Pediatric dentists play a major role in treating most of the anterior teeth fractures due to the fact that most patients who suffer such traumatic injuries are between the ages of seven and fourteen. Several techniques has been developed to restore the fractured incisors to the original shape and color, these include full-coverage of the traumatized tooth, or restoring the incisors with a resin. The purpose of this study is to find the ideal combination of tooth preparation and restorative material, namely, to determine if stair step chamfer preparations provide more retention in class IV restorations than the plain chamfer preparation technique when restored with a combination of a hybrid composite resin and a microfilled composite resin. This was done by comparing the shear strength values between the buccal stair-step chamfer preparation, and a modification on it (buccal and lingual stair-step chamfer preparation) and the plain chamfer preparation techniques in class IV restorations on anterior incisors using different composite resin materials. The Instron machine was used to test shear strength. One hundred and two bovine incisor teeth were freshly harvested from the slaughterhouse. The teeth were prepared and restored according to the following six groups; Plain Chamfer preparation with Tetric Ceram Composite, Plain Chamfer preparation with Renamel Composite, buccal stair-step chamfer preparation with Tetric Ceram composite, buccal stair-step chamfer preparation with Renamel composite, Buccal and lingual stair-step preparation with Tetric Ceram Composite, Buccal and lingual stair-step chamfer preparation with renamel composite. All samples were fractured using the Instron testing machine then the surface area were measured using Image-J software. Shear strength for every sample was calculated using the load numeric result from the Instron machine and the measured surface area. The Two-Factorial (AB) Analysis of Variance For Independent Samples showed that the buccal stair-step chamfer preparation showed significantly higher shear strength and fracture resistance than plain chamfer or the buccal and lingual stair-step chamfer preparation. The combination of Renamel Hybrid and Renamel Microfill composite materials showed better results than the Tetric Ceram composite when used with all three preparation techniques, but did not show a statistical significance. It was concluded that buccal stair-step preparation technique provided the ideal preparation technique with bonded composite resins in fractured anterior teeth. Only 7% of the entire sample size had an adhesion failure versus 93% that had cohesion failure. There was no significant difference in shear strength, between the restorative materials used, in conjunction with all the preparation techniques.

Clinicians often utilized composite resin restorations in combination with different types of preparation to restore class IV fractures on anterior incisors. A new preparation technique called (stair-step chamfer technique) is investigated in this study to detect bond strength to tooth structure. Eighty-eight bovine teeth were divided into 4 groups. Group I had twenty-three samples with a 45° bevel that extended 2 millimeters beyond the fracture line. Group II had twenty-three samples with a circumferential chamfer, which extended 2mm beyond the fracture line and half the enamel thickness in depth. Group III had twenty-three samples with a facial stair-step chamfer, which followed the anatomical contour and extended 2 mm beyond the fracture line with a lingual plain chamfer. Group IV had eighteen samples as controls,which were untreated teeth. The first three groups were prepared and restored with hybrid composite resin in conjunction with a single step bonding agent and as surface penetrating sealer, then tested for shear-bond strength on the Instron machine. The results were that there was no significant difference found between the treated teeth when tested for shear-bond strength. However, according to the site of the fracture, the stair-step chamfer technique gave significantly better results. It can be concluded that, the stir-step chamfer technique provides the clinician better environment to place a composite resin restoration resulting in good shear-bond strength and better esthetics.

Most (99%) patients treated at this university clinic do not need any form of sedation as rapport and behavioral management skills are more than sufficient and are safe. Those aged 1 to 5 years, who needed the use of oral sedation (Midazolam), showed 70% success. Those who needed nitrous oxide / oxygen ranged in age from 8 to 18 years and were later treated without any sort of conscious sedation after one or two sessions of nitrous oxide / oxygen sedation.

No abstract