Hardness of enamel exposed to Coca-Cola and artificial saliva.

The purpose of this study was to determine the rate of change in indentation hardness of enamel in permanent teeth exposed to Coca-Cola. In a further experiment, the ability of a commercially available artificial saliva to remineralize enamel treated with Coca-Cola was tested. Ten enamel specimens were randomly chosen to be treated with Coca-Cola (experimental groups) and seven with water (control group). The fluids were applied for 1, 2, 3 h and overnight (15 h), washed off with a few drops of water and the moist enamel indentation hardness tested after each interval. With Coca-Cola treatment, the mean enamel hardness was 92.6% (s.d. = 7.9) of the original baseline hardness after 1 h, 93.25% (s.d. = 10.15) after 2 h, 85.7% (s.d. = 12.03) after 3 h and 80.3% after 15 h. The mean indentation hardness of control specimens treated with water was 108.7% (s.d. = 16.09) of the original hardness after 1 h, 99.09% (s.d. = 18.98) after 2 h, 98.97% (s.d. =11.24) after 3 h and 98.42% (s.d. = 22.78) after 15 h. In a separate experiment, the hardness of 9 enamel specimens was tested, as previously described, before and after treatment with Coca-Cola overnight and again after application of artificial saliva for 3 min. Coca-Cola reduced the mean indentation hardness of enamel in the teeth, but the hardness was partially restored with artificial saliva (Salivart) and increased by 18% from the demineralized enamel hardness.

Tongue piercing: a restorative perspective.

The implication of a traumatic injury to a permanent molar tooth as a complication by tongue piercing with ornamental jewelry is reported. An appropriate restorative management of the fractured tooth is described. The dentist's role in prevention and treatment of unfavorable complications is outlined. The rationales for selection of specific treatment modalities, in view of the degree of damage to hard dental tissues, are discussed. The range of hard tissue injuries resulting from tongue jewelry varies from a simple crack propagating into the enamel to a fractured tooth. A variety of factors must be considered before employing the available restorative methods.

Establishing the gingival emergence profile of restorations by using a resilient gingival replica.

All references to gingival morphology are destroyed once the die is trimmed during construction of crowns, onlays, or veneers. The need for reconstruction of a gingival replica to assist in the reproduction of a restoration's gingival contour and emergence profile is discussed. A simple, practical approach to duplicate the natural sulcus and free gingival morphology with currently available materials is presented. The advantages and limitations of implementing this technique and its multiple uses in prosthodontic and implant reconstructions and implant cases are presented.

Calcium release after acid pretreatment of fluoridated and nonfluoridated enamel.

Spectrophotometric analysis of calcium released by the acid-etching procedure was used to evaluate the effect of topical fluoride on the acid resistivity of enamel. The influence of superficial enamel surface reduction (chamfering) on the efficacy of the etching procedure was investigated.

Esthetic management of perimolysis with porcelain laminate veneers.

This report deals with the dental manifestations of bulimia nervosa. Differential diagnosis of perimolysis was identified and compared with other manifestations of systemic or exogenous causal factors. Conservative cosmetic dental management of the dental erosion that occurred as a result of bulimia nervosa was described and discussed in comparison with other currently accepted treatment modalities.

A longitudinal study of untreated mucogingival defects.

A study was conducted to observe the changes in areas with untreated mucogingival defects over a 4-year period. Upon entering dental school, a group of freshman students were assessed for Plaque Index, Gingival Index, probing depth, and width of keratinized gingiva. These same students were reassessed for the same parameters at the end of their senior year. Of the 112 sites in 39 individuals, 33 sites revealed a slight increase in keratinized gingiva, 69 sites were unchanged, and 10 sites showed a slight decrease. These changes were minimal and not statistically significant. The Plaque Index, Gingival Index, and probing depth mean values showed a small but statistically significant improvement. In this group of students with a high degree of oral hygiene, areas with inadequate zones of attached gingiva were able to be maintained without further recession and without surgery.

Oral hygiene for the partially edentulous.

THE EFFECTIVENESS of a proximal brush on the interdental hygiene for partially edentulous individuals was investigated. Nineteen partially edentulous adults participated in a crossover study. Three groups were instructed to use the toothbrush alone or a toothbrush combined with either toothpicks or proximal brush. The effectiveness of the cleansing devices was measured by the amount of plaque remaining on the examined surfaces. The results indicated that the cleaning efficiency of the proximal brush is greater than that of the toothpicks on the proximal surfaces of teeth adjacent to edentulous areas. On the other hand, the toothpicks were more effective on the proximal surfaces of teeth in contact.

Physical properties of a visible-light-cured composite resin.

This investigation has demonstrated some differences in physical properties between Fotofil and Adaptic. Clinically, these differences might be insignificant because the upper and lower limits of the values obtained for both were within the range for clinically acceptable composite resins as recorded in previous studies.

Radiographic assessment of proximal infrabony pocket topography.

A method for determining the topography of interproximal infrabony pocket lesions has been presented, utilizing three intraoral radiographys. Three periapical films for the urea to be examined should be taken in a standard manner, one with the central beam angulation horizontal, another at -20degrees and the third at +20degrees. Following processing, the dried films should be examined, commencing with the -0degrees film and comparing the width of the transitional zone with that of the -20degrees film and then the film exposed with the central beam angulation at +20degrees. Following this sequence, if the transitional zone decreases in width between the 0degree and -20degrees film, then the bony destruction is greater for the buccal plate. Should the transitional zone increase in width when the above sequence of examining the film is undertaken, the bone destruction is greater for the lingual plate of bone. In each case the third film will confirm the diagnosis. In the case of horizontal bone destruction in a buccolingual direction, the transitional zone will be absent or of minimal width on the 0degree film when compared with the film exposed at +20degrees and -20degrees.

The accuracy of the Schei ruler: a laboratory investigation.

A study has been carried out to assess the accuracy of the Schei ruler for measuring the amount of alveolar bone loss from radiographs. A dried human mandible was used for the purpose of this study. A preliminary test was conducted to achieve a standard radiographic technique. Two sets of radiographs were taken of anterior and posterior segments after successive modification of the height of the alveolar bony crest. These heights were measured directly and also by means of the Schei ruler for each stage, using first the root length, and secondly, the total tooth length, as references for obtaining the percentage of remaining alveolar bone. There are two points which may be concluded from this investigation: 1. The ruler proved to be a sensitive tool for measuring the amount of alveolar bone loss as well as being efficient in this application because of its simplicity and ability to give direct readings of the percentage of the bone lost (or remaining). 2. The use of the total tooth length as a reference for the percentage bone loss, overcomes the difficulties of locating other reference points.