Links

Dental Cosmos http://quod.lib.umich.edu/d/dencos/

Simplant http://www.ctscan.co.uk/products/softwares/simplant_about.html

Quintessence publishing http://www.quintpub.co.uk/index.php?modules=content&page=contact_us

Clinical Journal of Periodontology http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1600-051X

Thermafil instructions Densply https://cheshiresmile.co.uk/wp-content/uploads/2011/02/Brochure_Thermafil.en1_0.pdf

Pulp Capping

Keys to Clinical Success with Pulp Capping: A review of the literature by Hilton is an excellent review article on both direct and indirect pulp capping. Operative Dentistry, 2009; 34-5, 615-625

The author indicated several key points that must be considered when evaluating studies on pulp capping. First, clinical pulp capping studies rarely reflect clinical reality.  Many are carried out on healthy teeth that are planned for orthodontic extraction. Second, the histologic pulp status of a tooth cannot be determined by clinical signs and symptoms.  It is also noted that studies in animals are not necessarily predictive of human outcomes.

An electron micrograph of calcium hydroxide

The conclusions to the review were:

  1. Avoid exposing the pulp. The chances for tooth survival are excellent if the tooth is asymptomatic and well sealed, even if residual caries remains.
  2. Control haemorrhage with water, saline or sodium hypochlorite. Water and saline are the most benign to the pulp; sodium hypochlorite is best at controlling haemorrhage and disinfecting.
  3. ZOE, GI/RMGI and adhesives are poor direct pulp-capping agents and should be avoided for this application.
  4. MTA demonstrates comparable results to calcium hydroxide as a direct pulp cap agent in short-term data.
  5. Calcium hydroxide remains the “gold standard” for direct pulp capping. It has the longest track record of clinical success, is the most cost-effective and is the likely effective component in MTA.
  6. Provide a well-sealed restoration immediately after pulp capping. This will provide protection against ongoing leakage and bacterial contamination that can compromise the success of the pulp cap.

It is also worth pointing out that MTA is hideously expensive!

Removing Crowns

It is often best to remove large amalgam, composite and cast restorations from teeth that are planned for endodontics. Dentistry leaks and cement lutes fail. There is often hidden dental caries beneath repairs. It is necessary to visually assess the amount and quality of remaining tooth tissue in order to determine if teeth are beyond reasonable restoration before endodontics commences.

 Komet crown-cutter

Removing crowns

Use a round diamond to remove the porcelain veneer from PBC’s. Use a transmetal bur to brush cut through the metal casting, use the largest bur for maximum strength. They can fracture in use although this has only ever happened twice in 6 years. Make sure you, the patient, your assistant all wear safety glasses.

A WAMKey  or equivalent can be used to lift off crowns safely as illustrated below.

WAMKey

Removing restorations does place an additional burden on patients but very often teeth are borderline restorable and beyond and it is in the patients best interest to determine this before root canal commences.

Removing plastic and cast restorations frequently reveals dental caries, the dentist can assess for fractures and provide for an effective seal between visits when the root canals have been prepared and dressed with non-setting calcium hydroxide.

 The WAMKey is inserted and rotated, the oval profile is used to lift off the crown

 The crown is lifted away

 Evidence of leakage

 Extensive caries, the tooth is unfortunately beyond  reasonable restoration

7 Endodontic Tips

A lot of these tips I picked up at the Spring British Endodontic Society Meeting, hey I am a slow typist!

1 Vapour lock

This is a potential obstruction for irrigants when a liquid is trying to exchange places with a gas a ‘bubble’ is created at the apex and irrigant exchange does not reach or take place at this critical location. Effectively aspirate by pulling back slightly with the irrigant syringe to remove any vapour lock. It is interesting to observe the gas bubble followed by a cloud of cut dentine and debris feedback into the syringe. Once the vapour is removed the apical third is effectively cleaning the all important apical third.

2 Hypochlorite

This is the most effective irrigant available to dentists and it is recommended. I use ASDA thin bleach, diluted 50:50 in safety tipped syringes warmed to coffee temperature (60 degrees) in a baby bottle warmer. Use a rubber file stop to indicate the working length so you are never  going to risk binding at the apex or putting the tip through an open apex. An open apex is a considerable risk during re-treatments when the previous operator inadvertently reamed open the apical foramina larger than a size 40 hand file! Rubber dam is mandatory in any case and patient safety is paramount.

3 Apical cleaning

Apical irrigation does not effectively start until an F2 ProTaper (red) has reached length. Only from this point forward does the apical disinfection start. If possible finish to the F3 ProTaper (blue) to increase the exchange during apical irrigation and disinfection. There is good evidence that supports this,  Van der Sluis et al evaluated the effects of apical preparation size on irrigant flow inside root canals showed increasingly that root canal enlargement sizes larger than 25 improve the performance of syringe irrigation. International Endodontic Journal 43, 874-881,2010

4 Ultrasonics

At the Spring meeting ultrasonic tips were recommended as an adjunct to canal cleaning. I have introduced them into our endodontic protocol and now activate the canals flooded with hypochlorite between files, and at final cleaning. Judging by the amount of debris that is observed this is worthwhile.

5 Sterile non-setting calcium hydroxide

I have started to use Calasept instead of Hypo-Cal which tends not to block the delivery syringe. This is spun into place using a spiral filler to make sure there is no air lock at the apex which would enable bacteria to grow in this critical area. It is diluted with sterile saline.

6 Don’t mix chlorhexidine and EDTA

If you mix them you create a precipitate. If you use chlorhexidine as an irrigant remove it carefully with paper points first before using EDTA. We have stopped using lubricants such as File-Eze which contains EDTA, they are unnecessary anyway if you have the canal flooded with hypochlorite that is all the lubrication you need.

7 Measure your paper points

Make sure you do not push paper points through the apex, remnants of paper points can cause irritation to the apical tissues. Measure the points using your working length and locking tweezers so you know they stay within the canal (Hu-Friedy Locking Endodontic Pliers, EPL1).