Comparison Between Micro- and Macrosurgical Techniques for the Treatment of Localized Gingival Recessions Using Coronally Positioned Flaps and Enamel Matrix Derivative

Background: The aim of this study is to compare the macro- and microsurgery techniques for root coverage using a coronally positioned flap (CPF) associated with enamel matrix derivative (EMD). Methods: Thirty patients were selected for the treatment of localized gingival recessions (GRs) using CPF associated to EMD. Fifteen patients were randomly assigned to the test group (TG), and 15 patients were randomly assigned to the control group (CG). The microsurgical approach was performed in the TG, and the conventional macrosurgical technique was performed in the CG. The clinical parameters evaluated before surgery and after 6 months were GR, probing depth, relative clinical attachment level, width of keratinized tissue (WKT), and thickness of keratinized tissue (TKT). The discomfort evaluation was performed 1 week postoperative. Results: There were no statistically significant differences between groups for all parameters at baseline. At 6 months, there was no statistically significant difference between the techniques in achieving root coverage. The percentage of root coverage was 92% and 83% for TG and CG, respectively. After 6 months, there was a statistically significant increase of WKT and TKT in TG only. Both procedures were well tolerated by all patients. Conclusions: The macro- and microsurgery techniques provided a statistically significant reduction in GR height. After 6 months, there was no statistically significant difference between the techniques regarding root coverage, and the microsurgical technique demonstrated a statistically significant increase in WKT and TKT. J Periodontol 2010;81:1572-1579.

Comparative clinical study of the effectiveness of different dental bleaching methods - two year follow-up

This study evaluated color change, stability, and tooth sensitivity in patients submitted to different bleaching techniques. Material and methods: In this study, 48 patients were divided into five groups. A half-mouth design was conducted to compare two in-office bleaching bleaching techniques (with and without light activation): G1: 35% hydrogen peroxide (HP) (Lase Peroxide - DMC Equipments, Sao Carlos, SP, Brazil) + hybrid light (HL) (LED/Diode Laser, Whitening Lase II DMC Equipments, Sao Carlos, SP, Brazil); G2: 35% HP; G3: 38% HP (X-traBoost - Ultradent, South Jordan UT, USA) + HL; G4: 38% HP; and G5: 15% carbamide peroxide (CP) (Opalescence PF - Ultradent, South Jordan UT, USA). For G1 and G3, HP was applied on the enamel surface for 3 consecutive applications activated by HL. Each application included 3x3' HL activations with 1' between each interval; for G2 and G4, HP was applied 3x15' with 15' between intervals; and for G5, 15% CP was applied for 120'/10 days at home. A spectrophotometer was used to measure color change before the treatment and after 24 h, 1 week, 1, 6, 12, 18 and 24 months. A VAS questionnaire was used to evaluate tooth sensitivity before the treatment, immediately following treatment, 24 h after and finally 1 week after. Results: Statistical analysis did not reveal any significant differences between in-office bleaching with or without HL activation related to effectiveness; nevertheless the time required was less with HL. Statistical differences were observed between the result after 24 h, 1 week and 1, 6, 12, 18 and 24 months (integroup). Immediately, in-office bleaching increased tooth sensitivity. The groups activated with HL required less application time with gel. Conclusion: All techniques and bleaching agents used were effective and demonstrated similar behaviors.

Probing the Enamel Topography After Acid Erosion by Scanning Electrochemical Microscopy

In this work, we present an investigation on the thickness of the eroded enamel layer in tooth samples after exposure to citric and hydrochloric acid by using Scanning Electrochemical Microscopy (SECM). Approaching curves with typical negative feedback behavior were obtained in enamel samples for evaluation of topographic changes. In a control experiment, SECM images showed no significant difference in the current monitored during the scan, implying that enamel demineralization did not occur in mineral water medium. Topographic SECM images obtained after contact with citric and hydrochloric acid for different periods of time showed a significant increase in the current relative to a previously protected surface, indicating the structural loss of enamel. The thickness of the enamel layer eroded after contact with hydrochloric acid was significantly higher when compared to the one obtained with citric acid. Hence, our results showed that the enamel acid erosion is a relatively fast process, which is strongly dependent on parameters such as pH, time, acid strength and acid concentration.

Xylitol concentrations in artificial saliva after application of different xylitol dental varnishes

Objective: The present study analyzed xylitol concentrations in artificial saliva over time after application of varnishes containing 10% and 20% xylitol. Material and Methods: Fifteen bovine enamel specimens (8x4 mm) were randomly allocated to 3 groups (n=5/group), according to the type of varnish used: 10% xylitol, 20% xylitol and no xylitol (control). After varnish application (4 mg), specimens were immersed in vials containing 500 mu L of artificial saliva. Saliva samples were collected in different times (1, 8, 12, 16, 24, 48 and 72 h) and xylitol concentrations were analyzed. Data were assessed by two-way repeated-measures ANOVA (p<0.05). Results: Colorimetric analysis was not able to detect xylitol in saliva samples of the control group. Salivary xylitol concentrations were significantly higher up to 8 h after application of the 20% xylitol varnish. Thereafter, the 10% xylitol varnish released larger amounts of that polyol in artificial saliva. Conclusions: Despite the results in short-term, sustained xylitol releases could be obtained when the 10% xylitol varnish was used. These varnishes seem to be viable alternatives to increase salivary xylitol levels, and therefore, should be clinically tested to confirm their effectiveness.

Dental anomalies in Richieri-Costa-Pereira syndrome

Objective. The objective of this study was to investigate the prevalence of dental anomalies in individuals with Richieri-Costa-Pereira syndrome. Study Design. A total of 13 individuals with Richieri-Costa-Pereira syndrome who were older than 8 years with at least 1 available panoramic radiograph were assessed. Dental anomalies were evaluated clinically and radiographically and classified as hyperplastic, hypoplastic, or heterotopic and as alterations of shape, number, position, and structure. Enamel alterations were classified by the DDE index. Results. All individuals exhibited anomalies, with predominance of hypoplastic disorders, mainly agenesis of mandibular incisors and second premolars and demarcated creamy-white enamel opacities primarily affecting the maxillary premolars. Conclusions. Individuals with Richieri-Costa Pereira syndrome exhibit high prevalence of tooth agenesis, especially mandibular incisors and premolars, as well as high frequency of enamel opacities. These findings are compatible with the mandibular cleft observed in all individuals and also reflect the hypoplastic characteristic of the syndrome. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:99-106)

Validation of fingernail fluoride concentration as a predictor of risk for dental fluorosis

The aim of this study was to validate the use of fingernail fluoride concentrations at ages 2-7 years as predictors of the risk for developing dental fluorosis in the permanent dentition. Fifty-six children of both genders (10-15 years of age) had their incisors and premolars examined for dental fluorosis using the Thylstrup-Fejerskov index. Fingernail fluoride concentrations were obtained from previous studies when children were 2-7 years of age. Data were analyzed by unpaired t test, ANOVA, and Fisher's exact test when the fingernail fluoride concentrations were dichotomized (<= 2 or > 2 mu g/g). Children with dental fluorosis had significantly higher fingernail fluoride concentrations than those without the condition, and the concentrations tended to increase with the severity of fluorosis (r(2) = 0.47, p < 0.0001). Using a fingernail fluoride concentration of 2 mu g/g at ages 2-7 years as a threshold, this biomarker had high sensitivity (0.84) and moderate specificity (0.53) as a predictor for dental fluorosis. The high positive predictive value indicates that fingernail fluoride concentrations should be useful in public health research, since it has the potential to identify around 80% of children at risk of developing dental fluorosis. Copyright (C) 2012 S. Karger AG, Basel

Combined effect of anterior malocclusion and inadequate lip coverage on dental trauma in primary teeth

Objectives: The main objective of this study was to investigate whether the interaction of malocclusion (open bite or increased overjet) combined with inadequate lip coverage strengthens its association with traumatic dental injury (TDI) in the primary teeth of preschool children compared to the presence of malocclusion alone. Subjects and methods: A cross-sectional survey was conducted with 376 children aged 3659 months who attended the National Day of Childrens Vaccination. Presence of TDI, tooth discoloration, and sinus tract were evaluated in the children. Variables associated with occlusion were also evaluated. A Poisson regression analysis was performed to verify the association between the explanatory variables and TDI as well as possible interactions among the variables. Then, the prevalence ratio was calculated. Results: The prevalence of TDI was 27.7%. The maxillary central incisor was the most affected tooth, without differences between the right and left sides. Boys had more dental trauma than girls (P = 0.04). The most common TDI was crown fracture restricted to the enamel (58.4%). Children with a combination of anterior open bite or increased overjet and inadequate lip coverage presented a higher prevalence of TDI than when the malocclusions were presented alone (P < 0.05). The same trends were observed when we included, in the final adjusted model, increased overjet instead of open bite. Conclusions: Anterior malocclusions of primary teeth such as increased overjet and anterior open bite are statistically significantly associated with dental trauma only when inadequate lip coverage is also present.

Enzyme replacement prevents enamel defects in hypophosphatasia mice

Hypophosphatasia (HPP) is the inborn error of metabolism characterized by deficiency of alkaline phosphatase activity, leading to rickets or osteomalacia and to dental defects. HPP occurs from loss-of-function mutations within the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNAP). TNAP knockout (Alpl-/-, aka Akp2-/-) mice closely phenocopy infantile HPP, including the rickets, vitamin B6-responsive seizures, improper dentin mineralization, and lack of acellular cementum. Here, we report that lack of TNAP in Alpl-/- mice also causes severe enamel defects, which are preventable by enzyme replacement with mineral-targeted TNAP (ENB-0040). Immunohistochemistry was used to map the spatiotemporal expression of TNAP in the tissues of the developing enamel organ of healthy mouse molars and incisors. We found strong, stage-specific expression of TNAP in ameloblasts. In the Alpl-/- mice, histological, mu CT, and scanning electron microscopy analysis showed reduced mineralization and disrupted organization of the rods and inter-rod structures in enamel of both the molars and incisors. All of these abnormalities were prevented in mice receiving from birth daily subcutaneous injections of mineral-targeting, human TNAP at 8.2?mg/kg/day for up to 44 days. These data reveal an important role for TNAP in enamel mineralization and demonstrate the efficacy of mineral-targeted TNAP to prevent enamel defects in HPP. (C) 2012 American Society for Bone and Mineral Research.

Temperature rise during Er:YAG cavity preparation of primary enamel

This study aimed to assess in vitro thermal alterations taking place during the Er:YAG laser cavity preparation of primary tooth enamel at different energies and pulse repetition rates. Forty healthy human primary molars were bisected in a mesio-distal direction, thus providing 80 fragments. Two small orifices were made on the dentin surface to which type K thermocouples were attached. The fragments were individually fixed with wax in a cylindrical PlexiglassA (R) abutment and randomly assigned to eight groups, according to the laser parameters (n = 10): G1 -aEuro parts per thousand 250 mJ/ 3 Hz, G2 -aEuro parts per thousand 250 mJ/ 4 Hz, G3 -aEuro parts per thousand 250 mJ/ 6 Hz, G4 -aEuro parts per thousand 250 mJ/10 Hz, G5 -aEuro parts per thousand 250 mJ/ 15 Hz, G6 -aEuro parts per thousand 300 mJ/ 3 Hz, G7 -aEuro parts per thousand 300 mJ/ 4 Hz and G8 -aEuro parts per thousand 300 mJ/ 6 Hz. An area of 4 mm(2) was delimited. Cavities were done (2 mm long x 2 mm wide x 1 mm thick) using non-contact (12 mm) and focused mode. Temperature values were registered from the start of laser irradiation until the end of cavity preparation. Data were analyzed by one-way ANOVA and Tukey test (p a parts per thousand currency signaEuro parts per thousand 0.05). Groups G1, G2, G6, and G7 were statistically similar and furnished the lowest mean values of temperature rise. The set 250 mJ/10 and 15 Hz yielded the highest temperature values. The sets 250 and 300 mJ and 6 Hz provided temperatures with mean values below the acceptable critical value, suggesting that these parameters ablate the primary tooth enamel. Moreover, the temperature elevation was directly related to the increase in the employed pulse repetition rates. In addition, there was no direct correlation between temperature rise and energy density. Therefore, it is important to use a lower pulse frequency, such as 300 mJ and 6 Hz, during cavity preparation in pediatric patients.

Systemically alendronate was incorporated into dental tissues but did not cause morphological or mechanical changes in rats teeth

This study evaluated the effect of the systemic use of sodium alendronate in rats in vivo. Forty-five Wistar rats aged 36 to 42 days and weighing 200 to 230 g were randomly assigned to a control group (n = 20), which received distilled water, and an experimental group (n = 25), which received 2 weekly doses of 1 mg/kg of chemically pure sodium alendronate. The animals were killed after 60 days of treatment. The tibias were removed for analysis of bone mineral density by dual-energy X-ray absorptiometry (DXA). Then, the maxillary incisors were extracted for analysis of the mineralized dental tissues using fluorescence spectroscopy (FS), scanning electron microscopy (SEM), bright field microscopy (BFM), and cross-sectional microhardness (CSMH) testing. DXA and CSMH data were subjected to statistical analysis by Kruskal-Wallis test (5% significance level). The experimental group presented higher bone mineral density than the control group by DXA. FS analysis revealed presence of alendronate in the mineralized dental tissues of the specimens of the experimental group. Significant morphological differences were not found by SEM and BFM. Enamel and dentin (100 and 300 mu m from the dentinoenamel junction) CSMH data did not show significant difference between the control and experimental groups. Based on the obtained results, we conclude that while alendronate increased the bone mineral density and was incorporated into the mineralized dental tissues it did not cause significant alterations in the morphology and microhardness of rat incisor enamel and dentin. Microsc. Res. Tech. 75:12651271, 2012. (C) 2012 Wiley Periodicals, Inc.

Effect of dental tissue conditioners and matrix metalloproteinase inhibitors on type I collagen microstructure analyzed by Fourier transform infrared spectroscopy

This study aimed to evaluate the chemical interaction of collagen with some substances usually applied in dental treatments to increase the durability of adhesive restorations to dentin. Initially, the similarity between human dentin collagen and type I collagen obtained from commercial bovine membranes of Achilles deep tendon was compared by the Attenuated Total Reflectance technique of Fourier Transform Infrared (ATR-FTIR) spectroscopy. Finally, the effects of application of 35% phosphoric acid, 0.1M ethylenediaminetetraacetic acid (EDTA), 2% chlorhexidine, and 6.5% proanthocyanidin solution on microstructure of collagen and in the integrity of its triple helix were also evaluated by ATR-FTIR. It was observed that the commercial type I collagen can be used as an efficient substitute for demineralized human dentin in studies that use spectroscopy analysis. The 35% phosphoric acid significantly altered the organic content of amides, proline and hydroxyproline of type I collagen. The surface treatment with 0.1M EDTA, 2% chlorhexidine, or 6.5% proanthocyanidin did not promote deleterious structural changes to the collagen triple helix. The application of 6.5% proanthocyanidin on collagen promoted hydrogen bond formation. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.

Implant Osseointegration in Circumferential Bone Defects Treated with Latex-Derived Proteins or Autogenous Bone in Dog's Mandible

Background: In sites with diminished bone volume, the osseointegration of dental implants can be compromised. Innovative biomaterials have been developed to aid successful osseointegration outcomes. Purpose: The aim of this study was to evaluate the osteogenic potential of angiogenic latex proteins for improved bone formation and osseointegration of dental implants. Materials and Methods: Ten dogs were submitted to bilateral circumferential defects (5.0 x 6.3 mm) in the mandible. Dental implant (3.3 x 10.0 mm, TiUnite MK3 (TM), Nobel Biocare AB, Goteborg, Sweden) was installed in the center of the defects. The gap was filled either with coagulum (Cg), autogenous bone graft (BG), or latex angiogenic proteins pool (LPP). Five animals were sacrificed after 4 weeks and 12 weeks, respectively. Implant stability was evaluated using resonance frequency analysis (Osstell Mentor T, Osstell AB, Goteborg, Sweden), and bone formation was analyzed by histological and histometric analysis. Results: LPP showed bone regeneration similar to BG and Cg at 4 weeks and 12 weeks, respectively (p >= 3.05). Bone formation, osseointegration, and implant stability improved significantly from 4 to 12 weeks (p <= 2.05). Conclusion: Based on methodological limitations of this study, Cg alone delivers higher bone formation in the defect as compared with BG at 12 weeks; compared with Cg and BG, the treatment with LPP exhibits no advantage in terms of osteogenic potential in this experimental model, although overall osseointegration was not affected by the treatments employed in this study.

The erosion and abrasion-inhibiting effect of TiF4 and NaF varnishes and solutions on enamel in vitro

Objective. Previous in vitro study has shown that TiF(4) varnish might reduce enamel erosion. No data regarding the effect of this experimental varnish on enamel erosion plus abrasion, however, are available so far. Thus, this in vitro study aimed to analyse the effect of TiF4 compared with NaF varnishes and solutions, to protect against enamel erosion with or without abrasion. Methods. Enamel specimens were pre-treated with experimental-TiF4 (2.45% F), experimentalNaF (2.45% F), NaF-Duraphat (2.26% F), and placebo varnishes; NaF (2.26% F) and TiF4 (2.45% F) solutions. Controls remained untreated. The erosive challenge was performed using a soft drink (pH 2.6) 4 u 90 s / day (ERO) and the toothbrushing abrasion (ERO+ ABR) 2 u 10 s / day, for 5 days. Between the challenges, the specimens were exposed to artificial saliva. Enamel loss was measured profilometrically (lm). Results. Kruskal-Wallis / Dunn tests showed that all fluoridated varnishes (TiF4-ERO: 0.53 +/- 0.20, ERO+ ABR: 0.65 +/- 0.19/ NaF-ERO: 0.94 +/- 0.18, ERO+ ABR: 1.74 +/- 0.37 / Duraphat-ERO: 1.00 +/- 0.37, ERO+ ABR: 1.72 +/- 0.58) were able to significantly reduce enamel loss when compared with placebo varnish (ERO: 3.45 +/- 0.41 / ERO+ ABR: 3.20 +/- 0.66) (P < 0.0001). Placebo varnish, control (ERO: 2.68 +/- 0.53 / ERO+ ABR: 3.01 +/- 0.34), and fluoridated (NaF-ERO: 2.84 +/- 0.09 / ERO+ ABR: 2.40 +/- 0.21 / TiF4-ERO: 3.55 +/- 0.59 / ERO+ ABR: 4.10 +/- 0.38) solutions did not significantly differ from each other. Conclusion. Based on the results, it can be concluded that the TiF4 varnish seems to be a promising treatment to reduce enamel loss under mild erosive and abrasive conditions in vitro.

Impact of experimental Nano-HAP pastes on bovine enamel and dentin submitted to a pH cycling model

This in vitro study evaluated the preventive potential of experimental pastes containing 10% and 20% hydroxyapatite nanoparticles (Nano-HAP), with or without fluoride, on dental demineralization. Bovine enamel (n=15) and root dentin (n=15) specimens were divided into 9 groups according to their surface hardness: control (without treatment), 20 Nanop paste (20% HAP), 20 Nanop paste plus (20% HAP + 0.2% NaF), 10 Nanop paste (10% HAP), 10 Nanop paste plus (10% HAP + 0.2% NaF), placebo paste (without fluoride and HAP), fluoride paste (0.2% NaF), MI paste (CPP-ACP, casein phosphopeptide-amorphous calcium phosphate), and MI paste plus (CPP-ACP + 0.2% NaF). Both MI pastes were included as commercial control products containing calcium phosphate. The specimens were treated with the pastes twice a day (1 min), before and after demineralization. The specimens were subjected to a pH-cycling model (demineralization–6-8 h/ remineralization-16-18 h a day) for 7 days. The dental subsurface demineralization was analyzed using cross-sectional hardness (kgf/mm 2 , depth 10-220 µm). Data were tested using repeated-measures two-way ANOVA and Bonferroni's test (p<0.05). The only treatment able to reduce the loss of enamel and dentin subsurface hardness was fluoride paste (0.2% NaF), which differed significantly from the control at 30- and 50-µm depth (p<0.0001). The other treatments were not different from each other or compared with the control. The experimental Nanop pastes, regardless of the addition of fluoride, were unable to reduce dental demineralization in vitro.

In situ effect of chewing gum containing CPP–ACP on the mineral precipitation of eroded bovine enamel

Objectives: Stimulation of salivary flow is considered a preventive strategy for dental erosion. Alternatively, products containing calcium phosphate, such as a complex of casein phosphopeptide–amorphous calcium phosphate (CPP–ACP), have also been tested against dental erosion. Therefore, this in situ study analyzed the effect of chewing gum containing CPP–ACP on the mineral precipitation of initial bovine enamel erosion lesions. Methods: Twelve healthy adult subjects wore palatal appliances with two eroded bovine enamel samples. The erosion lesions were produced by immersion in 0.1% citric acid (pH 2.5) for 7 min. During three experimental crossover in situ phases (1 day each), the subjects chewed a type of gum, 3 times for 30 min, in each phase: with CPP–ACP (trident total), without CPP–ACP (trident), and no chewing gum (control). The Knoop surface microhardness was measured at baseline, after erosion in vitro and the mineral precipitation in situ. The differences in the degree of mineral precipitation were analyzed using repeated measures (RM-) ANOVA and post hoc Tukey’s test ( p < 0.05). Results: Significant differences were found among the remineralizing treatments ( p < 0.0001). Chewing gum (19% of microhardness recovery) improved the mineral precipitation compared to control (10%) and the addition of CPP–ACP into the gum promoted the best mineral precipitation effect (30%). Conclusions: Under this protocol, CPP–ACP chewing gum improved the mineral precipitation of eroded enamel. Clinical significance: Since the prevalence of dental erosion is steadily increasing, CPP–ACP chewing gum might be an important strategy to reduce th eprogression of initial erosion lesions.