Randomized in vivo evaluation of photodynamic antimicrobial chemotherapy on deciduous carious dentin

The aim of this randomized in vivo study was to compare antimicrobial chemotherapies in primary carious dentin. Thirty-two participants ages 5 to 7 years underwent partial caries removal from deep carious dentin lesions in primary molars and were subsequently divided into three groups: control [chlorhexidine and resin-modified glass ionomer cement (RMGIC)], LEDTB [photodynamic antimicrobial chemotherapy (PACT) with light-emitting diode associated with toluidine blue solution and RMGIC], and LMB [PACT with laser associated with methylene blue solution and RMGIC]. The participants were submitted to initial clinical and radiographic examinations. Demographic features and biofilm, gingival, and DMFT/DMFS indexes were evaluated, in addition to clinical and radiographic followups at 6 and 12 months after treatments. Carious dentin was collected before and after each treatment, and the number of Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Fusobacterium nucleatum, Atopobium rimae, and total bacteria was established by quantitative polymerase chain reaction. No signs of pain or restoration failure were observed. All therapies were effective in reducing the number of microorganisms, except for S. sobrinus. No statistical differences were observed among the protocols used. All therapies may be considered as effective modern approaches to minimal intervention for the management of deep primary caries treatment2010FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP#2010/07212-5; #2011/08392-

Chemical and physical factors of desensitizing and/or anti-erosive toothpastes associated with lower erosive tooth wear.

Toothpastes have a complex formulation and their different chemical and physical factors will influence their effectiveness against erosive tooth wear (ETW). We, therefore, investigated the effect of different desensitizing and/or anti-erosive toothpastes on initial enamel erosion and abrasion, and analysed how the interplay of their chemical and physical factors influences ETW. Human enamel specimens were submitted to 5 erosion-abrasion cycles using 9 different toothpastes and an artificial saliva group, and enamel surface loss (SL) was calculated. Chemical and physical factors (pH; presence of tin; calcium, phosphate and fluoride concentrations; % weight of solid particles; wettability; and particle size) of the toothpaste slurries were then analysed and associated with the amount of SL in a multivariate model. We observed that all desensitizing and/or anti-erosive toothpastes presented different degrees of SL. Besides pH and fluoride, all other chemical and physical factors were associated with SL. The results of this experiment indicate that enamel SL occurs independent of whether the toothpastes have a desensitizing or anti-erosive claim, and that lower SL is associated with the presence of tin, higher concentration of calcium and phosphate, higher % weight of solid particles, smaller particle size, and lower wettability

Influence of desensitizing and anti-erosive toothpastes on dentine permeability: An in vitro study.

OBJECTIVE This study analyzed the effect of desensitizing and/or anti-erosive toothpastes on dentine permeability. METHODS One-mm dentin discs were prepared from human molars and exposed to EDTA solution (5 min, 17%). Initial dentine permeability was measured, under constant pressure. Specimens were randomly allocated into 10 groups: four anti-erosive toothpastes (calcium silicate + sodium phosphate, potassium nitrate, stannous chloride + chitosan, oligopeptide-104); four desensitizing toothpastes (arginine + calcium carbonate, calcium sodium phosphosilicate, strontium acetate, stannous fluoride); and two controls (regular fluoridated toothpaste, and human saliva). They were submitted to a 5-day erosion-abrasion cycling model. Erosion consisted of immersion in citric acid (2 min, 0.3%, natural pH ˜ 2.6, 4x/day), followed by 1 h exposure to human saliva. Specimens were brushed for 15 s (2 N, 45 strokes) with the toothpaste slurries (total exposure time of 2 min). After 5 cycles, the final dentine permeability was determined. Dentine permeability change was calculated as a percentage of the initial hydraulic conductance (%Lp). Data were analyzed with one-way ANOVA and Tukey tests (α=0.05). RESULTS The toothpastes calcium silicate + sodium phosphate and potassium nitrate, showed significant decrease in %Lp, with no difference between them. The regular fluoridated toothpaste also decreased the %Lp, not differing from potassium nitrate. No desensitizing toothpaste showed change in %Lp. Human saliva, oligopeptide-104 and stannous chloride + chitosan presented significant increase in %Lp, without difference between them. CONCLUSION Calcium silicate + sodium phosphate, potassium nitrate, and the regular fluoridated toothpaste decreased dentine permeability, whereas the desensitizing toothpastes tested did not. CLINICAL RELEVANCE Toothpastes had distinct impacts on dentine permeability, which may reflect a variable effect on the treatment of dentine hypersensitivity. Within the limitations of a laboratory-based study, toothpastes with an anti-erosive claim could also be effective in reducing the pain in dentine hypersensitivity

Terapia fotodinámica antimicrobiana como complemento en el tratamiento restaurador directo

La Caries dental es una enfermedad multifactorial que afecta a gran parte de la población, presentando microorganismos dentro de su proceso de desarrollo, por tal motivo, el objetivo principal en este reporte de caso es reducir el nivel de los microorganismos presentes en los tejidos afectados por la enfermedad caries, ya sea en el esmalte o la dentina para lograr una restauración exitosa.  Este proceso restaurador se realizó con el uso de láser de baja potencia junto con un elemento cromóforo el cual penetra en los microorganismos, creando una reacción que elimina los microorganismos presentes en el proceso carioso; este proceso se denomina Terapia Fotodinámica (PDT). La Terapia Fotodinámica antimicrobiana (aPDT) es una técnica que combina la activación de un fotosensibilizador con una luz en presencia de oxígeno produciendo la reactivación de radicales que inducen a la muerte celular de los microorganismos. La aPDT es utilizada para reducir microorganismos, siendo un potencial antimicrobiano en el proceso de caries dental en un procedimiento de restauración directa, evitando así el proceso de caries recidivante, el cual ocurre cuando no hay un previo proceso exhaustivo de eliminación de los restos bacterianos después de limpiar la cavidad con instrumentos rotatorios. El siguiente reporte de caso clínico presenta un paciente con una lesión cariosa, en la que se introduce la aPDT en el proceso de restauración de la pieza 35, como una alternativa coadyuvante para una gran reducción y eliminación de los microorganismos implicados en el proceso de caries, mejorando así la calidad de nuestra restauración con resina, prolongando de esta manera el tiempo de vida de esta restauración

Effect of erosive challenge and Nd:YAG laser irradiation on bond strength of adhesive systems to dentin

Purpose To evaluate the effect of Nd:YAG laser irradiation and erosive challenge on bond strength of two adhesive systems to dentin. Methods Twenty bovine incisors were cut and grounded to obtain eighty slabs of flat dentin. Specimens were allocated into eight groups, based on: adhesive system—a two-step etch-and-rinse and a two-step self-etch; laser irradiation—Nd:YAG (1 W/10 Hz) or control (no laser irradiation); and erosive challenge after restorative procedure—presence or absence of erosive challenge. Nd:YAG laser groups were submitted to laser irradiation before the restorative procedure. Blocks of composite resin were built up on the bonded surfaces with a Southern Dental Industries device to perform shear bond strength (SBS) test. After, each specimen of erosive challenge, groups were subjected to immersion in Sprite Zero® (20 ml/2 h/24 °C/under agitation). The SBS test (0.5 mm/min) was performed after 24 h of water storage at 37 °C. Failure mode was evaluated with a stereomicroscope (X400). Data were analyzed with three-way ANOVA and Tukey’s post hoc tests (α=0.05). Results The etch-and-rinse adhesive system presented higher bond strength values than self-etch adhesive. Laser irradiation increased the bond strengths values when erosive challenge was present. The predominant failure mode observed was adhesive. Conclusions The irradiation of Nd:YAG laser positively influences the bond strength values when erosive challenges are present. Moreover, the etch-and-rinse adhesive system is a better option to be used in dentin in this clinical condition