Background: Endo-perio lesions are clinical manifestations of inflammation in the periodontal and pulp tissue. Damage to the periodontal ligament can inhibit its ability to regenerate. Therefore, laser therapy use is expected to improve the prognosis with regard to healing lesions. Unfortunately, the duration of irradiation during laser diode therapy can influence the viability and proliferation of human periodontal ligament fibroblast (hPDLF) cells. Purpose: This study aims to determine the effects of different irradiation exposure times of the 650 nm laser diode of the pulsed mode type on the viability and proliferation of human periodontal ligament fibroblast cells. Methods: This study constituted a laboratory experiment on hPDLF cells using 650 nm laser diode irradiation. Six groups formed the research subjects in this study, namely; two control groups, two radiation groups respectively subjected to irradiation exposure of 15 seconds and 35 seconds duration followed by 24-hour incubation, and two radiation groups exposed to irradiation for 15 and 35 seconds respectively followed by 72-hour incubation period. The viability and proliferation of those cells were subsequently calculated by ELISA reader, while the data was analyzed by means of one-way ANOVA and Tukey tests. Results: The significance value of the viability scores between the 15-second irradiation group and the 35-second irradiation group was less than 0.05, indicating that there was a significant difference between these treatment groups. Similarly, the significance value of proliferation scores between the 15-second irradiation group and the 35-second irradiation group was less than 0.05, again indicating a significant difference between these treatment groups. Conclusion: Irradiation using a 650 nm laser diode 15 seconds and 35 seconds in duration can induce an increase in the viability and proliferation of hPDLF cells.

Background: Root canal treatment constitutes a treatment sequence for infected pulp to eliminate the etiological factors of pulp necrosis and periapical lesion. Enterococcus faecalis (E. faecalis) is an organism commonly found in a high proportion of root canal failure because of its ability to form biofilm. Degradation of extracellular polymeric substance (EPS) by oxidizing agents such as sodium hypochlorite is the first step in removing biofilm. However, the toxicity of sodium hypochlorite constitutes the main concern and, therefore, the safest alternative irrigants possible are required. The use of fruits, herbs and plants is widespread, especially in the fields of medicine and dentistry. Food crops are known to be rich in bioactive compounds, especially polyphenols, which have antioxidant and antimicrobial properties. Cocoa pod husk extract can, therefore, represent an alternative irrigant. Purpose: This study aimed to determine the minimum inhibitory concentration of cocoa pod husk extract in relation to the thickness of E. faecalis EPS biofilm. Methods: Four groups of E. faecalis cultured biofilm samples were analysed: group one contained E. faecalis without cocoa pod husk as a positive control; group two contained E. faecalis with 1.56% cocoa pod husk extract; group 3 contained E. faecalis with 3.125% cocoa pod husk extract; and group 4 contained E. faecalis with 6.25% cocoa pod husk extract. The biofilm thickness of all groups was measured by confocal laser scanning microscopy with statistical analysis subsequently undertaken by means of a post hoc test and Tukey HSD. Results: The average values of EPS biofilm thickness were as follows: group 1: 9500 nm; group 2: 8125 nm; group 3: 8000 nm; and group 4: 6375 nm. A post hoc Tukey HSD test indicated a significant difference between group 1 and group 4, while in group 2 and group 3 compared to group 1, there were no significant differences with the values of each being p = 0.340 and p = 0.267 (p>0.05). Conclusion: 6.25% cocoa pod husk extract reduces E. faecalis EPS biofilm thickness.