Validity of a portable microhardness testing system (Cariotester) for diagnosis of progression in active caries lesions.

This study aimed to evaluate the validity of a portable microhardness testing system (Cariotester) for diagnosis of progression in active caries lesions by comparing data from this device and a laser fluorescence device (DIAGNOdent). Carious dentin in 12 specimens (stained clearly with a caries detector dye) was incrementally removed with a round bur at 150 μm depth intervals from the dentin surface in the direction of the pulp chamber. After each increment (total 138 sites), the Knoop hardness (HK) (evaluated with Cariotester) and DIAGNOdent (D) values were measured.

Detection of dentinal microcracks using infrared thermography.

Introduction: It is difficult to make a definite diagnosis of a cracked tooth solely based on an inspection within the root canal, especially in case of microcracks. At present, there seems to be no established method to detect dentinal microcracks in roots; therefore, the current detection techniques need to be improved. Vibrothermography (VibroIR) helps to detect microcracks by the friction heat generated from ultrasonic vibration.

Resistance of surface coating resins against toothbrushing abrasion.

Purpose: To evaluate the durability of a resin coating system after toothbrushing abrasion resistance and surface hardness of the coating resin.

Methods: Rectangular blocks of Top Coat (TC) or the bonding resin of the two-step self-etching adhesive Clearfil SE Bond (SEB) were prepared by irradiation with halogen light units. After immersion in distilled water at 37 degrees C until stabilized water absorption, the specimens were subjected to toothbrushing abrasion tests in which a toothbrush was moved on the specimen at 60 strokes/minute with a 400 gf vertical load with toothpaste slurry.

Relationship between laser fluorescence and bacterial invasion in arrested dentinal carious lesions.

This study investigated the relationship between caries assessment using a laser fluorescence device (DIAGNOdent), and bacterial invasion in arrested carious dentin detected by polymerase chain reaction (PCR). The ten extracted human molars used in this study had black or dark brown, hard occlusal carious lesions, and were found to be only weakly stained or unstained with a caries detector dye of 1% acid red in propylene glycol. In those extracted human molars, dentin was removed in the direction of the pulp chamber at 150-μm intervals.

Relationship between the color of carious dentin with varying lesion activity, and bacterial detection.

Objectives: To investigate the relationship between the color of carious dentin with varying lesion activity, and bacterial detection in the lesions.

Methods: In 26 extracted human molars with coronal dentin caries and four extracted sound human molars, dentin was removed by a round bur every 150 microm from the dentin surface, in the direction of the pulp chamber. Before and after removal, images of nine-color samples and the dentin surface stained with a caries detector dye (1% acid red in propylene glycol) were taken simultaneously by a charge-coupled device (CCD), and dentinal tissue samples were taken with a new round bur.

Evaluating the objectivity of caries removal with a caries detector dye using color evaluation and PCR.

Objectives: This laboratory study evaluated the objectivity of caries removal with a caries detector dye by color and bacterial evaluations.

Methods: In 41 cases of dentin caries (32 extracted human molars), carious tissues were removed using a caries detector dye. Images of dentin surfaces with color-matching stickers were acquired using a CCD camera, and dentinal tissue samples were collected with new round burs.

Relationship between colors of carious dentin and laser fluorescence evaluations in caries diagnosis.

This in vitro study investigated the relationship between assessments of dentin caries using a laser fluorescence device (DIAGNOdent) and a caries detector dye during caries removal. The dentin of eight extracted carious molars was removed at 300-microm interval points from the dentin surface toward the pulp chamber. Before and after each removal, images of the carious surfaces were taken in association with color-matching stickers (for color correction) and the surfaces were evaluated by DIAGNOdent based on fluorescence emission from the tooth surface.

The accuracy of electrical method for microleakage evaluation by a three-dimensional analysis.

Objectives: This in vitro study aimed to investigate the accuracy of an electrical method for the evaluation of microleakage by a three-dimensional analysis of dye penetration.

Methods: Coronal cavities were prepared on buccal, palatal or lingual surfaces in extracted human molars. The cavities were then filled with resin composites and were subjected to 10,000 load cycles (425g).

Three-dimensional evaluation of gap formation of cervical restorations.

Objectives: In some studies gap formation has been evaluated in just one section of the restorative. This in vitro study aimed to design a quantitative three-dimensional method for evaluation of the contraction gap in restoratives.

Methods: Cervical cavities were prepared on buccal, palatal or lingual surfaces in human extracted molars and were then filled with resin composites.

The relationship between the color of carious dentin stained with a caries detector dye and bacterial infection.

This in vitro study aimed to design a method for the objective evaluation of carious dentin using numerical values. This study also investigated the relationship between the color of carious dentin stained with a caries detector dye using this objective method and the rate of bacterial detection as detected by a polymerase chain reaction (PCR). In 15 molars with occlusal dentin caries and three extracted sound molars, dentin was removed in multiple steps with 300 microm removed each step.

Effect of endodontic irrigation on bonding of resin cement to radicular dentin.

The influence of endodontic irrigation on shear bond strengths of resin cement to radicular dentin was investigated. Human radicular dentin blocks were divided into four groups and subjected to one of four endodontic irrigations: ethylenediaminetetraacetic acid (EDTA) group, 17% EDTA for 60 s; EDTA/sodium hypochlorite (NaOCl) group, 17% EDTA for 60 s followed by 10 ml of 5% NaOCl for 15 s; NaOCl group, 10 ml of 5% NaOCl for 15 s; and control group, no treatment. Morphological changes of dentin surface after endodontic irrigation were observed by scanning electron microscopy (SEM).

Relationship between bacterial infection and evaluation using a laser fluorescence device, DIAGNOdent.

The aim of this in vitro study was to investigate the relationship between bacterial infections in carious dentin when detected by two different methods -- polymerase chain reaction (PCR), and a laser fluorescence device, DIAGNOdent. Dentin was removed every 300 micro m in the direction of the pulp chamber in 10 extracted molars with occlusal dentin caries and 3 extracted sound molars. Dentin surfaces were evaluated using DIAGNOdent, and dentinal tissue samples were removed by using a round bur before and after each removal.

In vitro study of caries detection through sound dentin using a laser fluorescence device, DIAGNOdent.

The objective of this study was to investigate the feasibility of proximal surface caries detection using a laser fluorescence device, DIAGNOdent, through the sound dentin surrounding the cavity wall after removal of occlusal caries. Extracted sound human molars were ground to prepare horizontal and vertical dentin plates 1.4 mm thick.

Validity of electrical conductance measurements in evaluating marginal leakage around resin composite restorations.

This in vitro study evaluated the influence of the cavity size of restoratives on a new electrical method for detecting marginal leakage. Cavities were prepared on the buccal coronal and root surfaces of 32 extracted non-carious human molars and were divided into four groups having different cavity depths (0.5 approximately 4.