12th July 2006

someone please tell me how the tooth clearing is done I have misplaced my earlier mails - Sanjay

I think 30%nitric acid for 24 hrs , then ethanol  for 36 hrs then h2o for 1 day , i would had given u exact
info but this is what i remember as my hard diskis dead and creamated with full state honors - Gurpreet Singh

Sanjay, I think it's a laboratory method for seeing the accesoory canals. can be done after the tooth
is extracted. - Ananya

Here are some cleared teeth, we are required to complete as part of a tooth project while in our first year.

HERE IS THE PROTOCOL WE USE AT UNIVERSITY OF SOUTHERN CALIFORNIA

Unfortunately at times you do not have control over the apices being dissolved and the gutta percha
tends to stick out!!

a) Use 5% nitric acid to decalcify the teeth. Place enough acid in each clean and dry container to cover tooth.
   Allow this to sit for 2-3 days. To verify that the decalcification is progressing, take a radiograph of
   the molar. As the tooth decalcifies, the image will become more soft tissue-like . If the teeth are allowed
   to sit in the acid too long, the apices have a tendency to dissolve. Agitate the solution to speed the process.

b) Once the teeth are sufficiently decalcified, carefully pour the acid into a container and dispose of properly.
   Rinse the teeth under running water for 3 hours. If that is not possible, rinse thoroughly and store at least
   over night in water and rinse thoroughly again. Dry the teeth and their containers.

c) The next step is to dehydrate the teeth. This is done using serial dilutions of alcohol starting with 80%
   Allow the teeth to sit in the 80% (Isopropyl)alcohol for at least one hour. This is followed by the 95%
   and finally 100% alcohol. Once the dehydration process is complete, allow the teeth to bench dry about 1 hour.

d) Put the teeth back into the cleaned and dried containers. Pour oil of wintergreen (methyl salicylate) over
   the teeth in sufficient volume to cover the teeth.

I have my doubts about whether these teeth could be appropriately used for instrumentation after clearing,
due to the demineralization process - weakening etc.   -  Rajiv Patel



Recipe (posted by Sameh Barsoum in 2003)

1 Place the tooth in 5% NaOCl for 12 hours to remove all organic material from the surface.
2 Place in  5% HNO3 for 3-6days for complete decalcification, check with X-rays if desired Thoroughly rinse with water
3 Dehydrate in alcohol of increasing concentration for 1 day  for each concentration(70%, 85% und 99%)
4 Place in methylsalycilate for several hours  - Rob Kaufmann

Castellucci Clearing Protocol:

1  Half an hour in 5 %NaOCl to dissolve PDL
2  3 days in nitric acid 5% at room temp.
3  Rx to check completeness of demineralization, one more day perhaps
4  4 hour rinse in tap water
5  12 hours in 80% ethyl alcohol
6  2 hours in 90% 2 hours in overproof
7  2 hours in methyl salicyclate

- Sanjay

Int Endod J. 2003 Jan;36(1):54-63. Related Articles, Links

A preliminary analysis of the morphology of lateral canals after root
canal filling using a tooth-clearing technique.

Venturi M, Prati C, Capelli G, Falconi M, Breschi L.

Dipartimento di Scienze Odontostomatologiche, University of Bologna, Bologna, Italy.

AIM: This study used a modified tooth-clearing technique to allow observation of accessory canals following filling with a warm
gutta-percha technique and one of two endodontic cements.

METHODOLOGY: Ten extracted human maxillary molars with three roots were selected and divided into two equal groups of five teeth.
Each group had 15 canals. Root canal preparation was performed with a modified double flared technique; irrigation with 5% NaOCl
and lubrication with RC-Prep were used. The canals were then filled with gutta-percha and cement utilizing a warm vertical
condensation technique in the apical third followed by thermo-mechanical compaction in the middle and coronal thirds. Pulp Canal
Sealer or AH-Plus were used in the experimental groups. The teeth were demineralized with a modified buffered acid solution, cleared
in methylsalicylate and examined under a stereomicroscope. Accessory canals were evaluated in the apical, middle and coronal thirds
of each root canal and categorized as narrow or wide, following observation on four surfaces. The depth of penetration of gutta-percha
and cement into lateral canals was scored using a 5-point system. RESULTS: Complete transparency of the roots was achieved. Accessory
canals were detected in all specimens. In coronal ramifications, gutta-percha filled the empty spaces (coronal thirds, grades 3 and 4:
70.9% in AH-Plus group and 68.8% in Pulp Canal Sealer group). In the apical accessory canals, gutta-percha entered less frequently
(apical thirds, grades 3 and 4: 17.9% in the AH-Plus group and 3.2% in the Pulp Canal Sealer group); cement without gutta-percha
(grades 1 and 2) was present in 55.5% in the AH-Plus group and 38.7% of the Pulp Canal Sealer group. Analysis showed that AH-Plus cement
resulted in significantly greater filling of the apical accessory canals compared to Pulp Canal Sealer.

CONCLUSIONS: The modified tooth-clearing technique allowed observation of fine morphological details in all specimens. Effective
gutta-percha filling was evident in most of the wide coronal lateral canals whilst the apical narrow ramifications were often incompletely filled by cement.
Overall AH-Plus demonstrated better diffusion into lateral accessory
canals compared to Pulp Canal Sealer.

Publication Types:
Evaluation Studies

PMID: 12656515 [PubMed - indexed for MEDLINE]