The aims of this study were to improve the mechanical and chemical properties of conventional restorative glass ionomer cement (GIC) by adding hydroxyapatite (HAp) preparations with different characteristics, and to investigate the underlying reaction mechanisms. Fuji IX GP ® was used as the control GIC. The experimental GICs consisted of four HAp-particles with different characteristics added at 8 mass% to Fuji IX-powder. All cements were prepared by mixing with Fuji IX-liquid (P/L=3.6). Four HApparticles were analyzed, and then the mechanical strengths and the fluoride-ion-release-recharge-behaviors of five GIC groups were evaluated. The results of this study demonstrate that the addition of HAp particles with highly reactive properties such as high specific surface area can enhance the flexural strength and fluoride ion release properties of conventional restorative GIC. Our results further indicate that HAp functions as an adsorbent and an ion exchangeable agent, resulting in improved mechanical and chemical properties of GIC.

No abstract

Aristolochic acid (AA) is considered to be a causative agent for progressive interstitial renal fibrosis, leading to AA nephropathy. Lysophosphatidic acid (LPA) is a mediator in the onset of renal fibrosis. In this study, we analyzed the molecular species of LPA and its precursor lysophospholipids in kidney tissue from rats exposed to AA. Daily intraperitoneal injections of AA for 35 days to rats gave rise to fibrosis in kidney, decreased the kidney levels of LPA, lysophosphatidylserine and lysophosphatidylinositol. In rat renal cell lines (NRK52E and NRK49F), AA-induced cytotoxicity was potentiated by Ki16425, LPA1,3 receptor antagonist. The level of mRNA encording α-smooth muscle actin was significantly increased by AA-treatment only in NRK52E cells, while the mRNA level of collagen III was decreased in both NRK52E and NRK49F cells. These results suggest that endogenous LPA in rat kidney prevents AA-induced renal fibrosis.

No abstract

The prevalence of infraoccluded or impacted primary molars was reported to be from 1.3% to 8.9% of the population with higher incidence between siblings. This is a report of a rare case of a 10-year-and-11-month-old boy with a previously erupted primary maxillary right second molar that was restored by with an amalgam filling at about three years of age. After seven years, the said tooth was found X-ray photographically to be completely embedded into the alveolar bone with an "impacted" maxillary permanent second premolar. There was also mesial tipping of the adjacent permanent first molar. The management of this case included the use of a space regainer to correct the molar tipping, surgical removal of the ankylotic infraoccluded primary molar and the use of a palatal holding arch to correct the torsiversion. This report underscores the need for early recognition of infraoccluded/ ankylosed primary teeth by dentists for regular monitoring and timely and appropriate intervention. Infraocclusion in primary dentition is mainly in primary molars which develop during the early mixed dentition. The prevalence of infraoccluded primary molars was reported to be from 1.3% to 8.9% of the population 1,2) with higher incidence between siblings 3,4). In many cases, they appear below the plane of occlusion above the gingival margin but a few can be severely occluded to be covered by gingiva 2) or become totally embedded in bone 5). If left untreated, the commonly reported occlusal consequences are space loss due to tipping of adjacent teeth and/or over eruption of the opposing teeth 2). Other complications include the insufficient development of adequate width and height of supporting bone which may complicate future dental treatment 6). Severe infraocclusion in primary molars