ABSTRACT
BACKGROUND: Laser etching addresses the disadvantages of conventional acid etching technique, such as enamel decalcification and formation of white spot lesions. The aim of the present study was to evaluate and compare the shear bond strength (SBS), adhesive remnant index (ARI), and the surface characteristics of the samples treated with conventional acid etching and Er, Cr: YSGG laser etching with variable output power and time durations. METHODOLOGY: The study sample included 78 extracted teeth divided into six groups of 13 teeth each, and 3 samples from each group were utilized for analyzing etch patterns, and the remaining 10 teeth from each group were used for evaluating the shear bond strength. In Group I phosphoric acid etching was done, whereas in Group II- VI Laser etching 1.5 W/10 s, 1.5 W/15 s, 3 W/5 s, 3 W/10 s, 3 W/15 s. Statistical analysis for shear bond strength testing was performed using one-way ANOVA followed by Post HOC tests. RESULTS: The mean shear bond strength of Group I was 7.16 Mpa and Group III of 5.43 Mpa. Group II, IV, V, and VI had mean shear bond strength of 4.93 Mpa, 3.88 Mpa, 4.05 Mpa, and 4.88 Mpa, respectively. The ARI scores Group I had a significant number of samples with scores 2 other groups showed increased Score 0. The etch pattern of groups I, II, III showed the combined dissolution of both prism cores, and peripheries were seen. In group IV, the etching pattern was irregular with the pitted type of surface. In groups V and VI, relatively flat and smooth enamel surface was seen. CONCLUSION: The bond strength attained by laser etching (1.5 W/10 s and 1.5 W/15 s) was comparable to that obtained by the acid etching technique.
ABSTRACT
Background: Knowledge of bone density in maxilla and mandible will allow the clinician to plan the anchorage strategies and placement of implants with necessary precautions. The study aims to evaluate the deflection changes of titanium alloy self-drilling mini implants from the intended path that occurs during placement in varying bone densities. Material and Methods: 63 titanium alloy self-drilling mini implants of the lengths 6mm, 8mm, and 10mm with diameter of 1.3mm were placed in three homogenous solid rigid polyurethane foam (saw bone) with bone densities of 20pcf, 30pcf, and 40pcf simulating anatomic sites in maxilla and mandible. 7mini implants of each length in all bone densities were tested for study. The implants were inserted perpendicularly into artificial bone block held in a custom made stand. The bone blocks were then radiographically exposed and the deviation of the long axis of the implantfrom a true vertical line was measured. Results: There was a decrease in deflection of the mini implant with increase in density. On the other hand, increase in length resulted in increase in the amount of deflection. Conclusions: Longer mini implants can be used in less dense bone as in maxilla, whereas shorter mini implants can be used in high dense bone as in mandible to increase the stability and success rate of implants. Bone density and implant length play a role in deflection of mini implant from its intended path of insertion. Key words:Orthodontic Mini implants, deflection, bone density, anchorage.
ABSTRACT
AIM: To study the associations of dermatoglyphic pattern and the dental archform among the young adult population. MATERIALS AND METHODS: The sample consisted of 150 randomly selected patients, within the age ranging from 15 to 25 years. The fingerprint patterns of the study subjects were recorded with a rolling impression technique using blue printer ink and the archform was assessed from the cast prepared from the impression of their lower dental arches. The data obtained were subjected to statistical analysis using SPSS software. The fingerprint patterns for each digit were analyzed and correlated with archform using appropriate statistical tests (chi-square test). RESULTS: Although no fingerprint pattern was found to be specific for a particular dental archform, increased frequencies of whorls in subjects with square or ovoid archform, high frequencies of ulnar loop pattern with ovoid or tapered archform, and radial loop finger ridge pattern in those with tapered archform were observed. CONCLUSION: Dermatoglyphic analysis can be used as an indicator for determining the dental archform at an early stage, thereby aiding in the orthodontic treatment of malocclusion aiming to establish favorable occlusion and long-term stability.
