Microbiological evaluation of photo-activated disinfection in endodontics (An in vivo study)

Abstract

Objective To determine the microbiological effect of photoactivated disinfection (PAD) as an adjunct to normal root canal disinfection in vivo. Design A randomised trial carried out in general dental practice. Subjects and methods Patients presenting with symptoms of irreversible pulpitis or periradicular periodontitis requiring endodontic therapy were selected at random. A microbiological sample of the canal was taken on accessing the canal, after conventional endodontic therapy, and finally after the PAD process (photosensitiser and light) had been carried out on the prepared canal. All three samples from each canal were plated within 30 minutes of sampling and cultured anaerobically for five days. Growth of viable bacteria was recorded for each sample to determine bacterial load. Results Thirty of the 32 canals were included in the results. Cultures from the remaining two did not reach the laboratory within the target time during which viability was sustained. Of the remaining 30, 10 canals were negative to culture. These were either one of the canals in multi rooted teeth where the others were infected or where a pre-treatment with a poly-antibiotic paste had been applied to hyperaemic vital tissue. Sixteen of the remainder were negative to culture after conventional endodontic therapy. Three of the four which had remained infected cultured negative after the PAD process. In the one canal where culturable bacteria were still present, a review of the light delivery system showed a fracture in the fibre reducing the effective light output by 90%. Conclusions The PAD system offers a means of destroying bacteria remaining after using conventional irrigants in endodontic therapy.

An alternative regimen for root canal disinfection

“…This follows previous work in which it was established that the use of hypochlorite was successful in eliminating culturable bacteria from the walls of the canals in only 76% of the cases treated. 23 Citric acid is a well documented chelating agent and had been used frequently in dentistry as a means of smear removal and breakdown of any biofilm layer. Its use, prior to a disinfecting agent, as a biofilm disrupter would facilitate the passage of the disinfecting solution into both the lateral canals and open dentinal tubules.…”

“…Recently a novel disinfecting system has been tested as an adjunct to conventional root canal therapy using sodium hypochlorite and citric acid as root canal cleaners. 23 The PAD process uses a photosensitiser, specifically Tolonium chloride solution (TC) (a pharmaceutical grade of Toluidine Blue O), and light of a specific wavelength [633±2nm]. This may be used in conjunction with a biofilm/smear remover such as citric acid.…”

“…It was filed backwards to remove debris from the canal walls and this instrument together with the swarf sample (dentine debris) obtained was placed in a sterile bottle as described previously. 23 Great care was taken in multi-rooted teeth to ensure that no cross contamination occurred between the canals during the sampling process as each canal was regarded as a test unit. The initial sample was transported immediately to the Medical Microbiology Department at the local general hospital (Aberdeen Royal Infirmary, Grampian University Hospitals Trust) for culturing.…”

Comparison of the Antibacterial Effect of 810 nm Diode Laser and Photodynamic Therapy in Reducing the Microbial Flora of Root Canal in Endodontic Retreatment in Patients With Periradicular Lesions

“…14 Several studies have shown that oral bacteria are sensitive to photodynamic therapy (PDT). 15,16 In recent years, in vitro [17][18][19][20][21][22][23][24][25][26] and in vivo [27][28][29] studies have been performed to investigate the antibacterial effect of the PDT on the microorganisms in root canal. Most of these studies have focused on the PDT capability as a complementary technique besides the conventional endodontic treatment.…”

Photonic real-time monitoring of bacterial reduction in root canals by genetically engineered bacteria after chemomechanical endodontic therapy

“…Microbial infection plays an important role in the development of dental pulp necrosis and formation of periapical lesions (1). It is well established that the eradication of intracanal bacteria is difficult, and current endodontic techniques are unable to consistently disinfect the the root canal systems (2). Accepted treatment procedures to eliminate the infection include root canal debridement and mechanical shaping or smoothing (3), irrigation with disinfectant agents, such as sodium hypochlorite or hydrogen peroxide, application of an interappointment intracanal dressing containing an antimicrobial agent and finally, root canal sealing (4).…”