ANTIMICROBIAL EFFICACY OF 2-HYDROXYISOCAPROIC ACID (HICA) TOWARDS ENTEROCOCCUS FAECALIS AS ALTERNATIVE ENDODONTIC INTRACANAL MEDICAMENT Introduction: Antibiotics are used as intracanal medicaments in endodontic therapy. However, increasing antimicrobial resistance has led to research on alternative medications. 2-hydroxyisocaproic acid (HICA) is a derivative of leucine, a normal component of human plasma that shows potential as an intracanal medicament. Objective: To determine the antimicrobial efficacy of HICA against Enterococcus faecalis (E. faecalis). Methods: The antimicrobial activity was screened by measuring the Zone of Inhibition (ZOI) using the disk diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The positive control was a Triple Antibiotic Paste (TAP) containing minocycline, metronidazole, and ciprofloxacin. Sixty-six teeth were prepared, and the canals were filled with E. faecalis suspension before incubation for 21 days. Later, HICA at a concentration of 16 mg/mL, TAP at 1 mg/mL, and saline (negative control) were introduced and further incubated for seven days under anaerobic conditions at 37°C. Viable bacterial counts in the canals were used as indicators of bacterial growth. Results: At 256 mg/mL concentration, HICA exhibited a ZOI of 15.72 ± 1.60 mm, and MIC and MBC were 8 mg/mL and 16 mg/mL, respectively. TAP, at a concentration of 4 mg/mL, exhibited a ZOI of 30.74 ± 0.71 mm, and its MIC was equal to MBC at 0.25 mg/mL. The viable bacterial counts extracted from the canal were 4.33 ± 0.23log10 for saline, 4.03 ± 0.21log10 for HICA and 3.97 ± 0.34log10 for TAP. Compared with saline, both TAP and HICA exhibited a significant difference in bacterial counts (p < 0.01). Interestingly, the efficacies of TAP and HICA were similar, with p-values of 0.79. Discussion: The ZOI indicated that HICA exhibited an antimicrobial effect. E. faecalis growth was repressed at 8 mg/mL, and cell death was observed at 16 mg/mL. At 16 mg/mL, HICA showed antimicrobial efficacy comparable to 1 mg/mL of TAP. Conclusion: HICA shows potential as an alternative intracanal medicament to eradicate E. faecalis in endodontic treatment.

VALIDITY AND RELIABILITY OF DIGITAL PHOTOS AS A DIAGNOSTIC TOOL FOR DETERMINATION OF CARIES Objectives: The impact of COVID-19 on dental care and the adoption of tele-dentistry for caries detection needs investigating. The pandemic led to the use of digital photography, including DSLR cameras and smartphones, for remote dental operations. Literature suggests that use of digital images was found to enhance caries detection sensitivity compared to visual examination. The study aims were 1) to compare the reliability of visual inspection and digital photographs for caries diagnosis among dental clinicians and 2) to compare diagnostic tools of determination of caries between full ICDAS codes and modified ICDAS codes utilization. Methods: The research involved 45 postgraduate dental students examining 45 extracted permanent teeth using full ICDAS scores and modified ICDAS scores in three phases (Full Visual ICDAS, Digital ICDAS and Combination of Visual and Digital ICDAS). Kappa scores, sensitivity, specificity and Area Under the Curve (AUC) readings between participants answers and benchmark answers were determined. Results: Statistical analysis revealed that introducing digital images reduced inter-rater agreement, however modified ICDAS codes utilization showed comparable results between visual and digital methods. Intra-rater agreement for visual and modified ICDAS was high, while digital images showed moderate agreement. Sensitivity for caries detection was around 93% for visual and digital methods, and specificity ranged from 67% to 80%. The AUC values indicated good performance (0.89) for both full and modified ICDAS with visual examination and lower values for digital examination (0.81-0.82). Discussion: Results were consistent with prior studies however this research highlights video/image efficacy, emphasizing validity, reliability, and improved clinician planning using modified ICDAS. Conclusion: Use of digital photographs for caries diagnosis were promising and the use of modified ICDAS codes were comparable to conventional use of full ICDAS codes. Overall, the study demonstrated the potential benefits of digital methods in dental caries diagnosis and tele-dentistry practices.