ABSTRACT Lactobacillus acidophilus (L. acidophilus) is one of the etiological agents for dental caries and dominant in the deep carious lesion. L. acidophilus has also been identified in persistent root canal infection and also related to the failure of endodontic treatment. Photodynamic therapy is a therapeutic process involving the combination of a nontoxic photosensitizer and a light source. The excited photosensitizer reacts with reactive oxygen species (ROS), which induce injury and death of the microorganism. This study aimed to prove the effect of irradiation time of photodynamic therapy to the number of L. acidophilus. Forty-two Eppendorf tubes were treated with 0.5 ml L. acidophilus distributed into seven groups. Group 1 as the control group received no treatment. Groups 2, 3, 4, 5, 6 and 7 were treated with a combination of 0.5 ml toluidine blue O (TBO) as a photosensitizer and 630 nm photoactivated (Fotosan®) exposure time for 10, 20, 30, 40, 50 and 60 sec. Then, all were stored in an incubator of 37ºC for 48 h. Later, the colony-forming unit (CFU) was counted for each group. There were significant differences in the number of L. acidophilus in CFU of the various irradiation times. The longer the photodynamic therapy irradiation was, the lesser the number of live L. acidophilus became. At 50 sec and 60 sec irradiation, none of the L. acidophilus was found alive.
Photochemotherapy ; Lactobacillus acidophilus

Introduction: Anadara-granosa synthesization through hydrothermal-method produces beta-tricalcium(beta-TCP), a biomaterial that is able to provide a pathway for calcium-ions in dentin reparative formation thus qualifies TCP as pulp-capping material.Nanoencapsulation is needed as calcium-ions have shown its rapid solubility which is the main cause of high probability risk of tunnel defect.The present study aimed to understand the correlation between stirring time, particle size and level of calcium of beta-TCP nanoencapsulation synthesized from Anadara-granosa-shells. Methods: Anadara-granosa-shells powder was hydrothermically-processed for 18hours and sintered for 3hours. After homogenous beta-TCP powder mixed with aquadest in magnetic stirrer acquired, Na-alginate was added during the stirring process following CaCl2 drop by drop into the mixture.Sample divided into 6-test groups according to the stirring time; P1-one hours;P2-two hours;P3-three hours;P4-four hours;P5-five hours;P6-six hours.All samples centrifuged at 2500rpm for 6minutes and freeze-dried for 12hours.PSA-test and Calcium level-test were performed on the sample test groups, followed by ANOVA-test and post hoc with significance level of P-value=0,05. Results: Data showed average of particle-sizes P1=±336.44; P2=±325.7; P3=±340.94; P4=±452.6; P5=±556.6; P6=± 593.93.ANOVA-test result indicated a significant difference and backed up by Gomes howell test result.Significant differences were found between group first-second-third and group four-five-six also between group five and group six. Calcium level test result was P1=±10.41; P2=±9.53; P3=±9.87; P4=±5.52; P5=±5.33; P6=±5.25.ANOVA-test showed a significant difference and supported by post-hoc LSD-test.Significant differences noted between group one and other groups also between group-two-three and group-four-five-six. Conclusion: In the process of Nanoencapsulation of Anadara-granosa-shells, particle size gradually increased and calcium level gradually decreased along with the longer stirring time was performed.