Fluoride content of tank water in Australia.

BACKGROUND: The aims of this study were to: (1) analyse the fluoride content of tank water; (2) determine whether the method of water collection or storage influenced fluoride content; and (3) survey participant attitudes towards water fluoridation. METHODS: Plastic tubes and a questionnaire were distributed through dentists to households with water tanks in Victoria. A midstream tank water sample was collected and fluoride analysed in triplicate using ion chromatography RESULTS: All samples (n = 123) contained negligible amounts of fluoride, with a mean fluoride concentration of <0.01 ppm (range: <0.01-0.18 ppm). No statistically significant association was found between fluoride content and variables investigated such as tank material, tank age, roof material and gutter material. Most people did not know whether their tank water contained fluoride and 40.8% preferred to have access to fluoridated water. The majority thought fluoride was safe and more than half of the respondents supported fluoridation. Fluoride content of tank water was well below the optimal levels for caries prevention. CONCLUSIONS: People who rely solely on tank water for drinking may require additional exposure to fluoride for optimal caries prevention.

Biomarkers of chemotherapy-induced diarrhoea: a clinical study of intestinal microbiome alterations, inflammation and circulating matrix metalloproteinases.

PURPOSE: A common side effect of chemotherapy treatment is diarrhoea. Unfortunately, the underlying mechanisms of chemotherapy-induced diarrhoea (CD) are poorly understood. We aimed to determine if faecal microbes of CD patients were displaced, if faecal calprotectin increased during CD and if there were alterations in circulating matrix metalloproteinases, nuclear factor kappa B (NF-κB), IL-1ß and TNF. PATIENTS AND METHODS: Twenty-six cancer patients receiving chemotherapy were enrolled and requested to provide stool samples and blood samples at various times during their chemotherapy cycle. Stool samples were analysed using conventional culture techniques and qRT-PCR. ELISA kits determined faecal calprotectin levels, levels of circulating matrix metalloproteinases and circulating NF-κB, IL-1ß and TNF. RESULTS: The majority of patients with CD showed decreases in Lactobacillus spp., Bifidobacterium spp., Bacteroides spp. and Enterococcus spp. Increases were observed in Escherichia coli and Staphylococcus spp. Methanogenic archaea were also quantified, with all patients except one showing a decrease. Faecal calprotectin levels were increased in 81.25 % of patients with CD. Circulating MMP-3 and MMP-9 significantly increased following chemotherapy. Circulating levels of NF-κB, IL-1ß and TNF were increased following chemotherapy, although this did not reach significance. CONCLUSIONS: We demonstrated that CD is associated with marked changes in intestinal microflora, methanogenic archaea, matrix metalloproteinase and serum levels of NF-κB, IL-1ß and TNF. These changes may result in diminished bacterial functions within the gut, altering gut function and initiating intestinal damage, resulting in the onset of diarrhoea. More importantly, these changes may provide clinicians with a possible new target for biomarkers of toxicity.

Radioembolization in combination with systemic chemotherapy as first-line therapy for liver metastases from colorectal cancer.

PURPOSE: To report clinical experience with radioembolization (RE) plus systemic chemotherapy as a first-line treatment for liver metastases from colorectal cancer (CRC). MATERIALS AND METHODS: Clinical outcomes were evaluated retrospectively among 19 patients with unresectable liver metastases from CRC who had a good performance status and a low burden of extrahepatic disease (EHD) and were eligible for RE. Most (74%) had disease confined to the liver. Concurrent treatment with 5-fluorourail/leucovorin (n = 7) or 5-fluorourail/leucovorin/oxaliplatin (FOLFOX; n = 12) was started 3-4 days before single treatment with RE. RESULTS: Overall response rate according to the Response Evaluation Criteria in Solid Tumors was 84% (two complete responses and 14 partial responses). Median progression-free survival (PFS) time was 10.4 months and median overall survival (OS) time was 29.4 months. For patients with disease confined to the liver, PFS improved (10.7 mo vs 3.6 mo; P = .09), with significant prolongation of OS (median, 37.8 mo vs 13.4 mo; P = .03) compared with those who had EHD. Nine patients, including three long-term (> 3 y) survivors, remained alive after a median follow-up of 18.6 months. Serious treatment-related toxicities included febrile neutropenia with concurrent FOLFOX treatment, a perforated duodenal ulcer, and one death from hepatic toxicity. CONCLUSIONS: The present findings confirm the effectiveness of RE plus systemic chemotherapy for metastatic CRC. Patients with liver-confined disease derived the greatest benefit, with median survival times beyond 36 months. Larger datasets from ongoing phase III trials are needed to further define the safety and efficacy of RE in the first-line setting.

High-risk human papillomavirus in the oral cavity of women with cervical cancer, and their children.

BACKGROUND: Association of High-risk Human Papillomavirus (HR-HPV) with oral cancer has been established recently. Detecting these viruses in oral cavity is important to prevent oral lesions related to them. The purpose of this study was to evaluate the prevalence of HR-HPV in the oral cavity of women with cervical cancer, and their children. A total of 70 women, previously diagnosed with cervical cancer, and 46 children of these women, born by vaginal delivery only, were selected for this study. Buccal swabs were collected from their oral cavity and HPV detection was carried out using Hybrid Capture 2 high-risk HPV (HC2 HR-HPV) detection system. RESULTS: Out of 70 women with cervical cancer, four (5.71%) were found to be positive for HR-HPV in their oral cavity. No association of HR-HPV was found with sociodemographic profile, marital status, reproductive history, tobacco and alcohol usage, contraceptive pills usage, and presence of oral lesions (p>0.05). Among children, HR-HPV in the oral cavity was detected in only 1 of the 46 subjects examined (2.17%). Clinically healthy oral mucosa, without any oral lesions, was observed in all the HR-HPV positive subjects. CONCLUSION: The result of this study showed that there is low, if any, risk of HR-HPV infection in the oral cavity of women with cervical cancer. Further, our study suggests that there is very low risk for children of women with cervical cancer, to acquire and sustain HR-HPV in their oral cavity until childhood or adolescence.

Deletion analyses of SMN1 and NAIP genes in Malaysian spinal muscular atrophy patients.

BACKGROUND: The survival motor neuron 1 (SMN1) gene has been recognized to be responsible for spinal muscular atrophy (SMA) because it is homozygously deleted in more than 90% of SMA patients, irrespective of their clinical severity, whereas the neuronal apoptosis inhibitory protein (NAIP) gene is now considered to be a modifying factor of the severity of SMA. In Malaysia, it remains to be elucidated whether deletion of the SMN1 gene is also a main cause of SMA or whether deletion of the NAIP gene is found in the SMA patients. METHODS: To clarify the pathogenesis of SMA in Malaysia, a deletion analysis of the SMN1 and NAIP genes was performed in 24 Malaysian SMA patients. Deletion analysis of exons 7 and 8 of the SMN1 gene was performed according to the method described by van der Steege et al., while deletion analysis of exon 5 of the NAIP gene was performed according to a method described by Roy et al. RESULTS: Homozygous deletion of SMN1 exon 7 and exon 8 were identified in 19 out of 24 patients (79%). As to the NAIP gene, deletion of exon 5 was detected in six out of 24 patients (25%). NAIP gene deletion was correlated with severity of the disease. CONCLUSIONS: Deletion of the SMN1 exon 7 is a major cause of SMA in Malaysia, and NAIP gene deletions are not rare in type I SMA in Malaysia. The lower percentage of the SMN1 gene deletion may be due to the possibility that the present study included some patients without SMN1 gene abnormality and/or some patients with non-deletion type mutations in the SMN1 gene.

Shear bond strength of microwaveable acrylic resin for denture repair.

Microwaveable acrylic denture resins are believed to provide an effective means of repairing fractured dentures. This in vitro investigation compared the bond strength of a microwaveable acrylic resin as a denture repair material to two established auto-polymerized resins. Fifty-one specimens were made using Lucitone 199 as a simulated denture base, and were then divided into three groups of 17 samples each. Each test group was bonded with the following acrylic resins: Acron Mc, Rapid Repair and Palapress. A shear bond strength test was carried out 24 h after the samples were bonded. Fracture analysis showed that bond failure was adhesive for all groups. Shear bond values showed a statistically significant difference at P < 0.05 level between Acron Mc and Rapid Repair; Palapress and Rapid Repair, and indicated that Acron Mc and Palapress were superior to Rapid Repair as a repair material. However, there was no statistical difference found between Acron Mc and Palapress. Microwaveable acrylic resins produce repaired junctions of adequate strength.

A clinical report about an unusual occurrence of post-anesthetic tongue swelling.

Dentures are routinely removed from the oral cavity before general anesthetic procedures. They are only reinserted much later when the patient returns to the room. This clinical report describes an edentulous patient who developed acute tongue swelling from venous congestion as a result of tongue recovery from general anesthesia. Her complete dentures were used to separate the residual ridges during the recovery period and relieved the congestion. Denture insertion increased the height and volume of the oral cavity, which reduced pressure on the tongue, preventing a cycle of tongue compression, congestion, and swelling. This unusual complication suggests that it may be prudent for the edentulous patient to be accompanied by their dentures in the perioperative period.

Viability of magnetic denture retainers: a 3-year case report.

The purpose of this article is to report on the use of a neodymium-iron-boron magnet enclosed in a laser-welded stainless steel casing as a viable method of retention for removable partial dentures. This mode of retention dispenses with unsightly clasps, at the same time providing direct tooth support via the overdenture abutment. Magnetic attachments are simpler to incorporate into the prosthesis than mechanical attachments, which require springs, coplanar surfaces, or screws. Overdentures of this nature have the added advantage of being more stable and retentive than conventional partial dentures, and they are easily removed and seated without the patient having to grapple with clasps and complex paths of insertion. This particular magnetic attachment exhibited no deterioration after 3 years in function, and the results so far have been promising.

Bond strengths of glass ionomer restoratives to primary vs permanent dentin.

An in vitro experiment was conducted to evaluate the shear bond strength of a conventional GIC (glass ionomer cement) and a RMGIC (resin modified glass ionomer cement) when applied to dentin of primary and permanent teeth. Results show that the bond strength of the RMGIC was more than thrice that of the conventional GIC. Fracture analysis showed that the bond failures were cohesive in the cement.

An evaluation of bond strengths of denture repair resins by a torsional method.

Chemical cure resin materials are generally used in the repair of dentures. Different repair resins used may yield different results. The bond strength of three autopolymerizing resins were evaluated using a torsional test method. The results showed that Palapress and Caulk resins had a higher repair strength than Rapid Repair resin.

Denture stomatitis in an elderly edentulous Asian population.

Denture stomatitis is a common oral disease in denture wearers. Multiple aetiological and predisposing factors are believed to be responsible for its initiation and progression. The aim of this study was to assess the relationship between denture age, denture hygiene habits, denture wearing and denture cleanliness in an elderly edentulous Asian population. Seventy-five edentulous patients, all wearing maxillary complete dentures were divided into two groups. The test group comprised 36 patients (14 male and 22 female) with Type II denture stomatitis. The control group comprised 39 subjects (14 male and 25 female) with clinically healthy palatal mucosa. A standardized interview and clinical appraisal were carried out. The dye disclosing method was used to assess denture cleanliness and the resultant staining pattern scored. Statistical appraisal between the two groups revealed significant differences in denture hygiene habits (P < 0.05), denture wearing behaviour (P < 0.01) and denture cleanliness (P < 0.01). No significant difference was observed in the age of dentures between the test group and controls (P > 0.05). In the studied Asian edentulous population, a relationship between denture hygiene habits, denture wearing behaviour and denture cleanliness to the presence of denture stomatitis was observed.

A clinically viable index for quantifying denture plaque.

A denture plaque index using the dye disclosing method was evaluated in 24 patients with Type II denture stomatitis and 17 control subjects with healthy palatal mucosa. Patients with denture stomatitis had statistically significantly higher plaque scores than did controls, indicating a quantitative increase in denture plaque in patients with denture stomatitis. When this plaque index was tested by two examiners for intraexaminer and interexaminer reproducibility, it yielded a 92% to 96% reproducibility. The plaque index used in this study seems to satisfy the criteria for an ideal clinical index: It is simple, reliable, reproducible, and economical and can be carried out in the shortest possible time in a clinical setting.

The use of removable partial dentures amongst private dental practitioners in Singapore.

A questionnaire survey was carried out in 1995 amongst university trained general dental practitioners in the city state of Singapore to assess the use of removable partial dentures (RPD). 37% of the original sample of 469 completed and returned the questionnaire. The results of this survey indicate that RPDs are a common treatment modality in Singapore. Acrylic partial dentures appear to be the preferred choice for RPD treatment. The work profile of those who had a postgraduate qualification in removable prosthodontics did not differ from that of the general dental practitioner.

Shear bond strength of denture teeth to base: a comparative study.

Fracture and debonding of plastic teeth from the denture base are common clinical problems. In this study, a shear, or peeling, load was applied to the tooth-denture base junction. The bond strength of a high-impact, heat-cured denture base to three commercial brands of denture teeth, Bioform, Dentacryl, and TNR, was assessed. Ninety-three percent of the specimens exhibited cohesive failure within the body of the tooth and not adhesive failure at the tooth-denture base junction. Some of the teeth exhibited brittle fracture while others underwent distortion on loading. Dentacryl displayed the highest cohesive bond strength, followed by Bioform and TNR.

Advertising in dentistry--a position paper.

The limitations on advertising set by current regulations are examined and the possible consequences of relaxing these regulation discussed. The opinions of the dental profession on this issue, as determined through a questionnaire survey of members of the Singapore Dental Association (SDA), are included. Finally, some recommendations are made with respect to modifying current advertising laws.