The thermomechanical properties of gutta-percha. II. The history and molecular chemistry of gutta-percha

By Goodman A, Schilder H, Aldrich W.

Date: 06/1974
Journal: Oral Surg Oral Med Oral Pathol,

Purpose: 

To review history of gutta percha and its molecular chemistry​

Summary:  

  • The Malays and Chinese are said to have used it first. ​
  • In Europe (in the middle of the 7th century), John Trandescant wrote in  his book “The playable mazer wood, being warmed in water, will-work to any form.” This was thought to apply to gutta-percha.​
  • In the early 1840’s it was reintroduced into Europe, under the name gutta-percha.​
  • GP was also used in the manufacturing of cements, surgical & Musical instruments, paper, maps, and boats. Rubber soon dispelled the gutta-percha illusion. ​
  • GP, the naturally occurring polymer of isoprene, has been known to dentistry for almost 125 years.​
  • Natural rubber & GP both are high-molecular-weight polymers, and structured from the same basic building unit or isoprene ​
  • GP exists in the trans state, meaning the CH2 groups are on opposite sides of the isoprene chains, resulting in a more linear arrangement. This gives GP harder, more brittle and less elastic properties​
  • In 1942 C.W. Bunn explained how GP can exist in 2 different crystalline forms, alpha & beta. ​
  • The alpha state is the natural form, and when heated above 65o C it turns amorphous. If cooled slowly at 0.5o C/hr it can return to the alpha form, and if not it turns into the commercial beta form. ​
  • Beta GP becomes amorphous at 56 C.​
  • The main difference between the two structures is the molecular repeat distance, which is smaller with the beta form.​

Clinical significance: 

An important background information of the history and molecular chemistry of gutta-percha.​