1. CCC TOPIC

2. Degradation of trans poly-isoprene over time
Presented by: Bassem Ageeli
Computer number:
Supervised by: Prof. Gomaa

3. What is trans poly-isoprene ?
Trans vs. Cis

4. What is trans poly-isoprene ?
polymer is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds.

5. What is trans poly-isoprene ?
Isoprene: It is a monomer of a natural rubber (C5H8).

6. What is trans poly-isoprene ?
It is a polymer that comes from a natural rubber.

7. What is trans poly-isoprene ?
Uses
1- Insulation material for transatlantic telegraph cables.
2- Golf ball.
3- Chewing gum
4- Decoration object.

8. How could we use it in dentistry?

9. Valios et al, Journal of applied polymer science 100, 4082-8, 2006
Does TPI degrade?
It resists biological degradation ?
Warneke et al, Microbiology (2007), 153, 347–356
It degrades slowly over time(Aging).
Bacterial infection accelerate degration.
Maniglia-Ferreira et al, International Endodontic Journal 40, 25–30, 2007
Valios et al, Journal of applied polymer science 100, , 2006

10. (Valois et al. , International Endodontic Journal, 38,425-429, 2005)
Effects of 2% chlorohexidine and 5.25% sodium hypochlorite on gutta-percha cones studied by atomic force microscopy
(Valois et al. , International Endodontic Journal, 38, , 2005)

11. Reinfection is one of the curical factor that influnce the outcome of RCT. We have to decontaminate gutta percha to decrease the risk ratio.
In this article, a comparison between 2% CHX and 5.25% NaOCl as a decontamintion solution was occur.
Gutta percha is randomely selected and its point was cutted 3mm from the tip and attach to a glass base.

12. Gutta percha was divided to 3 groups:
1- immersed in 2% CHX
2- immersed in 5.25% NaOCl
3- control
After comulative times of 1, 5, 10, 20, 30 min. , the samples was evaluated using AFM.
AFM: is a hardware consist of a sharp tip mounted at the end of a microscopic cantilever. It probes the surfaces. Its laser beam detection system detect the bending and send the data to a processor to show it in the moniter.

13. They found:
1- NaOCl increased the surface irregularities and decreased the physical properties after 1 min.
2- CHX did not affect gutta percha.
3- they have the same antimicrobial activity.
4- CHX safely used even for 30 min.
5- NaOCl increase plasticity of gutta percha.

14. In vivo aging of gutta-percha endodontic cone.
Degradation of trans-polyisoprene over time following the analysis of root fillings removed during conventional retreatment.
(Maniglia-Ferreira et al., International Endodontic Journal 40, 25–30, 2007)
In vivo aging of gutta-percha endodontic cone.
(Batista et al. , Journal of applied polymer science 100, , 2006)

15. In this 2 articles, the root fillings material evaluated to see if it degrades over time.
They used 71 ( ) teeth root canal treated since 2 – 30 years. Teeth status were investigated (periapical lesion and degradation). These teeth were conventialy retreated.
Removed gutta percha solved in a chloroform. Then, they were filtered by passing them throw cotton filter. Finally, centrifuged.
They used IR spectroscopy and Gel permeation chemo therapy to evaluate the results.

16. Gel permeation chromatography

17. IR spectroscopy

18. Symmetrical stretching Asymmetrical stretching
IR spectroscopy
Symmetrical stretching
Asymmetrical stretching
Twisting
Scissoring
Rocking
Wagging

19. They found:
TPI is degraded by a slow oxidization reaction over time. The amount of degradation of tooth with periapical infection after 5 years is equal to that of tooth without periapical infection after 15 years.
Aging of TPI does not depend on time only. There are many factors like storage, and periapical infection.

20. Conclusion
1-Disinfection of gutta-percha cones is better performed with 2% chlorhexidine.
2-Gutta percha was found to start slow degradation with time inside the root canal specially in persistent periapical infection cases.
3-Possible dental problems caused by gutta percha degradation ?

21. Refernces
Valois CRA, Silva LP, and Azevedo RB: effects of 2% chlorhexidine and 5.25% sodium hypochlorite on gutta-percha cones studied by atomic force microscopy. International Endodontic Journal, 38, , 2005.
C. Maniglia-Ferreira, J. B. A. Silva Jr, R. C. M. de Paula, J. P. A. Feitosa, A. A. Zaia, C. C. R. Ferraz, B. P. F. A. Gomes & F. J. Souza-Filho, Degradation of trans-polyisoprene over time following the analysis of root fillings removed during conventional retreatment. International Endodontic Journal 40, 25–30, 2007
Joao Batista A, Silva JBA Jr, Paula RCM, Feitosa JPA, Gurgel-Filho ED, Maniglia_Ferreira C, Souza-Filho FJ, In vivo aging og gutta-percha endodontic cone. Journal of applied polymer science 100, , 2006

22. Special thanks
CCC topic supervisor: Prof. Madiha Gomaa Organic chemistry division: Dr. Sharif Rostom Dr. Khaled Khan

23. THANK YOU