The effect of selected commercially available mouth-rinses vs. curcumin photosensitizers in an artificial mouth model mimicking their use before meals on early colonizers single species biofilm

OBJECTIVE

The aim of the study was to determine the bacterial-adherence to the experimental pellicle pretreated with commercially available oral-rinse/ photosensitizer (mimicking use of oral-rinse/ photosensitizer before meals).

MATERIALS AND METHODS

An artificial mouth (NAM) system was used for the development of single-species biofilm (Actinomyces viscosus, Streptococcus mitis and Streptococcus sanguinis respectively). Two commercially available oral-rinses containing active ingredients [Essential oils (EO) and Chlorhexidine gluconate (CHX) were used. Curcumin photosensitizer (PS) was used as a photosensitizer against the microbes. For the adherence study, the experimental pellicle on the beads (in the capillary tubes of the NAM system) was pretreated with the oral-rinse and photosensitizer before the inoculation of bacteria; this would resemble the use of rinse/ photosensitizer before meal. The bacterial population of the biofilm was determined using serial dilution assay and expressed as colony forming unit per ml. Deionized distilled water was used in place of oral-rinse/photosensitizer and served as a negative-control. For the qualitative study, bacterial population viewing was carried out using Scanning Electron Microscope (SEM).

RESULTS

It was observed that on treatment with the oral-rinses the bacterial population of S.mitis, S.sanguinis and A.viscosus (adherence) was significantly reduced where the reduction was less for EO-based oral-rinse compared with that of CHX and curcumin PS in the following sequence EO<CHX<PS (p<0.05).

CONCLUSIONS

From the results, it appears that curcumin photosensitizer and oral-rinses contain CHX to be preferably used before-meal and EO after-meal.

Effect of photosensitizers on modulating bond strength of different luting cements used for cementation of resin modified composite fiber posts

OBJECTIVE

The aim of the study was to evaluate the tensile BS of FPs luted with conventional and self-adhesive resin modified GIC cement on disinfection of post-space radicular dentin with various photo-activated photosensitizer (chitosan, TB and Clp6).

MATERIALS AND METHODS

Sixty-six orthodontically extracted mandibular pre-molars were selected on specific exclusion/inclusion criteria, trailed by thorough debridement of plaque/calculus and disinfected by immersion in Chloramine T trihydrate solution for 48 hrs. The selected teeth were sectioned from the cement-enamel junction removing the crown. The radicular region of the samples was entrenched perpendicularly in heat cure resin modified acrylic. The pulpal tissue was detached using K-files trailed by canal shaping with ProTaper Next rotary NiTi (Dentsply Sirona, Gloucestershire, UK) files under continuous irrigation with NaOCl. The canals were dried using paper points trailed by obturation by Pro Taper Next Obturators gutta-percha points (Dentsply, UK) coated with ADSEAL (Meta Biomed, Chungcheongbuk-do, South Korea). After incubation for seven days in an environment mimicking oral cavity, post space was created using peso reamers. The space was disinfected by G1: chitosan 3 mg/mL; G2: 13-15 mg/mL TB and G3: Clp6. After photo-irridation the FPs were luted with conventional (n=11) and resin modified self-adhesive cement (n=11) for each group respectively. The specimens were incubated for 48 hrs prior to tensile BS testing. The type of bond fracture/failure was evaluated under 30x magnification. The tensile BS was statistically analyzed using ANOVA trailed by Tukey's test to respective groups.

RESULTS

FPs luted using self-adhesive resin modified cement with prior to disinfection by TBs displayed highest tensile BS 291.47 N ± 5.36. On the contrary, post-space disinfected by Clp6 displayed statistically significant (p ≤ 0.05) lowest bond strength (276.62 N ± 4.31). Intra-group analysis displayed statistically significant difference in bond strength of the luting dental materials (p ≤ 0.05).

CONCLUSIONS

The self-adhesive resin modified cement revealed utmost bond strength on pre-treatment of post-space with respective photo-activated photosensitizer (chitosan, TB & Clp6) in contrast to conventional GIC.