In Situ Effect of Dentifrices Associated to CO2 Laser in the Permeability of Eroded Root Dentin

Objective: The aim of this study was to evaluate, through a crossover 2 x 2 in situ trial, the effect of a desensitizing dentifrice associated with CO2 laser irradiation to control the permeability of eroded root dentin. Background data: Facing the increased prevalence of erosive lesion and the need for preventive means to control painful symptoms related to them. Methods: Eighty slabs of bovine root dentin were subjected to initial erosive challenge (citric acid 0.3%, 2 h), followed by a remineralizing period in artificial saliva (24 h). Specimens were then divided according to dentin treatment: desensitizing dentifrice, desensitizing dentifrice + CO2 laser, fluoride anticavity dentifrice. and fluoride anticavity dentifrice + CO2 laser. After a 2-day lead-in period, 10 volunteers wore an intraoral palatal appliance containing four root dentin slabs, in two phases of 5 days each. During the intraoral phase, one side of the appliance was immersed in 0.3% citric acid, and the opposite side was immersed in deionized water, four times a day. One hour after the immersions, all specimens were brushed with dentifrice slurry provided by the researcher. After a 7-day washout period, volunteers were crossed over on the different dentifrice group. Each phase having been completed, the specimens were evaluated for permeability through an optical microscope. Results: Data were analyzed using ANOVA and no significant difference (p = 0.272) was found between the surface treatments performed on bovine root dentin. Conclusions: It can be concluded that fluoride anticavity or desensitizing dentifrice, regardless of the association with the CO2 laser irradiation, was able to control the permeability of eroded root dentin.

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies - USP (HRAC-USP) - Part 2: Pediatric Dentistry and Orthodontics

The aim of this article is to present the pediatric dentistry and orthodontic treatment protocol of rehabilitation of cleft lip and palate patients performed at the Hospital for Rehabilitation of Craniofacial Anomalies - University of So Paulo (HRAC-USP). Pediatric dentistry provides oral health information and should be able to follow the child with cleft lip and palate since the first months of life until establishment of the mixed dentition, craniofacial growth and dentition development. Orthodontic intervention starts in the mixed dentition, at 8-9 years of age, for preparing the maxillary arch for secondary bone graft procedure (SBGP). At this stage, rapid maxillary expansion is performed and a fixed palatal retainer is delivered before SBGP. When the permanent dentition is completed, comprehensive orthodontic treatment is initiated aiming tooth alignment and space closure. Maxillary permanent canines are commonly moved mesially in order to substitute absent maxillary lateral incisors. Patients with complete cleft lip and palate and poor midface growth will require orthognatic surgery for reaching adequate anteroposterior interarch relationship and good facial esthetics.

Toxicity of photodynamic therapy with LED associated to Photogem (R): An in vivo study

The aims of this study were to evaluate the effects of PhotogemA (R)-mediated photosensitization on rat palatal mucosa and the biodistribution of the photosensitizer in this tissue. A solution of PhotogemA (R) (500 or 1000 mg/l) was applied to the palatal mucosa for 30 min and the exposure time to blue LED (460 nm) was 20 min (144 J/cm(2)). At 0, 1, 3, and 7 days, palatal mucosa was photographed for macroscopic analysis. After killing, the palate was removed for microscopic analysis. Thermal mapping evaluated temperature change in the tissue during irradiation. All experimental groups revealed intact mucosa in the macroscopic analysis. Tissue alterations were observed microscopically for only four out of 80 animals subjected to PDT. Fluorescence emitted by PhotogemA (R) was identified and was limited to the epithelial layer. A temperature increase from 35 to 41A degrees C was recorded. PhotogemA (R)- mediated PDT was not toxic to the rat palatal mucosa.

Clinical microscopic analysis of protaper retreatment system efficacy considering root canal thirds using three endodontic sealers

To evaluate the efficacy of ProTaper Universal rotary retreatment system and the influence of sealer type on the presence of filling debris in the reinstrumented canals viewed in an operative clinical microscope. Forty-five palatal root canals of first molars were filled with gutta-percha and one of the following sealers: G1, EndoFill; G2, AH Plus; G3, Sealapex. The canals were then reinstrumented with ProTaper Universal rotary system. Roots were longitudinally sectioned and examined under an operative clinical microscope (10x), and the amount of filling debris on canal walls was analyzed using the AutoCAD 2004 software. A single operator used a specific software tool to outline the canal area and the filling debris area in each third (cervical, middle, and apical), as well as the total canal area. Data were analyzed by Kruskal-Wallis test and Tukey test at P < 0.05. Sealapex demonstrated significant differences in the average of filling debris area/canal among the 3 thirds. This group revealed that apical third showed more debris than the both cervical and middle third (P < 0.0001). Endofill presented significantly more filling debris than Sealapex in the cervical third (P < 0.05). In the middle (P = 0.12) and apical third (P = 0.10), there were no differences amongst groups. Debris was left in all canal thirds, regardless of the retreatment technique. The greatest differences between techniques and sealers were found in the cervical third. Microsc. Res. Tech. 75:12331236, 2012. (C) 2012 Wiley Periodicals, Inc.

Orthodontic measurements and nasal respiratory function after surgically assisted rapid maxillary expansion: an acoustic rhinometry and rhinomanometry study

The present study sought to assess nasal respiratory function in adult patients with maxillary constriction who underwent surgically assisted rapid maxillary expansion (SARME) and to determine correlations between orthodontic measurements and changes in nasal area, volume, resistance, and airflow. Twenty-seven patients were assessed by acoustic rhinometry, rhinomanometry, orthodontic measurements, and use of a visual analogue scale at three time points: before surgery; after activation of a preoperatively applied palatal expander; and 4 months post-SARME. Results showed a statistically significant increase (p < 0.001) in all orthodontic measurements. The overall area of the nasal cavity increased after surgery (p < 0.036). The mean volume increased between assessments, but not significantly. Expiratory and inspiratory flow increased over time (p < 0.001). Airway resistance decreased between assessments (p < 0.004). Subjective analysis of the feeling of breathing exclusively through the nose increased significantly from one point in time to the next (p < 0.05). There was a statistical correlation between increased arch perimeter and decreased airway resistance. Respiratory flow was the only variable to behave differently between sides. The authors conclude that the SARME procedure produces major changes in the oral and nasal cavity; when combined, these changes improve patients' quality of breathing.

Does the neonatal clinical risk for illness severity influence pain reactivity and recovery in preterm infants?

Background: The biobehavioural pain reactivity and recovery of preterm infants in the neonatal period may reflect the capacity of the central nervous system to regulate neurobiological development. Objective: The aim of the present study was to analyse the influence of the neonatal clinical risk for illness severity on biobehavioural pain reactivity in preterm infants. Methods: Fifty-two preterm infants were allocated into two groups according to neonatal severity of illness, as measured by the Clinical Risk Index for Babies (CRIB). The low clinical risk (LCr) group included 30 neonates with CRIB scores <4, and the high clinical risk (HCr) group included 22 neonates with CRIB scores >= 4. Pain reactivity was assessed during a blood collection, which was divided into five phases (baseline, antisepsis, puncture, recovery-dressing and recovery-resting). Behavioral pain reactivity was measured using the scores, and magnitude of responses in Neonatal Facial Coding System (NFCS) and Sleep-Wake States Scale (SWS). The heart rate was continuously recorded. Results: The HCr demonstrated a higher magnitude of response on the SWS score from the baseline to the puncture phase than the LCr. Also, the HCr exhibited a higher mean heart rate and minimum heart rate than the LCr in the recovery-resting phase. In addition, the HCr exhibited a higher minimum heart rate from the baseline to the recovery-resting phase than the LCr. Conclusion: The infants exhibiting a high neonatal clinical risk showed high arousal during the puncture procedure and higher physiological reactivity in the recovery phase.

Root and Root Canal Morphology of Four-rooted Maxillary Second Molars: A Micro-Computed Tomography Study

Introduction: This study examined the anatomy of 4-rooted maxillary second molars by using micro computed tomography. Methods: Twenty-five 4-rooted maxillary second molars were scanned to evaluate the size and curvature of the roots; the distance and spatial configuration between some anatomical landmarks; the number of root canals and the position of apical foramina; the occurrence of fusion of roots and enamel pearls; the configuration of the canal at the apical third; the cross-sectional appearance, the volume, and surface area of the root canals. Data were compared by using analysis of variance post hoc Tukey test (alpha = 0.05). Results: The specimens were classified as types I (n = 16), II (n = 7), and III (n = 2). The size of the roots was similar (P > .05), and most of them presented straight with 1 canal, except the mesiobuccal that showed 2 canals in 24% of the samples. The configuration of the pulp chamber was mostly irregular quadrilateral-shaped. The lowest mean distance of the orifices was observed between the buccal roots (P < .05). Accessory canals were present mostly in the apical third. Location of the apical foramina varied considerably. Fusion of roots and enamel pearls occurred in 44% and 8% of the samples, respectively. Mean distance from the pulp chamber floor to the furcation was 2.15 +/- 0.57 mm. No statistical differences were found in the bi-dimensional and 3-dimensional analyses (P > .05). Conclusions: All analyzed parameters showed differences between roots, except for the length of the roots, the configuration of the canals at the apical third, cross-sectional appearance, volume, and surface area of the canals. (J Endod 2012;38:977-982)

Degradation of the resin-dentin bonds after simulated and inhibited cariogenic challenge in an in situ model

The aim of this study was to evaluate the resindentin bonds of two simplified etch-and-rinse adhesive after simulated cariogenic and inhibited cariogenic challenge in situ. Dental cavities (4 mm wide, 4 mm long, and 1.5 mm deep) were prepared in 60 bovine teeth with enamel margins. Restorations were bonded with either adhesive Adper Single Bond 2 (3MESPE) or Optibond Solo Plus (Kerr). Forty restorations were included in an intra-oral palatal appliance that was used for 10 adult volunteers while the remaining 20 dental blocks were not submitted to any cariogenic challenge [NC group] and tested immediately. For the simulated cariogenic challenge [C+DA], each volunteer dropped 20% sucrose solution onto all blocks four times a day during 14 days and distilled water twice a day. In the inhibited cariogenic challenge group [C + FA], the same procedure was done, but slurry of fluoride dentifrice (1.100 ppm) was applied instead of water. The restored bovine blocks were sectioned to obtain a slice for cross-sectional Vickers microhardness evaluation and resindentin bonded sticks (0.8 mm2) for resindentin microtensile evaluation. Data were evaluated by two-way ANOVA and Tukey's tests (a = 0.05). Statistically lower microhardness values and degradation of the resindentin bonds were only found in the C + DW group for both adhesives. The in situ model seems to be a suitable short-term methodology to investigate the degradation of the resindentin bonds under a more realistic condition. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 14661471, 2012.

Upper airway expansion after rapid maxillary expansion evaluated with cone beam computed tomography

Objective: Cone-beam computed tomography (CBCT) is a reliable method of assessing the oral cavity and upper airways. We conducted this study to examine the changes introduced by rapid maxillary expansion in the nasal cavity, nasopharynx, and oropharynx as seen with images obtained by CBCT. Materials and Methods: We evaluated 15 patients with maxillary width deficiency treated with RME. Patients were subjected to CBCT at the beginning of RME and after the retention period of 4 months. Results: The nasal cavity presented a significant transverse increase in the lower third, in the anterior (1.08 mm +/- 0.15), medium (1.28 mm +/- 0.15), and posterior regions (0.77 mm +/- 0.12). No significant change occurred in the nasopharynx in volume (P = .11), median sagittal area (P = .33), or lower axial area (P = .29) resulting from the RME. A significant change was noted in the oropharynx in volume (P = .05), median sagittal area (P = .01), and lower axial area (P = .04) before and immediately after the RME. Conclusions: RME is able to increase the transverse width of the nasal cavity, but it does not have the same effect in the nasopharynx. Changes noted in the oropharynx may be due to the lack of a standardized position of the head and tongue at the time of image acquisition. (Angle Orthod. 2012;82:458-463.)

Soft tissue profile changes after rapid maxillary expansion with a bonded expander

The aim of this study was to evaluate the short-and long-term treatment effects of rapid maxillary expansion (RME) on the soft tissue facial profile of subjects treated with a modified acrylic-hyrax device. The sample comprised 10 males and 10 females in the mixed dentition. Their average age was 9.3 years +/- 10 months pre-treatment (T1), with a narrow maxilla and posterior crossbite, treated with a modified fixed maxillary expander with an occlusal splint. Lateral cephalometric radiographs obtained at T1, immediately post-expansion (T2), and after retention (T3) were used to determine possible changes in the soft tissue facial profile. The means and standard deviations for linear and angular cephalometric measurements were analysed statistically using analysis of variance and Tukey's test (alpha = 0.05). The measurements at T2 differed significantly from those at T1 and T3. However, RME did not produce any statistically significant alteration (P > 0.05) in the soft tissue profile for any of the cephalometric landmarks evaluated when compared at T1 and T3. The use of a fixed expander associated with an occlusal splint did not cause significant alterations in the soft tissue facial profile at T3. This modified device is effective for preventing the adverse vertical effects of RME such as an increase anterior face height in patients with a crossbite.

Influence of adenotonsillectomy on hard palate dimensions

Objective: To evaluate hard palate width and height in mouth-breathing children pre- and post-adenotonsillectomy. Methods: We evaluated 44 children in the 3-6 year age bracket, using dental study casts in order to determine palatal height, intercanine width, and intermolar width. The children were divided into two groups: nasal breathing (n = 15) and mouth breathing (n = 29). The children in the latter group underwent adenotonsillectomy. The study casts were obtained prior to adenotonsillectomy, designated time point 1(11), at 13 months after adenotonsillectomy (T2), and at 28 months after adenotonsillectomy (13). Similar periods of observation were obtained for nasal breathing children. Results: At T1, there was a significantly lower intercanine width in mouth breathing children; intermolar width and palate height were similar between groups. After surgery, there was a significant increase in all the analyzed parameters in both groups, probably due to facial growth. Instead, the increase in intercanine width was substantially more prominent in mouth breathing children than in nasal breathing children, and the former difference failed in significance after the procedure. Conclusions: There were no significant differences between the nasal-breathing and mouth-breathing children in terms of intermolar width and palatal height prior to or after tonsillectomy. Although intercanine width was initially narrower in the mouth-breathing children, it showed normalization after the surgical procedure. These results confirm that the restoration of nasal breathing is central to proper occlusal development. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Prevalence of oral habits in children with cleft lip and palate

This study investigated the prevalence of oral habits in children with clefts aged three to six years, compared to a control group of children without clefts in the same age range, and compared the oral habits between children with clefts with and without palatal fistulae. The sample was composed of 110 children aged 3 to 6 years with complete unilateral cleft lip and palate and 110 children without alterations. The prevalence of oral habits and the correlation between habits and presence of fistulae (for children with clefts) were analyzed by questionnaires applied to the children caretakers. The cleft influenced the prevalence of oral habits, with lower prevalence of pacifier sucking for children with cleft lip and palate and higher prevalence for all other habits, with significant association (P < 0.05). There was no significant association between oral habits and presence of fistulae (P > 0.05). The lower prevalence of pacifier sucking and higher prevalence of other oral habits agreed with the postoperative counseling to remove the pacifier sucking habit when the child is submitted to palatoplasty, possibly representing a substitution of habits. There was no causal relationship between habits and presence of palatal fistulae

Complicações após expansão de maxila cirurgicamente assistida

Introduction: The treatment of adult transverse maxillary deficiency is the surgically assisted maxillary expansion. Several surgical techniques have been described for this and complications have been related to these procedures. Objective: the aim of this study was evaluate the incidence of complications associated with surgically assisted maxillary expansion. Material and method: 33 individuals undergone surgically assisted maxillary expansion by subtotal Le Fort I osteotomy with a step in the zygomatic-maxillary buttress and associated to pterigomaxillary disjunction and osteotomy of intermaxillary suture. Operative complications, post-operative complications and the distance between the upper teeth were recorded. Result: 12 men and 21 women with an average age of 24.64 years undergone the procedure. The interdental distances increased from preoperative to 2 months post?operative time. The prevalent complications were sinusitis (6%) and teeth displacement and inclination (6%). Conclusion: Surgically assisted maxillary expansion is an effective and low morbidity procedure to treat transverse maxillary deficiency in adults.

Correction of Class II malocclusion with Class II elastics: a systematic review

Introduction: The aim of this prospective clinical study was to investigate the cephalometric changes produced by bonded spurs associated with high-pull chincup therapy in children with Angle Class I malocclusion and anterior open bite. Methods: Thirty patients with an initial mean age of 8.14 years and a mean anterior open bite of 3.93 mm were treated with bonded spurs associated with chincup therapy for 12 months. An untreated control group of 30 subjects with an initial mean age of 8.36 years and a mean anterior open bite of 3.93 mm and the same malocclusion was followed for 12 months for comparison. Student t tests were used for intergroup comparisons. Results: The treated group demonstrated a significantly greater decrease of the gonial angle, and increase in overbite, palatal tipping of the maxillary incisors, and vertical dentoalveolar development of the maxillary and mandibular incisors compared with the control group. Conclusions: The association of bonded spurs with high-pull chincup therapy was efficient for the correction of the open bite in 86.7% of the patients, with a 5.23-mm (SD, 61.69) overbite increase.

Different protocols to produce artificial dentine carious lesions in vitro and in situ: hardness and mineral content correlation

This study compared dentine demineralization induced by in vitro and in situ models, and correlated dentine surface hardness (SH), cross-sectional hardness (CSH) and mineral content by transverse microradiography (TMR). Bovine dentine specimens (n = 15/group) were demineralized in vitro with the following: MC gel (6% carboxymethylcellulose gel and 0.1 m lactic acid, pH 5.0, 14 days); buffer I (0.05 m acetic acid solution with calcium, phosphate and fluoride, pH 4.5, 7 days); buffer II (0.05 m acetic acid solution with calcium and phosphate, pH 5.0, 7 days), and TEMDP (0.05 m lactic acid with calcium, phosphate and tetraethyl methyl diphosphonate, pH 5.0, 7 days). In an in situ study, 11 volunteers wore palatal appliances containing 2 bovine dentine specimens, protected with a plastic mesh to allow biofilm development. The volunteers dripped a 20% sucrose solution on each specimen 4 times a day for 14 days. In vitro and in situ lesions were analyzed using TMR and statistically compared by ANOVA. TMR and CSH/SH were submitted to regression and correlation analysis (p < 0.05). The in situ model produced a deep lesion with a high R value, but with a thin surface layer. Regarding the in vitro models, MC gel produced only a shallow lesion, while buffers I and II as well as TEMDP induced a pronounced subsurface lesion with deep demineralization. The relationship between CSH and TMR was weak and not linear. The artificial dentine carious lesions induced by the different models differed significantly, which in turn might influence further de- and remineralization processes. Hardness analysis should not be interpreted with respect to dentine mineral loss