Disinfection of caries-affected dentin using potassium titanyl phosphate laser, Rose bengal and Ozonated water on shear bond strength of deciduous teeth

AIM

To assess the efficacy of disinfection of caries-effected dentin (CAD) using KTP laser and different decontamination methods using ozonated water (OW), Rose Bengal photosensitizer (RBP), chlorhexidine (CHX), and Er, YAG laser on the shear bond strength (SBS) of adhesive resin bonded to deciduous teeth.

MATERIAL AND METHODS

A total of 50 extracted and radiographically verified carious primary molars were collected and scrutinized according to ICDAS criteria. Specimens were allocated randomly into five groups (n = 10) as per the type of CAD disinfectants. KTP laser, OW, RBP, CHX (control), and Er, YAG laser. After cavity sanitization, a resin adhesive (prime and bond NT) was smeared on the dentinal exterior followed by incremental composite filling. SBS evaluation was performed by employing specimens in the universal testing machine. The debonded surface was assessed under 40x magnification in a stereomicroscope to ascertain fracture mode. Statistical analysis was done by using the ANOVA and the Post Hoc Tukey multiple comparison tests (p < 0.05).

RESULTS

The highest SBS was exhibited by group 2 i.e., when OW was employed for CAD disinfection (10.25 ± 0.24 MPa). Whereas, the lowest SBS bond value was unveiled by samples in group 3 when RBP was applied for dentin surface sanitization (7.85 ± 0.59 MPa).CAD disinfection with KTP laser (8.25 ± 0.41 MPa), CHX (8.19 ± 0.73 MPa), and RBP displayed comparable bond values (p > 0.05).

CONCLUSION

Ozonated water and Er, YAG laser could be employed as cavity disinfectants in primary teeth as they demonstrated better shear bond strength without jeopardizing the adhesive binding capacity of restorative resins bonded to caries-affected dentin.

Efficacy of porphyrin derivative, Chlorhexidine and PDT in the surface disinfection and roughness of Cobalt chromium alloy removable partial dentures

AIM

The present study aimed to evaluate the effect of different cleansers and photodynamic therapy (PDT) on disinfection of Co/Cr removable partial denture colonized with C. albicans, S.aureus and S.mutans.

MATERIAL AND METHODS

Twenty-five Co/Cr removable partial dentures were constructed. and inoculated by American Type Culture Collection (ATCC) of Candida albicans, S.aureus, and S.mutans in an in-vitro setup. Co/Cr removable partial dentures were randomly allocated into five groups and framework was immersed in 15 mL of contaminated culture medium broth. Based on the cleansing method, disinfected dentures in group 1 were cleansed with porphyrin derivative; group 2 was exposed to 0.12% chlorhexidine digluconate; samples in group 3 and group 4 were subjected to sodium perborate enzyme and citric acid respectively. Through a surface analyzer, the surface roughness of Co/Cr and methacrylate resin was measured in 3 different zones in micrometers before and after disinfection. Two-way ANOVA and Tukey's test was used to analyze the data. Levene test was used to assess the normal distribution of data. Significance level p< 0.05 RESULTS: The results of metal roughness displayed that Co/Cr used as an alloy did not exhibit significant difference when exposed to different chemical disinfectants and photosensitizer (p > 0.05). Similarly, surface roughness (Ra) of heat polymerized acrylic resin using cleansers and PDT demonstrated no significant difference. Intergroup comparison showed that, hematoporphyrin derivative displayed comparable cleansing property against S. aureus, C.albicans, and S. mutans compared to to 0.12% CHX digluconate (p>0.05). The intragroup comparison showed hematoporphyrin derivative and CHX were equally effective against all bacteria (p>0.05).

CONCLUSION

CHX digluconate and hematoporphyrin derivative demonstrated high antimicrobial activity against S.aureus, S.mutans, and C.albicans with minimum Ra of an acrylic denture and Co/Cr metallic framework.