Color changes of restorative materials exposed in vitro to cola beverage.

Purpose: The purpose of this in vitro study was to evaluate the color stability of restorative materials when exposed to a cola beverage.

Methods: Color changes in restorative materials caused by exposure to a cola beverage were studied using a split-plot experimental design. Three restorative materials (composite, resin-modified glass ionomer cement, and compomer) and 3 shades of each material under 2 surface conditions (polished and unpolished) were studied.

Toothbrush bristle wear and adherence of Streptococcus mutans.

Purpose: The purpose of this study was conducted to determine if bristle wear impacts the adherence of Streptococcus mutans on toothbrushes and to evaluate whether it affects the extent of adherence at 0, 8, and 24 hours after air-drying.

Methods: Sixty toothbrushes--composed of 20 each from 3 different groups and defined by brand, brush trim, and head shape--were used in this study. Bristle wear on half of the toothbrushes was achieved using an orthodontic typodont with metal bonds and brackets and evaluated by 4 independent observers.

The shear bond strength of acetone and ethanol-based bonding agents to bleached teeth.

Purpose: The purpose of this in vitro study was to evaluate the: (1) shear bond strength (SBS) of acetone and ethanol-based bonding agents to composite resin 24 hours after being bleached with 35% hydrogen peroxide; and (2) interface morphology and mode of fracture (IMMF) between composite resin and enamel.

Methods: Forty extracted teeth were randomly assigned into 4 groups: (1) group 1: 35% H2O2 + acetone; (2) group 2: H2O2 + ethanol; (3) group 3: acetone; (4) group 4: ethanol. All teeth were acid etched, bonding agents were applied, and a composite resin stub was bonded and stored again in saline for 24 hours.

An in vitro evaluation of the effect of sealant characteristics on laser fluorescence for caries detection.

Purpose: The purposes of this study were to: (1) evaluate the ability of a laser fluorescence (LF) unit to detect simulated caries under pit and fissure sealants; (2) determine the effect of an opacifying agent in sealants on LF values; and (3) determine interexaminer reproducibility values of the unit in a highly controlled, laboratory setting. Sealant characteristics specifically considered were: (1) filler content; (2) opacity; and (3) intrinsic fluorescence.

Methods: Three sealants were used in this study: 2 unfilled and 1 filled.

Effectiveness of two nitrous oxide scavenging nasal hoods during routine pediatric dental treatment.

Purpose: This study compared the effectiveness of 2 nasal hoods (Porter/Brown and Accutron) in reducing waste nitrous oxide gas during conscious sedation for routine pediatric dental treatment.

Methods: Thirty children, ages 3 to 8 years (mean=5.4 +/- 1.

Colony forming unit levels of salivary Lactobacilli and Streptococcus mutans in orthodontic patients.

The purpose of this study was to compare the levels of Lactobacilli (LB) and Streptococcus mutans (SM) colony forming units (CFU) in the saliva of subjects before and after orthodontic appliance placement. This was a controlled, prospective two-group, two-measurement, clinical trial performed on 64 study patients, 12-15 years old. Subjects in the experimental group were sampled for LB and SM in stimulated saliva collected on the same day but prior to band and bracket placement.

Anxiolytic-like action in mice treated with nitrous oxide and oral triazolam or diazepam.

Few animal studies have explored the interaction of nitrous oxide (N2O) with a benzodiazepine (BNZ) administered by the oral route, as used in clinical procedures involving "conscious sedation". The purpose of this study was to evaluate the relative "anxiolytic-like" and sedative effectiveness of N2O, oral triazolam (TRIAZ; Halcion) or oral diazepam (DIAZ; Valium), either alone or in various combinations of drugs and doses. One hundred and twelve Swiss Webster male mice, 35-45 days old, were assigned to 28 groups, each of which contained four mice.

Effect of primer solvent and curing mode on dentin shear bond strength and interface morphology.

Unlabelled: There is a need to study the main and interactive bonding effects of differences in solvent and curing mode used for adhesive monomers in dentin bonding systems.

Objective: Two solvents (acetone and ethanol) and curing methods (light cure, dual cure) were evaluated on their effects on bond strength and interfacial morphology.

Method And Materials: The adhesives studied were based on two monomers, pyromellitate of glyceryl dimethacrylate (PMGDM) and 2-hydroxy ethyl methacrylate (HEMA).

Milk and egg albumen are superior to human saliva in preserving human skin fibroblasts.

The purpose of this in vitro study was to compare egg albumen, whole bovine milk, human saliva, and tissue culture medium (MEM) for effect on the viability of human skin fibroblasts and their osmolalities. Confluent monolayers of fibroblasts were grown. Growth medium was poured off and dishes were divided into five groups, 15 dishes each of: 1) chick egg albumen; 2) fresh whole milk; 3) human saliva; 4) tissue culture medium; and 5) bench-dried storage without any media.

Fluoride uptake by proximal surfaces from professionally applied fluorides: an in vitro study.

This study was performed to examine the uptake of fluoride by mesial enamel surfaces of extracted teeth from different types of topical fluoride. Forty-eight extracted human molars and twelve premolars were randomly divided into four groups and mounted in twelve wax blocks with five teeth in proximal contact in each block. Each group was treated for four minutes with either 1.

Oral soft tissue manifestations and CD4 lymphocyte counts in HIV-infected children.

This study investigated the prevalence of oral soft tissue lesions in children infected with HIV and the relationship of CD4 lymphocyte levels with the prevalence of those lesions. Sixty HIV-positive children enrolled in the Children's Hospital AIDS Program (age 5.8 +/- 3 years) were selected for study.

Michael Buonocore and the Eastman Dental Center: a historic perspective on sealants.

Dr. Michael Buonocore is known for his innovative research on the preparation of the enamel surface with a weak acid to enhance adhesion of an organic plastic chemical sealant and the polymerization in situ of a sealant with ultraviolet light. His co-workers at Eastman Dental Center aided and extended his research findings.

Mercury release from dental amalgams: an in vitro study under controlled chewing and brushing in an artificial mouth.

The release of mercury vapor from class I amalgam restorations prepared in human molar teeth was studied during chewing simulations in an artificial mouth of a bi-axial servo-hydraulic mechanical test system. So that the total mercury released from the restoration over a fixed time could be determined, a closed chamber surrounded the envelope of chewing motion. In addition, the influence of sampling frequency on mercury release was corrected by the use of different sampling frequencies over a fixed time interval of mercury release measurement and extrapolation to zero sampling time.

Microscopic appearance of enamel white-spot lesions after acid etching.

Ultrastructural changes in surface characteristics of enamel white-spot lesions were compared with changes in the adjacent clinically sound enamel after they were etched with 30% phosphoric acid. Ten human permanent first molars exhibiting natural white-spot lesions were used as study specimens. The lesion surfaces and their adjacent sound enamel were etched with 30% phosphoric acid for 60 seconds.

Fluoride exchange from glass ionomer preventive resin restorations.

The purposes of this in vivo study were to determine if placing a sealant over a glass ionomer restoration modifies its fluoride release, and to examine the effect on glass ionomer of a 4-min application of topical fluoride. Fluoride release from glass ionomer preventive resin restorations placed in 21 bovine teeth was measured before and after removing their sealants. Fuji II, Ketac Silver, and Fuji LC were evaluated, representing the three generations of glass ionomers.

Assessing chloral hydrate dosage for young children.

Results of this study demonstrate that a dose of 75 mg/kg of chloral hydrate supplemented by nitrous oxide is superior to the dose of 50 mg/kg, for behavior management of young children sedated for dental treatment.

Occlusal composite restorations: 4-year results.

A study was performed to determine the success of a conservative cavity preparation using the principle of sealing for prevention rather than cavity extension for prevention. A total of 332 restorations were placed in 240 teeth of 110 subjects, aged 6 to 14, with a mean age of 8 years. After 4 years, 205 restorations were examined.

Occlusal restoration using fissure sealant instead of "extension for prevention".

This study was conducted to determine the success of a conservative cavity preparation using the principle of "sealing for prevention" rather than cavity "extension for prevention". Three hundred and twenty one restorations were placed in 234 teeth of 110 subjects, ages six to fourteen, with a mean age of eight years. After three years, 273 restorations were examined.