LAUSR

BACKGROUND Nowadays khat chewing habit is increasing among population in southern part of Saudi Arabia, Jazan and till date there is no literature investigating the effect of khat on oral biofilm on dental materials. AIM OF THE STUDY To evaluate and compare the bacterial biofilm on different types of dental restorative materials used in replacing missing tooth structures among khat chewers and non-khat chewers. MATERIALS AND METHODS Hundred twenty biofilm samples were collected from different dental restorations such as All-ceramic (AL), metal ceramic (MC), metal crowns or bridges (M), composite (C), glass ionomer (GI) and amalgam (A) restorations in non-khat and khat chewers (K). DNA extraction was done and subjected to PCR. Bacterial species such as Streptococcus, Neisseria, Bacillus, Granulicatella and Veillonella were identified and counted. PCR products were also sequenced to detect similarity. Association between bacterial type and dental materials among non-khat and khat chewers were tested with Chi-Square test (Fishers Exact test). RESULTS The frequency and percentage of Streptococcus species was marginally higher among khat chewers (42; 70%) comparing with non-khat chewers (38; 63.3%) group. But the Veillonella species were higher among non-khat chewers (9: 15%), compared to the khat chewers group (7; 11.7%). No statistically significant difference was detected among species in both groups. In non-khat and khat chewer group, the maximum hits were related to Streptococcus spp in glass inomer, amalgam, and composite (restorative materials), followed by metal ceramic and metal (prosthetic materials). Veillonella spp showed maximum hits in metal group among non-khat chewers and in all-ceramic among khat chewers. Statically significant differences were recorded among composite and amalgam samples with p values 0.047 and 0.036 in khat chewer group. CONCLUSION Khat have a statistically significant differences on oral biofilm in the composite and amalgam restorative materials, but there were no significant differences found among any materials and species between the groups.