Nasal mucus transportability in children with cleft palate

Objectives: Children with cleft palate (CP) have a high prevalence of sinusitis. Considering that nasal mucus properties play a pivotal role in the upper airway defense mechanism, the aim of the study was to evaluate nasal mucus transportability and physical properties from children with CP. Setting: Hospital for Rehabilitation of Craniofacial Anomalies, School of Dentistry, University of Sao Paulo, Bauru, SP, Brazil and Laboratory of Experimental Air Pollution, School of Medicine, University of Sao Paulo, Sao Paulo, SP, Brazil. Methods: Nasal mucus samples were collected by nasal aspiration from children with CP and without CP (non-CP). Sneeze clearance (SC) was evaluated by the simulated sneeze machine. In vitro mucus transportability (MCT) by cilia was evaluated by the frog palate preparation. Mucus physical surface properties were assessed by measuring the contact angle (CA). Mucus rheology was determined by means of a magnetic rheometer, and the results were expressed as log G* (vectorial sum of viscosity and elasticity) and tan delta (relationship between viscosity and elasticity) measured at 1 and 100 rad/s. Results: Mucus samples from children with CP had a higher SC than non-CP children (67 +/- 30 and 41 +/- 24 mm, respectively, p < 0.05). Mucus samples from children with CP had a lower CA (24 +/- 16 degrees and 35 +/- 11 degrees, p < 0.05) and a higher tan delta 100 (0.79 +/- 0.24 and 0.51 +/- 0.12, p < 0.05) than non-CP children. There were no significant differences in mucus MCT, log G* 1, tan delta 1 and log G* 100 obtained for CP and non-CP children. Conclusions: Nasal mucus physical properties from children with CP are associated with higher sneeze transportability. The high prevalence of sinusitis in children with CP cannot be explained by changes in mucus physical properties and transportability. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Effect of 4% titanium tetrafluoride solution on dental erosion by a soft drink: An in situ/ex vivo study

Objective: This in situ/ex vivo study assessed the effect of titanium tetrafluoride (TiF4) on permanent human enamel subjected to erosion. Design: Ten volunteers took part in this study performed in two phases. In the first phase (ERO), they wore acrylic palatal appliances containing two enamel blocks, divided into two rows: TiF4 (F) and no-TiF4 (no-F). During the 1st day, the formation of a salivary pellicle was allowed. In the 2nd day, the TiF4 solution was applied on one row (ERO + F), whereas on the other row no treatment was performed (ERO + no-F). From 3rd until 7th day, the blocks were subjected to erosion, 4x per day. In the 2nd phase (no-ERO), the volunteers wore acrylic palatal appliances containing one enamel block, during 2 days, to assess the effect of TiF4 only (no-ERO + F). Enamel alterations were determined using profilometry (wear), microhardness (%SMHC) tests, scanning electron microscope and microprobe analysis. The %SMHC and wear were tested using ANOVA and Tukey`s post hoc tests (p < 0.05). Results: The mean of %SMHC and wear ( mu m) values ( +/- S.D.) were, respectively: ERO + F -73.32 +/- 5.16(A)/2.40 +/- 0.60(a); ERO + no-F -83.49 +/- 4.59B/1.17 +/- 0.48(b) and no-ERO + F -67.92 +/- 6.16(A)/0.21:E 0.09(c). In microscope analysis, the no-F group showed enamel with honeycomb appearance. For F groups, it was observed a surface coating with microcracks. The microprobe analysis revealed the presence of the following elements (%) in groups ERO + F, ERO + no-F and no-ERO + F, respectively: Ca (69.9, 72.5, 66.25); P (25.9, 26.5, 26.06); Ti (3.0, 0, 5.93). Conclusions: The TiF4 was unable to reduce dental erosion. (c) 2007 Elsevier Ltd. All rights reserved.

Healing of critical-size cranial defects in guinea pigs using a bovine bone-derived resorbable membrane

Purpose: To investigate the healing of critical-size cranial bone defects (9-mm-diameter) in guinea pigs treated with a bovine bone-derived resorbable membrane. Materials and Methods: A sample of 42 guinea pigs was divided into test (n = 20), control (n = 20), and standard (n = 2) groups. A full-thickness trephine defect was made in the fronto-parietal bone of each animal. In the test group, the internal and external openings of the defect were each closed with a separate membrane, and the space between them was filled with blood clot and a central spacer. In the control group, the defect was filled only with the blood clot and spacer. At 1, 3, 6, and 9 months later, the calvarias (5 per period) for both the test and control groups were collected, fixed, radiographed, and histologically processed. The Standard-group animals were sacrificed immediately after surgery and used to determine the initial size of defect radiographically. The areas of defects in the radiographs were measured with image-analysis software and were compared between groups and periods by multiple regression analysis with the Bonferroni correction. Results: At 1 and 3 months, newly formed woven bone was histologically observed in both test and control groups. Radiographically, this new bone occupied an average of 32% of the defect area at 1 month and 60% at 3 months in the test group. In the control group, 21% of the defect was filled at 1 month and 39% at 3 months. However, the differences between treatments were not statistically significant (P > .05). At 6 and 9 months, a significant increase in newly formed lamellar bone was seen histologically in both groups. Radiographically, for the test group, the new bone occupied an average of 82% of the defect area at 6 months and 96% at 9 months. For the control group, new bone composed an average of 45% of the defect area at 6 months and 40% at 9 months. The differences between the test and control groups were statistically significant at 6 and 9 months (P < .05). Complete or almost complete filling of the defect was observed in several cases. Conclusion: It was concluded that the bovine bone-derived membrane is highly biocompatible and is able to promote good healing of critical-size defects in calvaria of guinea pig.

Influence of nicotine on healing process of autogenous bone block grafts in the mandible: A histomorphometric study in rats

Purpose: The aim of this study was to perform qualitative and quantitative analyses of the effect of nicotine on autogenous bone block grafts and to describe events in the initial healing phase and the differences in the repair processes between animals exposed to nicotine and controls. Materials and Methods: Forty-eight female Wistar rats were randomly divided into 2 groups, the nicotine group and the saline group. All animals received either nicotine (3 mg/kg) or saline 4 weeks before the surgical procedure and continued to receive nicotine from surgery to sacrifice at 7, 14, or 28 days. The autogenous bone block graft was harvested from the calvaria and stabilized on the external cortical area near the angle of the mandible. Results: The histologic analyses of the nicotine group depicted a delay in osteogenic activity at the bed-graft interface, as well as impairment of the organization of the granulation tissue that developed instead of blood clot. Nicotine-group specimens exhibited less bone neoformation, and the newly formed bone was poorly cellularized and vascularized. The histometric analysis revealed significantly less bone formation in the nicotine group at both 14 days (23.75% +/- 6.18% versus 51.31% +/- 8.31%) and 28 days (42.44% +/- 8.70% versus 73.00% +/- 4.99%). Conclusion: Nicotine did jeopardize the early healing process of autogenous bone block grafts in rats but did not prevent it.

Effect of a 4% titanium tetrafluoride (TiF4) varnish on demineralisation and remineralisation of bovine enamel in vitro

Objectives: This in vitro study assessed the effect of a 4% TiF4 varnish on demineralisation and remineralisation of sound enamel and artificial carious enamel lesions, respectively. Methods: Bovine sound and carious enamel (n = 110) were randomly allocated to each type of varnish: Duraphat (R))-D (NaF, 2.26%F, pH 4.5, Colgate-Brazil, n = 30), Duofluorid (R)-F (NaF, 2.71%F, pH 8.0, FGM-Brazil, n = 30), TiF4-T (2.45%F, pH 1.0, FGM-Brazil, n = 30) and no-fluoride-P (FGM-Brazil, pH 5.0, n = 20). For the formation of artificial enamel caries, half of the blocks were immersed in 32 mL buffer acetate solution (16 h), whereas the other half was maintained sound. The varnishes were applied onto the enamel surfaces. Thus, the samples were subjected to pH cycles (37 degrees C) for 7 days. The response variables tested were surface and cross-sectional hardness. Data were tested using Kruskal-Wallis test (p < 0.05). Results: All F varnishes significantly reduced demineralisation and increased remineralisation in comparison to placebo. The TiF4 did not significantly reduce the surface enamel softening when compared with the other F varnishes, but it decreased the loss of subsurface hardness to the same extent. In enamel blocks with previous artificial carious lesions, the TiF4 significantly improved the rehardening compared to the other varnishes up to 30 mu m depth. Conclusions: The TiF4 varnish was able to decrease the demineralisation and increase the remineralisation of previously sound and carious enamel, respectively. It was equally effective compared to NaF varnishes on reducing the demineralisation at subsurface, but it was more effective on improving the remineralisation at surface and subsurface. (c) 2007 Elsevier Ltd. All rights reserved.

Effect of different concentrations of fluoride in dentifrices on dentin erosion subjected or not to abrasion in situ/ex vivo

This in situ/ex vivo study assessed the effect of different concentrations of fluoride in dentifrices on dentin subjected to erosion or to erosion plus abrasion. Ten volunteers took part in this crossover and double-blind study performed in 3 phases (7 days). They wore acrylic palatal appliances containing 4 bovine dentin blocks divided in two rows: erosion and erosion plus abrasion. The blocks were subjected to erosion by immersion ex vivo in a cola drink (60 s, pH 2.6) 4 times daily. During this step, the volunteers brushed their teeth with one of three dentifrices D (5,000 ppm F, NaF, silica); C (1,100 ppm F, NaF, silica) and placebo (22 ppm F, silica). Then, the respective dentifrice slurry (1: 3) was dripped on dentin surfaces. While no further treatment was performed in one row, the other row was brushed using an electric toothbrush for 30 s ex vivo. The appliances were replaced in the mouth and the volunteers rinsed with water. Dentin loss was determined by profilometry and analyzed by 2-way ANOVA/Bonferroni test (alpha = 0.05). Dentin loss after erosive-abrasive wear was significantly greater than after erosion alone. Wear was significantly higher for the placebo than for the D and C dentifrices, which were not significantly different from each other. It can be concluded that the presence of fluoride concentrations around 1,100 ppm in dentifrices is important to reduce dentin wear by erosion and erosion + abrasion, but the protective effect does not increase with fluoride concentration. Copyright (C) 2008 S. Karger AG, Basel.

The effect of an experimental 4% TiF(4) varnish compared to NaF varnishes and 4% TiF(4) solution on dental erosion in vitro

This in vitro study assessed the effect of an experimental 4% TiF(4) varnish compared to commercial NaF and NaF/CaF(2) varnishes and 4% TiF(4) solution on enamel erosion. For this, 72 bovine enamel specimens were randomly allocated to the following treatments: NaF varnish (2.26% F), NaF/CaF(2) varnish (5.63% F), 4% TiF(4) varnish (2.45% F), F-free placebo varnish, 4% TiF(4) solution (2.45% F) and control (not treated). The varnishes were applied in a thin layer and removed after 6 h. The solution was applied to the enamel surface for 1 min. Then, the specimens were alternately de- and remineralized (6 times/day) in an artificial mouth for 5 days at 37 degrees C. Demineralization was performed with the beverage Sprite (1 min, 3 ml/min) and remineralization with artificial saliva (day: 59 min, 0.5 ml/min; during the night: 0.1 ml/min). The mean daily increment of erosion and the cumulative erosion data were tested using ANOVA and ANCOVA, respectively, followed by Tukey`s test (alpha = 0.05). The mean daily erosion increments and cumulative erosion (micrometers) were significantly less for the TiF(4) varnish (0.30 +/- 0.11/0.65 +/- 0.75) than for the NaF varnish (0.58 +/- 0.11/1.47 +/- 1.07) or the NaF/CaF(2) varnish (0.62 +/- 0.10/1.68 +/- 1.17), which in turn showed significantly less erosion than the placebo varnish (0.78 +/- 0.12/2.05 +/- 1.43), TiF(4) solution (0.86 +/- 0.11/2.05 +/- 1.49) and control (0.77 +/- 0.16/2.06 +/- 1.49). In conclusion, the TiF(4) varnish seems to be a promising treatment to reduce enamel loss under mild erosive conditions. Copyright (C) 2008 S. Karger AG, Basel.

Effects of Erosive, Cariogenic or Combined Erosive/Cariogenic Challenges on Human Enamel An in situ/ex vivo Study

Individuals with cariogenic diet can also consume erosive beverages. Thus, it seems necessary to investigate a possible caries/erosion interaction. To test in situ/ex vivo a combination of these challenges, 11 subjects wore intraoral appliances containing four enamel blocks randomly assigned. In the first 2-week phase, the appliances were immersed in a cola drink 3 times/day. Two blocks were free of plaque (erosion only: EO) and two blocks were covered with plaque (erosion + plaque: EP). In the second 2-week phase, four new blocks were all covered with plaque and subjected to a sucrose solution 8 times/day. Among the four new blocks, two were also subjected to the cola drink 3 times/day (erosion + caries: EC) while the other two were not (caries only: CO). Thus, in EO, the specimens were fixed at the intraoral appliance level. In EP, EC and CO they were fixed 1.0 mm under the appliance level and covered with plastic meshes for dental plaque accumulation. Changes in wear and hardness were measured. Data were tested using ANOVA and Tukey`s test (p < 0.05). Mean values of wear (mu m) and change in hardness (kp/mm(2)) were: EO 4.82/310; EP 0.14/48; EC 0.34/245; CO 0.42/309. With respect to surface softening, EP and EC differed significantly from each other and from EO and CO, which did not differ significantly. EO presented significantly higher wear than the other groups. The data suggest that the presence of dental plaque can decrease the acid attack of an erosive drink and the association of erosive and cariogenic challenges showed less enamel alterations when compared to erosive or cariogenic challenges only. Copyright (C) 2008 S. Karger AG, Basel

Biomarkers of Fluoride in Children Exposed to Different Sources of Systemic Fluoride

There has been no comparison between fluoride concentrations in urine and nails of children exposed to different sources of systemic fluoride. The aim of this study was to compare the relationship between fluoride intake with urinary fluoride excretion and fluoride concentrations in fingernails and toenails of children receiving fluoride from artificially fluoridated water (0.6-0.8 mg F/L, n = 25), naturally fluoridated water (0.6-0.9 mg F/L, n = 21), fluoridated salt (180-200 mg F/Kg, n = 26), and fluoridated milk (0.25 mg F, n = 25). A control population was included (no systemic fluoride, n = 24). Fluoride intake from diet and dentifrice, urinary fluoride excretion, and fluoride concentrations in fingernails/toenails were evaluated. Fluoride was analyzed with an ion-selective electrode. Urinary fluoride excretion in the control community was significantly lower when compared with that in the fluoridated cities, except for the naturally fluoridated community. However, the same pattern was not as evident for nails. Both urinary fluoride output and fluoride concentrations in fingernails/toenails were significantly correlated to total fluoride intake. However, the correlation coefficients for fluoride intake and urinary fluoride output were lower (r = 0.28, p < 0.01) than those observed for fingernails/toenails (r = 0.36, p < 0.001), suggesting that nails might be slightly better indicators of fluoride intake at the individual level.

Ten-year survival of ART restorations in permanent posterior teeth

This study evaluated the 10-year clinical performance of high-viscosity glass-ionomer cement placed in posterior permanent teeth by means of the Atraumatic Restorative Treatment (ART) approach. One operator placed 167 single- and 107 multiple-surface restorations in 43 high-risk caries pregnant women (mean decayed teeth = 9.8 +/- 5.5). Examinations were performed at 1-, 2-, and 10-year intervals according to ART criteria. In the last evaluation, the US Public Health Service (USPHS) criteria were also used. After 10 years, 129 restorations (47.1%) were evaluated and achieved a cumulative survival rate of 49.0% (SE 7.2%). The 10-year survival of single- and multiple-surface ART restorations assessed using the ART criteria were 65.2% (SE 7.3%) and 30.6% (SE 9.9%), respectively. This difference was significant (jackknife SE of difference; p < 0.05). Using the USPHS criteria, the 10-year survival of single- and multiple-surface ART restorations were 86.5% and 57.6%, respectively. The primary causes of failure were total loss (9.3%) and marginal defects (5.4%). The survival rates observed, especially for the single-surface restorations, confirm the potential of the ART approach for restoring and saving posterior permanent teeth.

Cariogenic Microorganisms and Oral Conditions in Asthmatic Children

This study evaluated the caries risk of asthmatic patients on the basis of mutans streptococci (MS) and lactobacilli levels in saliva samples as well as the index of oral hygiene and dental caries (DMFT index). The study population was composed of 80 asthmatic children, aged 3-15 years, who use specific medication, and 80 matched, healthy control children. The parents were interviewed about oral health-related factors. The World Health Organization criteria were used for dental examinations. The Kohler and Bratthal methodology was used to detect salivary MS levels and dilutions of saliva were done for lactobacilli counting. No differences between asthma and control groups were observed for caries prevalence in children aged 3-6 and 7-10 years, except in severe cases in the younger group. However, higher caries prevalence for permanent dentition was observed in 11- to 15-year-old asthmatic children. An increased dental biofilm was observed in the asthma group, as well as salivary levels of MS. No differences were observed in levels of lactobacilli. No statistical correlations were found between medication, frequency of treatment, method of consumption and caries experience, dental biofilm and salivary levels of MS or lactobacilli. However, there was a correlation between MS levels and treatment duration. The logistic regression revealed that MS level is an important risk factor for increased caries experience. Asthma should be evaluated as a risk factor for caries experience because it can increase the levels of MS and the dental biofilm. Copyright (C) 2011 S. Karger AG, Basel

Heat Release, Time Required, and Cleaning Ability of Mtwo R and ProTaper Universal Retreatment Systems in the Removal of Filling Material

Introduction: This ex vivo study evaluated the heat release, time required, and cleaning efficacy of MTwo (VDW, Munich, Germany) and ProTaper Universal Retreatment systems (Dentsply/Maillefer, Ballaigues, Switzerland) and hand instrumentation in the removal of filling material. Methods: Sixty single-rooted human teeth with a single straight canal were obturated with gutta-percha and zinc oxide and eugenol-based cement and randomly allocated to 3 groups (n = 20). After 30-day storage at 37 degrees C and 100% humidity, the root fillings were removed using ProTaper UR, MTwo R, or hand files. Heat release, time required, and cleaning efficacy data were analyzed statistically (analysis of variance and the Tukey test, alpha = 0.05). Results: None of the techniques removed the root fillings completely. Filling material removal with ProTaper UR was faster but caused more heat release. Mtwo R produced less heat release than the other techniques but was the least efficient in removing gutta-percha/sealer. Conclusions: ProTaper UR and MTwo R caused the greatest and lowest temperature increase on root surface, respectively; regardless of the type of instrument, more heat was released in the cervical third. Pro Taper UR needed less time to remove fillings than MTwo R. All techniques left filling debris in the root canals. (I Endod 2010;36:1870-1873)

Short-term in situ/ex vivo study of the anticariogenic potential of a resin-modified glass-ionomer cement associated with adhesive systems

Objective: As resin-modified glass-ionomer cement (RMGIC) is an adhesive material, its association to dentin bonding agents (DBAs) was previously proposed. This study investigated the adjunctive behavior of an RMGIC with etch-and-rinse bonding systems under in situ/ex vivo cariogenic challenge. Method and Materials: Bovine enamel blocks (3 3 2 mm) were randomly assigned to group VP, Vitremer + its own primer (3M ESPE); group VSB, Vitremer + Single Bond (3M ESPE); and group VPB, Vitremer + Prime & Bond 2.1 (Dentsply). Two blocks of each group were randomly placed in an acrylic palatal appliance, so each appliance included six blocks. Volunteers (n = 10) wore these appliances according to given instructions to promote a sucrose challenge eight times/day for 15 days. After this period, the blocks were removed from the devices and cleaned, and demineralization was assessed through longitudinal microhardness analysis (Knoop indenter, 25 g/5 s). Data were submitted to three-way ANOVA and Tukey test (P < .05). Results: No treatment was able to completely avoid demineralization. All materials showed a statistically significant difference in mineral loss when the microhardness on the outer enamel was compared with deeper regions (P < .05). Conclusion: Association of the tested RMGICs with etch-and-rinse DBAs did not seem to be more beneficial against caries than the conventional treatment with RMGIC. (Quintessence Int 2010; 41: e192-e199)

Comparison of GPX with or without solvent and hand files in removing filling materials from root canals-An ex vivo study

Objective. The aim of this study was to compare GPX instruments and hand files for gutta-percha removal. Study design. Fifty maxillary central incisors with a single straight canal were instrumented and filled. The teeth were divided into 5 groups of 10 specimens each, according to the gutta-percha removal techniques: group 1: GPX (21-mm-long teeth); group 2: GPX and xylol as solvent (21-mm-long teeth); group 3: GPX (25-mm-long teeth); group 4: GPX and xylol as solvent (25-mm-long teeth); and group 5: hand files and xylol as solvent. The amount of time for gutta-percha removal and the number of fractured instruments were evaluated. Radiographs were taken, and the teeth were grooved longitudinally and split. The area of residual debris was measured using Sigma Scan software. Results. The time for filling material removal was significantly shorter when GPX was used (P < .05). Overall, hand files and solvent produced fewer remnants of filling materials (P < .05). In the GPX 25 mm-long teeth group, the filling material was not removed in the apical third. Conclusions. Under the experimental conditions, the GPX instruments proved to be faster than hand instruments in removing root filling materials; however, hand instruments left a smaller amount of residual filling materials on the canal walls. The GPX instruments did not pull the gutta-percha beyond its tip. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 110: 675-680)

In vivo Dentin Microhardness beneath a Calcium-Phosphate Cement

A minimally invasive caries-removal technique preserves potentially repairable, caries-affected dentin. Mineral-releasing cements may promote remineralization of soft residual dentin. This study evaluated the in vivo remineralization capacity of resin-based calcium-phosphate cement (Ca-PO(4)) used for indirect pulp-capping. Permanent carious and sound teeth indicated for extraction were excavated and restored either with or without the Ca-PO(4) base (control), followed by adhesive restoration. Study teeth were extracted after 3 months, followed by sectioning and in vitro microhardness analysis of the cavity floor to 115-mu m depth. Caries-affected dentin that received acid conditioning prior to Ca-PO(4) basing showed significantly increased Knoop hardness near the cavity floor. The non-etched group presented results similar to those of the non-treated group. Acid etching prior to cement application increased microhardness of residual dentin near the interface after 3 months in situ.