Whitening effect by stain inhibition from a chewing gum with sodium hexametaphosphate in a controlled twelve-week single-blind trial.

OBJECTIVE: A twelve-week clinical study was conducted to assess the effect of a chewing gum containing sodium hexametaphosphate (4%) on the inhibition of stain formation. METHODOLOGY: Fifty-four subjects were entered and completed all aspects of the study. Twenty-seven of the subjects were smokers, and the other half did not smoke. Subjects were randomly assigned to the test gum or no-gum group. Each participant received a full oral prophylaxis at the beginning of each period of observation. Those chewing the test gum agreed to chew four times a day, for five minutes each time, over twelve weeks. Those assigned to the no-gum group agreed not to chew any gum. After twelve weeks, participants were scored for stain deposits (Lobene Index), received a second oral prophylaxis, and joined the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for stain deposits and the study was completed. In order to enhance stain formation during the entire 24-week study period, all participants received a supply of a chlorhexidine (0.12%) dentifrice without anionic agents to use three times a day. Stain levels were scored by the same examiner for all measurements and recorded on computer. The examiner was blinded to all treatment assignments. RESULTS: There were no reported problems associated with the chewing gum. The Lobene Index mean score for stain extent was 0.54 +/- 0.36) in the test-gum group and 0.81 +/- 0.47) for the no-gum group. The difference between the mean scores was highly significant with paired sample t-test (p < 0.001). Mean stain intensity was 0.57 +/- 0.38) in the test group and 0.95 (+/- 0.72) in the control group, with a statistically significant difference at p < 0.01. CONCLUSION: The results indicated that chewing gum containing sodium hexametaphosphate reduced induced stain formation by 33% compared to a no-gum treatment.

A review of polymerization shrinkage stress: current techniques for posterior direct resin restorations.

In general excellent results cannot be guaranteed when using resin-based composites for posterior restorations. This is due to polymerization shrinkage which can still be regarded as the primary negative characteristic of composite resins. A review of available literature regarding the polymerization process, its flaws, and suggested strategies to avoid shrinkage stress was conducted. Several factors responsible for the polymerization process may negatively affect the integrity of the tooth-restoration complex. There is no straightforward way of handling adhesive restorative materials that can guarantee the reliability of a restoration. At present, the practitioner has to coexist with the problem of polymerization shrinkage and destructive shrinkage stress. However, evolving improvements associated with resin-based composite materials, dental adhesives, filling, and light curing techniques have improved the predictability of such restorations. This critical review paper is meant to be a useful contribution to the recognition and understanding of problems related to polymerization shrinkage and to provide clinicians with the opportunity to improve the quality of composite resin restorations.

Restorative alternatives for the treatment of an impacted canine: surgical and prosthetic considerations.

Impaction occurs more frequently with maxillary canines than with any other tooth except maxillary third molars. For functional and aesthetic purposes, impaction must be treated in a manner that facilitates recreation of the anatomical structures in the canine region. The general treatment of choice is surgical and orthodontic restoration of the impacted canine. When this protocol is impossible due to anatomical limitations or the patient's indications, alternative treatments are necessary. The authors introduce two case presentations in which impacted maxillary canine teeth were restored with alternatives to orthodontic therapy.

Clinical evaluation of the use of fiber posts and direct resin restorations for endodontically treated teeth.

PURPOSE: Restoration of root-treated teeth is routinely performed in clinical practice with a choice of therapeutic options, considering many factors to provide optimal mechanical properties, esthetics, and longevity. The aim of the present work was to present a preliminary clinical report on the use of fiber posts and direct resin composites for restoring root-treated teeth. MATERIALS AND METHODS: Thirty-eight anterior and 62 posterior endodontically treated teeth were selected from 3 private prosthodontic offices. The protocol used included endodontic treatment, with translucent fiber posts (DT post) bonded to the post-space using a '1-bottle' adhesive (One-Step, Bisco) and a dual-cure resin cement (DuoLink, Bisco). Direct resin restorations were performed using a micro-hybrid resin composite (Gradia Direct, GC) and a layering technique. Both opaque dentin and enamel and translucent enamel shades were used. RESULTS: Patients were recalled after 6, 12, 24, and 30 months, and the restorations assessed according to predetermined clinical and radiographic criteria. These clinician-mediated evaluation methods confirmed the good clinical performance of the restorations. CONCLUSION: Restoration of endodontically treated teeth with fiber posts and direct resin composites is a treatment option, that in the short term conserves remaining tooth structure and results in good patient compliance.