Quintessence International, 04/1994

Successful osseointegration of dental implants largely depends on flap management during implant installation. To obtain optimal biologic conditions for osseointegration, implants and associated bone should be completely covered with soft tissue during the entire healing period. To achieve this, a modified flap design, the eversed crestal flap, is proposed. This technique is aimed at eversion of flap margins by using a combination of vertical mattress and simple sutures to enable tight coaptation of flaps, thus ensuring primary wound closure throughout the healing process.

Use of periodontal surgical procedures should generally be considered, prior to prosthodontic treatment, for ridge augmentation and correction of minor soft tissue deficiencies. However, in certain instances surgery may be contraindicated or undesirable. An adequate functional and cosmetic result can often be achieved by incorporating pink ceramic material in the patient's fixed prosthesis. Five case reports are reviewed to demonstrate some appropriate uses of this material.

Human natural teeth were used in manufacturing two complete prostheses and two partial removable dentures in three patients. All four prostheses continue to function satisfactorily. The practitioner, by utilizing the patient's natural teeth in preference to artificial teeth, achieves an excellent means of solving the patient's esthetic problems.

This investigation quantitatively analyzed the apical seal in teeth in which one of three gutta-percha root canal-obturating techniques was used. The seal obtained with each technique was measured with dye penetration and spectrophotometric analysis. No statistically significant difference was found among the lateral condensation, sectional cone, and modified sectional cone techniques in their ability to produce an apical seal.

This study evaluated the load, applied to the marginal ridge, required to produce failure in Class II posterior composite resin restorations with four different preparation designs. In group 1, the preparation had an extens ion through the occlusal groove. The other three groups employed a proximal box-only (slot) preparation. Group 2 preparations had facial and lingual retention grooves that extended from the gingival floor to the occlusal surface; group 3 preparations were slots without grooves; and group 4 preparations were slots without grooves and with unsupported proximal enamel. After the restorations were thermocycled, their marginal ridges were flattened and loaded to failure. Mean (SD) failure loads were 438 (73) N in group 1; 383 (52) N in group 3; 297 (72) N in group 3; and 281 (63) N in group 4. Mean failure loads of groups 1 and 2 were not significantly different from each other but were significantly greater than failure loads for groups 3 and 4. Mean failure loads of groups 3 and 4 were not significantly different.

A number of studies have reported that acid etching of dentin is toxic to the cells of the odontoblastic layer and dental pulp. Other studies report that pulpal inflammation is a consequence of bacterial microleakage. The purpose of this study was to observe the degree of pulpal healing after pretreatment of vital dentin prior to placement of All-Bond and Scotch-bond 2 composite resin adhesives. Zinc oxide-eugenol cement and an acidic cement were employed as controls. One hundred twelve Class V nonexposed cavity preparations were placed throughout the dentitions of five healthy adult rhesus monkeys and observed at 3, 25, and 80 days. Various dentinal pretreatment procedures were employed. The All-Bond Universal primer system was placed on air-dried vital dentin in 23 cavities and on damp vital dentin in 27 cavities. Scotchbond 2 was placed as per manufacturer's instructions. All treatment procedures, materials, and times were represented in all animals. Placement of silicate cement resulted in the most severe pulpal responses at all time periods. Stained bacterial profiles in the remaining dentin on the axial walls of inflamed control pulps were associated with severe pulpal inflammation. These results indicate that acid etching of vital dentin does not impair pulpal healing in deep Class V cavities

Some variations in luting technique from those recommended by manufacturers may hold clinical advantages, but it is also necessary to evaluate other parameters of the performance of the restored unit. Among these is fracture resistance. Accordingly, indirect composite resin restorations were placed in standardized preparations under standardized conditions. Restorations were placed in three groups of 10 teeth, each group with a different luting procedure: luting with a composite resin restorative material, conventional luting but without enamel etching, and luting with a 4-META material. In another group the restorations were luted in accordance with the manufacturer's recommendations, while two groups of sound teeth acted as control. Following compressive loading on a universal testing machine, the force required to cause fracture was recorded. The results indicated that optimal fracture resistance of teeth restored with indirect composite resin restorations was obtained when the 4-META-based luting material was used.

Standard anatomy textbooks describe the mandibular canal as having a consistent, standard path. The fact that variations in its path exist in a significant percentage of the population is of extreme importance for the surgeon who is performing procedures in close proximity to the mandibular canal. A rare, radiographically detectable variation of the standard anatomy of the mandibular canal is reported.

This in vitro study investigated the effect of Scotchbond Dual Cure bonding agent on microleakage of sealant bonded to saliva-contaminated enamel. To determine microleakage, sealants were placed on previously extracted premolars, with or without bonding agent, in the presence or absence of salivary contamination. The curvilinear extent of microleakage was measured on the mesial and distal aspects of the sealant-enamel interface with a digital-image analyzer. The results revealed a statistically significant difference between the microleakage of the contamination/sealant group and the other three groups. The Scotchbond/sealant group exhibited slightly less leakage than did the sealant only and contamination/Scotchbond/sealant groups. Scanning electron microscopy was used to examine the enamel-material interface. Placement of Scotchbond between the sealant and enamel reduced microleakage of sealants applied under conditions of salivary contamination.

Transmigration of mandibular canines across the midline is rare. Two 14-year-old female patients from South India were found to exhibit this phenomenon. In one patient, the mandibular right canine had crossed the midline and migrated to the left, up to the mesial root apex of the permanent first molar, near the lower border of the mandible. In the other patient, the permanent mandibular left canine had crossed the midline and migrated up to the root of the mandibular right canine. Both of these patients are being observed regularly for further migration. The literature on this rare condition is reviewed and its etiologic possibilities and treatment modalities are discussed.