Quintessence International, 06/1990

Glass-ionomer cement has been advocated for use as a base under composite resin restorations. Forty-nine restorations were studied over a 2-year period to test the efficiency of the glass-ionomer cement-composite resin sandwich technique in Class II cavities. The restorations, all placed by one clinician, were assessed at 6-month intervals for color, anatomic form, marginal adaptation, and surface roughness. Seventeen restorations failed during the follow-up period because of progressive loss of glass-ionomer material. Despite the good performance of the composite resin at the occlusal sum faces, the sandwich technique failed to provide acceptable restorations in this clinical trial.

The purpose of this study was to determine the failure mode of a posterior composite resin bonded to a glass-ionomer cement that was treated with and without a cationic vinyl functional silane coupling agent while the etch times were varied. Bond failure occurred at the glass-ionomer cement-composite resin interface (adhesive failure) in specimens that were not etched and when no coupling agent was used. When the samples were etched for 5, 15, or 30 seconds, approximately 50% failed within the glass-ionomer cement (cohesive failure). The use of the coupling agent produced a failure mode of 80% to 100% within the glass-ionomer cement. With a 15-second etch, the coupling agent produced 100% failure within the glass-ionomer cement, while only 50% of the samples without the coupling agent failed within the glass-ionomer cement. With a 30-second etch, all the samples treated with the coupling agent failed within the glass-ionomer Cement, while only 60% of the samples not treated with the coupling agent failed within the glass-ionomer cement. Without the coupling agent, groups in which the glass-ionomer cement was not etched showed a lower shear bond strength than did groups in which the cement was etched for 5, 15, or 30 seconds. With the coupling agent, the groups in which the glass-ionomer cement was not etched had lower bond strengths than did the group in which the glass-ionomer cement was etched for 15 seconds. Analysis of the data revealed all these differences to be statistically significant.

The purpose of this study was to examine the effect of a stonnous fluoride pretreatment of dentin on the shear bond strength of a dentinal adhesive system with a composite resin restorative material. Dentinal specimens from 31 extracted human third molars were used in a matched-pair design. Statistical analysis of the data showed that pretreatment of dentin with the stannous fluoride solution significantly decreased the bond strength of the dentinal adhesive system (P = .0005). Clinicians should consider the negative effects of fluoride pretreatment of dentin when used in conjunction with dentinal adhesives and composite resin restorative materials.

Diabetes mellitus is a chronic disorder affecting the metabolism of carbohydrates, fats, and proteins. Increasing numbers of diabetic patients are presenting in the dental office, perhaps as a result of the improved longevity of diabetic patients. The pathophysiology, complications, and oral manifestations associated with the disease, as well as the medical and dental management of the diabetic patient are reviewed.

The purpose of this study was to evaluate the short-term clinical effect of zirconium silicate chewing gum on plaque and gingivitis. Initial scoring using the Plaque, Gingival, and Quigley-Hein indices was carried out. Twenty subjects then began a 2-week period of refraining from any type of oral hygiene. The indices were used again to determine a baseline score, which indicated the development of experimental gingivitis. The subjects then chewed the gum for 30 minutes, and the plaque indices were rescored. Subjects were divided into two groups of ten each: group A resumed brushing and flossing, along with the 30 minutes of gum chewing, and group B flossed and chewed gum only. At 1 day and 1 week all subjects were rescored. Pairwise and student's t tests were performed. The immediate effect of chewing the gum for 30 minutes was to reduce plaque up to 19% overall. The reductions increased to 38% by 1 day, and 46% by 1 week for group A, while group B showed reductions of 26% at 1 day and 22% 1 week. Both groups showed significant reductions (P .01) in their gingivitis scores after 1 week. Zirconium silicate chewing gum may serve as an adjunct for the control of plaque and gingivitis.

Studies of the denture-nearing habits of elderly people have revealed that patients keep their dentures past the time when they should be replaced. In South Africa few studies are available, although the indications are that many old (and young) people in the black community do not have dentures at all. For elderly pensioners and for those who are out of work or without Medical Aid, the obstacle to having dentures made is mainly a financial one. A technique for the construction of dentures in two visits has been devised to reduce the cost and time required to make new dentures. The technique makes use of a bitefork to allow maxillomandibular registration to be made at the first visit and preformed anterior arch segments that allow the occlusal plane to be determined. Posterior arch segments are used in the laboratory to complete the assembly of the denture. The technique may be a useful option for poor and elderly patients, for whom time away from work, transport, and the cost of dentures are important factors in having dentures made.

Previous investigators have described oral manifestations of degenerative connective tissue diseases such as systemic lupus erythematosus, but little data exists on the profile and prevalence of these signs and symptoms in a given patient population. The purpose of this study was to describe the prevailing oral symptoms and signs of a population of patients with systemic lupus erythematosus. Sixteen women with diagnosed systemic lupus erythematosus were thoroughly examined and completed a questionnaire regarding specific oral symptoms. The results indicated certain prevalent objective manifestations: xerostomia; angular cheilitis; chapped lips; mucositis; glossitis; caries; and periodontal disease. Analysis of the questionnaires revealed the following subjective complaints: xerostomia, problems with caries; periodontal disease; difficulties in chewing, swallowing, and eating; dysguesia; and glossodynia. The high prevalence of oral problems indicates the necessity for thorough oral examinations as well as recognition and preventive management of these prevalent oral manifestations in dental patients with systemic lupus ervthematosus.

This paper presents the etiology and rationale for early correction of posterior crossbites in the primary and early mixed dentitions. Six cases have been selected to demonstrate the principles and philosophy of various treatment modalities so that practitioners be able to recognize and understand the etiology of crossbite conditions and to formulate an approach for the diagnosis and the best method of treatment for the correction of posterior crossbite in the young child.

A review of recent developments in the use of tooth-colored materials for restoration of cervical lesions is presented. While glass-ionorner cement restorations in this area currently offer tile best prognosis, an improved prognosis for composite resin restorations may result from improved dentinal adhesives and through use of glass-ionomer cement bases or liners.

Chemomechanically treated dentin has been reported to enhance dentinal bonding. This was evaluated in vitro in 96 mixed Class V restorations. Thirty-two cavities were prepared mechanically only and had bevels in enamel and butt joints in dentin, and 32 cavities were further treated chemomechanically for 10 minutes, while 32 carious lesions were excavated only chemomechanically and had bevels in enamel and dentin. Eight identically prepared cavities from each preparation group were assigned to each one of four different bonding techniques and restored accordingly Restoration quality was assessed for margins in enamel and dentin separately and quantitated as percentage of excellent margin before and after thermal cycling and degree of dye penetration. C'hemomechanical preparation procedures did not provide better results than the ordinary mechanical preparation. In addition, the chemoinechanical preparation procedures were time-consuming and resulted in ragged cavity margins.

The article presents the author's views on inadequate use of Precision Instruments or collimation techniques by dentists. According to him, the only reason for the modern dentists not using these instruments and techniques is ignorance. To rectify this ignorance, the author has demonstrated a proper intraoral radiographic technique pictorially in the article. He also adds that change in dental radiographic techniques is a requirement today.

In the past, dentinal adhesives were evaluated in Class V or cylindrical dentinal cavities. There have been relatively few reports on the effectiveness of dentinal adhesives in posterior restorations. In the present study, five of the most recently developed dentinal adhesives were examined to determine their ability to seal margins. None of the dentinal adhesive and posterior composite resin combinations demonstrated a complete seal at the proximal cervical margins of Class II mesio-occlusodistal restorations. In general, margins finished in enamel were sealed against leakage better than were those finished in dentin. A glass-ionomer lining cement did not eliminate the marginal leakage of Class II composite resin restorations.