial population harmful to the periodontal health of the individual. The present study evaluated the changes in thickness, live/dead bacterial ratio, and mineral content in dental biofilm over 6 months in patients with either stainless steel or ceramic orthodontic attachments. METHODS: Eighty patients who require fixed orthodontic appliance treatment with first premolar extraction for correcting their malocclusion were selected and bonded with either stainless steel or ceramic orthodontic attachments on the buccal side. The attached buttons were retrieved at different periods-1 week, 1 month, 3 months, and 6 months. They were stained and visualized through confocal microscopy to detect biofilm thickness and the ratio of live/dead bacteria. Xray diffraction was used to identify the presence of calcium and phosphorous. RESULTS: Ceramic attachments showed a greater increase in biofilm thickness in comparison to stainless steel attachments except in the initial 1week evaluation. A higher live/dead bacterial ratio was observed in stainless steel attachments than in their ceramic counterparts at all four evaluation periods. Both stainless steel and ceramic surfaces exhibited the presence of mineral deposition (calcium and phosphorous) at all periods. CONCLUSIONS: More biofilm adhesion was observed over ceramic surfaces than over stainless steel orthodontic attachments. Stainless steel attachments exhibited biofilm with a higher live/dead bacterial ratio than their ceramic counterparts at all evaluation periods. The presence of calcium and phosphorous in the adhered biofilm, pointing toward its calcification process, was identified.
ABSTRACT
Background: Smile plays an essential part in facial esthetics. There have been some mathematical and geometric theories regarding smile designing in literature. The purpose of the study was to assess RED proportion and golden proportion among patients attending a tertiary care centre at Kochi, Kerala. Methods: Standardised frontal images of 106 subjects, 50 male and 56 females, were captured in the age bracket of 18-25 years. Pictures of the patients were obtained using a DSLR camera (CANON EOS-60D) and then digitally analysed. Measurements of each maxillary anterior tooth was recorded and then the theories of RED and golden proportion were employed and the figures recorded were statistically analysed. Results: The RED proportion was observed to be inconsistent, while progressing distally, Golden proportion was observed to be in 6-29% of the existing subject population. Conclusion: Within the limited sample size of the study, RED (Recurring Esthetic Dental) proportion and golden proportion failed to exist in Keralites.
ABSTRACT
OBJECTIVE: Increased levels of heat shock proteins after several types of stress play a central role in cellular homeostasis allowing for continued cell survival. This study was aimed at quantitatively analysing the expression pattern of major damage associated molecular patterns (DAMPs) - HSP70, and the amount of nuclear damage incident in periodontal ligament compression side cells. MATERIAL AND METHODS: Sixteen subjects with bimaxillary dentoalveolar protrusion requiring extraction of all first premolars as part of orthodontic treatment were selected. Extractions were carried out pretreatment from control group. In the experimental group, a buccally directed spring, with force range of 70-120gms promoting bodily movement of maxillary first premolars was placed. Periodontal ligament was scraped from the middle third of the root from the compression side, the cells were isolated and cultured followed by HSP70 protein estimation with western blot analysis and the extend of nuclear damage was assessed with COMET assay. RESULTS: Western Blot analysis of HSP70 revealed a statistically significant increased expression of HSP70 (P<0.05; CI=95%) in the force applied group compared with the control group. COMET assay could demonstrate significant amount of nuclear fragmentation in the compression side periodontal ligament cells in comparison to control group (P<0.05; CI=95%). CONCLUSIONS: All these findings demonstrated, for the first time, that orthodontic force application augments release of HSP70 from periodontal ligament cells as a measure to restore tissue homeostasis. Further the study demonstrated that orthodontic forces induce DNA fragmentation, which is quantified more than double the amount observed in the control group.
Subject(s)
HSP70 Heat-Shock Proteins , Periodontal Ligament , Bicuspid , Humans , Stress, Mechanical , Tooth Movement TechniquesABSTRACT
BACKGROUND: The response of periodontal ligament cells (PDLC) from adult subjects in comparison to those obtained from younger ones to mechanical forces has been a matter of interest recently because of induced senescent changes. This study evaluated and compared cell surface changes and activity, integrin beta 1, and ß-actin mRNA fold changes as well as klotho protein secretion capabilities of PDLC from young and adult donors before and after subjecting to orthodontic forces. METHODS: A total of 40 subjects with bimaxillary dentoalveolar protrusion requiring extraction of first premolars for orthodontic treatment were selected and divided into two groups. Force ranging from 80 to 90 g was applied to maxillary first premolars and extraction was carried out at two different time periods-pre-treatment (control group) and 28 days after force application (experimental group). Periodontal ligament was obtained, and cell surface changes and activity were observed with atomic force microscopy (AFM) and fluorescent tagging. mRNA fold change of integrin beta-1 and ß-actin mRNA, as well as beta-galactosidase assay, was performed, and levels of klotho protein were evaluated. RESULTS: AFM nanoindentation and fluorescent tagging indicated increased surface morphological changes in younger cells compared to adult ones. We observed a decrease in integrin beta 1 but an increase in ß-actin mRNA levels in PDLC obtained from younger subjects compared to adults, while an increase was observed in SA-ß-GAL from adult cells. The level of klotho protein was lower in adult cells in comparison to younger ones. LIMITATIONS: Large sample studies are required to find out a variation in aging characteristics between young and adult PDLC. CONCLUSIONS: The study observed significant differences between PDLC obtained from younger and adult subjects in response to orthodontic force application.
