Applied Microscopy

Korean Society of Microscopy (한국현미경학회)
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A Microscope Study of Fluoride Effects on the Rat Incisor Enamel Formation

흰쥐 절치의 법랑질 형성에 미치는 불소의 효과에 관한 현미경적 연구

  • Lim, Do-Seon (Department of Dental Hygiene, Seoul Health College) ;
  • Chang, Byung-Soo (Department of Cosmetology, Hanseo University) ;
  • Jeong, Je-O (Department of Oral Histology, College of Dentistry, Chosun University) ;
  • Jeong, Soon-Jeong (Department of Oral Histology, College of Dentistry, Chosun University) ;
  • Jeong, Moon-Jin (Department of Oral Histology, College of Dentistry, Chosun University)
  • 임도선 (서울보건대학 치위생과) ;
  • 장병수 (한서대학교 보건학부 피부피용학과) ;
  • 정제오 (조선대학교 치과대학 구강조직학교실) ;
  • 정순정 (조선대학교 치과대학 구강조직학교실) ;
  • 정문진 (조선대학교 치과대학 구강조직학교실)
  • Published : 2004.06.01
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Abstract

The aim of the present study was to examine in detail, both at light and electron microscopical levels, the morphological variations in ameloblast of the fetal rat incisor enamel organ. Rats were started on distilled water at the beginning of pregnancy. The pups were sacrificed 11 days after delivery and animals were perfused intravascularly with glutaraldehyde and the incisors were removed. To examine on the ultrastructure of the ameloblast, the study employed primary light microscopy but electron microscopy was used to clarify some of the light microscopic finding. Longitudinal sections through the incisors of the rat show a continuous layer of ameloblasts on the labial surface of the tooth. This layer contains the entire sequence of developmental stages in enamel production. The ameloblast layer was divided into three main zones: 1) Presecretory zone, region of ameloblasts facing pulp. 2) Secretory zone, region of inner and outer enamel secretion. 3) Maturation zone, region of reduced ameloblasts. In particularly, the present study has shown that two distinctively different types of ameloblasts appear in the enamel organ during enamel maturation in the rat incisor. These two types have been designated ruffle-ended ameloblasts (rAB) and smooth-ended ameloblasts (sAB). The fluoride produces marked alteration in the fine structure of ameloblast from teeth of young rats, such as large confluent distensions of the endoplasmic reticulum and swelling of isolated mitochondria. This experimental data suggested that exposure prolonged of animal to high level of fluoride appears to induce a few dramatic changes in the normal appositional growth and initial mineralization of enamel created during amelogenesis.

불소 투여가 백서태아 발육에 따른 법랑질형성 과정에 미치는 영향을 알아보고자 임신한 어미흰쥐에 대조군은 증류수만을 음용시켰고, 실험군은 100, 200 및 300 ppm의 불소가 함유된 음용수를 투여하였다. 이후, 생후 11일 된 어린 흰쥐를 희생하였고, 하악절치를 발치하여 법랑질형성 동안에 일어나는 법랑모세포의 형태 및 구조적 변화를 광학현미경과 투과전자현미경으로 관찰하였다. 흰쥐태아 치아기의 조직학적 구성은 전분비대, 분비대 및 성숙대로 관찰되었으며, 특히 성숙대의 법랑질에서 물과 유기물을 선택적으로 제거하는 평탄끝법랑모세포(smooth-ended ameloblast)와 무기이온을 추가로 공급하는 주름끝법랑모세포(ruffle-ended ameloblast)가 관찰되었다. 또한 치아기는 가장 외측으로부터 외법랑상피, 성상세망, 중간층, 법랑모세포층, 법랑기질층, 상아기질층, 치수로 이루어져 있었다. 이러한 조직학적 구성은 백서태아에서도 성체에서 관찰되는 구조들과 동일한 것으로 확인되었다. 한편, 불소투여군에서 각 대(zone)의 법랑모세포들은 구조적 및 형태적인 변화가 확인되었는데, 조면소포체가 공포화되고 막성계의 유실로 붕괴되었으며, 라멜라 형태인 동심원상의 팽윤된 구조가 미토콘드리아의 기질에서 관찰되었다. 특히 고농도 실험군인 300 ppm투여군에서 법랑모세포사이에 세포막이 유실된 세포들이 관찰되었다. 그러므로 임신중인 흰쥐에 투여된 불소는 흰쥐태아의 치아발육과정 중 법랑질형성에 관여하는 법랑모세포에 영향을 미쳐 전환주기에 변화를 주고 법랑모세포의 미세구조적 변화와 형태적인 변화를 초래하였다.

Keywords

References

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