In vitro fermentation of gum acacia – impact on the faecal microbiota

Interest in the consumption of gum acacia (GA) has been associated with beneficial health effects, which may be mediated in part by prebiotic activity. Two doses of GA and fructooligosaccharide (FOS) (1 and 2%) were tested for their efficacy over 48?h in pH- and temperature-controlled anaerobic batch cultures inoculated with human faeces. Samples were taken after 0, 5, 10, 24 and 48?h of fermentation. The selective effects of GA (increases in Bifidobacterium spp. and Lactobacillus spp.) were similar to those of the known prebiotic FOS. The 1% dose of substrates showed more enhanced selectivity compared to the 2% dose. The fermentation of GA also led to SCFA production, specifically increased acetate after 10, 24 and 48?h of fermentation, propionate after 48?h and butyrate after 24 and 48?h. In addition, FOS led to significant increase in the main SCFAs. These results suggest that GA displays potential prebiotic properties.     

Dentists' familiarity with tobacco cessation programs in dental settings in Iran

Objectives: The current study assessed Iranian dentists' practice, knowledge, perceived barriers, and attitudes toward helping patients to quit. We hypothesized that Iranian dentists would have limited knowledge and awareness of tobacco cessation methods or of their important role in encouraging patients to quit. We expected the combination of quantitative and qualitative research to yield important insights regarding effective methods of engaging Iranian dentists in tobacco intervention. Methods: From a list of registered dentists following an initial screening, we randomly selected a total of 1,000 dental practices in 10 randomly selected provinces. Following an initial letter describing the study, we mailed a questionnaire. For the qualitative part of the study, we used a convenience purposeful sampling of 16 dentists. Results: Despite repeated contacts, only 35 percent of those contacted returned completed surveys. Key findings not only included generally positive attitudes toward tobacco cessation programs, but also identification of major barriers including concerns about patient resistance, lack of supportive organization, and opportunities for training. Dentists were far more likely to ask patients about smoking than to provide actual cessation support. Female dentists were more likely to ask patients. The qualitative interviews shed further light on barriers to intervention. Conclusions: Interpretation of the findings is limited by the relatively low response rate. However, despite identified barriers to intervention, we are encouraged by dentists' overall knowledge and interest in tobacco cessation services. We plan to use the current findings to inform development of continuing education programs and incorporation of tobacco cessation counseling into dental school curricula in Iran.     

Palatal neurofibroma associated with localized periodontitis

BACKGROUND: Neurofibromatosis type 1 (NF1) is the most common form of neurofibromatosis. While typically considered a dermatologic disorder, intraoral signs of neurofibromatosis occur quite commonly. This clinical entity can be confused with periodontitis because of the presence of periodontal pockets. In this report, we present the case of a palatal neurofibroma with radiographic involvement in a patient with NF1. METHODS: A 40-year-old female patient was referred from her general dentist to evaluate advanced periodontitis in the maxillary left quadrant. The patient's medical history was significant for a soft tissue lesion excised from her back 11 years previously and diagnosed as a neurofibroma. Subsequent medical examination at that time confirmed a systemic diagnosis of NF1. A comprehensive periodontal evaluation was performed, and panoramic and periapical radiographs were taken. Teeth were tested for vitality. An incisional biopsy was completed for histopathologic examination. RESULTS: The periodontal evaluation revealed the presence of 6 to 9 mm probing depths adjacent to teeth #14 and #15. Panoramic and periapical radiographs showed a circumscribed 0.8x0.9-cm unilocular radiolucency superimposed over the root of tooth #13 and extensive horizontal bone loss on the distal side of #15. Incisional biopsy confirmed the presence of a neurofibroma, and because of the extent of the lesion, the patient was referred to the Oral and Maxillofacial Surgery service for complete excision. CONCLUSIONS: Neurofibromas can cause extensive destruction of alveolar bone, mimicking periodontitis. Due to the potential systemic and genetic implications, the diagnosis of neurofibroma requires appropriate medical referral.     

Comparison of methods for measurement of hypoplastic lesions

Enamel hypoplasia is a quantitative defect of enamel thickness. Methods previously used for its measurement have limitations in clinical studies. The aim of this study was to investigate new methods of measurement using image analysis. Lesions on 8 teeth affected by enamel hypoplasia were quantified from study models and impression surfaces using an image-analysis system. The measurements made included lesion area and tooth surface area; from these the proportion of tooth surface area affected was calculated. For comparison, manual measurement was performed on impression surfaces and study models, using digital callipers. Images were also acquired of lesions on 12 exfoliated teeth, and the lesion area and total tooth area were calculated. For assessment of intra-operator reliability, the +/– repeatability coefficient was calculated. Measurement of the surface of lesions direct from the exfoliated teeth gave the best results overall, followed by direct image analysis of the silicone impression.     

Intravenous procedural sedation: an alternative to general anesthesia in the treatment of early childhood caries

Providing comprehensive dental treatment for preschool children with early childhood caries (ECC) is probably the greatest challenge facing most dentists; many elect to hospitalize a child with ECC and provide treatment under general anesthesia. However, as waiting lists for hospital admission are long, ECC continues to progress and can cause pain or acute infection. Hospital treatment also results in substantial costs beyond those for dental treatment. This paper describes a cost-effective intravenous sedation program being used in a pediatric dental practice in Kelowna, British Columbia. The program offers an alternative to general anesthesia that allows qualified dentists to provide comprehensive dental treatment to children with ECC safely and efficiently in the private practice setting.     

Adhesive analysis of voids in Class II composite resin restorations at the axial and gingival cavity walls restored under in vivo versus in vitro conditions.

OBJECTIVES: Adhesive analysis, under the scanning electron microscope of microtensile specimens that failed through the adhesive interface, was conducted to evaluate the amount of voids present at the axial versus gingival cavity walls of class II composite restorations restored under in vivo and in vitro conditions. METHODS: Five patients received class II resin composite restorations, under in vivo and in vitro conditions. A total of 14 premolar teeth yielded 59 (n=59) microtensile adhesive specimens that fractured through the adhesive interface. The fractured surfaces of all specimens were examined and the % area of voids was measured. RESULTS: Voids at the adhesive joint were highly predictive of bond strengths. An increase in the number of voids resulted in a decrease in the microtensile bond strength. The area of voids at the adhesive interface was as follows: in vivo axial 13.6+/-25.6% (n=12); in vivo gingival 48.8+/-29.2% (n=12); in vitro axial 0.0+/-0.0% (n=19) and in vitro gingival 11.7+/-17.6% (n=16). SIGNIFICANCE: Composite resin may bond differently to dentin depending upon the amount of voids and the cavity wall involved. The bond to the gingival wall was not as reliable as the bond to the axial wall. An increase in the amount of surface voids was a major factor for reducing microtensile bond strengths of adhesive to dentin.     

The Accuracy of Implant Verification Casts Compared With Casts Produced From A Rigid Transfer Coping Technique

Purpose Prosthodontic techniques for implant-supported prostheses continue to evolve in an effort to facilitate treatment and minimize costs. Because research has shown no impression transfer technique to be without error, some clinicians have attempted to control the fit of prosthetic frameworks by reorienting sections of patterns or frameworks intraorally, fabricating a verification cast, and completing the prosthesis to fit such a cast. One manufacturer has attempted to meet both impression-making and verification-cast objectives by providing metallic impression copings (MICS) with extensions that allow contact between the copings for rigid fixation with acrylic resin before impression making. The purpose of this study was to determine the accuracy of casts produced from the MICS transfer process compared with casts produced from sectioned frameworks, where both techniques used a low-polymerization-shrinkage acrylic resin polymer to rigidly join the sections. Materials and Methods Using stainless steel measurement spheres as a reference point on each implant analog, the distances between analogs on the experimental casts were compared with the distances measured on the master cast. Seven casts were produced for each group and measured with a machinist's microscope at a 4-μm level of precision. Results The results revealed that the MICS transfer exhibited a mean error of 41 μm, which was significantly less than the verification-cast group mean error of 57 μm (p < .01, Student's t test). Conclusions Given these results, clinicians can consider the rigid transfer technique as provided in the MICS transfer to be more accurate than the verification technique as outlined in this study.     

Bone resorption and serum levels of vitamin D metabolites in the hypophosphataemic rat

The supplementation of a low phosphate diet with vitamin D has been shown to result in an increase in bone resorption in the hypophosphataemic rat. The aim of the present study was to determine if administration of vitamin D to rats fed a vitamin D and phosphate-depleted diet would result in an increase in the circulatory levels of the active vitamin D metabolite 1,25(OH)₂D₃ and an associated increase in bone resorption. Three groups of weanling Sprague-Dawley rats were used. The first group consisted of control animals on a normal laboratory stock diet and the second and third groups were experimental animals receiving a vitamin D-and phosphate-deficient diet with the third group receiving vitamin D supplementation. All animals were housed in the dark. After 30 days on the diet the experimental animals received 0.1 mmol NaH₂PO₄ by intraperitoneal injection. Blood was sampled at zero, 3, 6, 18 and 48 h post-injection and analysed for the vitamin D metabolites 25(OH)D₃ and 1,25(OH)₂D₃, calcium and inorganic phosphate (Pi). The serum analyses revealed that the level of 25(OH)D₃ in the hypophosphataemic animals was significantly lower than that of the control animals. However the 1,25(OH)₃D₃ level was initially significantly higher, then dropped to the control level at 18 h post-intraperitoneal injection of phosphate. Further, the serum levels of 25(OH)D₃ and 1,25(OH)₂D₃, calcium and Pi in the hypophosphataemic animals supplemented with vitamin D were significantly higher than those of the vitamin D-deficient animals. Also the vitamin D-supplemented animals exhibited significantly greater levels of bone resorption. These results therefore, are consistent with a role of 1,25(OH)₂D₃ in bone resorption in hypophosphataemic rats.     

Understanding Dental Service Use by Older Adults: Sociobehavioral Factors vs Need

Objectives: This study investigated correlates of dental care use in a representative sample of adults aged 70 and older throughout New England. Methods : Data were collected in in-home interviews and dental examinations. Following Andersen's behavioral model of health services utilization, varied measures of sociodemographic characteristics, dental health attitudes and practices, perceived need for care, and need objectively determined by clinical examination were included as potential correlates. Results : Recency of last visit was associated with positive attitudes toward dental care, regular dental hygiene, and having a usual source of care. Among dentulous subjects, recency of last visit also was related to sex and living arrangements. Frequency of visits for dentulous subjects was associated with the same variables, as well as with age and social class or education, in addition to need for care. For edentulous subjects, only a usual sourse of care and higher social class were associated with more frequent visits. Conclusions : Perceived need and attitudes toward dental care are important influences on use of care. Older persons must be convinced of the importance of regular dental care.