38. Effect of Chlorhexidine Rinsed Blood Contamination on Bond Strength of Brackets Bonded with Self-etch Primer- An in Vitro Study

The present invitro type of study has done to check the effect of blood contamination & chlorhexidine combination on the bond strength of brackets bonded with self-etch primer technique. The study consisted of ninety sound human upper premolars (extracted for orthodontic purpose) fixed in a self-cure acrylic block and segregated into three groups of 30 samples each. 0.022 slot metal MBT brackets (Gemini series-3M unitek) were bonded with self-etch primer using Transbond XT composite, CA, USA and light cure for 40 seconds) on clean buccal surface. Teeth were divided into 3 groups-Group A/Control group, Group B, Group C. A computer was used to record the force applied to debond the bonded bracket in the unit of Newton. The analysis of variance indicated that there were significant differences (F value = 6.891, p value=0.002) in bond strengths between the various groups tested. The highest value of shear bond strength occurred when chlorhexidine (Group C) was used to remove the blood contamination (mean=15.874 MPa). When bonding was done in ideal condition (Group A), shear bond strength obtained was slightly lower (mean=14.497 MPa) as compared to Group C. On the other hand, lowest shear bond strength among all three groups occurred when blood contamination (Group B) was removed with water (mean=11.059 MPa). Analysis of the study showed that shear bond strength of orthodontic brackets to enamel significantly decreased during bonding with self-etch primer in blood contamination condition. Self-etch primer displayed considerably superior performance with the use of chlorhexidine instead of water to wash the blood contamination.

Evaluation of Changes in Microbiology and Periodontal Parameters During and After Fixed Orthodontic Appliances

The objective of the study was to evaluate the changes in microbiology through quantitative analysis of aerobic and anaerobic colonies and periodontal measurements during and after 1 month of removal of fixed orthodontic appliances. This prospective study comprised 30 patients, aged 12-30 years seeking orthodontic treatment in the department of Orthodontics and Dentofacial Orthopaedics of People's College of Dental Sciences and Research Centre, Bhopal from May 2016 to November 2017. Microbiological samples (supra- and subgingival plaque) and periodontal measurements like bleeding on probing (BOP), periodontal pocket depth (PPD) with oral hygiene assessment indices {plaque index (PI), gingival index (GI)} were used at 2 time interval: when patient undergoing orthodontic treatment >12 month (baseline, T₁) and 1 month after the removal of appliance (T₂). Bacterial culture method used to detect aerobic and anaerobic colony forming units (CFU) and their ratio (aerobic/anaerobic). Data analyzed using paired t-test and chi-square test. There was a significant decrease in an aerobic and anaerobic CFU (both supra- and subgingivally) and increase in CFU ratio (relatively less anaerobes) (p≤0.05) at T₂. Supragingival plaque sampling showed greater diminution in the CFU count as compared to the subgingival CFU, as these sites are more accessible for maintaining hygiene. Also, periodontal measurements showed significant decrement (PI, GI, PPD and BOP) at T₂ (p≤0.05). Fixed orthodontic treatment has transient effect on periodontium as supra- and subgingival CFU count decreases and periodontal health was ameliorated after removal of appliances which was accompanied with periodontopathic bacteria and clinical periodontal signs of inflammation during treatment.

Soft & Hard Tissue Assessment around Immediate & Delayed Implants: A Clinico-Radiographical Study

The aim of the modern dentistry is to provide the predictable treatment in short duration. Replacement of missing teeth in shorter duration helps in fulfilling patient's aesthetics and functional demands. Endosseous dental implants are predictable method for replacing missing dentition. The evolution in implant surgical techniques is focused on decreasing treatment duration, e.g. implants can be placed in fresh extraction socket. Therefore, this non-randomized clinical controlled study was designed to determine that whether the treatment outcomes obtained by short treatment duration (immediate implant) are comparable with conventional treatment options (delayed implant) by evaluating the peri-implant soft and hard tissue level, clinically and radiographically {by Cone beam computed tommography (CBCT)}. Total of 30 implants were placed in 13 patients, according to Type 1 ITI protocol (Group 1; 15 implants) and Type 4 ITI protocol (Group 2; 15 implants). Implants in each group were loaded with definitive restoration after 3 months of placement. Hard tissue parameters (marginal bone width and height and probing depth) and soft tissue parameters (width of keratinised gingiva and papillary index) were evaluated at baseline, 3 months post implant insertion and 3 months post prosthetic loading. The results showed statistically significant reduction in width of marginal bone in delayed implants as compared to immediate implants. In contrast, significant reduction in marginal bone height and width of keratinised gingiva was evident in immediate implants. Significant reduction in pocket depth (after 2nd stage surgery and 3 months post prosthetic loading) was noted around delayed implants (p<0.05). Moreover, esthetic results showed regeneration of interproximal papillae in both the groups till the end of study period. This study was concluded that both the groups showed similar results but in some aspects delayed implants was superior to immediate implants. Careful evaluation of implant placement sites before implant installation promotes optimal implant esthetics and survival outcomes.