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Xerostomia, known as dry mouth, is caused by decreased salivary flow. Treatment with lubricating oral rinses provides temporary relief of dry mouth discomfort; however, it remains unclear how their composition affects mineralized dental tissues. Therefore, the objective of this study was to analyze the effects of common components in xerostomia oral rinses on biomimetic apatite with varying carbonate contents. Carbonated apatite was synthesized and exposed to one of the following solutions for 72 hours at varying pHs: water-based, phosphorus-containing (PBS), mucin-like containing (MLC), or fluoride-containing (FC) solutions. Post-exposure results indicated that apatite mass decreased irrespective of pH and solution composition, while solution buffering was pH dependent. Raman and X-ray diffraction analysis showed that the addition of phosphorus, mucin-like molecules, and fluoride in solution decreases mineral carbonate levels and changed the lattice spacing and crystallinity of bioapatite, indicative of dissolution/recrystallization processes. The mineral recrystallized into a less-carbonated apatite in the PBS and MLC solutions, and into fluorapatite in FC. Tap water did not affect the apatite lattice structure suggesting formation of a labile carbonate surface layer on apatite. These results reveal that solution composition can have varied and complex effects on dental mineral beyond dissolution, which can have long term consequences on mineral solubility and mechanics. Therefore, clinicians should consider these factors when advising treatments for xerostomia patients.

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BACKGROUND: Sjögren syndrome (SS) is associated with xerostomia and xerophthalmia. Pilocarpine has been shown to stimulate the secretion of saliva. OBJECTIVES: To investigate and compare the efficacy of pilocarpine and artificial saliva as symptomatic treatments for xerostomia and xerophthalmia in patients with SS. METHODS: A double-blind randomized controlled study was performed. A total of 72 patients with SS were assigned randomly to receive 10 drops of pilocarpine (5 mg) or 10 drops of artificial saliva orally, three times daily for 12 weeks. Whole saliva and tear flow were evaluated at baseline and periodically throughout the study to provide a global assessment of dryness and to report any adverse effects. RESULTS: Patients receiving pilocarpine had a statistically significant improvement in their salivary flow (P < 0·001), lacrimal flow (P < 0·001) and their subjective global assessment (P < 0·001), compared with patients who received artificial saliva. The most common side-effects were sialorrhoea and nausea. CONCLUSIONS: Pilocarpine is more effective than artificial saliva for enhancing salivary and lacrimal secretion in patients with SS. This is the first study to compare the efficacy of pilocarpine and artificial saliva for the treatment of xerostomia and xerophthalmia in SS.

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AIM: To evaluate the changes of static and kinetic frictional forces between the brackets and wires following exposure to a soft drink, acidic food ingredient, and acidulated fluoride prophylactic agents. MATERIALS AND METHODS: Two types of Roth prescription mandibular incisor brackets were used: 3M Unitek Victory stainless steel (SS) brackets (n = 40) and Transcend 6000 polycrystalline alumina (PCA) brackets (n = 40) as well as eighty 0.019 × 0.025" dimension ortho technology SS wires of 50 mm length each. Subsequently, brackets tied with SS wires divided into eight subgroups (n = 10) and were immersed in vinegar (pH = 3.5 ± 0.5), Pepsi ® (pH = 2.46), Colgate Phos-Flur mouth rinse (pH = 5.1), and artificial saliva (control group pH = 7) for 24 h. Changes in surface morphology under scanning electron microscope ×1000, surface roughness (Ra) with surface profilometer (single bracket and single wire from each subgroup), and frictional resistance using universal testing machine were evaluated. RESULTS: Highest mean (standard deviation) static frictional force of 2.65 (0.25) N was recorded in Pepsi ® followed by 2.57 (0.25) N, 2.40 (0.22) N, and 2.36 (0.17) N for Vinegar, Colgate Phos-Flur mouth rinse, and artificial saliva groups, respectively. In a similar order, lesser mean kinetic frictional forces obtained. PCA brackets revealed more surface deterioration and higher frictional force values than SS brackets. A significant positive correlation was observed between frictional forces and bracket slot roughness (r = 0.861 and 0.802, respectively, for static and kinetic frictional forces, p < 0.001 for both) and wire roughness (r = 0.243 and 0.242, respectively, for static and kinetic frictional forces, p < 0.05 for both). CONCLUSIONS: Findings may have long-term implications when acidic food substances are used during fixed orthodontic treatment. Further, in vivo studies are required to analyze the clinical effect of acidic mediums in the oral environment during orthodontic treatment.

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STATEMENT OF PROBLEM: The passive film on the surface of titanium can be destroyed by immersion in a fluoridated acidic medium. Coating with titanium nitride (TiN) may improve the corrosion resistance of titanium. PURPOSE: The purpose of this in vitro study was to investigate the effect of duplex treatment with plasma nitriding and TiN coating on the corrosion resistance of cast titanium. MATERIAL AND METHODS: Cast titanium was treated with plasma nitriding and TiN coating. The corrosion resistance of the duplex-treated titanium in fluoride-containing artificial saliva was then investigated through electrochemical and immersion tests. The corroded surface was characterized by scanning electron microscopy (SEM) with energy-dispersive spectroscopy surface scan analysis. The data were analyzed using ANOVA (α=.05) RESULTS: Duplex treatment generated a dense and uniform TiN film with a thickness of 4.5 µm. Compared with untreated titanium, the duplex-treated titanium displayed higher corrosion potential (Ecorr) values (P<.001) and lower corrosion current density (Icorr) values (P<.001). SEM results showed that the surface of untreated titanium was more heavily corroded than that of duplex-treated titanium. Surface scan analysis of duplex-treated titanium that had been immersed in artificial saliva containing 2 g/L fluoride revealed fluorine on the titanium surface, whereas fluorine was not observed on the surface of untreated titanium after immersion in fluoride-containing artificial saliva. The concentration of titanium ions released from the treated titanium was less than the amount released from untreated titanium (P<.001). CONCLUSIONS: Duplex treatment by plasma nitriding and TiN coating significantly improved the corrosion resistance of cast titanium in a fluoride-containing environment.

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STATEMENT OF PROBLEM: The mechanical properties of new titanium alloys with an elastic modulus closest to cortical bone have been studied. However, potentially damaging conditions experienced in the oral cavity, such as fluoride ions, can initiate a localized or crevice process of corrosive degradation in the alloy surfaces. PURPOSE: The purpose of this in vitro study was to evaluate the effects of long-term immersion in artificial saliva or in fluoride solution on mean roughness (Ra), Vickers hardness, and topography of the new titanium alloy Ti-35Nb-7Zr-5Ta (TNZT) compared with those of cp Ti and Ti-6Al-4V (TAV). MATERIAL AND METHODS: Disks (N=210) were divided into cp Ti, TAV, and TNZT and subdivided according to the following treatments: no immersion (N(-), control), immersion in artificial saliva (S), and immersion in fluoride (F) during periods equivalent to 5, 10, 15, and 20 years. The Ra and Vickers hardness were measured with a profilometer and a hardness tester. The topography was analyzed by scanning electronic microscopy. Data were compared using the Kruskal-Wallis and Dunn tests (α=.05). RESULTS: Values of Ra and hardness were significantly different among the metals (Ra: TAV

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BACKGROUND: Metals react chemically/electrochemically in electrolytic solutions, such as that present in the oral cavity, which leads to corrosion of metal dental implants. Corrosion can increase the failure rate of dental implants. PURPOSE: This study evaluated the corrosion behavior of nicotine on Ti-6Al-4V under physiological conditions. It was hypothesized that nicotine in artificial saliva would have an adverse effect on the corrosion of Ti-6Al-4V. METHODS: Ti-6Al-4V discs were electrochemically analyzed using a three-electrode electrochemical cell. The disks were immersed in an electrolytic artificial saliva with varying pH (3.0 and 6.5) and nicotine concentration (control, 1 mg/mL, 5 mg/mL, and 20 mg/mL). Open circuit potential, cyclic polarization, and electrochemical impedance spectroscopy (EIS) tests were conducted. RESULTS: Electrochemical parameters indicated that the presence of nicotine significantly reduced (p < .05) the corrosion rate. For example, there was a decrease in corrosion current density from 2.94 × 10(-3) µA/cm(2) to 1.43 × 10(-3) µA/cm(2) in control compared with 20 mg/mL nicotine at pH 6.5. EIS results exhibited an unexpected trend in that the presence of nicotine decreased polarization resistance. This suggested a decrease in passive film growth. CONCLUSIONS: At certain concentrations, nicotine inhibits local corrosion; however, it also prevents the formation of a protective oxide film.

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O objetivo deste estudo foi investigar o efeito degradante da saliva artificial e do ácido lático sobre diferentes cimentos resinosos fotopolimerizáveis e avaliar os efeitos citotóxicos dos extratos da degradação em saliva artificial sobre fibroblastos Balb/c 3T3 de ratos. Os cimentos Variolink II (base), AllCem Veneer e RelyX Veneer foram testados. Para caracterização microestrutural destes materiais, análise termogravimétrica (TGA), cálculo do grau de conversão (GC) e análise da distribuição granulométrica das partículas de carga, foram realizados. O GC foi calculado utilizando-se a espectroscopia infravermelha por transformada de Fourier (FTIR). Dez amostras de cada cimento foram construídas em matriz teflon (0,5 mm x 5 mm) e fotoativadas pelo diodo emissor de luz (LED) Elipar S10 (3M ESPE). Após obtenção dos espectros FTIR iniciais (24h após a fotopolimerização), 5 amostras de cada cimento foram, individualmente, imersas em 10 ml de saliva artificial (pH = 7,0) e outras 5 em 10 ml de solução de ácido lático (pH = 4,0), por 18 dias, a 37°C. Depois, as amostras foram submetidas a novas análises espectroscópicas FTIR, sob as mesmas condições iniciais, e posteriormente, seus espectros foram comparados qualitativamente aos obtidos antes do processo de degradação. A viabilidade celular de fibroblastos 3T3, frente aos possíveis efeitos citotóxicos dos resíduos dos cimentos livres na solução de saliva artificial após 18 dias de degradação, foi testada através da redução do brometo de dimetiltiazol-difeniltetrazólico (MTT). As culturas foram expostas aos extratos salivares por 24h e 72h. Células controle foram expostas à solução de saliva artificial pura. Dados foram submetidos a ANOVA e teste Tukey. Os resultados demonstraram maior conteúdo de partículas de carga significante ao cimento Variolink II (65,86%±0,17; p<0,05) quando comparado aos cimentos RelyX Veneer (62,29%±0,30) e AllCem Veneer (62,15%±37,84); distribuição granulométrica trimodal aos cimentos Variolink II (0,2 ­ 3,3µm) e RelyX Veneer (0,6 ­ 29µm), e monomodal ao AllCem Veneer (1 ­ 4,1µm); maior GC ao cimento AllCem Veneer (71,23%±5,53; p<0,05), enquanto RelyX Veneer (66,00%±6,84) e Variolink II (62,24%±2,45) não diferiram entre si (p=0,1306). A solução de ácido lático contribuiu para maiores alterações sobre o conteúdo inorgânico do cimento Variolink II, porém este material demonstrou maior degradação polimérica após imersão em saliva artificial. O cimento RelyX Veneer degradou tanto em saliva artificial quanto em ácido lático, não havendo diferenças em relação à solução degradante. O cimento AllCem Veneer não revelou degradação química após imersão em ambos os meios testados. Em 24h de exposição, os resíduos do cimento AllCem Veneer garantiram a maior viabilidade celular para fibroblastos 3T3 (90,0±6,3), enquanto os do cimento Variolink II a menor (7,43±0,17). Após 72h de exposição, todos os extratos salivares ofereceram citotoxicidades importantes aos fibroblastos. Concluiu-se que os cimentos resinosos avaliados são passíveis de sofrerem degradação em condições que simulam o ambiente oral. Existiu uma relação direta entre degradação química dos cimentos resinosos e efeitos citotóxicos in vitro a fibroblastos 3T3.

The aim of this study was to evaluate the degradation of different light-activated resin cements after aging in artificial saliva and lactic acid solutions, and the in vitro cytotoxicity of salivary extracts obtained from the resin cements degradation on mouse fibroblast (Balb/c 3T3). The resin cements Variolink II, AllCem Veneer and RelyX Veneer were tested. For microstructure characterization, TGA, degree of conversion (DC) and granulometric distribution of filler particles were employed. The DC was calculated from baseline FTIR spectra obtained from uncured and cured samples of each resin cement. These samples were development on teflon mold (0.5 mm x 5.0 mm) and photoactivated by a LED (Elipar S10; 3M ESPE). After baseline FTIR spectra obtaining, 5 samples of each cement were immersed in 10 ml of artificial saliva (pH = 7.0) and the others 5 samples were immersed in 10 ml of lactic acid solution (pH = 4.0), individually, for 18 days, at 37°C. Then, the samples were submitted to new FTIR analyzes, at the same anterior conditions, and their new spectra were compared with the baselines by qualitative FTIR method. The cell viability of 3T3 fibroblast was evaluated of MTT test. The cells were exposed to salivary extracts for 24 h and 72 h. Control cells were exposed to pure artificial saliva solution. The data were submitted to ANOVA and Tukey's test. The results revealed significant higher mass percentage of filler particles for Variolink II (65.86%±0.17; p<0.05) when compared with RelyX Veneer (62.29%±0.30) and AllCem Veneer (62.15%±37.84); trimodal granulometric distribution for Variolink II (0.2 ­ 3.3 µm) and RelyX Veneer (0.6 ­ 29.0 µm), and monomodal distribution for AllCem Veneer (1.0 ­ 4.1 µm); significant higher baseline DC for AllCem Veneer (71.23%; p<0,05), while RelyX Veneer (66.00%±6.84) and Variolink II (62.24%±2.45) were not different from each other (p=0.1306). The lactic acid solution contributed to higher changes of the inorganic matrix for Variolink II cement. However, this cement revealed more polymeric degradation after aging in artificial saliva when compared with lactic acid solution. RelyX Veneer had chemical degradation in both solutions. AllCem Veneer not showed any chemical degradation after aging in both solutions. Within 24 h of exposure, the chemical wastes of the AllCem Veneer cement guaranteed the higher cell viability to 3T3 fibroblasts (90.0±6.30) and there was no difference with the control group (80.3±8.70). The chemical wastes of the Variolink II cement guaranteed the smaller cell viability at the same time (7.43±0.17). After 72 h of exposure, all salivary extracts, except for control group, caused important cytotoxic effects to 3T3 fibroblasts. Then, the resin cements evaluated in this study can suffer chemical degradation under conditions that simulate the oral environment. There was a direct relationship between chemical degradation and in vitro cytotoxicity.

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INTRODUCTION: The main objective of this study was to reexamine the mechanical properties of elastomeric chains after stretching in various artificial saliva solutions and in air. MATERIALS AND METHODS: Five brands of elastomeric chain manufactured by different companies were selected. For each brand, four types were tested in different artificial media. A dismountable test kit was used to stretch the chains up to various initial force levels. They were then immersed in pre-prepared solutions, with control samples exposed to air only. Residual force was measured at multiple time points using a hand-held dynamometer. RESULTS AND DISCUSSION: The force delivered by the elastomeric chains decayed rapidly and differently over time. This decay varied depending on multiple factors, discussed here.

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AIM: The aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under pH cycling with two types of acid demineralizing saliva. MATERIALS AND METHODS: Brackets were bonded to 120 extracted human premolars, using Rely-a-bond (n = 40), Tru- Bond (n = 40) and Ortho-one (n = 40) orthodontic bonding agents. Each group of resin was divided into 2 subgroups (n = 20): immersion in remineralizing artificial saliva for 14 days and acid saliva with pH 4.3. After 14 days of pH cycling the caries preventive effect on the development of white spot lesion was evaluated considering the presence of inhibition zones to white spot lesions using two scores: 0 = absence and 1 = presence. Kruskal-Wallis ANOVA and Mann-Whitney U tests were used. RESULTS: Formation of white spot lesions was observed only under pH cycling using acid saliva with pH 4.3; with Rely-a-bond and Tru-Bond being significantly more effective in preventing the appearance of white spot lesions effect than Ortho-one. CONCLUSION: The acidity of the demineralizing solution influenced the formation of white spot lesions around orthodontic brackets under highly cariogenic conditions. Rely-a-bond and Tru-bond presented higher caries-preventive effect than Orthoone. CLINICAL SIGNIFICANCE: The development of fluoride-containing materials cannot be regarded as a permanent means to control dental caries lesions, but a complement along with other preventive methods.

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OBJECTIVE: Besides the use of saliva substitutes, patients suffering from hyposalivation are instructed to apply fluoride products to prevent caries. Some saliva substitutes have been shown to demineralise enamel; an effect that might be counteracted by the application of fluoride gels or mouthrinses. Combined use of these products with remineralising or neutral saliva substitutes might result in more pronounced remineralisation. METHODS: Demineralised bovine enamel specimens were either stored in mineral water [W, control; saturation with respect to octacalcium phosphate (S(OCP)): 0.7], an experimental demineralising carboxymethylcellulose (CMC)-based solution (C, S(OCP): 0.3), or in a modified (S(OCP)) saliva substitute [Saliva natura (SN), S(OCP): 1.6] for five weeks (37 degrees C). After two weeks half of the exposed surfaces were nail varnished. The following treatments were applied twice daily for 10min each time (n=14-18/group): 1: no treatment, 2: Meridol mouthrinse, 3: Elmex sensitive mouthrinse, 4: ProSchmelz fluoride gel, and 5: Elmex gelée. Mineral parameters before and after storage were evaluated from microradiographs. RESULTS: Specimens stored in C showed significantly higher mineral loss compared to W and SN (p<0.05; ANOVA). For C additional use of fluorides resulted in less demineralisation (p<0.05) compared to C alone. SN in combination with ProSchmelz led to significantly higher remineralisation compared to all other groups (p<0.05). CONCLUSIONS: Use of fluorides reduces the detrimental effects of the demineralising solution. Treatment with ProSchmelz in combination with storage in a saliva substitute supersaturated with respect to OCP yielded to most pronounced remineralisation under the conditions chosen.

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The aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under pH cycling with two types of acid demineralizing saliva. Brackets were bonded to 60 bovine incisors, using either Transbond Plus Color Change (n=30) or Orthodontic Fill Magic (n=30) orthodontic resins. Each group of resin was divided into 3 subgroups (n=10): immersion in remineralizing artificial saliva for 14 days, pH cycling with high cariogenic challenge in acid saliva with pH 5.5, and acid saliva with pH 4.5. After 14 days of pH cycling, the caries preventive effect on the development of white spot lesion was evaluated considering the presence of inhibition zones to white spot lesions using two scores: 0= absence and 1= presence. Kruskal Wallis and Mann-Whitney tests (a=0.05) were used. Formation of white spot lesions was observed only under pH cycling using acid saliva with pH 4.5; with Transbond Plus Color Change being significantly more effective (p<0.05) in preventing the appearance of white spot lesions effect than Orthodontic Fill Magic. The acidity of the demineralizing solution influenced the formation of white spot lesions around orthodontic brackets under highly cariogenic conditions. Transbond Plus Color Change resin presented higher caries preventive effect than Orthodontic Fill Magic.

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The aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under pH cycling with two types of acid demineralizing saliva. Brackets were bonded to 60 bovine incisors, using either Transbond Plus Color Change (n=30) or Orthodontic Fill Magic (n=30) orthodontic resins. Each group of resin was divided into 3 subgroups (n=10): immersion in remineralizing artificial saliva for 14 days, pH cycling with high cariogenic challenge in acid saliva with pH 5.5, and acid saliva with pH 4.5. After 14 days of pH cycling, the caries preventive effect on the development of white spot lesion was evaluated considering the presence of inhibition zones to white spot lesions using two scores: 0= absence and 1= presence. Kruskal Wallis and Mann-Whitney tests (a=0.05) were used. Formation of white spot lesions was observed only under pH cycling using acid saliva with pH 4.5; with Transbond Plus Color Change being significantly more effective (p<0.05) in preventing the appearance of white spot lesions effect than Orthodontic Fill Magic. The acidity of the demineralizing solution influenced the formation of white spot lesions around orthodontic brackets under highly cariogenic conditions. Transbond Plus Color Change resin presented higher caries preventive effect than Orthodontic Fill Magic.

O objetivo do presente estudo foi avaliar in vitro o efeito preventivo a cárie de resinas ortodônticas fluoretadas submetidas à ciclagem de pH utilizando dois tipos de saliva desmineralizadora. Bráquetes de incisivos centrais foram colados em 60 incisivos bovinos, utilizando a resina ortodôntica Transbond Plus Color Change (n=30) ou Fill Magic (n=30). Cada grupo foi dividido em 3 subgrupos (n=10): imersão em saliva artificial remineralizante por 14 dias e simulação de alto desafio cariogênico com ciclagem de pH em saliva ácida com pH 5,5 ou pH 4,5. Após 14 dias de ciclagem de pH, o efeito preventivo de cárie foi avaliado por meio da formação de halo de inibição da mancha branca, adotando-se os escores: 0-ausência e 1-presença. Os testes Kruskal Wallis e Man-Whitney (a=0,05) foram aplicados. A formação de lesões de mancha branca foi observada somente na ciclagem de pH com saliva ácida a pH 4,5; sendo o Transbond Plus Color Change significantemente mais efetivo na prevenção ao desenvolvimento de mancha branca quando comparados ao Fill Magic (p<0,05). O pH da solução desmineralizante influenciou na formação de lesões de mancha branca circunjacentes aos bráquetes em condições de alto desafio cariogênico. A Transbond Plus Color Change apresentou maior efeito preventivo de cárie em relação ao Fill Magic.

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This in vitro study evaluated the effect of a prolonged erosive pH cycling on the superficial microhardness change (SMHC) and the erosive wear of different restorative materials. Eighty enamel specimens with prepared cavities of 1.5 x 1.5 mm were randomly divided into eight groups according to the restorative materials used for the fillings (RMGI - resin-modified glass-ionomer, CGI - conventional glass-ionomer, CR- composite resin, A - amalgam) and immersion media used (ERO - erosive medium or SAL - artificial saliva). During 35 days, half of the specimens were immersed in a cola drink (ERO), for 5 min, three times a day, and they remained in SAL between the erosive cycles. The other half of the specimens was immersed in SAL only, for the entire experimental period (control). Data were tested for significant differences by anova and Tukey's tests (P < 0.05). Scanning electron microscopy images were made to illustrate the enamel erosive wear and restorative materials alterations. The mean SMHC (%) and mean erosive wear (mum) of the materials were: RMGI-ERO (30/0.5); CGI-ERO (37/0.5); CR-ERO (-0.3/0.3); A-ERO (-4/0.3); RMGI-SAL (4/0.4); CGI-SAL (-6/0.4); CR-SAL (-3/0.2) and A-SAL (2/0.4). Scanning electron microscopy images showed pronounced enamel erosive wear on groups submitted to erosive pH cycling when compared with groups maintained in saliva. In conclusion, the prolonged pH cycling promoted significantly higher alterations (SMHC and erosive wear) on the glass-ionomer cements than the CR and amalgam.

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OBJECTIVES: To report the use of Quantitative Light-induced Fluorescence (QLF) to determine if there was a tendency for bleached enamel to take up extrinsic stains more than unbleached enamel. METHODS: Bovine teeth devoid of stains were selected, the roots removed and enamel gently pumiced. Each tooth was sectioned into two and each half randomly assigned to two groups (bleached or unbleached). Windows were created on each half using clear acid resistant varnish. 38% Hydrogen peroxide gel was applied to the exposed windows of the bleached group for 1 hour. The teeth were rinsed and dried. Bleached and unbleached halves of the same teeth were then mounted on glass rods attached to pot lids using green stick. QLF images were taken. The teeth were subjected to a cycle of artificial saliva, chlorhexidine and tea (2 minutes in each solution). This was repeated 5 times. QLF images were taken at the end of each cycle. RESULTS: The uptake and progression of stain was detected in all the sections by QLF. Using paired t- test (SPSS) there was no significant difference between the two groups for the change from baseline to the final stain cycle (p > 0.05), however there was variability in stain uptake within the groups as the cycles progressed. CONCLUSION: Bleaching of enamel in vitro does not appear to increase the susceptibility of enamel to extrinsic staining.

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OBJECTIVE: Xerostomia is a subjective sensation of mouth dryness often occurring as an unwanted effect of psychotropic drugs. METHODS: The clinical efficacy and acceptability of a new oxygenated glycerol triester (OGT) oral spray (1 or 2 sprays up to 4 times daily) in the treatment of xerostomia was compared with those of a commercially available artificial saliva substitute (ASS [Saliveze]) in a 2-week, open-labeled, randomized, parallel-group study. Clinical assessment of xerostomia included evaluation of mouth dryness by means of a 10-cm-long visual analog scale, objective blinded assessment of the oral tissue condition by a dental hygienist by means of a 4-point ordinal scale, and subjective patient-based assessment of dry mouth symptoms by means of dichotomous responses to a questionnaire. [Day 14 - baseline] patient-based mouth dryness score was the primary end point. RESULTS: Seventy-four patients (41 women and 33 men, 44 +/- 15 years) undergoing long-term psychotropic drug treatment were consecutively enrolled. At day 14, OGT resulted in better efficacy than ASS in mouth dryness score (mean difference, 1.2 +/- 0.4; P = 0.006), speech difficulties (mean difference, 1.2 +/- 0.4; P = 0.005), taste (mean difference, 1.1 +/- 0.4; P = 0.02), and overall mouth condition (mean difference, 1.4 +/- 0.9; P = 0.005). Taste of OGT was better than that of ASS (mean difference, 1.4 +/- 0.6; P = 0.04), as was OGT acceptability (mean difference, 1.4 +/- 0.9; P = 0.005). CONCLUSION: Oxygenated glycerol triester lubricant oral spray was superior to a commercially available ASS in improving xerostomia and overall condition of the oral tissue.

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OBJECTIVE: To investigate the toxicity of fluoride corrosion extracts of stainless steel (SS) and nickel-titanium (NiTi) wires on a human osteosarcoma cell line (U2OS). MATERIALS AND METHODS: The SS and NiTi wires were corroded by an electrochemical method with the application of three kinds of electrolytes: 0.2% pH 3.5 acidulated phosphate fluoride (NaF) in artificial saliva, and pH 4 and pH 6.75 artificial saliva solutions. The extracts were analyzed for nickel, chromium, and titanium ions by the atomic absorption method. The extracts were diluted with medium to different concentrations (1, 0.1, and 0.01 microL/mL). The cell survival rate was determined by the ability of test cells to cleave the tetrazolium salt to form a formazan dye. RESULTS: The results were compared using one-way analysis of variance. Differences between the treatment means were analyzed using a Student-Newman-Keuls (SNK) test and were considered significant at P < .05. The release of ionic nickel was different in different extract groups (P < .05). The SS and NiTi wires in the 0.2% pH 3.5 NaF artificial saliva group caused a dose-dependent decrease in the survival rate (P < .05). Survival rates of cells in the groups exposed to extracts of SS and NiTi wires in pH 4 and pH 6.75 artificial saliva solutions showed no statistical differences (P >.05). CONCLUSIONS: Orthodontic wires in acidulated fluoride saliva solution can cause U2OS cell toxicity.

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OBJECTIVES: The aim of this study was to examine the influence of storage media on the elastic properties of dentin and tooth enamel with respect to the storage period. Several reports suggest that saline and other aqueous solutions may induce chemical reactions and the dissolution of minerals, which in turn may cause alterations of elastic tissue properties. METHODS: Three non-erupted human wisdom teeth were extracted and divided in three slices. Sections were stored in three different media for a maximum period of 21 days. During this time all sections were inspected by time-resolved 50-MHz scanning acoustic microscopy. RESULTS: Storage in saline solution resulted in a progressive decrease of the acoustic impedance up to 70% in dentin but not in enamel tissue. Hank's balanced salts solution and artificial saliva appeared to maintain the elastic properties of dentin and enamel during the entire time of storage. The measurements of surface wave velocities did not show significant differences. High resolution (900 MHz) inspection of sections cut perpendicular to the surface exposed to the storage media for 21 days revealed a progressive increase of impedance in dentin up to the initial values at a depth of approximately 300 microm. SIGNIFICANCE: These findings suggest that quantitative SAM is a suitable tool for assessing surface and sub-superficial elastic properties of tooth tissue.

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In this study, we investigated the effect of different solutions--coffee, tea, Turkish coffee, artificial saliva, mouthwash, denture cleanser, and distilled water--on the bond strength of soft lining materials (one acrylic- and three silicone-based) to acrylic resin. Acrylic specimens (40x10x10 mm) were prepared for the bond strength test. The specimens were stored in different solutions and tested after 24 hours, seven days, and 30 days. Using analysis of variance, the bond strength of soft lining materials to acrylic resin was found to be related to the type of material, storage time, and storage solution. Visco-gel had the lowest bond strength to cured acrylic resin, where its strength ranged from 0.149 MPa to 0.784 MPa. The bond strength of Visco-gel was also found to increase with time. Molloplast-B and Ufi Gel P demonstrated better bond strength than Visco-gel and Mollosil.

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The aim of this investigation was to determine the influence of fluoride in certain mouthwashes on the risk of corrosion through galvanic coupling of orthodontic wires and brackets. Two titanium alloy wires, nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi), and the three most commonly used brackets, titanium (Ti), iron-chromium-nickel (FeCrNi) and cobalt-chromium (CoCr), were tested in a reference solution of Fusayama-Meyer artificial saliva and in two commercially available fluoride (250 ppm) mouthwashes, Elmex and Meridol. Corrosion resistance was assessed by inductively coupled plasma-atomic emission spectrometry (ICP-MS), analysis of released metal ions, and a scanning electron microscope (SEM) study of the metal surfaces after immersion of different wire-bracket pairs in the test solutions. The study was completed by an electrochemical analysis. Meridol mouthwash, which contains stannous fluoride, was the solution in which the NiTi wires coupled with the different brackets showed the highest corrosion risk, while in Elmex mouthwash, which contains sodium fluoride, the CuNiTi wires presented the highest corrosion risk. Such corrosion has two consequences: deterioration in mechanical performance of the wire-bracket system, which would negatively affect the final aesthetic result, and the risk of local allergic reactions caused by released Ni ions. The results suggest that mouthwashes should be prescribed according to the orthodontic materials used. A new type of mouthwash for use during orthodontic therapy could be an interesting development in this field.

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We report on the development and the initial testing of a new microbial-based caries model. Specimens were fixed on a rotating mount within a reaction chamber hermetically surrounded by a sterilised glove box. A cariogenic environment was obtained by inoculation with Streptococcus mutans (ATCC 25175) combined with a continuously repeating supply of sucrose solution, trypticase soy broth and artificial saliva applied by dripping. Twenty-five caries-free upper premolars were used. The mesial parts of the occlusal fissures had been sealed with a resin-based fissure sealant (test group 1). To produce marginal gaps, the distal parts had been moistened with saliva before resin application (test group 2). Five teeth served as control and were exposed to all fluids under sterile conditions before being removed from the system after 7 days. Test specimens were infected with S. mutans and were incubated for another 14 days. No unintentional contamination occurred during the 3-week period of operation. Demineralizations were evaluated by using confocal laser scanning microscopy. Only the test specimens showed clearly visible signs of biofilm formation and caries-like lesions. The mean primary lesion depth did not differ significantly between test groups. Wall lesion depths and surface areas of demineralizations underneath the fissure sealants were significantly higher in test group 2. Thus, our model allows the simultaneous production of primary and secondary caries-like enamel lesions in a considerable number of specimens and facilitates the possibility to manipulate and transfer them without necessarily terminating the experiment, opening new possibilities for in vitro caries research.

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