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.

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.

Heat-killed Enterococcus faecalis Alters Nitric Oxide and CXCL12 Production but not CXCL8 and CCL3 Production by Cultured Human Dental Pulp Fibroblasts

Introduction: Fibroblasts are the most abundant cells in dental pulp. To investigate their capacity to produce the chemokines CCL3, CXCL8, and CXCL12 as well as nitric oxide (NO), we evaluated the production of these mediators in supernatants of cultured human dental pulp fibroblasts (HDPF) stimulated by heat-killed Enterococcus faecalis (HKEF). Methods: Primary cultures of HDPF were stimulated with medium alone or HKEF (1:1, 10:1, or 100:1 bacteria:fibroblast) for 1, 6, and 24 hours. Chemokines and NO were assessed through enzyme-linked immunosorbent assay and Griess reaction, respectively. Statistical analysis was performed by using analysis of variance and Tukey post test. Results: CCL3 was not detected, whereas constitutive CXCL8 was not affected. Production of CXCL12 was increased at 1 and 6 hours, and NO was increased at the concentration of 1:1 bacteria:fibroblast at 24 hours. Viability and proliferation assays did not reveal cell number differences. Conclusions: These findings demonstrate that heat-killed E. faecalis is able to increase production of CXCL12 and NO by HDPF. (J Endod 2010;36:91-94)

Dental caries status and salivary properties of asthmatic children and adolescents

Aims. This study aimed to investigate the dental caries status and salivary properties in 3- to 15-year-old children/adolescents. Methods. The sample was split in two groups: asthma group (AG), composed of 65 patients who attended Public Health Service; asthma-free group (AFG), composed of 65 nonasthmatic children/adolescents recruited in two public schools. Stimulated salivary samples were collected for 3 min. Buffering capacity and pH were ascertained in each salivary sample. A single trained and calibrated examiner (kappa = 0.98) performed the dental caries examination according to WHO criteria. Results. The AFG showed salivary flow rate (1.10 +/- 0.63 mL/min) higher (P = 0.002) than AG (0.80 +/- 0.50 mL/min). An inverse relationship was observed between asthma severity and salivary flow rate (Phi coefficient, r phi: 0.79, P = 0.0001). Children with moderate or severe asthma showed an increased risk for reduced salivary flow rate (OR: 17.15, P < 0.001). No association was observed between drug use frequency (P > 0.05) and drug type (P > 0.05) with salivary flow rate. Buffering capacity was similar in both groups. No significant differences were encountered in dental caries experience between AFG and AG groups. Conclusions. Although asthma can cause reduction in flow rate, the illness did not seem to influence dental caries experience in children with access to proper dental care.

Chronic maxillary sinusitis associated with dental impression material

A 62-year-old man was referred for routine treatment of hyperplasia of the mucosa in the anterior lower jaw. An oroantral fistula was detected in the right superior alveolar ridge. The patient had no complaints. Plain radiographs showed a radiopaque foreign body in the posterior region associated with opacification of the maxillary sinus. Computed tomography showed the same hyperdense foreign body located in the posterior lower part of the sinus and an abnormal soft tissue mass in the entire right maxillary sinus. When asked about sinusitis, the patient mentioned occasional episodes of pus taste and intermittent crises of headache lasting for one week. The patient has been edentulous for 20 years. Sinus debridement was performed and the oroantral fistula was closed. The clinical suspicion of the presence of zinc oxide-eugenol paste was confirmed by microscopical and chemical analysis. After 6 months of follow-up, the fistula continued to be closed and sinusitis did not recur. This clinical case of maxillary chronic sinusitis illustrates a different odontogenic origin.

Dental caries in adolescents from public schools in Maputo, Mozambique

Aim: To assess dental caries prevalence in adolescents at urban and sub-urban areas of Maputo-City, Mozambique and to identify its relationship with dental fluorosis, dental plaque, nutritional status, frequency of sugar consumption and the concentration of fluoride in public water supply. Methods: Subjects (n=601) were randomly selected from five urban schools and five sub-urban schools. Clinical examinations were performed under standardised conditions by a trained examiner using DMFT index, SiC index, fluorosis index, PHP, BMI, a sugar consumption questionnaire and water supply analysis. The bivariate analysis and Pearson correlation was used (p<0.05). Results: The mean (DMFT) was 0.9 (+/- 1.65 SD). Children in urban schools showed less dental caries (0.8 +/- 1.49SD) than children in sub-urban schools (1.1 +/- 1.80SD, p=0.03). Only 8.15% had very mild to moderate fluorosis but most presented poor oral hygiene. Cases of malnutrition were found in more sub-urban schools (n = 109; 36.22%) than in urban schools (n = 66; 22.00%) (p=0.03). The frequency of sugar consumption was higher among urban children compared to suburban schools (p<0.00). The level of fluoride in water consumption in urban schools was 0.4 ppmF, above the level of fluoride in sub-urban schools, 0.2 ppmF. Conclusion: Dental caries should not be considered a major oral health problem in Maputo at the moment. However the data suggest the implementation of a population strategy to reduce dental caries rates, in children of both urban and sub-urban areas, in Maputo.

Agenesis of maxillary lateral incisors and associated dental anomalies

Introduction: The objectives of this study were to evaluate the prevalence of dental anomalies in patients with agenesis of maxillary lateral incisors and to compare the findings with the prevalence of these anomalies in the general population. Methods: A sample of 126 patients, aged 7 to 35 years, with agenesis of at least 1 maxillary lateral incisor was selected. Panoramic and periapical radiographs and dental casts were used to analyze other associated dental anomalies, including agenesis of other permanent teeth, ectopia of unerupted permanent teeth, microdontia of maxillary lateral incisors, and supernumerary teeth. The occurrence of these anomalies was compared with prevalence data previously reported for the general population. Statistical testing was performed with the chi-square test (P<0.05) and the odds ratio. Results: Patients with maxillary lateral incisor agenesis had a significantly increased prevalence rate of permanent tooth agenesis (18.2%), excluding the third molars. The occurrence of third-molar agenesis in a subgroup aged 14 years or older (n = 76) was 35.5%. The frequencies of maxillary second premolar agenesis (10.3%), mandibular second premolar agenesis (7.9%), microdontia of maxillary lateral incisors (38.8%), and distoangulation of mandibular second premolars (3.9%) were significantly increased in our sample compared with the general population. In a subgroup of patients aged 10 years or older (n = 115), the prevalence of palatally displaced canines was elevated (5.2%). The prevalences of mesioangulation of mandibular second molars and supernumerary teeth were not higher in the sample. Conclusions: Permanent tooth agenesis, maxillary lateral incisor microdontia, palatally displaced canines, and distoangulation of mandibular second premolars are frequently associated with maxillary lateral incisor agenesis, providing additional evidence of a genetic interrelationship in the causes of these dental anomalies. (Am J Orthod Dentofacial Orthop 2010;137:732.e1-732.e6)

Influence of Dental Plaque on Human Enamel Erosion: In Situ/Ex Vivo Study

Purpose: The objective of the present in situ study was to evaluate the influence of dental plaque on human enamel erosion. Materials and Methods: Thirteen volunteers wore acrylic palatal devices with four enamel specimens that were prepared from freshly extracted impacted human third permanent molars (4 x 4 mm), randomly selected and distributed into two vertical rows, corresponding to the following groups: GI, erosion of dental plaque-free samples, and GII, erosion of dental plaque-covered samples. For the formation of dental plaque, the specimens were placed 1 mm below the level of the appliance and covered with a plastic mesh to allow the accumulation of dental plaque. The palatal device was continuously worn by the volunteers for 14 consecutive days and then immersed in a soft drink (Coca-Cola (R), 150 ml) for 5 min, three times a day. Half of the surfaces of specimens were coated with nail varnish for profilometry tests. The study variables included the depth of enamel surface wear (profilometer, vertical ranges in pm) and the percentage of superficial microhardness change (%SMHC). Data were analysed using the t test (P < 0.05). Results: The %SMHC and depth of enamel surface wear were significantly higher for GI (-87.82% +/- 3.66 and 4.70 mu m +/- 1.65) than for GII (-13.79% +/- 4.22 and 0.14 mu m +/- 0.03). Conclusions: It was concluded that the dental plaque formed in situ was able to protect the enamel surface against erosion by a cola soft drink, thus reducing the depth of enamel surface wear and the %SMHC.

Risk factors for dental erosion in a group of 12- and 16-year-old Brazilian schoolchildren

Background. Dental erosion is a multifactorial disease and is associated with dietary habits in infancy and adolescence. Aim. To investigate possible associations among dental erosion and diet, medical history and lifestyle habits in Brazilian schoolchildren. Design. The sample consisted of a random single centre cluster of 414 adolescents (12- and 16-years old) of both genders from private and public schools in Bauru (Brazil). The O`Brien [Children`s Dental Health in the United Kingdom, 1993 (1994) HMSO, London] index was used for dental erosion assessment. Data on medical history, rate and frequency of food and drinks consumption, and lifestyle habits were collected by a self-reported questionnaire. Odds ratios with 95% confidence intervals were used to assess the univariate relationships between variables. Analysis of questionnaire items was performed by multiple logistic regression analysis. The statistical significance level was set at 5%. Results. The erosion present group comprised 83 subjects and the erosion absent group 331. There were no statistically significant correlations among dental erosion and the consumption of food and drinks, medical history, or lifestyle habits. Conclusion. The results indicate that there was no correlation between dental erosion and the risk factors analysed among adolescents in Bauru/Brazil and further investigations are necessary to clarify the multifactorial etiology of this condition.

The Effect of Framework Design on Fracture Resistance of Metal-Ceramic Implant-Supported Single Crowns

This study evaluated the effect of framework design on the fracture resistance of metal-ceramic implant-supported crowns. Screw-retained molar crowns with a screw access hole composed of metal or porcelain were compared to a cement-retained crown (control). For each group (n = 10), five crowns were subjected to dynamic loading (1,200,000 x 100 N x 2 Hz at 37 degrees C). Afterward, all specimens were loaded to failure using a universal testing machine. Significant differences could be established between the cement-and screw-retained groups (P <= .05), but no difference was found between the screw-retained groups and the specimens subjected to dynamic loading. Occlusal discontinuity of screw-retained crowns affects their resistance, and the metallic support on the screw access hole did not reinforce the crowns. Int J Prosthodont 2010;23:350-352.

Finite-Element Analysis of Stress on Dental Implant Prosthesis

Background: Understanding how clinical variables affect stress distribution facilitates optimal prosthesis design and fabrication and may lead to a decrease in mechanical failures as well as improve implant longevity. Purpose: In this study, the many clinical variations present in implant-supported prosthesis were analyzed by 3-D finite element method. Materials and Method: A geometrical model representing the anterior segment of a human mandible treated with 5 implants supporting a framework was created to perform the tests. The variables introduced in the computer model were cantilever length, elastic modulus of cancellous bone, abutment length, implant length, and framework alloy (AgPd or CoCr). The computer was programmed with physical properties of the materials as derived from the literature, and a 100N vertical load was used to simulate the occlusal force. Images with the fringes of stress were obtained and the maximum stress at each site was plotted in graphs for comparison. Results: Stresses clustered at the elements closest to the loading point. Stress increase was found to be proportional to the increase in cantilever length and inversely proportional to the increase in the elastic modulus of cancellous bone. Increasing the abutment length resulted in a decrease of stress on implants and framework. Stress decrease could not be demonstrated with implants longer than 13 mm. A stiffer framework may allow better stress distribution. Conclusion: The relative physical properties of the many materials involved in an implant-supported prosthesis system affect the way stresses are distributed.

Reliability and Failure Modes of Implant-Supported Y-TZP and MCR Three-Unit Bridges

Purpose: Chipping within veneering porcelain has resulted in high clinical failure rates for implant-supported zirconia (yttria-tetragonal zirconia polycrystals [Y-TZP]) bridges. This study evaluated the reliability and failure modes of mouth-motion step-stress fatigued implant-supported Y-TZP versus palladium-silver alloy (PdAg) three-unit bridges. Materials and Methods: Implant-abutment replicas were embedded in polymethylmethacrylate resin. Y-TZP and PdAg frameworks, of similar design (n = 21 each), were fabricated, veneered, cemented (n = 3 each), and Hertzian contact-tested to obtain ultimate failure load. In each framework group, 18 specimens were distributed across three step-stress profiles and mouth-motion cyclically loaded according to the profile on the lingual slope of the buccal cusp of the pontic. Results: PdAg failures included competing flexural cracking at abutment and/or connector area and chipping, whereas Y-TZP presented predominantly cohesive failure within veneering porcelain. Including all failure modes, the reliability (two-sided at 90% confidence intervals) for a ""mission"" of 50,000 and 100,000 cycles at 300 N load was determined (Alta Pro, Reliasoft, Tucson, AZ, USA). No difference in reliability was observed between groups for a mission of 50,000. Reliability remained unchanged for a mission of 100,000 for PdAg, but significantly decreased for Y-TZP. Conclusions: Higher reliability was found for PdAg for a mission of 100,000 cycles at 300 N. Failure modes differed between materials.

A comparison of the dental health of Brazilian and Canadian independently living elderly

Objective: To compare the dental status of Brazilian and Canadian elderly populations with respect to socioeconomic and quality of life factors. Materials and methods: A total of 496 adults aged 60-75 years, having four or more teeth, and physically and cognitively suitable for a clinical oral examination were included. Subjects answered questions concerning their lifestyle and completed the Geriatric Oral Health Assessment Index (GOHAI) questionnaire. Results: In all populations, the majority were females, aged between 60 and 65 years and married. Although the Canadian New Immigrant population had lower mean income, they had more remaining teeth (23.04 +/- 6.1), more functional teeth (sound and restored teeth) (14.92 +/- 5.7), more sound teeth (15.40 +/- 7.6), but more carious teeth (2.97 +/- 3.0). The Brazilian population had higher numbers of restored teeth (12.26 +/- 6.8) and fewer remaining teeth (17.80 +/- 7.6). In all populations, females, married and younger (60-65 years old) adults were more likely to retain 20 or more teeth. The mean GOHAI scores were similar for Canadians (40.55 +/- 5.7) and Canadian New Immigrants (39.28 +/- 6.5), but were higher than that among Brazilians (31.97 +/- 8.9). Conclusions: The numbers of remaining teeth were related to greater education and higher income status for Brazilian and Canadian populations. However, Canadian New Immigrants with lower income and education retained more teeth than the other populations.

Evaluation of the presence or absence of papilla between tooth and implant

Objective: The purpose of this study was to evaluate the papilla level adjacent to single-tooth implants in the maxillary anterior region in individuals with cleft lip, alveolus, and palate to verify whether there is correlation among the vertical distance, horizontal distance, dental/prosthetic crown shape, and periodontal/peri-implant biotype with the presence of interproximal papilla. Design: Cross-sectional. Setting: Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo (HRAC/USP). Patients: 77 papillae in 40 patients. Interventions: The periodontal/peri-implant biotype was clinically evaluated and characterized as thin or thick. Intraoral photographs were used to evaluate the presence or absence of papilla. Main Outcome Measures: Classification in scores (0 to 3) and determination of length (CL) and width (CW) of crowns adjacent to papillae. The CW/CL ratio was calculated for each crown in order to characterize it as square-shaped or triangular-shaped. The vertical and horizontal distances were obtained by radiographic evaluation. Results: The correlations between vertical distance and papilla score and horizontal distance and papilla score were statistically significant (p= .02 and p = .01). There was no significant difference between crown shape and periodontal/peri-implant biotype in distinct correlations with the papilla score (p = .41 and p = .07). Conclusion: The results suggest that the vertical and horizontal distances may have independent or combined relationship with the existence of interproximal papilla; the periodontal/peri-implant biotype (phenotype) was not correlated with the presence or absence of papilla, as well as the shape of the dental/prosthetic crown.

Survival of Dental Implants in the Cleft Area-A Retrospective Study

Objective To evaluate the survival rate of dental implants placed in the cleft area Design Retrospective study Setting Hospital for Rehabilitation of Craniofacial Anomalies, Brazil Institutional Tertiary Healthcare Center Patients 120 patients who received dental implants in the grafted cleft area in the years 1999 to 2005 Interventions Clinical data were evaluated from the records of 120 patients according to the following criteria placement grafted, cleft area, and age at surgery, age at placement of dental implants, site and dimension of implants, interval between placement of implants and the last clinical follow-up, and interval between placement and removal or indication for removal of implants Main Outcome Measures Percentage of survival rate of implants Results Mean age at placement of the bone graft was 17 6 years and 21 years at placement of implants A total of 123 cleft areas received secondary bone graft and bone graft to install implants (regraft) The mean survival rate was 34 months since placement of the implant to the last clinical follow-up and 26 months since placement of the prosthesis Seven dental implants were removed The survival rate since placement to the last clinical follow-up was 94 3% Conclusion Rehabilitation of the cleft area with dental implants is a viable and secure alternative, with good prognosis