ABSTRACT
The purpose of this study was to develop a customized polishing protocol using standard zirconia polishing kit with polishers of different grit and to study their effect on the surface roughness of zirconia and compare it to that of laboratory polished zirconia samples and machine polished titanium implant abutments. Methods: The samples used in this study were 15 zirconia blocks and 10 machine polished titanium implant abutments (5 Biohorizon and 5 MIS). The 15 zirconia blocks were again divided into three groups. The first group consisted of 5 zirconia samples polished by customised polishing protocol (coarse + medium+ fine). The second group consisted of 5 zirconia samples which were sent to lab1 which used Komet company burs and 5 zirconia samples were sent to lab2 which used carborundum burs and sandpaper for polishing. The fourth group consisted of 5 machine polished titanium implants from MIS system and fifth group consisted of 5 machine polished titanium implants from Biohorizon system. After polishing, the mean surface roughness values (Ra) of zirconia samples and titanium implant abutments were calculated quantitatively by optical profilometer and qualitatively by scanning electron microscope (SEM). Results: The mean surface roughness value of customised polishing protocol using coarse+medium+fine polisher was 0.11 µm which was almost equal to the mean surface roughness values of lab1 polished zirconia samples - 0.131 µm and that of machine polished titanium implant abutments –Biohorizon: 0.201 µm MIS: 0.0859 µm and was within the optimal range of 0.2µm. Conclusions: Within the limitations of this study it was concluded that, the mean surface roughness values of zirconia samples polished by customised polishing protocol , lab1 polished samples and machine polished titanium implant abutments were found to be similar & closer to the critical Ra values (0.2µm) suggesting that the chairside polishing of zirconia can be carried out using the customized polishing technique
ABSTRACT
Genetic variation was assessed utilizing intron-flanking EST-specific markers among genotypes of Artemesia annua collected from two sampling sites viz. Nubra (9,600 ft) and Leh (11,500 ft) valleys of the trans-Himalayan region, Ladakh, India. The available ESTs (3,60,906) sequences of A. annua were aligned with the genomic sequences of Arabidopsis to developed ‘intron-flanking’ EST-PCR based primers. These primers anneal with the conserved region of exon (flanking to the intron) and amplified the introns. Out of the 39 primers selected and tested on 20 genotypes of A. annua, we successfully exploited 81 codominant intron length polymorphism (ILP) markers, with an average of 2.08 markers per primer and 92.04% polymorphism detection. Clustering of genotypes revealed distribution of genotypes into 2 distinct clusters with respect to their site of collection. Significantly, this study demonstrates that Arabidopsis genome sequence can be useful in developing gene-specific PCR-based markers for other non-model plant species like A. annua in the absence of genome sequences.