The burden of restorative dental treatment for children in Third World countries

OBJECTIVE: To analyse whether developing countries have sufficient health dollars to treat existing diseases in general and dental caries in particular in their child population. METHODS: Assessments of the costs of treating existing and future caries by the conventional approach. Analysis of WHO dental databases and spreadsheet calculations of costs based upon population projections, prevalence and trends in patterns of caries. FINDINGS: Even though the caries levels are low and most of the disease occurs on the occlusal and the buccal/lingual surfaces, more than 90% of the dental caries remains untreated in Third World countries. Calculations reveal that to restore the permanent dentition of the child population of low-income nations using traditional amalgam restorative dentistry would cost between pounds 1,024 ($US1618) and pounds 2,224 ($US3513) per 1,000 children of mixed ages from 6 to 18 years. This exceeds the available resources for the provision of an essential public health care package for the children of 15 to 29 low-income countries. CONCLUSIONS: To treat caries with the traditional method of restorative dentistry is beyond the financial capabilities of the majority of low-income nations, as three-quarters of these countries do not even have sufficient resources to finance an essential package of health care services for their children.     

Dental fracture fragment attachment: fracture model and luting agent comparisons

PURPOSE: The purpose of this study was twofold: 1. To compare two different research models for simulating a traumatic anterior tooth fracture: the blunt trauma method (standard method) and an AL2O3 sectioning method (experimental method). 2. To compare the bond strength of tooth fragments bonded with resin modified glass ionomer vs. a light cured composite resin. METHODS: Two hundred bovine incisors were used in the study and kept in plain tap water throughout. The study consisted of five basic steps: 1. Fracture of the teeth by either blunt trauma (chisel and hammer) or AL2O3 sectioning disc. 2. Luting of the fractured fragments back to the teeth using either a composite resin or resin modified glass ionomer. 3. Thermocycling of the repaired teeth. 4. Dislodging the teeth to determine the strength of repair. 5. Determination of fracture type. RESULTS: One-way ANOVA revealed a statistically significant difference in the forces required to fracture the resin modified glass ionomer and composite resin regardless of whether the teeth were originally fractured with the blunt force method (p=0.030) or the disc sectioning method (p=.001). One-way ANOVA also revealed a statistically significant difference between the forces required for fracture by blunt trauma and the disc fracture techniques with the resin modified glass ionomer group (p=0.000345). However, there was no significant difference when the two techniques were compared for the composite resin (p= 0.2941). CONCLUSIONS: 1. The resin modified glass ionomer was significantly stronger than the composite resin when both the blunt trauma and the disc fracture techniques were employed. 2. The study's results do not support substituting the ease of the AL2O3 disc for the more time-consuming blunt trauma method.     

Real-time quantitative polymerase chain reaction for enumeration of Streptococcus mutans from oral samples

This study compared SYBR Green real-time quantitative PCR (qPCR) with standard plate counting for the enumeration of Streptococcus mutans in oral samples. Oral samples (n = 710) were collected from high-caries-risk children for quantification of S. mutans by qPCR using primer pairs. The S. mutans copy number was calculated with reference to a qPCR quantification cycle (Cq) standard curve and compared with the absorbance value at 600 nm of a standard suspension of S. mutans UA159. The S. mutans copy number results were evaluated in relation to standard plate count (SPC) results obtained from each sample following culture on Petri plates containing S. mutans selective media and reported as colony-forming units (CFUs). The mean S. mutans copy number calculated from qPCR was higher than the SPC CFUs (1.3 × 10(6) and 1.5 × 10(5) CFUs, respectively). The qPCR values were usually higher in individual samples and qPCR detected the presence of S. mutans 84% (231/276) of the time that the SPC did not, compared with 33% (4/12) of the time when qPCR failed to detect S. mutans and the SPC did. The qPCR technique was found to be more sensitive for detection of S. mutans from oral samples, a method that is not dependent on the viability of the sample taken and therefore is proposed as a more reliable and efficient means of quantification of S. mutans.     

Systemic bone disease in patients with mandibular atrophy

Although the etiology of alveolar ridge resorption is unclear, the labile alveolar bone may be highly sensitive to changes in systemic bone mineral content. Ten patients presenting with severe mandibular atrophy were studied by photon absorption densitometry. Four patients exhibited a significant reduction in radial midshaft mineral content. All four had systemic bone disease revealed on undecalcified histological sections although serum biochemical studies were normal. Common factors were severe mandibular atrophy, decreased bone density, and systemic bone disease. Photon absorption densitometry is suggested as a screening mechanism for systemic bone disease in patients with severe mandibular atrophy.     

Experimental evaluation of microsurgical repair of the lingual nerve

Epineural microsurgical repair of the lingual nerve has been shown to be effective in leading to return of sensation in an animal model. Cadaver dissections have provided information regarding surgical access to the operative site, some possible anatomic variations that may be encountered, and a method for nerve repositioning to allow a gain in length.