Efficacy and persistence of tooth bleaching using a diode laser with three different treatment regimens.

Statement Of Problem: Studies have measured the effectiveness of tooth bleaching, however there are very few studies that have measured the persistence in color change after a 6-month follow-up.

Purpose: This study assessed the efficacy of the laser bleaching process using different regimens, and the persistence of color change over a 6-month period.

Method And Materials: Sixty patients divided into three equal groups were subjected to bleaching using a diode laser with 34% hydrogen peroxide.

Variables related to materials and preparing for bond strength testing irrespective of the test protocol.

Introduction: Resin bonding can be compared to making a sandwich with the tooth on one side and the restoration on the other, a layer of bonding resin is applied to either side and a filled resin (composite) placed in between. This presentation considers factors that influence the restoration side of the sandwich and various ways that the assembled testpieces may be "aged" prior to testing. The materials to be bonded may be either ceramic, metal or composite formed by methods such as casting, pressing, sintering or machining.

Inadvertent injection of sodium hypochlorite into the periradicular tissues during root canal treatment.

This paper describes a sodium hypochlorite (NaOCl) incident occurring during routine endodontic treatment of a patient who presented with chronic periapical periodontitis of a maxillary canine tooth and discusses the immediate and late treatment of this case.

Comparison of Shear Bond Strength, Fatigue Limit and Fatigue Life in resin-bonded metal to enamel bonds.

Objective: To compare the Shear Bond Strength (SBS) of resin-bonded metal/enamel bonds with the Fatigue Limit and Fatigue Life of identical joints.

Methods: 285 discs of Ni/Cr-alloy (dia 5 mmx4 mm) were cast and treated by either (1) Sandblasting with aluminium oxide or (2) Sandblast+15 min electrolyticetch in HCl. The discs were bonded to etched enamel (37% HPO4/30 s) using 3 bonding systems.

Bonding of composite to water aged composite with surface treatments.

Objective: The purpose of this study was to determine the shear bond strength of new composite to water aged composite with and without interfacial surface treatment.

Methods: Two hundred and eighty cylindrical samples were prepared for each of three resin composites (Spectrum, Dentsply; Durafill, Kulzer; Herculite, Kerr). Seventy samples of each material were bonded immediately and the remaining were stored in water.

Thermal conductivity through various restorative lining materials.

Objectives: Traditional teaching has advocated the placement of insulating materials under restorations to protect against 'thermal shock'. Often this involves placement of a thick zinc-oxide eugenol cement lining. The purpose of this in vitro study was to assess the heat transfer through four lining materials and dentine and to relate these findings to the temperature exposures that may be experienced in the oral environment.

The measurement of degradation and wear of three glass ionomers following peroxide bleaching.

Objectives: To investigate, for three glass ionomer dental materials, the effects of a hydrogen peroxide solution on the elution of key elements, and the effects of a novel 6% hydrogen peroxide tooth whitening gel on subsequent wear rates with a toothpaste slurry.

Methods: Discs specimens of three glass ionomers (ChemFlex, Fuji II and Ketac-Fil) were prepared. One set of discs was exposed to either 6% hydrogen peroxide in phosphate buffer, phosphate buffer, water, a carbonated beverage or 38% orthophosphoric acid for 60 min.

The recharge of esthetic dental restorative materials with fluoride in vitro-two years' results.

Objectives: A range of esthetic restorative dental materials are now available to dental clinicians. The aim of this study was to evaluate the relative fluoride recharge potential of a number of these materials in vitro over two years.

Methods: Disc samples (12 mm x 2 mm) of each of the materials were placed into artificial saliva at neutral pH.