J. De Boever

Long-term clinical study of porcelain-fused-to-gold restorations

S everal years ago porcelain-fused-to-gold (PFG) restorations were introduced to fixed partial denture prosthodontics. The new materials and related clinical techniques represent an important step toward an optimal solution to many problems in fixed prosthodontics, especially in the anterior region. The method combines the esthetic qualities of porcelain with the strength, accuracy, and marginal adaptation of the metal. Several studies have been published on the clinical and material aspects of PFG restorations.‘-6 The chemical characteristics of the porcelain-to-gold bonding and the possible defects caused by inadequate laboratory procedures also have been reported.‘-‘” Much attention has been paid to the strength of the bonding between gold and porcelain.“.?’ Hobo and Shillingburg2r described the specific preparation techniques and the coping design. In histologic studies others showed the positive clinical tolerance of the marginal periodontium to the porcelain.?“‘“’ As far as we know, only one long-term clinical study of PFG restorations has been published.3’ The purposes of this clinical long-term survey were to examine the frequency of mechanical failures of PFG restorations and to provide some suggestions for their possible prevention. -

Tooth pulpal reflexes in jaw musculature in man

Abstract Electrical stimulation of the tooth pulp elicited a short-latency, transient bilateral suppression of the voluntary masseter electromyogram. The threshold of this pulp reflex was somewhat higher than the pulpal sensory threshold, which coincided with the occurrence of a slight but distinct painful pricking sensation. When tested following pulp stimulation, the myotatic masseter reflex exhibited a phase of depression that had a much longer duration in resting conditions than during voluntary jaw closure. It is concluded that nociceptive afferents in the oro-facial area, most probably belonging to the A-delta group, have oligosynaptic inhibitory reflex connections with jaw-closing motoneurons.

The width of the attached gingiva during orthodontic treatment: A clinical study in human patients

Studies of the influence of orthodontic movement on the width of the attached gingiva gave conflicting results. Therefore, it was decided to evaluate this parameter in human patients during a full orthodontic movement with fixed appliances. Retrusion of six maxillary anterior teeth was performed in thirteen patients scheduled in a prophylactic program that included a 2-week recall during the entire experiment. Before and after treatment the plaque index, the sulcus bleeding index, the width of the keratinized and the attached gingiva, and the marginal gingiva mobility index were measured. The results indicated that retrusion of the maxillary anterior teeth had no influence on any of the measured parameters.

Successful pregnancy in an abortion-prone woman: Prostaglandin and hormone levels during implantation, gestation and lactation

Serum progesterone, human chorionic gonadotropin, prostaglandin E2, F2 alpha and 13,14-dihydro-15-keto-PGF2 alpha and urinary immunoractive prostaglandins E2 and F2 alpha were measured throughout gestation in a woman who previously had experienced three abortions, an immature birth of a twin and a term single pregnancy. Prostaglandin-mediated symptoms such as uterine sensitivity and contractions, backache, spotting, vomiting and diarrhea were carefully registered and have been correlated with the variations in prostaglandin levels. The effect of therapy with a prostaglandin synthetase inhibitor and a beta-adrenergic drug on prostaglandin levels was also studied. The rise of prostaglandin E2 level observed during implantation is discussed.