The relationship between alcohol consumption and oral malodour.

OBJECTIVE: To analyse the relationship between alcohol consumption and oral malodour. SUBJECTS: 235 individuals, aged 46.5 +/- 15.3 years (mean +/- SD), who complained of oral malodour. METHODS: An organoleptic test (OLT) was used to estimate the degree of oral malodour, gas chromatography was used to measure volatile sulphur compounds (VSCs), and a questionnaire was used to gather data about the subjects' habits related to alcohol consumption. RESULTS: Of the 55 individuals who consumed alcohol daily, 17 (30.9%) had strong malodour (OLT score, 4), and there were significant differences among the 'daily', 'sometimes', and 'no alcohol' groups (Kruskal-Wallis test, p < 0.01). The daily group also had a higher VSC concentration than the 'sometimes' and 'no alcohol' groups (t-test, p < 0.05), and there was no difference in the VSC concentration among the subjects with strong malodour. Analyses of the relationships between drinking habits and the clinical factors causing oral malodour revealed that daily drinking was positively associated with a probing pocket depth > or = 5 mm (chi2 test, p < 0.01). CONCLUSION: This study found an association between daily alcohol consumption and strong malodour, especially related to periodontal disease.

Detection of Helicobacter pylori DNA in the saliva of patients complaining of halitosis.

Helicobacter pylori infection, which causes peptic ulcers and gastric cancer, is considered a possible cause of halitosis. Recently, the oral cavity was identified as a possible H. pylori reservoir, particularly in the presence of periodontal disease, which is a cause of halitosis. The purpose of this study was to evaluate by PCR the prevalence of oral H. pylori in the saliva of subjects complaining of halitosis. Samples were obtained from 326 non-dyspeptic subjects, comprising 251 subjects with actual malodour and 75 subjects without halitosis. DNA was extracted from the samples, and the presence of H. pylori and periodontopathic bacteria including Porphyromonas gingivalis, Treponema denticola and Prevotella intermedia was examined by PCR. H. pylori was detected in 21 (6.4 %) of 326 samples. The methyl mercaptan concentration and periodontal parameters including tooth mobility, periodontal pocket depth (PPD) and occult blood in the saliva were significantly greater in the H. pylori-positive subjects. Each of the periodontopathic bacteria was also detected at a significantly higher frequency in the H. pylori-positive subjects. Among those patients with a PPD of > or =5 mm and a tongue coating score of < or =2, no difference was observed in oral malodour levels between the H. pylori-positive and -negative subjects. However, the presence of occult blood in the saliva and the prevalence of Prevotella intermedia were significantly greater in the H. pylori-positive subjects. H. pylori was detected in 16 (15.7 %) of 102 subjects with periodontitis, suggesting that progression of periodontal pocket and inflammation may favour colonization by this species and that H. pylori infection may be indirectly associated with oral pathological halitosis following periodontitis.

Failure probability of implant-supported restorations using highly filled all-composite crowns.

OBJECTIVES: To evaluate the effect of the surface preparation of a gold cylinder on the failure probability of highly filled all-composite restorations used as implant-supported prostheses, and to determine the effect of the location of load application. METHOD AND MATERIALS: Gold cylinders (Nobel Biocare) were prepared with 1 of 4 different surface preparations (n = 20 per surface treatment), and then an indirect resin composite (Targis, Ivoclar Vivadent) was applied. The 4 surface treatment conditions were (1) untreated (prep 1); (2) airborne-particle abraded with 50-Microm alumina (prep 2); (3) airborne-particle abraded with 50-Microm alumina followed by application of a metal conditioner (Alloy Primer, J. Morita) (prep 3); and (4) airborne-particle abraded with 50-Mum alumina followed by application of the bonding primer for the indirect resin system (Targis Link) (prep 4). A compressive load was applied vertically at 1 mm and 2 mm from the access cavity on the occlusal surface until the restorations failed. RESULTS: The prep 4 specimens had the highest fracture resistance. The fracture resistance at the 1-mm location was significantly higher than that at the 2-mm location. The failure load of the all-composite restorations with any of the surface preparations was lower than that of the resin-veneered restorations used as controls. CONCLUSION: The prep 4 conditions decreased the probability of fracture of the highly filled all-indirect resin composite restorations. Eccentric loading of the all-composite restorations should be minimized in light of the higher probability of failure associated with such a loading condition.

Effect of water storage on the flexural properties of three glass fiber-reinforced composites.

PURPOSE: The effect of water sorption on the flexural strength and flexural modulus of three fiber-reinforced composites was studied. MATERIALS AND METHODS: Bar-shaped specimens of each material were prepared according to the manufacturers' instructions. The flexural strength and modulus of each specimen were tested after the specimens were immersed in distilled water for 1, 7, 60, and 180 days. SEMs were taken to examine the mode of failure. The volume percentage of fiber content of each fiber-reinforced composite was experimentally estimated. RESULTS: The ascending order of flexural strength and modulus among the materials was generally: FibreKor < Stick < Vectris. The flexural strengths of Stick and FibreKor specimens at 1 and 180 days were not significantly different. Although the 180-day Vectris specimens possessed significantly lower flexural strength than the 1-day specimens, the flexural strengths of Vectris specimens at 1, 7, 60, and 180 days remained significantly higher than those of Stick and FibreKor. The difference in flexural modulus for each fiber-reinforced composite related to the duration of water immersion was not significant. CONCLUSION: Water immersion affected the flexural strengths of the three composites to a different degree but did not affect their flexural moduli significantly. For each duration of water immersion, the flexural property of the fiber-reinforced composite, in ascending order of significant difference, was: FibreKor < Stick < Vectris.

Stimulation of growth of Porphyromonas gingivalis by cell extracts from Tannerella forsythia.

OBJECTIVE: In order to examine if Tannerella forsythia stimulates the growth of Porphyromonas gingivalis, an in vitro study was performed. BACKGROUND: P. gingivalis and T. forsythia are often isolated simultaneously from active periodontitis sites, indicating that these bacteria somewhat interact in the periodontal environment. We reported previously that mixed infection of P. gingivalis and T. forsythia synergistically induced lesion formation in a murine abscess model, and gingipains of P. gingivalis played an important role in this synergism. One of the possible mechanisms of this synergism is growth promotion by coinfection of the two bacteria. METHODS: Cell extracts of T. forsythia were added to the nutrition-decreased medium and the promotion of growth of P. gingivalis was examined. RESULTS: Sonicated extract of T. forsythia stimulated growth of P. gingivalis in nutrition-decreased medium in a dose-dependent manner. Proteins appeared to be the nature of growth-promoting factor, and the cell extract of T. forsythia had no stimulating effect on the growth of P. gingivalis strain devoid of gingipain activities. CONCLUSION: A product or a component of T. forsythia seemed to stimulate growth of P. gingivalis under nutrition-limited conditions. Gingipains are considered to play an important role in digestion or uptake of this growth-promoting factor. The interaction between T. forsythia and P. gingivalis in growth may be in part related with the synergistic virulence in a murine model.

Water sorption and dimensional stability of three glass fiber-reinforced composites.

PURPOSE: Water sorption and dimensional stability of three fiber-reinforced composites were studied. Two composites (Vectris, FibreKor) were resin impregnated industrially, and one composite (Stick) was polymer preimpregnated but required further manual impregnation. MATERIALS AND METHODS: Bar-shaped specimens of each material were prepared according to manufacturers' instructions. The water sorption and dimensional change of each specimen were calculated according to the change in its weight and dimension before and after immersion. Specimens were immersed in distilled water for 1, 7, 60, and 180 days. SEMs were taken to examine the quality of the fiber-matrix interface. The volume percentage of fiber content of each fiber-reinforced composite was experimentally estimated. RESULTS: A general trend of increasing water sorption for each immersion period according to the material type was: Vectris < FibreKor < Stick. There were no significant differences in dimensional change among the materials and immersion periods. CONCLUSION: The preimpregnated fiber-reinforced composite (Stick) showed higher water sorption than the industrially impregnated fiber-reinforced composites (Vectris, FibreKor). Despite a variation in the water sorption of the fiber-reinforced composites studied, all were within a 32 microg/mm3 criterion established by the ISO. The magnitude of dimensional change was small enough that it should not raise any significant clinical concern.

Probability of failure of highly filled indirect resin-veneered implant-supported restorations: an in vitro study.

PURPOSE: The study compared the probability of failure of three highly filled resin-veneered restorations to that of conventional metal-ceramic restorations when used as implant-supported prostheses. The effect of the location of load application on the fracture resistance of the restorations was also studied. MATERIALS AND METHODS: Twenty samples each of the three resins, Artglass, Targis, and Estenia, were applied on type IV gold frameworks. Twenty metal-ceramic restorations of equal dimensions (VMK 95 and Degudent Universal) were used as controls. Compressive load was applied vertically at 1 mm (n = 10) and 2 mm (n = 10) from the periphery of the occlusal table until the restorations failed. Weibull analysis was applied to the data. RESULTS: There was no significant difference in the probability of failure among the metal-ceramic restorations and three resin-veneered restoration systems. Loading the resin-veneered restorations at the 1-mm location significantly increased their probability of failure when compared to the 2-mm loading location. The loading location did not significantly change the probability of failure of the metal-ceramic restorations. CONCLUSION: The probability of failure of resin-veneered restorations tested was not significantly different from that of the metal-ceramic restoration under two compressive loading conditions. Eccentric loading of resin-veneered restorations should be minimized in light of the higher probability of failure associated with such a loading condition.