Vinícius Rangel Geraldo-Martins

In vitro analysis of inhibitory effects of the antibacterial monomer MDPB-containing restorations on the progression of secondary root caries

OBJECTIVE This study aimed to analyze in vitro inhibitory effects of restorative materials containing the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the formation of artificial secondary root caries lesions. METHODS Class V cavities (2mmx2mm) were prepared in 75 human root fragments. Specimens were randomly divided into five groups (n=15 fragments per group) and restored as follows: (I) MDPB-free adhesive system+MDPB-free composite (negative control); (II) resin modified glass ionomer (RM-GIC; positive control); (III) MDPB-free adhesive system+MDPB-containing composite (2.83% MDPB); (IV) MDPB-containing adhesive system+MDPB-free composite; (V) MDPB-containing adhesive system+MDPB-containing composite. Artificial secondary root caries lesions were produced by a biological artificial caries challenge. The restored specimens were immersed into a culture medium containing Streptococcus mutans and sucrose for 15 days. Histological slices (80+/-20 microm) of the specimens were used for measuring the mean depths of the artificial lesions produced in both margins of the restorations using polarized light microscopy. Results were expressed in percentage related to the mean depth of the negative control, considered 100%. Data were compared by ANOVA followed by the Tukeys test (p< or =0.05). RESULTS The depths of lesions adjacent to cavities filled with RM-GIC (GII; 85.17+/-15.2%) were significantly (p<0.01) shallower than those adjacent to restorations with MDPB-free composite (GI; 100.00+/-10.04%), despite the presence of MDPB in the adhesive system (GIV; 101.95+/-21.32%). The depths of lesions adjacent to cavities restored with MDPB-containing composite (GIII; 82.68+/-12.81% and GV; 85.65+/-15.42%), despite the adhesive system used, were similar to those of RM-GIC (GII). Mean lesions depths in these groups decreased from 13% (GV) to 17% (GIII) in relation to the negative control (GI). CONCLUSIONS MDPB-containing composite inhibits the progression of artificial secondary root caries lesions regardless of adhesive systems.

The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fishers test (α=5%). Results The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05). Conclusions The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin.

Assessment of root caries removal by Er,Cr:YSGG laser

The present study aimed to compare root caries removal by air turbine and Er,Cr:YSGG laser, and examine morphological changes after these caries removal techniques under scanning electron microscopy (SEM). Seventy two extracted human carious-free third molars were used in this study. After the in vitro root caries induction using S. mutans, the carious lesions were removed by the conventional technique, using burs (control), and by the Er,Cr:YSGG laser, using 13 different parameters, between 1 and 4,0 W. During caries removal, preparation time was recorded for all groups. The results appointed out that the conventional method was the fastest one. When only laser treatment was evaluated, the higher parameters seemed to remove caries faster then the lower ones. SEM revealed that the surfaces treated by air turbine were smooth, but with debris. The laser groups demonstrated smooth undulations, with little or absence of smear layer, and no signs of carbonization. These results suggest that caries removal by Er,Cr:YSGG laser was effective. Therefore, this equipment requires training on cavity preparation, in order to avoid damages in dental hard tissues.

Prospective evaluation of cytokine in saliva of preterm and fullterm neonates.

Little is known about the ontogeny of the cytokines in saliva of newborn. Previous studies showed that levels of immunoglobulin A (IgA) in saliva could be influenced by prematurity. So, the aim of this study was to analyze the levels of interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 12 (IL-12), and interferon gamma (IFN-γ) in sample saliva of fullterm (FT) and preterm (PT) neonates at birth (T0) and after 3 months of age (T3). Saliva from 50 infants (25 FT and 25 PT) were collected at T0 and T3 and analyzed by Luminex Corporation (Austin, Texas, United States) multiplex assay. Clinical characteristics and social-economic data were assessed through questionnaires. All cytokines could be detected at birth in levels higher than found in T3. The mean levels and frequency of detection of cytokines were significantly higher in PT than FT at T0 (P<0.05). There were a positive association between IL-10 and infection (P<0.05) and IL-6 and stress (P<0.005). Salivary cytokines were detected within the first hours after birth and their levels decreased after 3 months. The cytokine levels were different between PT and FT children and appear to be influenced by stress situation and/or antigenic microbial challenge. The results confirm the necessity for further studies about the mucosal immune system by using of saliva as a source of diagnostic by identification of biomarkers of the status of the immune.

Factors affecting the placement or replacement of direct restorations in a dental school.

Context: The knowledge of the reasons for the placement of direct restorations makes possible to trace an epidemiological profile of a specific population and to direct the teaching of dentistry to techniques that are commonly used today and will be continued performed in the future. Purpose: The aim of this study was to verify the reasons for placement and replacement of direct restorations in patients treated in the Dental Clinic of the Uberaba University – Brazil. Materials and Methods: This study evaluated 306 restorative procedures carried out on 60 patients. During the treatment planning, a form that contained information about the patients gender, tooth number, the classification of restorations, the reasons for placement and replacement of amalgam and tooth-colored restorations, the material that had to be removed and the new material used to fill the cavities was filled for each patient. Statistical analysis was carried out using Chi-square test (α = 0.05). Results: The data showed that most of the patients were female (66.7%). Of all the restorations placed, 60.45% were 1st-time placements, while 39.55% were replacements. For 1st-time restorations, the main reason for placement was primary caries (76.76%), followed by non-carious cervical lesions (15.14%). The amalgam restorations were replaced more frequently (67.77%). The primary reason for replacements was the presence of secondary caries (for both previous amalgam (42.68%) and composite (66.67%) restorations (P < 0.05). The resin composite was the most indicated material for the new restorations (98.04%) (P < 0.05). Conclusions: The main reason for placement of direct restorations was primary caries, while secondary caries was the main reason for replacements. In almost all cases, the material used to fill the cavities was the resin composite.

Effects of different desensitizing treatments on root dentin permeability

The objective of this study was to evaluate the effects of diode laser and a desensitizing dentifrice on dentin permeability. Fifty-two root dentin fragments were obtained (5 × 5mm) and treated with 24% EDTA gel. The samples were divided into 4 groups (n = 13): G1, control (no treatment); G2, diode laser (λ = 908 nm, 1.5 W, continuous mode, 20s); G3, application of abrasive dentifrice for 1 minute (Elmex Sensitive Professional (International Gaba); and G4, application of abrasive dentifrice for 1 minute followed by irradiation with diode laser. Ten samples per group were immersed in 2% methylene blue solution for 4h. The specimens were washed, longitudinally sectioned, observed under optical microscopy, photographed and assessed based on the degree of dye leakage. The remaining samples were observed under scanning electron microscopy (SEM). The leakage data were subjected to ANOVA test, followed by Tukeys t-test (α = 5%). Groups 2, 3 and 4 showed less dye penetration than the control group (p < 0.05), but were similar among each other. SEM images showed that dentinal tubules were open in G1, and fused and occluded in G2. Group 3 showed dentinal tubules that were occluded by the metal ions from the toothpaste. G4 presented similar characteristics to G3, and the presence of fused dentin. The diode laser and the dentifrice were effective in reducing dentinal permeability, and the combination of the two treatments did not show better results than either one used alone.

Streptococcus mutans in Umbilical Cord Blood, Peripheral Blood, and Saliva from Healthy Mothers

The aims of this study were to analyze the presence of Streptococcus mutans (SM)-DNA in cord blood (CB), maternal peripheral blood (PB), and maternal saliva (SA) and compare with data collected in health surveys. Sixty-four healthy women with pregnancies to term and without complications attending for elective cesarean section in the Clinical Hospital of Ribeirao Preto, Sao Paulo were included. Samples of PB and unstimulated SA were obtained on the day of hospitalization and samples of CB were collected after the delivery section. Samples were investigated using polymerase chain reaction for the presence of SM-DNA using specific primers. The results show over 50% of the sample of PB and CB showed SM-DNA detectable. There was a positive correlation between the SM detection in PB/CB and SA (P < 0.05). Pregnant women, who reported tooth brushing more than three times a day, often showed detectable SM-DNA in PB and CB (P < 0.05). In conclusion, the majority of children can have contact with SM-DNA during the intrauterine life by the CB. SM probably transferred from salivary habitat to PB and CB. The tooth brushing can be associated to S. mutans detection in blood samples.

Restorative Treatment on Permanent Teeth with Enamel Hypoplasia Caused By Trauma to the Primary Predecessors

Submit Manuscript | http://medcraveonline.com dentition after trauma to primary dentition are usually related to intrusive injury [4,5]. The type and severity of traumatic injuries are related to predisposing factors, such as child’s age, proximity of primary teeth and permanent germ, stage of root formation or resorption of primary teeth, permanent teeth root formation, root inclination of primary teeth when trauma occurred, treatment conduct and deciduous tooth repair, among others [1-7]. Primary tooth intrusion may result in a variety of pathologic alterations to permanent teeth, including hypoplasia, crown dilaceration, root angulation or dilaceration, partial or complete arrest of root formation, sequestration of the permanent tooth germ, and disturbances in eruption. Of these, hypoplasia (including enamel discoloration and/or enamel defects) is the most common sequel [8]. The present study relates a clinical case of an aesthetic treatment in permanent teeth with localized crown malformation, enamel hypoplasia as a result of traumatic injury in the primary central incisors.