Comparison of different modes of photo-activated disinfection against Porphyromonas gingivalis: An in vitro study.

BACKGROUND: Porphyromonas gingivalis (P. gingivalis), a Gram-negative periodontal pathogen, is frequently detected in subgingival plaques in patients with chronic periodontitis. Considering the insufficient results achieved by the current antimicrobial approaches, this study aimed to compare the susceptibility of P. gingivalis to the different modes of photo-activated disinfection in planktonic culture. METHODS: Cultures of P. gingivalis were assigned into three main groups of photothermal disinfection with 810 nm laser in continuous mode + EmunDo® (indocyanine green based photosensitizer), 808 nm laser in pulse mode + Perio green® (indocyanine green based photosensitizer); and antibacterial photodynamic therapy with 662 nm laser + Radachlorin® photosensitizer. Then, the bacterial viability was determined by serial dilution method by counting the number of colonies forming units. The results were analyzed by one-way analysis of variance and Tukey test (p < 0.05). RESULTS: All three groups showed significant reduction in the viability of P. gingivalis (p < 0.001). However; this reduction was significantly higher in photothermal therapy with EmunDo®. CONCLUSIONS: Both methods of photodynamic and photothermal therapy were successful in Significant eradication of P. gingivalis. Although, photothermal approach was more efficient with EmunDo® in combination with 810 nm laser irradiation.

Photo-activated elimination of Aggregatibacter actinomycetemcomitans in planktonic culture: Comparison of photodynamic therapy versus photothermal therapy method.

BACKGROUND: Periodontal pathogens are the main factors responsible for periodontal diseases and considering the limitations of conventional mechanical debridement, new treatment approaches are under investigation. This study was designed to evaluate and compare the antibacterial effects of two different systems of photodynamic and photothermal therapy on Aggregatibacter actinomycetemcomitans as the main pathogen involved in aggressive Periodontitis. METHODS: Cultures of Aggregatibacter actinomycetemcomitans were exposed to 662nm laser in presence of Radachlorin® photosensitizer (photodynamic group) or 810nm laser in presence of EmunDo® photosensitizer (photothermal group), then bacterial suspension of each well in the study groups were diluted and subcultured on the surface of Muller-Hinton agar plates. subsequently the number of colony forming units per milliliter of the wells were determined and checked by analysis of variance and Tukey test (p<0.05). RESULTS: Aggregatibacter actinomycetemcomitans suspensions showed significant reduction in both groups of photodynamic and photothermal therapy with no priority. CONCLUSION: Based on the results of this study, photodynamic and photothermal therapy can be proposed as a new promising approaches for bacterial elimination in periodontal diseases.

The susceptibility of Streptococcus mutans to antibacterial photodynamic therapy: a comparison of two different photosensitizers and light sources

Streptococcus mutans is the main etiological agent for dental caries. Recently, photodynamic therapy (PDT) has been introduced as a new modality in bacterial decontamination. Objective: This in vitro study was carried out to evaluate the susceptibility of Streptococcus mutans to antibacterial PDT using two different photosensitizers and light sources. Material and Methods: Standard suspensions of S. mutans were exposed to laser light at 662 nm and Radachlorin® or LED 630 nm in combination with Toluidine blue O (TBO). Radiation-only groups, photosensitizer alone, and groups with no treatment were used as controls. Bacterial suspension from each treatment was subcultured onto the surface of Mueller-Hinton agar plates and bacterial growth was assessed. The results were analyzed by analysis of variance and Tukey test (p<0.05). Results: PDT with TBO and Radachlorin® significantly reduced S. mutans viability, whereas no difference was observed between two groups of PDT. In the groups treated just with the photosensitizer or irradiated alone, no significant reduction of S. mutans colonies was observed. Conclusion: S. mutans colonies were susceptible to either 662 nm laser or LED light in the presence of Radachlorin® and TBO respectively with no priority. .

The susceptibility of Streptococcus mutans to antibacterial photodynamic therapy: a comparison of two different photosensitizers and light sources.

UNLABELLED: Streptococcus mutans is the main etiological agent for dental caries. Recently, photodynamic therapy (PDT) has been introduced as a new modality in bacterial decontamination. OBJECTIVE: This in vitro study was carried out to evaluate the susceptibility of Streptococcus mutans to antibacterial PDT using two different photosensitizers and light sources. MATERIAL AND METHODS: Standard suspensions of S. mutans were exposed to laser light at 662 nm and Radachlorin or LED 630 nm in combination with Toluidine blue O (TBO). Radiation-only groups, photosensitizer alone, and groups with no treatment were used as controls. Bacterial suspension from each treatment was subcultured onto the surface of Mueller-Hinton agar plates and bacterial growth was assessed. The results were analyzed by analysis of variance and Tukey test (p<0.05). RESULTS: PDT with TBO and Radachlorin® significantly reduced S. mutans viability, whereas no difference was observed between two groups of PDT. In the groups treated just with the photosensitizer or irradiated alone, no significant reduction of S. mutans colonies was observed. CONCLUSION: S. mutans colonies were susceptible to either 662 nm laser or LED light in the presence of Radachlorin and TBO respectively with no priority.

Pyogenic Granuloma: Surgical Treatment with Er:YAG Laser.

INTRODUCTION: Pyogenic granuloma (PG) is a common tumor-like growth of the oral cavity, considered to be of non-neoplastic nature, often caused by constant low-grade trauma as well as poor oral hygiene and maybe due to hormonal disturbances. Surgical excision, and removal of underlying cause in some cases, is the preferred method of treatment as it is only a benign lesion.In order to remove this lesion, scalpel, cryosurgery and laser are used. Currently different lasers, with adequate parameters, are used for the surgery of PG, which include CO2 (Carbon Dioxide Laser), Nd:YAG (Neodymium-Doped Yttrium Aluminium Garnet), Diode and Er Family amongst others. In this present case, due to the proximity of the lesion with dental hard tissue, Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) laser appears to be the more appropriate laser. The application of Laser is also a newly recommended technique. The aim of this study is to assess the stages of treatment, recovery and recurrence of PG when the Er:YAG laser is used. Furthermore this study aims to also evaluate the friendliness of this method with regards to the surgeon (therapist). CASE REPORT: A 24-year-old female was referred to the Laser Research Center of Dentistry of Tehran University of Medical Sciences with a complaint of gingival overgrowth and bleeding. This lesion was in the buccal and palatal side of the 5 and 6 maxillary teeth. Treatment plan included an excisional biopsy of the lesion using Er:YAG laser (3W, 300mJ, 10Hz, Short pulse, with contact headpiece). The bones were then cleaned of soft tissue before being smoothed using a curette. The excised specimen was preserved and sent for histopathological examination. RESULTS: The patient reported no pain after surgery and did not use any systemic antibiotics. The patient was satisfied after the surgery. Chlorhexidine mouthwash was given to the patient. Pathology results confirmed Pyogenic granuloma.After 2 weeks, complete healing was observed. The 9-month follow-up was also carried out in order to check the process of healing as well as the recurrence. CONCLUSION: Excisional surgery is the preferred treatment method for PG. The application of laser can be considered as an effective and safe technique for excision of this lesion with minimal invasion and many clinical advantages such as less intra-operative bleeding, hemostasis and reduced pain and times of healing.

Photoelimination of Streptococcus mutans with two methods of photodynamic and photothermal therapy.

BACKGROUND: Increasing resistance of oral pathogens to conventional antibacterial agents has resulted to find alternative therapies to overcome resistance development problems; hence this in vitro study was carried out to investigate the efficacy of photoelimination of Streptococcus mutans with two methods of photodynamic and photothermal therapy. METHODS: Standard Suspensions of S. mutans were treated in two groups of photodynamic therapy with Toluidine blue O and Rhadachlorin(®) and photothermal therapy by EmunDo(®) and their individual light sources, then Bacterial suspension from each treatment was subcultured on the surface of Mueller-Hinton agar plates and bacterial growth was assessed. The results were analyzed by analysis of variance and Tukey test (p<0.05). RESULTS: After treatments significant reduction of S. mutans viability in planktonic culture was observed in both groups of photodynamic and photothermal therapy with no priority. CONCLUSION: Photoelimination can be a novel modality in the eradication of S. mutans colonies in near future.

Evaluation of Accuracy of DIAGNOdent in Diagnosis of Primary and Secondary Caries in Comparison to Conventional Methods.

INTRODUCTION: Today the prevalence of teeth decays has considerably decreased. Related organizations and institutions mention several reasons for it such as improvement of decay diagnostic equipment and tools which are even capable of detecting caries in their initial stages. This resulted in reduction of costs for patients and remarkable increase in teeth life span. There are many methods for decay diagnostic, like: visual and radiographic methods, devices with fluorescence such as Quantitative light-induced fluorescence (QLF), Vista proof, Laser fluorescence (LF or DIAGNOdent), Fluorescence Camera (FC) and Digital radiography. Although DIAGNOdent is considered a valuable device for decay diagnostic ,there are concerns regarding its efficacy and accuracy. Considering the sensitivity of decaydiagnosis and the exorbitant annual expenses supported by government and people for caries treatment, finding the best method for early caries detection is of the most importance. Numerous studies were performed to compare different diagnostic methods with conflicting results. The objective of this study is a comparative review of the efficiency of DIAGNOdent in comparison to visual methods and radiographic methods in the diagnostic of teeth occlusal surfaces. METHODS: Search of PubMed, Google Scholar electronic resources was performed in order to find clinical trials in English in the period between 1998 and 2013. Full texts of only 35 articles were available. CONCLUSION: Considering the sensitivity and specificity reported in the different studies, it seems that DIAGNOdent is an appropriate modality for caries detection as a complementary method beside other methods and its use alone to obtain treatment plan is not enough.