Dentist and laboratory: a "love-hate" relationship.

The author's intent has been to promote a close working relationship between the dentist and the technician. Certainly, McCracken was doing that when he said that he hoped they could "work together in proper sequence to develop restorations that are biologically and mechanically sound and to produce removable partial dentures that reflect continuous progress in prosthetic dentistry". That's the secret. The dentist and the technician should work together and in proper sequence. Too often dental education and the dental profession have seemed to espouse the idea that the technician must function as an automaton in the fabrication of removable partial dentures. The practitioner of general dentistry can certainly ask for ideas and suggestions from the technician and still control the ultimate outcome. The dentist can share thoughts with the technician to ameliorate the "love-hate" relationship and still be responsible for the removable partial denture treatment.     

Clinical trials of intraoral dental xeroradiography.

A new dental xeroradiographic processor was clinically tested. In comparison with conventional radiographs, xeroradiographs often showed more anatomic detail of teeth and bone and required approximately half the exposure time. These characteristics, the speed of operation and the added features for convenience, suggest that xeroradiography may be important to dental radiography in the future.     

The presence of Candida albicans in hereditary benign intraepithelial dyskeratosis. An ultrastructural observation.

Specimens taken from the buccal mucosa of two patients with hereditary benign intraepithelial dyskeratosis (HBID) were studied by transmission electron microscopy. The ultrastructure of epithelial tissue in HBID was previously reported. Discovery of Candida albicans in this lesion was an accidental finding. The literature on the subject was reviewed and the ultrastructural features of Candida albicans were described.     

Effectiveness of a pit and fissure sealant in the prevention of caries: three-year clinical results.

With use of the half-mouth technique, a pit and fissure sealant was applied to the permanent first molars of 200 children between 6 and 8 years of age in a community with fluoridated water in Colombia, South America. Complete retention of sealant at 12, 24, and 36 months after application was 91.6%, 88.9%, and 87.5%, respectively. Partial retention of sealant was 5.8%, 7.1%, and 8.5% at the same intervals. The incidence of caries in all sealant-treated teeth at 36 months was 8% vs 53% in untreated paired teeth. Of the 238 teeth that completely retained sealant, only one tooth had occlusal caries at 36 months. No statistically significant difference in complete retention between maxillary and mandibular molars was noticed at any examination. The study confirms that this cold-cured pit and fissure sealant is effective in protecting the occlusal surfaces of teeth against caries for at least three years.     

Microleakage and enamel finish.

Cavity preparations that are finished with hand instruments allow significantly less marginal leakage than those which are completed only with rotary instruments. This does not mean that hand-instruments walls are perfectly smooth; it only means that these walls allow less marginal leakage. Cavity preparations restored with composite resin showed more marginal leakage than those restored with amalgam. Also, the degree of marginal leakage was greater in cavity preparations restored with composite resin than in those restored with amalgam. Cavity preparations are more prone to marginal leakage at sharply defined cavosurface acute angles than at the smooth or straight surfaces of the cavity. This pattern of marginal leakage was true for both amalgam restorations and composite restorations, but the degree of marginal leakage was greater when composite resin was used as a restorative material. Since less marginal leakage was found in the finished cavity preparations, it is obvious that all cavity preparations must be finished with hand instruments. This may not completely eliminate the problem of marginal leakage, but it will reduce the potential secondary caries both in degree and frequency. Also, since sharply defined acute angles did exhibit more marginal leakage, this part of the cavity preparation needs special attention. With amalgam and composite restorations at least, these angles should not be sharply defined but should be slightly round, so that better condensation of restorative materials can be obtained. This may reduce the degree of marginal leakage.     

The effect of fluoride and strontium application on dentin: in vivo and in vitro studies.

The effectiveness of topical 2% sodium fluoride applied with and without 10% strontium chloride pretreatment was compared in patients complaining of tooth hypersensitivity. In addition the radiopacity of 2% sodium fluoride and 25% strontium chloride treated dentin was studied in vitro. Reduction of sensitivity to cold and mechanical stimuli was evaluated during a period of 3 months by pain scoring in the exposed cervical dentin of homologous teeth on the two sides of the jaws. There was a significant decrease in the sensitivity of the exposed cervical dentin after treatment with sodium fluoride solution with or without pretreatment with strontium chloride solution. At the end of the experimental period the combined strontium and fluoride treatment was found to be more effective than that of fluoride alone in reducing sensitivity to cold. The increase in radiodensity of dentin samples immersed in strontium chloride was statistically significant, while there was no significant increase in density for the samples immersed in sodium fluoride solutions. A mineralization process is possibly the effective means by which fluoride or strontium diminishes sensitivity of dentin.