The effects of photodynamic therapy with blue light and papain-based gel associated with Urucum, on collagen and fibroblasts: a spectroscopic and cytotoxicity analysis.

Papacarie Duo™ is clinically used and has proven effectiveness; however, it is necessary to improve its antimicrobial action. The combined treatment of Papacarie Duo™ with Urucum (Bixa Orellana) could create a potential tool for dental caries treatment; its extract obtained from the seeds' pericarp contains a water-soluble primary pigment (cis-bixin) with smaller amounts of other carotenoids. The dicarboxylic acid salts of cis-norbixin and trans-norbixin occur in heated alkaline solutions. To analyze the absorption spectra and cytotoxicity (with human dermal fibroblasts) in different concentrations of Urucum, associated or not with Papacarie Duo™, we performed this in vitro study. The effects of pure Urucum, Papacarie Duo™, and PapaUrucum™ on the microstructure of collagen were also analyzed. The application of papain-based gel with Urucum did not present cytotoxicity, its exhibit UV absorption spectrum peak around 460 ± 20 nm. Also, it showed that the compound used did not alter the chemical structure of collagen. Consequently, this product could be used as a chemomechanical method to remove dentin caries as well as being a potential product for antimicrobial photodynamic therapy (aPDT) application.

Evaluation of photobiomodulation in salivary production of patients with xerostomy induced by anti-hypertensive drugs: Study protocol clinical trial (SPIRIT compliant).

INTRODUCTION: Hypertension (systemic arterial hypertension [SAH]) is a systemic condition that affects about 30% of the world population, according to data from the World Health Organization (WHO). Drugs used to control this disease have the potential to induce xerostomia, an oral condition in which the decrease of the salivary flow is observed and whose presence leads to the increase of the index of caries, periodontal disease, loss of the teeth, dysgeusia, difficulty of mastication, dysphagia, bad breath and oral burning and impairment of prothesis installed in the buccal cavity, including retention of removable and total dentures. METHODS: This is a randomized, placebo-controlled, blind clinical protocol that aims to analyze the impact of phobiomodulation (PBM) on salivary glands of patients with antihypertensive drug induced xerostomia. Patients will be divided into 2 groups: G1: older adults with xerostomia induced by antihypertensive drugs and treatment with PBM (n = 30); G2: placebo PBM (n = 30). The irradiation will be made using a diode laser emitting at 808 nm with 100 mW and 40 seconds of exposure per site at the salivary glands. Twenty sites will be irradiated weekly for 4 weeks. Non-stimulated and stimulated salivary flow will be analyzed before and after the treatment. RESULTS: This protocol will determine the effectiveness of photodynamic therapy regarding the reduction of xerostomia in older adults using antihypertensive drugs. CONCLUSION: This protocol will determine the effectiveness of photodynamic therapy regarding the reduction of xerostomia in older adults using antihypertensive drugs. TRIAL REGISTRATION: Clinicaltrials.gov - NCT03632096.

Influence of Nd:YAG laser on the penetration of a bioceramic root canal sealer into dentinal tubules: A confocal analysis.

OBJECTIVE: The aim of this in vitro study, is to evaluate the penetration of a bioceramic root canal sealer into dentinal tubules at 3 mm and 5 mm from the apex after Nd:YAG laser irradiation. METHODS: Forty freshly extracted human mandibular premolars were prepared using Reciproc® and irrigated with 17% ethylenediaminetetraacetic acid (EDTA). Teeth were divided into 4 groups: group 1, obturated with control sealer (AH Plus®); group 2, obturated with bioceramic sealer (Endosequence BC Sealer®); group 3, Nd:YAG laser + control sealer (AH Plus®); and group 4, Nd:YAG laser + bioceramic sealer (Endosequence BC Sealer®). The samples were transversely sectioned 3 mm and 5 mm from the apex and examined using confocal laser scanning microscopy. Two parameters were measured: 1) sealer penetration into dentinal tubules of the root canal and 2) sealer penetration into the perimeter of the root canal walls. RESULTS: Penetration analysis showed that bioceramic sealer had a higher penetration at depths of 3 and 5 mm than that of the control sealer, regardless of laser use (p <0.05). Perimeter analysis showed that there was no difference between both sealers at a depth of 3 mm (p <0.05), regardless of laser use. At a depth of 5 mm, bioceramic sealer and laser showed a greater perimeter of penetration (p <0.05) than the control sealer. CONCLUSION: The use of Nd:YAG laser did not compromise the penetration of bioceramic sealer into dentinal tubules of root canals at 3 mm and 5 mm from the apex.

Pilot study on laser propagation in maxillary and mandibular bone: Grey level image analysis for optical measurements.

BACKGROUND: Bone tissue anatomy, density and porosity vary among subjects in different phases of life and even within areas of a single specimen. The optical characteristics of changes in bone tissue are analyzed based on these properties. Photobiomodulation has been used to improve bone healing after surgery or fractures. Thus, knowledge on light propagation is of considerable importance to the obtainment of successful clinical outcomes. OBJECTIVE: This study determines light penetration and distribution in human maxillary and mandibular bones in three different regions (anterior, middle, and posterior). METHODS: A HeNe laser (633nm) irradiated maxillary and mandibular bones in the cervical-apical direction. The light propagation and scattering pattern were acquired and the grey level of the images was analyzed. Three-dimensional plots of the intensity profile and attenuation profiles were created. RESULTS: Differences in optical properties were found between the mandibular and maxillary bones. The maxilla attenuated more light than the mandible at all sites, leading to a shallower penetration depth. CONCLUSION: Our results provide initial information on the behavior of the propagation of red laser on alveolar bone using an optical method.