Dentin adhesive superior to copal varnish in preventing microleakage in primary teeth.

Microleakage presents a major challenge to the success of all restorations placed in the oral cavity, resulting in postoperative sensitivity, pulpal irritation, and secondary caries formation. The objective of this study was to evaluate the effects of an adhesive cavity liner under amalgam restorations in primary teeth. Sixty class V amalgam restorations were placed on the buccal and/or lingual surfaces of 38 primary molars and canine teeth. A dentin adhesive cavity liner was placed under 20 of the amalgam restorations. Another 20 restorations were lined with copal cavity varnish prior to amalgam condensation. The remaining 20 had no liner. All teeth were thermocycled in 0.5% basic fuschin dye, sectioned, and examined under a stereomicroscope to evaluate microleakage. While all specimens demonstrated leakage around the margins of the restorations, only the teeth with adhesive resin liners prevented leakage into the dentinal walls of the restoration. The copal cavity varnish group displayed microleakage approaching the pulpal chamber, whereas the unlined specimens consistently displayed dye penetration into the pulp chamber. At P < 0.01, the use of an adhesive cavity liner under amalgam restorations in primary teeth resulted in significantly less microleakage.

The effects of tack welding and increasing surface area on the tensile strength of silver electric and flame soldered stainless steel joints.

The purposes of this study were: 1) to compare silver solder joint strength using flame and electric soldering techniques, and 2) to determine the effect of tack welding and increasing metal-to-metal contact area prior to tack welding, on the tensile strength of silver solder joints. Six methods: (flame soldered; tack welded and flame soldered; increased contact area, tack welded, and flame soldered; electrosoldered; tack welded and electrosoldered; and increased contact area, tack welded, and electrosoldered) were used to produce 15 solder joints in each group. The tensile strength of the joints were tested with Instron Universal Testing Machine. Flame soldering resulted in joints with significantly higher tensile strength (P < or = 0.001). Tack welding had no significant effect on the tensile strength of the joints. Increasing the contact area had no significant effect on the tensile strength of tack welded electric soldered joints, but significantly weakened the flame soldered joints (P < or = 0.05).

Effect of sterilization on stiffness and dimensional stability of rubber-dam clamps.

Simulated clinical conditions were used to test the effect of sterilization on rubber-dam clamp stiffness and dimension. Sixty Hygienic and Ivory W7 clamps were either steam or dry heat sterilized and compared to controls. Stiffness and dimensional change between Ivory clamp groups was significant (p<.0001); the sterilized clamps showed less change than the controls. Hygienic groups showed a significant different between the control and dry heat groups (p<.05); the sterilized clamps showed less change than the controls. The change in stiffness and interjaw width for all Ivory clamps compared to all Hygienic clamps was significant (p<.0001). The Hygienic clamps changes less than the Ivory clamps. The results indicate that steam and dry heat sterilization do not affect retention of rubber-dam clamps.

Modifications of the palatal crib habit-breaker appliance to prevent palatal soft tissue embedment.

The authors recommended the use of an acrylic palatal button and .040 to .045 inch palatal wires as modifications to the palatal crib appliance. By enhancing the strength of the wire, and providing anterior support, these modifications can reduce the likelihood of the crib becoming embedded in the palatal soft tissues.

In vitro evaluation of an adhesive monomer as a bonding agent for orthodontic brackets to primary teeth and nickel-chromium ion crowns.

The adhesive monomer, Clearfil New Bond, was used to enhance the bond strength between orthodontic brackets and primary molars, premolars, and NiCr crowns. Twenty specimens of each had this dental adhesive applied according to the manufacturer's instructions in addition to a chemically cured composite material. The remaining specimens (20 each) were bonded without the adhesive monomer. Shear bond strengths were determined using a universal testing machine. Fracture sites were examined to determine the type of bond failure. All bond strengths were significantly increased with the addition of Clearfil New Bond (P < or = 0.0001). The shear bond strength to NiCr crowns with the addition of the adhesive monomer was 7.76 kg. This is comparable to the shear bond strength observed for primary molars (8.66 kg) and premolars (8.65 kg) without adhesive monomer. The observed decrease in adhesive bond failures with the addition of Clearfil New Bond indicated a stronger shear bond strength between the tooth surface and the bracket base. Clearfil New Bond can significantly increase the shear bond strength of orthodontic brackets to both primary molars and premolars. Additionally, it was shown that orthodontic brackets can be successfully bonded to Ni-Cr crowns at strengths comparable to primary or permanent enamel.

Progressive hemifacial atrophy (Parry-Romberg syndrome). Case report.

Progressive hemifacial atrophy (Parry-Romberg syndrome) is a slowly progressing facial atrophy of subcutaneous fat and the wasting of associated skin, cartilage, and bone. This disorder includes an active progressive phase (2 to 10 years) followed by a burning out of the atrophic process with subsequent stability. This article presents a review of the literature and a case report with unique dental involvement as a result of this disease process.

Partially arrested root formation in a permanent maxillary central incisor subsequent to trauma to the primary dentition.

When the primary dentition sustains a traumatic insult, the development of the succedaneous teeth can be disturbed leading to a number of malformations. In this case report, the patient presented with a history of prior trauma to his primary maxillary incisors which resulted in partially arrested root formation for a permanent incisor. The considerations in formulating a treatment plan which included orthodontics are discussed.