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Biomedical subjects

T Fusayama

Publications and source records attributed to T Fusayama.

At least 37 records · Page 2Linked to original sources
PubMed1985

A varnish to prevent etching unrestored enamel.

The prognosis of acid-etched enamel was investigated in both laboratory and clinical experiments. Acid etching produced irregularities even on the prismless layer that covers prism enamel. The irregularities produced by etching are not remineralized in vivo but are filled with organic debris. Brushing reduced the depth of the irregularities but did not eliminate them. A protective varnish against acid etching was developed. The varnish also serves as a guide to facilitate removal of excess resin beyond the cavosurface margin.

Acid Etching, Dental↗
PubMed1984

A tooth substance saving restorative technique.

The basic concept behind the Black system in the restoration of teeth is a mechanical one. It aims at the retention of restorations by perfect contact with, and the grip of, resilient sound dentinal cavity walls. This necessitates the cutting of sound dentin which is sometimes accompanied by pain and pulpal irritation. For the complete removal of infected carious dentin the conventional technique has depended upon the operator's perception of discoloured dentin and its changed hardness. It has been shown that carious dentin consists of two layers. Namely, a superficial layer which is infected, not remineralizable and necrotic, whereas the deeper layer is uninfected, remineralizable and vital. The first step in the tooth substance saving restorative technique is to use a dye to differentiate between the two layers. Pain on caries removal is virtually eliminated by the selective removal of the stained and necrotic superficial layer while assuring complete removal of all infected dentin. The second step is to use chemically adhesive composite resins which have been developed for both anterior and posterior use. They adhere to enamel and sound dentin and also to the deeper layer of carious dentin. Cutting painful tissue so as to provide the retention form of the classical technique is not required, nor is amalgam as a restorative material in operative dentistry.

Adhesives↗
PubMed1983

The ultrastructure and hardness of the transparent layer of human carious dentin.

The ultrastructure of the transparent layer of carious dentin was investigated in relation to hardness. This layer was the deeper part of the intermediately-softened inner carious dentin. Intratubular deposition of fine crystals was initially observed at the uppermost layer of normal dentin, increased in the subtransparent layer, and gradually shifted to deposition of rhomboid-shaped crystals in the transparent layer. Crystals were not seen in the tubules in the overlying discolored layer. Softening, due to demineralization of the intertubular and peritubular dentin, started at the bottom of the subtransparent layer and increased in the outward direction.

Crystallization↗
PubMed1983

Mechanism of differential staining in carious dentin.

The caries detector, 1.0% acid red solution in propylene glycol, failed to stain EDTA-demineralized bovine dentin matrix, but stained the same matrix when treated by lactic acid in a concentration above 0.01 M. Thus, acid of bacterial origin could possibly be responsible for the stainability change of carious dentin in vivo.

Animals↗
PubMed1983

The extent of the odontoblast process in normal and carious human dentin.

When observed by SEM, after being treated with the HCl-collagenase method, the odontoblast processes extended throughout the whole thickness of dentin in intact teeth and the whole thickness of normal and the inner carious dentin in carious teeth. Small holes and depressions were found on the processes in the transparent layer.

Adult↗
PubMed1983

Bovine teeth as possible substitutes in the adhesion test.

In order to find a substitute for human teeth in the adhesion test, the adhesive strength to bovine teeth was compared with that to human teeth using five dental cements and two composite resins. The adhesion to enamel and the superficial layer of dentin showed no statistically significant difference between human and bovine teeth, although the mean values were always slightly lower with bovine teeth. Adhesion to bovine dentin decreased considerably with the depth of dentin.

Adhesiveness↗
PubMed1982

A laboratory report on vibration etching for fissure sealants.

We have developed a vibration etching technique in which occlusal pits and fissures are simultaneously cleansed and acid-etched using a fissure needle mounted on an electromagnetic vibrator. When tested on extracted teeth, the needle completely cleansed the fissures by removing the contents and the prismless enamel layer, and widened them to from 100 to 150 micrometers to the depth reached by the needle. The sealant penetrated readily and adhered to the reduced and etched fissure walls interlocking with resin tags.

Acid Etching, Dental↗
PubMed1982

Pulpal response to a new adhesive restorative resin.

The pulpal response to a new adhesive restorative resin was histopathologically investigated using dogs, and was compared with a representative conventional resin. When filled without etching and cavity wall lining, bacterial penetration and pulpal response were less with the new resin. Lining of dentin walls and total etching of cavity walls, including dentin, caused less pulpal response under the new resin. Cavities which were totally etched and filled with the new resin showed only a slight pulpal response and no bacterial penetration.

Acid Etching, Dental↗