Quintessence International, 06/1997

The gingival complex plays a vital role in the overall beauty of a smile. To predictably achieve a successful esthetic and functional result, the dentist must be able to precisely predict the treatment outcome based on biologic determinants. In this article, the biologic requirements for gingival health are discussed. In addition, a differential diagnosis for excess gingival display and treatment options for this condition are discussed.

The clinical hemostatic effect of tranexamic acid mouthwash after oral surgery was evaluated in 47 patients receiving oral anticoagulant therapy. Surgery was performed after the anticoagulant medication was recued in 15 patients (control group) and with no change in anticoagulant therapy in 32 patients (test group). The only st atistical difference between the two treatment groups at baseline was the level of anticoagulation, which was significantly higher in the test group. There was no significant difference between the two treatment groups in the incidence of bleeding after oral surgery. The results indicated that a combination of local antifibrinolytic therapy and a local hemostatic agent is effective in preventing postoperative bleeding after oral surgery in patients treated with anticoagulants.

Orthodontic correction was used to treat a 12-year-old-boy with a mandibular first molar deeply impacted by an odontoma. Following surgical removal of the odontoma, the molar was exposed and brought to a proper position by orthodontic traction. The treatment time was 29 months. After a 20-month follow-up, the molar was still in a satisfactory position.

The aim of this study was to investigate the visibility of secondary caries in the gingivobuccal and gingivolingual corne rs of teeth restored with amalgam restorations. Standard Class II cavities were created in 15 orthodontically extracted mandibular premolar teeth, and the teeth were randomly divided into five groups of three teeth each. In four of the gruops, a 1.0- or 1.5-mm cavity was prepared in the gingivolingual or gingivobuccal corner of the restoration. No lesions were created in group 5, the control group. The teeth were restored with amalgam. The teeth were adapted in the actual tooth space of 15 volunteers with one mandibular premolar missing. Radiographs o f each patient were taken with the bisecting-angle technique and the bite wing technique. The radiographs were sorted at random and given to 15 members of the professoriate who were often involved in detecting caries and and to 17 members who were not normally involved in detecting caries. The bitewing technique was found to be more reliable than the bisecting-angle technique in detecting secondary caries in gingivobuccal approximal corners (P .05). It was also found that, in group 1, the bisecting-angle technique was more reliable than the bitewing technique in detecting caries in gingivolingual corners (P .05). No significant differences were found in the correct evaluation of radiographs between the faculty who were normally involved in the detection of caries and those who where not.

The purpose of this study was to determine the effect of intracanal medicaments on the sealing ability of commonly used provisional filling materials. Ninety extracted, unrestored human molars were prepared. The contents of the pulp chamber were removed, and distal and mesial root canal systems were cleansed to a size 25 file. Group A receive d a cotton pellet with no medication, group B a cotton pellet with Cresatin, and group C a cotton pellet with 2% iodine potassium iodide (IKI). The prepared teeth from each category were divided into three subgroups of 10 to receive Cavit, IRM, or TERM. After the fillings were placed, the teeth were thermocycled, stained, and sectioned longitudinally. The average dye penetration was greater in the medicated groups (B and C) than in the control group (A) for each provisional material tested. Statistical analysis revealed that sealing ability of all three filling materials was significantly affected by Cresatin and 2% IKI.

Nickel-titanium instruments purportedly resist deformation and loss of sharpness better than do stainless steel instruments but may be more susceptible to breakage. The processes of wear and breakage of nickel-titanium and stainless steel instruments were examined. Sixty files of five types (12 each) and three manufacturers were used. All were used repeatedly in curved canals until failure or for a maximu of 22 minutes. Each instrument was examined with scanning electron microscopy both new (control) and at s paced intervals for evidence of wear and fatigue. All new instruments were of good quality. Stainless steel instruments tended to wear the most rapidly, and next were nickel-titanium rotary instruments; the most resistant to wear were nickel-titanium hand instruments. There were few instrument separations. In general, nickl-titanium (particularly hand) instruments resisted deterioration better than did stainless steel. Nickel-titanium rotary instruments (2 of 12) had the most breakage.

Amine fluoride, the active ingredient of a currently marketed dentifrice in Germany and other European countries, and sodium fluoride were compared to a placebo dentifrice for their effectiveness in alleviating dentinal hypersensivitiy. This was a randomized, double-blind, two-center, parallel clinical study covering 8 weeks of product use by 115 subjects. The hypersensitivity of the affected teeth was assessed by tactile stimulation, cold air stimulation, and overall subjective patient response. The three treatment groups exhibited comparable baseline sensitivity. These three methods of clinical assessment demonstrated that the desensitizing ability of a relatively higher fluoride dentifrice (1,400 ppm), delivered either as amine fluoride or sodium fluoride, did not differ significantly from that of the placebo dentifrice

Reflectance spectroscopy measurements were used to compare the degree of surface color shift in two classes of visible light-cured resin composites (hybrid and small-particle) and a glass-ionomer restorative. The weathering times investigated were 0, 100, 200, 300, and 400 hours. Environmental factors of heat, ultraviolet light, and moisture were used to affect the surface integrity of the restoratives. The parameter of AE*ab (overall color difference) of the CIELAB system for measuring small color differences was used. Chroma changes [AC*ab] and hue differences [AH*ab] were also determined. Color shifts, chroma changes, and hue differences were observed for all restorative materials evaluated, regardless of the weathering conditions or time intervals imposed. Glass-ionomer cement demonstrated a significantly greater degree of color shfit than did the resin composites. There was no significant difference in the amount of overall color change between the two resin composites, although the difference in change in lightness was significant.

A study was designed to simulate the repair of an indirect resin composite restoration with conventionally cured resin composite. Two-part specimens were prepared to test the diametral tensile strength of the repair interface between the base material of an indirectly cured resin composite (Herculite XRV) and repairs carried out with three directly cured materials (Herculite XRV, TPH, and Charisma). The repairs were carried out with and without use of the bonding resin for the repair material. The diametral tensile strengths of all repaired specimens were significantly less than those of bulk unrepaired specimens. There were no significant differences between the diametral tensile strengths of repaired blocks when the repair materials were used without bonding resin. The use of an intermediate layer of bonding resin significantly increased the bond strengths obtained when Herculite XRV and TPH were used for repair. There was no significant difference between the strength values of Herculite XRV and TPH, but Charisma exhibited the lowest strengths of repaired specimens.