Validation of a Sulfuric Acid Digestion Method for Inductively Coupled Plasma Mass Spectrometry Quantification of TiO<Subscript>2</Subscript> Nanoparticles

A consistent analytical method incorporating sulfuric acid (H₂SO₄) digestion and ICP-MS quantification has been developed for TiO₂ quantification in biotic and abiotic environmentally relevant matrices. Sample digestion in H₂SO₄ at 110°C provided consistent results without using hydrofluoric acid or microwave digestion. Analysis of seven replicate samples for four matrices on each of 3 days produced Ti recoveries of 97%?±?2.5%, 91?% ±?4.0%, 94%?±?1.8%, and 73?% ±?2.6% (mean?±?standard deviation) from water, fish tissue, periphyton, and sediment, respectively. The method demonstrated consistent performance in analysis of water collected over a 1 month.     

Mandibulofacial dysostosis. Case report

A case of mandibulofacial dysostosis (Treacher Collins syndrome) is presented. Clinical features and skull radiographs revealed typical anomalies associated with the syndrome. Cleft of the soft palate and unerupted multiple supernumerary teeth were present in this case. No haematological, biochemical or immunological abnormalities could be detected in the patient. Pedigree analysis showed an autosomal dominant mode of transmission of the disease. Chromosomal studies did not reveal any structural or numerical discrepancies.     

The influence of dental status on the detection of IgG class anti-viral antibodies in human saliva.

An antibody-capture radioimmunoassay was used to measure levels of IgG class antibodies to rubella and hepatitis A viruses in serum and saliva of 30 edentulous, 30 partially dentate and 31 dentate individuals. The prevalence of seropositivity for rubella was 98.9 per cent and for hepatitis A 73.6 per cent. The serum reactivities were generally greater than those for saliva. There were 8 false-negative results for saliva out of the 182 tests performed, of which 4 were in the edentulous group, 3 in the partially dentate and 1 in the dentate group. For both rubella and hepatitis A virus antibodies the (geometric) mean ratios between the saliva and serum reactivities were similar across the three dental groups. The values for sensitivity, specificity and positive predictive value suggest that assay of saliva for antiviral IgG antibody is a satisfactory technique regardless of dental status.     

At-Home Bleaching System: Effects on Enamel and Cementum

An analysis by scanning electron microscopy was undertaken to investigate the effects of bleaching on enamel-cementum surface morphology. Teeth were investigated in five groups: control; vital bleached for 5, 15, and 30 days; and 37 percent phosphoric acid gel etched for 20 seconds. Only the gel-etched group exhibited etching patterns. Shade change in vital bleached teeth was noted in the group vital bleached for 30 days.     

Postoperative complaints following impacted mandibular third molar surgery in Ile-Ife, Nigeria.

An investigation into the pattern of complaints lodged by patients after impacted mandibular third molar surgery was done in a Nigerian teaching hospital over a period of 3 years. One hundred and twenty seven records were retrieved. Pericoronitis (71.2%), pulpitis (17.6%) and periodontitis (11.2%) were the reasons for surgery. No third molar surgery was done for prophylactic or orthodontic reasons. Sixty-one complaints were lodged by 49 (38.6%) patients on day 1, and 37 complaints by 35 patients on day 7. These complaints were verified by the findings of the examining clinician. Pain, swelling and trismus were the commonest complaints. A significant association (P = 0.042) was found between patients' complaints on the first postoperative day and the drug combination given. Similarly, there was a significant relationship (P = 0.0055) between the type of analgesics prescribed and the presence of postoperative pain. No significant relationship was however found between the complaints and patients' age, indication for extraction, impaction type and method of impacted tooth removal. Although the findings of this retrospective study are limited in their comparability, they suggest the need for an appraisal of pain management in patients undergoing mandibular third molar surgery in our hospital. Consequently, there should be a reduction in complaint rate thereby making selective review appointment on the first postoperative day feasible.