Survival rates of teeth treated with bacterial photo-dynamic therapy during disinfection of the root canal system

Treatment Outcome and Root Canal Preparation Techniques: 5-Year Follow-Up

OBJECTIVE

This study aims at comparing treatment outcome and tooth survival of root canal-filled teeth following manual vs rotary instrumentation techniques over a 5-year period.

METHODS

This was a single-centre study conducted as a follow-up to a short-term parallel-arm randomised controlled noninferiority trial in which root canal treatment was performed on teeth using either rotary or manual instrumentation. Patients were monitored at post 6-month, 1-year, 4-year, and 5-year review periods by blinded evaluators. Treatment outcome was categorised as favourable, uncertain, and unfavourable (employing European Society of Endodontology categorisation based on strict clinical and radiographic criteria), and 5-year tooth survival was determined by assessing whether tooth was in situ in the oral cavity or extracted. The Kaplan-Meier method and log rank test evaluated tooth survival. P value <.05 was considered statistically significant.

RESULTS

Ninety of 120 treated teeth were assessed in 37 men and 40 women with mean age of 30.6 ± 10.99 years. Treatment outcome was significantly more favourable in the rotary group compared to the manual group at post 6-month (P = .021) and 1-year (P = .043) review periods. The differences in favourable outcome (P = .498) and tooth survival (P = .296) between the 2 groups were, however, not significant at the 5-year review period.

CONCLUSIONS

The rotary instrumentation technique was shown to be more effective in resolving clinical symptoms and promoting periapical healing after the post 6-month and 1-year review compared to the manual instrumentation technique; however, both groups had similar favourable outcomes and survival rates after an extended 5-year review period.

Investigating the Antibacterial Effect of Passive Ultrasonic Irrigation, Photodynamic Therapy and Their Combination on Root Canal Disinfection

Introduction: Enterococcus faecalis is a gram-positive, facultative anaerobic bacterium associated with persistent endodontic infections. Conventional disinfection methods may not completely eradicate the bacteria within the root canal system. Therefore, novel modalities have been suggested to optimize root canal disinfection. The aim of this study was to evaluate and compare the antibacterial effect of photodynamic therapy (PDT), passive ultrasonic irrigation (PUI) and their combination in addition to conventional endodontic irrigation against E. faecalis biofilms in root canals. Methods: Root canals of 50 single-rooted extracted human teeth were prepared and incubated with E. faecalis for 21 days. They were then divided into 4 treatment groups and a control group as follows: (1) NaOCl-Syringe irrigation with 2.5% NaOCl, (2) PUI-Passive ultrasonic irrigation with NaOCl, (3) NaOCl+PDT-Photodynamic therapy following syringe irrigation with NaOCl, (4) PUI+PDT, (5) Control-Syringe irrigation with saline. Colony-forming units were counted and bacterial reduction was calculated for each treatment group. Results: All treatments led to significant reductions in the bacterial load compared to the control group. PUI and PUI+PDT led to the complete elimination of the bacteria from the root canals. NaOCl and NaOCl+PDT treatments reduced the bacteria by 99.9% and 99.5% respectively. NaOCl+PDT was significantly less effective in reducing the bacteria compared to other treatment groups. There were no significant differences between the NaOCl, PUI, and PUI+PDT groups. Conclusion: Passive ultrasonic irrigation with or without the combination of Photodynamic therapy completely eradicated the bacteria. The use of PDT as an adjunction to NaOCl syringe irrigation and PUI did not enhance their antibacterial effect.

Antibacterial Effects of a 940 nm Diode Laser With/ Without Silver Nanoparticles Against Enterococcus faecalis

Introduction: The final goal of root canal therapy is to remove of the most bacteria from the root canal. This study aimed at comparing the antibacterial effects of a diode laser with a wavelength of 940nm and silver nanoparticles and the synergic effects of both techniques on Enterococcus faecalis. Methods: Ninety single-rooted human teeth were decoronated and prepared with rotary files. The samples were irrigated with sodium hypochlorite and EDTA17%. Then they were autoclaved and contaminated with E. faecalis suspension (1.5 × 108 CFU/mL) for 21 days. The samples were fixed in a microtube and were randomly divided into 4 experimental (n=20) groups and a negative control group (n=10) as follows: Group 1: hypochlorite sodium 5%, Group 2: silver nanoparticle, Group 3: diode laser, and Group 4: diode laser and silver nanoparticle. The samples were obtained from dentin chips before and after the intervention. The data were analysed using the Kruskal-Wallis nonparametric test. Furthermore, alterations in bacterial colonies were entered using the Wilcoxon signed ranks test (α=0.05). Results: There was a significant decrease in colony counts for all groups after interventions (P value<0.05). Also, all groups showed more reductions in colony counts compared with the negative control group (P value <0.004). There was a significant reduction for group 1 in comparison with other groups (P value <0.001) and this group had an extreme decrease of colony counts (RCC=100%). There was an important differential between silver nanoparticles and diode laser groups in bacterial counts (P value<0.001) and silver nanoparticles (RCC=83.15%) had more efficiency than the diode laser (RCC=41/33%). RCC of group 4 was 68/52%. Conclusion: Followed by sodium hypochlorite 5%, silver nanoparticles were the most effective antibacterial substances. The 940 nm laser diode had less antibacterial effect compared to its use with silver nanoparticles.

Antibiofilm activity of laser ablation with indocyanine green activated by different power laser parameters compared with photodynamic therapy on root canals infected with Enterococcus faecalis

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is used as an adjunct to endodontic treatment to enhance microbial reduction in the root canal system. However, studies evaluating the impact of laser ablation with Indocyanine Green (ICG) are scarce. Thus, this in vitro study aimed to evaluate the efficiency of laser ablation with ICG using different laser parameters compared with aPDT using photosensitizer methylene blue (MB) and curcumin (CUR) on the reduction of E. faecalis biofilms on root canals.

METHODS

Forty-nine human premolars were used after biomechanical instrumentation for standardization. The root canals were contaminated with E. faecalis for 10 days to form biofilms, and divided into 7 groups (n = 7): 0.01% MB activated by red laser - MB+RL; 0.05% CUR activated by blue LED - CUR+BL; 0.05% ICG activated by infrared diode laser (2.5 W power, 30 ms interval, and 30 ms duration) - ICG+DL 2.5/30/30; 0.05% ICG activated by infrared diode laser (2.5 W power, 300 ms interval, and 100 ms duration) - ICG+DL 2.5/300/100; 0.05% ICG activated by infrared diode laser (3 W power, 300 ms interval, and 100 ms duration) - ICG+DL 3/300/100; sterile saline solution (negative control) - NC; and 2.5% NaOCl (positive control) - PC. Root canal sampling was performed prior to and immediately after the different treatment protocols. Data were submitted to One- and Two-Way ANOVA, followed by Student-Newman-Keuls test or Fisher LSD's test (α = 0.05).

RESULTS

All aPDT protocols promoted significant CFU reductions compared with the NC; the highest CFU reduction was observed for PC (p < 0.05). Among the protocols the highest CFU reduction was promoted by laser ablation with ICG+DL 3/300/100 (p < 0.05) except compared with aPDT using CUR+BL (p > 0.05).

CONCLUSIONS

Laser ablation protocol using ICG+DL proved to be efficient in reducing E. faecalis biofilms, especially when activated at 3/300/100 configuration.

Retrospective clinical evaluation of root canal treatment with or without photodynamic therapy for necrotic teeth and teeth subjected to retreatment

PURPOSE

To compare the effect of photodynamic therapy (PDT) as a procedure to complement root canal treatment (RCT), for both primary treatment and retreatment.

METHODS

This was a retrospective study based on analysis of clinical records. A total of 214 teeth that had undergone RCT on either a primary or retreatment basis, with or without complementary PDT, were evaluated. For 118 teeth that met the previously established inclusion criteria, the time until healing was evaluated. Complementarily, the need for application of calcium hydroxide (CaHy) between visits and the number of visits necessary for completing the treatment were assessed. Data were analyzed using the Mann-Whitney and χ² tests with a significance level of P < 0.05.

RESULTS

Periapical radiolucency resolution was achieved at 15 ± 9.33 months in the RCT + PDT group and 20.35 ± 22.1 months in the RCT group (P = 0.07). For primary treatment, CaHy was necessary in 72.4% of the RCT cases and 16.4% of the RCT + PDT cases (P < 0.01). For retreatment cases, CaHy was used in 82.7% of the RCT cases and 17% of the RCT + PDT cases (P < 0.01). In the RCT group, more than two visits were necessary for primary treatment in 18.6% of the cases, compared with 13.10% in the RCT + PDT group (P = 0.31), whereas for retreatment, more than two visits were necessary for 64.9% and 49.1% of cases, respectively (P = 0.05).

CONCLUSION

In comparison with RCT alone, teeth receiving RCT + PDT showed less variation in the time needed for periapical lesion healing, fewer cases required CaHy, and fewer cases required more than two visits to complete the treatment.