Quintessence International, 08/2005

Objective: This paper presents the results of an investigation focusing on the retention of all-ceramic posts. The aim of the study was to evaluate the influence of two luting agents-a glass-ionomer cement (Ketac Cem) and a resin cement (Panavia F)-on the retention of a prefabricated ceramic post (Cerapost) after different pretreatment techniques in vitro. Method and Materials: Forty freshly extracted incisors and canines were treated endodontically. The root canals were filled with laterally condensed gutta-percha and sealer. The teeth were assigned to 1 of 4 groups, each containing 10 specimens: sandblasted/nonsandblasted post cemented with glass-ionomer cement and sandblasted/nonsandblasted post cemented with resin cement. Tensile tests were carried out. The specimens were also quantitatively analyzed under a scanning electron microscope. Results: The retentive strengths of posts, sandblasted and nonsandblasted, and cemented with Panavia F resin cement, were significantly increased as compared to those cemented with Ketac Cem. Conclusion: Both the luting agent and the post-surface pretreatment had a significant influence on the retention of the ceramic post. Keywords: bond strength, glass-ionomer cement, resin cement, retention, zirconium oxide post

Objective: One of the primary aspects of complete denture prosthodontics is determining the correct proportion for the maxillary central incisor width to the lateral incisor width. It has been suggested that the anatomy of the patient's nose is a reliable guide for deciding this ratio. The aim of this study was to test the hypothesis about the relationship between the shape of the nose and the proportion of the central incisor width (CIW) to the lateral incisor width (LIW). Method and Materials: The CIW and LIW from a total of 138 subjects (73 males, 65 females) were measured intraorally. The interalar width (IAW) and the width of the root of the nose (WRN) were measured on standard photographs of the subjects. Spearman's rho test was used to analyze the correlation between the proportions of the CIW to the LIW and the IAW to the WRN.The Mann-Whitney U test was applied to test for any possible gender differences. Results: The IAW, the WRN, and the nose angle (NA) were statistically significantly wider in male subjects than in female subjects. The correlation between IAW/WRN, NA, and CIW/LIW was statistically significant only in female subjects. In the general population, the only statistically significant relationship was between CIW/LIW on the left side and IAW/WRN. Conclusion: Within the results of the IAW, WRN, and NA measurements, we suggest that males have wider, more triangular-shaped noses than females. The proportion of IAW to WRN seems to be a reliable guide for deciding the proportion of the maxillary central incisor width to the lateral incisor. Keywords: complete denture, esthetics, Gerber, interalar width, nose anatomy, width of the maxillary incisors

Several techniques using subepithelial connective tissue for root coverage have recently been described in the periodontal literature. The predictability of such procedures, however, varies among the different reports. The factors responsible for these differences are not fully understood. The purpose of this article is to review and comment on factors that may enhance the predictability of root coverage. Keywords: gingival recession, graft, root coverage, subepithelial connective tissue

Objective: The purpose of this study was to examine the hydration of a high-alkali dental porcelain (Ducera LFC) and its relative abrasive wear against human enamel. The hypothesis is that the composition of the porcelain (LFC) will form a softer, hydrated layer in artificial saliva, which will reduce wear against enamel relative to other dental porcelains. Method and Materials: The first experiment was to estimate the thickness of the hydrated layer formed on LFC by storage in artificial saliva using microindentation hardness. The second experiment involved an estimate of enamel wear relative to other porcelains (d-Sign, LFC, Ducera Gold, and the control substance, Ceramco II) of hydrated LFC using a pin-on-disk wear test. Results: The mean microindentation hardness values of hydrated and unhydrated LFC and the Ceramco II control were 5750 Mpa, 8230 Mpa, and 7180 MPa, respectively, at a stylus depth of 400 nm. The average enamel wear values measured with the porcelains are (in microns): LFC saliva (hydrated), 23.8; d-Sign, 35.6; LFC, 59.4; Ducera Gold (hydrated), 75; Ducera Gold, 81.3; Ceramco II, 109.4. Using Tukey's analysis at a 5% error level, there were significant differences between the wear of enamel against hydrated LFC and the more abrasive Ceramco II control. Conclusion: Comparing the effect of hydration of LFC on enamel wear, using an independent t test, hydrated LFC was significantly less abrasive than LFC (P < .008), but was not significantly less abrasive than d-Sign. Keywords: enamel wear, hydration, porcelain

Every clinician has experienced the frustration of the gingival tissues retracting or changing shape. Meritorious work has been done to cope with these changes and to promote a healthy periodontium and normal papillae. But, so far, there is no explanation for why these changes occur. In this paper, a theory is presented that may clarify the process. The inner vacuum in the mouth, present at each act of swallowing, applies the soft tissues of the tongue, lips, and cheeks against the hard tissues of the bones and teeth. This action molds the soft tissues, adapting them in accordance to the architecture of teeth and embrasures; therefore, the oral vacuum has the capability to adapt, enhance, or impede gingival tissue growth. Keywords: gingival esthetics, gingival growth, modeling, negative pressure, suction, vacuum

Objectives: The aim of this clinical, controlled double-blind trial was to evaluate the effectiveness and side effects of two different mouthrinses. Method and Materials: Ninety subjects with gingivitis (or slight periodontitis) were randomly allocated to three groups: group 1, Chlorhexamed (0.1% chlorhexidine); group 2, Hexoral (0.1% hexetidine); and group 3, a placebo-control compound. The subjects were instructed on how to use the mouthrinse. At baseline, as well as after 2 and 4 weeks, the Approximal Plaque Index (API), the Bleeding Index (BI), the Community Periodontal Index of Treatment Needs, the Gingival Index (GI), and the Discoloration Index (DI), were measured. Statistical analysis was carried out with the Kruskal-Wallis test, Fisher's exact test, and Wilcoxon test. Results: In group 1, the mean API improved significantly (P Keywords: chlorhexidine, discoloration, gingivitis, hexetidine, mouthrinses, plaque

Vital pulp therapy of immature, symptomatic permanent posterior teeth presents a challenge in pediatric endodontics. A case report is presented in which cervical pulpotomy with calcium hydroxide was performed on a cariously exposed mandibular first permanent molar. The patient was seen every 3 months for a total of 18 months for a clinical and radiographic follow up. During the follow-up period, root development, as evidenced by root lengthening, was observed. Apical closure was evident at the end of 19 months. As the root canals showed a tendency toward calcification, root canal treatment was carried out, followed by restoration of the tooth with a stainless-steel crown. The success of this single-visit apexogenesis procedure supports the contention that young pulp possesses remarkable reparative capacity, as well as resistance to bacterial infection due to greater vascularity, and that apexogenesis with calcium hydroxide apical closure pulpotomy can be attempted for continued root development of symptomatic, vital, permanent teeth. Keywords: apexogenesis, calcium hydroxide, mandibular molar, open apex, pulpotomy, symptomatic, vital