A comparative study of the strength of aluminous porcelain and all-ceramic crowns

This study compared the breaking strengths of all-ceramic crowns constructed with aluminous porcelain, the Cerestore system, and the Dicor system on an anterior tooth preparation. Fifteen crowns from each group were constructed to comparable dimensions on dies from the same master die. Ten crowns from the same group were cemented on the master die and loaded until catastrophic failure. Five crowns from each group were embedded and sectioned to examine internal adaptation. No significant difference was found between the load necessary to produce failure in the aluminous porcelain and Dicor crowns and the load needed to initiate crack formation in the Cerestore crowns. However, seven of the 10 Cerestore crowns showed a two-phase failure pattern; the difference between crack initiation and catastrophic failure was significant. Within the limitation of this study, neither the Cerestore (high alumina core) nor the Dicor (castable glass-ceramic) produced an all-ceramic crown superior to the current aluminous porcelain crown.     

The role of team dentistry in improving access to dental care in the UK

The role of professionals complementary to dentistry (PCDs) in improving access to NHS primary dental care is discussed. The pattern of under-supply of dentists in poor socio-economic areas is highlighted and identified, in drawing a parallel to the workings of primary medical teams, as a possible area where PCDs could be used.     

Aprotinin reduces blood loss and the need for transfusion in orthognathic surgery

A randomized, placebo-controlled, double-blind trial (n= 15 in each group) showed that patients given aprotinin intravenously (200 ml, [2000000 kallikrein inactivator units] before the operation and then 50 ml per h until the end of the operation) during simultaneous maxillary Le Fort 1 and mandibular sagittal split osteotomies, lost 52% less blood than controls (calculated by subtracting the volume of saline irrigant used from the volume of blood collected in the aspirator bottle and surgical drains). Patients given aprotinin lost a mean (SD) of 473 (190) ml compared with 986 (356) ml in controls. They also required significantly less transfused blood (1 was given 2 units in the aprotinin group compared with 9 given a mean of 1.5 units (range 1-4) in the control group). There were no complications attributable to this drug.     

The effects of diphenylhydantoin and vitamin D deficiency on developing teeth in the rat.

The effects of short-term (21 days) and long-term (116 days) treatment with oral diphenylhydantoin (DPH, 6 g/kg diet) on the development of rat teeth was investigated. Long-term DPH reduced the size of the incisors and of all the molars except the upper first. There was also a reduction in tooth weight and both changes were shown to be independent of body weight. Short-term DPH reduced the size of the incisors and upper third and second molars only.The relationship of these lesions to the shortened tooth roots found in epileptics on chronic anticonvulsant therapy and the stunted root development seen in hypoparathyroidism is discussed. It is suggested that DPH may induce a state of “pseudohypoparathyroidism” by inhibiting the action of parathyroid hormone on bone and tooth. This complication would appear to be additional to the so-called “anticonvulsant-induced osteomalacia”.