Are you Makoto Watanabe?

Claim your profile

Publications (3)1.75 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate the fit of acrylic maxillary denture bases processed by the methods of microwave, quick-wet-heat, slow-wet-heat, and self curing. Forty stone-casts were obtained using a mould of an undercut-free acrylic resin master cast of an edentulous maxilla. Standard acrylic replicas patterns sealed on casts and randomized to four groups (10 in each) were used to make denture bases using different processing methods for each of the four groups. The resultant discrepancy of fit between the denture base and the casts were measured using a silicone wafer. Varying fit discrepancies both within and between denture base groups was observed. The proportional fit-loss in the palatal region was significantly greater than the sulcular areas for all materials tested (p < 0.05). The fit-loss observed was greater in microwave-cured bases than for other materials examined. Careful selection of appropriate denture base materials and processing technique is important when providing complete dentures for edentulous patients.
    Full-text · Article · Sep 2010 · The European journal of prosthodontics and restorative dentistry
  • Masahiko Kikuchi · Fazal Ghani · Makoto Watanabe
    [Show abstract] [Hide abstract]
    ABSTRACT: Physical retention of a denture depends on adhesion of a salivary film to its fitting surface and supporting tissues. Adhesion is influenced by many factors. This study examined the effect of the texture of the fitting surface on denture retention. According to the method developed, mucosal-supported palatal bases were made for 10 dentate subjects who had no obvious oral disease, history of allergy to dental materials, or palatal mucosal undercuts. A specially designed strain gauge force transducer and a pen-chart recorder were used to record forces that were needed to dislodge the bases from the palate. Forces were recorded 30 times (10/day) for each subject. Similar forces were recorded after the fitting surface of each base was uniformly air-particle abraded under 4 kg/cm2 of pressure for 1 minute with 50-microm grit alumina dust. Data were analyzed with a 2-sample Student t test and a paired t test. Substantial variations for all measurements were observed both between and within subjects. Notwithstanding, these variations, the mean retention of the bases significantly (P <.05) increased by more than 2-fold when the fitting surface was air-particle abraded. These force values were similar to those recorded previously for well-fitting mucosal-supported palatal bases in a separate group of dentate subjects. While reinforcing the importance of good adaptation of the denture to the tissues, these findings also suggest that an additional improvement in denture retention can be accomplished after the fitting surface is air-particle abraded.
    No preview · Article · May 1999 · Journal of Prosthetic Dentistry
  • [Show abstract] [Hide abstract]
    ABSTRACT: 本研究は, 口蓋粘膜への荷重負荷が血流量に及ぼす影響を, レーザードップラー血流計を用いて検索することを目的に行った.実験は5名の健常者 (平均年齢26.4歳) を被験者とし, レーザードップラー血流計を用いて, 口蓋後側方部および口蓋正中部 (口蓋ヒダ部) に直径4mmのプローブを介して, 荷重量400gf, 40秒間の加圧を行ったときの血流量を測定した.さらに, 口蓋後側方部において, 同じく荷重量400gfで加圧時間を10, 20, 30秒と変化させた場合, および加圧時間40秒で荷重量を100, 200, 400gfと変化させた場合の血流量を測定した.その結果, 以下の結論を得た.1.加圧部位の相違による血流変化については, 口蓋後側方部の左右側粘膜では加圧終了直後に反応性の充血がほとんどの場合で出現したが, 口蓋正中部では反応性充血が出現しないか明確でない場合が多かった.2.加圧時間の相違による血流量変化については, 加圧時間が増加した場合, 加圧前の血流レベルに戻るまでの回復時間は延長する傾向がみられた.これに対して, 加圧時の血流減少量ならびに加圧後の血流増加量は加圧時間に関係なく, ほぼ一定となる傾向を示した.3.荷重量の相違による血流量変化については, 荷重量が増加した場合には, 回復時間は延長する傾向がみられた.また, 加圧時の血流減少量も荷重量増加に伴って増大する傾向を示した.一方, 加圧後の血流増加量については, 荷重量の変化によって一定の傾向は認められなかった.4.以上のことから, 加圧時間と回復時間, 荷重量と回復時間, および荷重量と加圧時血流減少量との間にはそれぞれ一定の関係が認められ, 顎粘膜の性状や特性を評価する指標として有効であることが示唆された.
    No preview · Article · Jan 1998