A Primary Care Randomized Controlled Trial of Hall and Conventional Restorative Techniques.

OBJECTIVES: To investigate treatment outcomes of different restorative techniques undertaken by dental therapists for primary molar carious lesions in a sample of children in New Zealand primary care. METHODS: This was a randomized controlled trial with children aged 3 to 8 y in New Zealand's Whanganui region. Children meeting inclusion criteria were randomly allocated to treatment with either the Hall technique (HT), in which a stainless-steel crown (SSC) is placed without any carious tissue removal or tooth preparation, or a non-Hall conventional restorative approach (NHT), including tooth preparation with selective carious tissue removal; this included SSC, amalgam, composite, or glass ionomer cement (GIC) restorations. Restorative outcomes after 12 and 24 mo were categorized as success, minor failure, or major failure. RESULTS: Of the 295 eligible children, 149 and 146 were allocated to the HT and NHT groups, respectively, with a total of 570 carious primary molars treated by 13 dental therapists. The participant follow-up rates at 12 and 24 mo were 95% and 91%. SSCs were the most commonly used restoration in the NHT group (60%), followed by GIC (28%). SSCs were the most successful restorations regardless of whether they were placed with the HT or NHT, with success rates of 89% and 92% at 12 mo and 85% and 86% at 24 mo. In the NHT group, the treatment material was a predictor of minor failure at 12 and 24 mo, with significantly more failures with GICs. CONCLUSIONS: SSCs placed by dental therapists are a highly successful restoration for the primary dentition, regardless of whether they are placed with the HT or conventionally. The high failure rate of glass ionomer restorations means that they cannot be recommended for widespread use in New Zealand primary care (Australian New Zealand Clinical Trials Registry, ACTRN12614000844640). KNOWLEDGE TRANSFER STATEMENT: The findings of this study can be used by policy makers and clinicians when deciding on which materials and which approach to use to maximize success and to minimize retreatment rates when providing restorative treatment for carious primary molars in children's primary oral health care. Results also suggest that undertaking research in the primary care setting may enhance translation of new knowledge and techniques into clinicians' hands.

A biocultural perspective on Marianas prehistory: recent trends in bioarchaeological research.

Fifteen years ago, the biohistory of Micronesia was still a blank slate relative to other regions of the Pacific. Since 1980, however, the Mariana Islands, one of the largest island chains in Micronesia, have been the focus of intensive archaeological investigation and human remains have been ubiquitous components of the archaeological assemblages recovered from the islands of Guam, Rota, Tinian, and Saipan. These investigations have provided us with a wealth of new data that will contribute substantially to our understanding of population adaptation to island ecosystems in this part of the Pacific. Much of the recent bioarchaeological research in the Marianas is the product of archaeological mitigation rather than directed research. Consequently, many of our research efforts have been articulated with the needs of cultural resource management (CRM) where research designs focus on several general problem areas: 1) subsistence adaptation with emphasis on the contribution of marine vs. terrestrial resources and the role of pelagic, or deep-ocean resources in the marine component of the diet; 2) regional (upland vs. coastal; interisland) and temporal variation in subsistence/settlement; and 3) geomorphologic variation in coastal sediments, particularly as influenced by storm events.

Stable isotopic analysis of human diet in the Marianas Archipelago, western Pacific.

Proportions of marine vs. terrestrial resources in prehistoric human diets in the southern Mariana Islands (Guam, Rota, Saipan), Micronesia, have been estimated by analysis of stable isotope ratios of carbon and nitrogen in bone collagen and of carbon in apatite. The isotopic composition of marine and terrestrial food resources from the Marianas have also been determined. Experimental evidence shows that collagen carbon isotopes mainly reflect those of dietary protein sources and thus overestimate the contribution of marine animal foods. Marine protein consumption apparently ranges from approximately 20% to approximately 50% on these islands. Experiments also demonstrate the carbon isotope ratio of bone apatite carbonate accurately reflects that of the whole diet. Carbonate carbon isotope data suggest some individuals consumed significant amounts of 13C-enriched (C4) plants or seaweeds. Sugar cane is an indigenous C4 crop and seaweeds are eaten throughout the Pacific, but they have not been considered by archaeologists to have been prehistoric dietary staples. Apatite carbon isotope analysis has apparently identified previously unrecognized prehistoric dietary adaptations in the Mariana Islands, but this must be confirmed by archaeobotanical evidence.

The effect of pH on the kinetics of arylsulphatases A and B.

The effect of pH on the kinetics of rat liver arylsulphatases A and B is very similar and shows that two groups with pK values of 4.4-4.5 and 5.7-5.8 are important for enzyme activity. Substrate binding has no effect on the group with a pK of 4.4-4.5; however, the pK of the second group is shifted to 7.1-7.5 in the enzyme-substrate complex. An analysis of the effect of pH on the Ki for sulphate inhibition suggests that HSO4-is the true product. A model is proposed that involves the two ionizing groups identified in the present study in a concerted general acid-base-catalysed mechanism.