Antimicrobial activity produced by six dentifrices.

The antimicrobial activity of six commercially available dentifrices and positive and negative controls as they come into contact with Streptococcus mutans, S. sanguis, and Actinomyces viscosus commonly found in the oral cavity. Sterile discs treated with the dentifrices were placed on agar plates with the controls. Zones of microbial inhibition were measured in millimeters after 48 hours. All of the test dentifrices demonstrated antimicrobial activity against the bacteria.

A single-component bonding system microleakage study.

The microleakage of a one-component bonding system is compared to a two-component system and a control. Class V cavity preparations were prepared in extracted teeth under high speed and water coolant so that incisal/occlusal margins were in enamel, and gingival margins were in dentin. Group I was restored with composite and no bonding agent; Group II was restored with Prime and Bond and composite, and Group III was restored with ProBond and composite. All specimens were thermocycled in fuchsin dye to evaluate the degree of microleakage. Significant differences were observed between the no bonding agent group and the Prime and Bond and ProBond groups. The results indicate that the one-step dentin bonding system has the ability to prevent microleakage effectively at both composite-enamel and composite-dentin tooth surface interfaces.

A two-year clinical evaluation of TPH for restoration of Class II carious lesions in permanent teeth.

To evaluate the clinical suitability of a barium silicate-filled composite (TPH) for restoration of posterior teeth, 50 Class II restorations were restored in 36 patients. Restorations included 22 molars and 32 premolars. Cavity preparations were protected with calcium hydroxide or a resin-modified glass ionomer cement, or both. Enamel was etched for 30 seconds with 37 percent H3PO4. All dentin surfaces were treated with a dentin bonding system that was placed, cured, and restored in 2 microns increments. The restorations were finished using diamond burs, polishing points, and paste. Evaluation periods were at zero (50 restorations), 6 months (35 restorations), 1 year (31 restorations), and 2 years (29 restorations), using the USPHS System and M-L indirect scale. At zero time, 50 restorations were scored "a" in all categories by using two independent evaluators. After 6 months, 35 restorations were graded with one "a" in postoperative sensitivity. After 1 year, 31 restorations were evaluated with one additional "b" for marginal integrity. After 2 years, 2 additional "b" for marginal integrity and 1 "b" for surface staining were noted. No "c" was observed in any categories throughout this study. Wear analysis revealed, on average, 2 microns of wear after 6 months, 7.8 microns of wear after one year, and 10.3 microns of wear after 2 years.

Tooth-colored inlays: new cementation technique.

A new technique for tooth-colored inlay cementation is introduced. Dual-cure fully filled restorative resin Sono-Cem (ESPE America, Norristown, PA) was used to cement tooth-colored restoration. A specially designed wooden tip in the gently vibrating Profin handpiece (Dentatus USA, New York) may be considered an excellent instrument for cementing porcelain and composite inlays with Sono-Cem cement. Also, a wide variety of diamond/tungsten plated abrasive Lamineer tips in a Profin Handpiece may be used for tooth preparation as well as for finishing restorations.

A comparison of antimicrobial activity of etchants used for a total etch technique.

The purpose of this study was to determine the antimicrobial activity of eight commercially available etchant materials and positive and negative controls as they came into contact with bacteria commonly found within the oral cavity. The following bacteria were used in this study: Streptococcus mutans, Streptococcus salivarius, and Actinobacillis actinomycetocomitants. The study was conducted in two parts: Part I--Etchants and controls placed within wells in agar plates; Part II--Enamel-dentin disks saturated with the etchants for 20 seconds and placed on the agar plates with the controls. Zones of microbial inhibition were measured in millimeters after 48 hours. The results of the study indicate that all of the etchants demonstrated antimicrobial activity against the bacteria tested.

Root surface biomodification using a dentin bonding conditioner.

OBJECTIVE: The purpose of this investigation was to compare by scanning electron microscopy (SEM) the surfaces of roots treated with a dentin conditioning agent and other materials that have been used routinely in periodontal therapy for root surface demineralization, namely, citric acid and tetracycline hydrochloride. MATERIALS AND METHODS: Sixteen freshly extracted human teeth were randomly divided into four equal groups; each tooth was hand scaled and planed prior to root surface conditioning with citric acid, tetracycline hydrochloride, and a dentin bonding conditioner; Tenure Dentin Conditioner (DenMat Corporation, Santa Maria, CA). The last has been used previously in conjunction with a resin-ionomer barrier in cases involving guided tissue regeneration. Root specimens were prepared for scanning electron microscopy and representative micrographs were taken at 1000x and 2000x. RESULTS: The results of this study indicate that there are morphological similarities between surfaces obtained with the dentin conditioning agent and the other acidic materials that are used routinely in periodontal regenerative therapy. CONCLUSIONS: Root surface demineralization has been shown to remove the smear layer, and provides a surface which is conductive to mechanical adhesion and cellular mechanisms for growth and attachment.

Repairing porcelain restorations intraorally: techniques and materials.

Ceramic and metal-ceramic restorations have the potential to fracture. Repairing porcelain restorations has become a serious cosmetic and clinical problem. By using porcelain-repair systems, porcelain fractures can be predictably fixed without removal of a prosthesis. The newest porcelain-repair systems show excellent durability of adhesion as well as bond strength. This article presents an overview of the techniques and materials and compares the four most-popular intraoral porcelain-repair systems.

Removal of enamel surface stains with at-home vital bleaching.

PURPOSE: To report the results obtained with an at-home bleaching product in the removal of enamel surface stains. MATERIALS AND METHODS: An individualized vacuum-formed mouthguard was fabricated and scalloped so that the terminal portion of the mouthguard ended approximately 1.0 mm from the gingiva. The patient was instructed to brush his teeth with Rembrandt Whitening Toothpaste prior to and after using the Rembrandt Gel Plus bleaching gel. In addition, the patient was informed as to the proper method of placing the gel in the mouthguard, and inserting the mouthguard into his mouth. The mouthguard was to be worn for 2-3 hours a day for a 2-week period. RESULTS: At the end of 2 weeks, the enamel surface stains were removed through the bleaching process.

Alcohol-containing mouthwasheses: effect on composite color.

This study investigated whether commercially available mouthwashes could affect or change the color of a hybrid composite resin. Twenty-four disks were fabricated and divided into eight equal groups for testing. At baseline, six colorimetric recordings and color parameters (L*, a*, b*) were recorded for each grouping of disks using a Chroma Meter CR-300 in reflectance mode. The groups of disks were immersed in their respective mouthwashes for 2 minutes a day in a vibratory fashion over a 6-month period. At the end of 6 months, color differences, delta E, were calculated between the base line and test recordings. The results indicate that rinsing with mouthwashes for 6 months can cause a hybrid resin to undergo color variations. Except for one product the color variations were not clinically significant.

Alcohol-containing mouthwashes: effect on composite hardness.

This study evaluated the effects of alcohol-containing mouthwashes on composite resin hardness. Eighty hybrid composite discs were fabricated and divided into eight equal groups: Listerine, Scope, Viadent, Plax, Lavoris, Clear Choice, and Rembrandt Mouth Refreshing Rinse. Water acted as a control. All of the discs were immersed by group in their respective liquids for two minutes a day over a period of six months. Disc hardness was measured six times at the center and periphery using a Barcol impressor. The baseline values were taken for each disc and compared to the test values at the end of six months. The results of the study indicate that the alcohol content in mouthwashes can affect composite hardness. This softening affect can be directly related to the percentage of alcohol in the mouthwash.

Dentifrice abrasiveness on microfill composite resin and dentin: a comparative study.

This in vitro study evaluated the abrasiveness of seven dentifrices on microfill composite resin discs and dentin surfaces. The composite resin discs and dentin surfaces were brushed in groups using slurries of the different dentifrices. Each specimen was subjected to 2400 strokes using medium bristle toothbrushes at a brush tension of 150 g. Any changes in surface roughness were noted through the use of a mechanical profiler or profileometer and scanning electron micrographs. The results of this study have indicated that Rembrandt Whitening Toothpaste was significantly less abrasive to the microfill composite discs and dentin surfaces compared to the other dentifrices tested (p < .05, ANOVA). Further clinical studies may be warranted to test the abrasiveness of dentifrices, especially if they are used over extended periods of time.

31P nuclear magnetic resonance spectroscopy study on kidney preservation. Effect of verapamil.

31P NMR spectroscopy has been used to evaluate the usefulness of verapamil, a calcium channel blocker, in preventing ischemic renal damage. Phosphorylated metabolites have been investigated before, during and after 48 hrs of hypothermic storage. The rapidity in adenosine triphosphate resynthesis and the phosphomonoesters and phosphodiesters levels after reperfusion at the end of the storage period (48 hrs), were significantly higher in verapamil-treated kidneys. Phosphomonoesters to inorganic phosphate ratio, during the storage period, is even higher. These findings suggest that verapamil may protect against ischemic renal damage and so it can be useful for renal preservation. Furthermore, it has been shown that 31P NMR spectroscopy puts into evidence the biochemical recovery and allows the assessment of the viability of organs.