Effect of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the effects of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae (SCAP) in vitro.</p><p><b>METHODS</b>SCAP were isolated and cultured respectively in alpha minimum essential medium (α-MEM) or α-MEM containing 1.8 mmol/L KH2PO4. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to examine the odonto and osteogenic potential of SCAP in the two media.</p><p><b>RESULTS</b>SCAP cultured in α-MEM containing 1.8 mmol/L KH2PO4 exhibited a higher ALP activity [(0.370 ± 0.013) Sigma unit×min(-1)×mg(-1)] at day 3 than control group [(0.285 ± 0.008) Sigma unit×min(-1)×mg(-1)] and KH2PO4-treated SCAP formed more calcified nodules at day 5 [(0.539 ± 0.007) µg/g] and day 7 [(1.617 ± 0.042) µg/g] than those in normal medium [(0.138 ± 0.037) µg/g, P < 0.01]. The expression of odonto- and osteogenic markers were significantly up-regulated after the stimulation of KH2PO4 at day 3 and 7 respectively, as compared with control group.</p><p><b>CONCLUSIONS</b>1.8 mmol/L KH2PO4 can promote the odonto and osteogenic differentiation potential of human SCAP.</p>

Bilateral maxillary fused second and third molars: a rare occurrence / 国际口腔科学杂志·英文版

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

Nonlinear finite element analysis of three implant- abutment interface designs / 国际口腔科学杂志·英文版

The objective of this study was to investigate the mechanical characteristics of implant-abutment interface design in a dental , using nonlinear finite element analysis (FEA) method. This finite element simulation study was applied on three commonly used commercial dental implant systems: model I, the reduced-diameter 3i implant system (West Palm Beach, FL, USA) with a hex and a 12-point double internal hexagonal connection; model II, the Semados implant system (Bego, Bremen, Germany) with combination of a conical (450 taper) and internal hexagonal connection; and model III, the Brinemark implant system (Nobel Biocare, Gothenburg,Sweden) with external hexagonal connection. In simulation, a force of 170 N with 45" oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum von Mises stress, principal stress and displacement while the Br Bnemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution, and produced a smaller displacement than the other two implant systems.

Study on the quality of life and social support among people living with HIV/AIDS and their family members / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the quality of life and related social support among people living with HIV/AIDS with related factors.</p><p><b>METHODS</b>331 people living with HIV/AIDS and 148 of their family members were selected using a typical sampling method. Questionnaires on general conditions, tables on history of infection, generic quality of life inventory-74 (GQOLI-74) and social support scale (SSS) were used.</p><p><b>RESULTS</b>Data from one-way analysis suggested that people living with HIV/AIDS and their family members with the different sexs, different villages and different cultural backgrounds had differences in GQOLI-74 scores (P < 0.05) while people living with HIV/AIDS with the different villages had differences in SSS scores (P < 0.05). Results from Multiple linear regression analysis revealed that being elderly and negative life events were negatively associated with social support (P < 0.05), while factors as more advanced educational background, harmonious neighborhood relationship and having bother pouring nature were the predictive factors (P < 0.05).</p><p><b>CONCLUSION</b>Many factors might affect dimensions of quality of life among people living with HIV/AIDS and their family members in rural areas of northern Anhui. Community care and social support of HIV/AIDS should still be greatly enhanced in the countryside of China. A community care mode based on family and neighborhood was expected to be developed.</p>