Stainelss steel crowns

 I have been doing more stainless steel crowns this year. In fact, prior to 3 months ago I hadn't done one at all. We learned about them briefly during the pediatric dentistry lectures at university and I attended a course on stainless steel crowns and pulpotomies at ADAQ as a new graduate. However I was always put off from doing them, partly because of my percieved complexity of the procedure as well as my stubbornness to change the way I do things. I thought that because I had more experience with doing composite resin fillings, that would be the way to go.

Actually, I have always found appointments with kids quite intimidating. I have done a fair few fillings on kids over the years, some successful and I am sure a lot unsuccessful. When undertaking procedures that intimidate us, we tend to hesitate from going all the way with the procedure. Essentially this means that things aren't done properly. I was afraid to give local anaesthetic to kids, so I was afraid to prep the caries deep and afraid to use proper matrixing and wedging. As a result, I retreated to a position as a new grad where I wasjust scooping food/some caries out on gross cavities with a spoon excavator, putting a mylar strip in and squrting resin modified glass ionomer into the cavity. Needless to say, this was far from ideal, as caries wasnt properly removed, the cavity wasnj't properly sealed with a matrix band and the restoration properties were not ideal. Needless to say, after departing from the practice, word got back to me that a lot of my restorations in children were failing. I wonder why.

Over the years, my technique eventually reached a point where I would avoid LA for 90% of the patients, just prep the cavity open in enamel with a high speed bur to expose the extent of the caries. I would use a slow speed on very low speed to remove the gross, soft decay. Put a metal sectional matrix in with finger pressure (pray that the cervical would seal). Etch, bond and highly filled flowable compsite letting the excess bleed around the embrasures which I would trim back after curing. This worked with reasonable success short term. Probably some of the retention was from the filling being locked into the undercut of the adjacent tooth. However I would still have some compliance issues as I still needed to prep and have good moisture control for the time period that we were doing the restoration. Tell-show-do was one of the strategies from university that stuck with me and I found that as long as the child was aware of what things were going to feel like, they were tolerant of a lot during the procedure. 

About 3 months ago, I listened to a podcast with Tim Keys, a Queensland pediatric dentist. The topic was on stainless steel and pediatric preformed zirconia crowns. He spoke about the technique of crowning deciduous teeth with and without tooth preparation as well as some statistics about the success rates of stainless steel crowns over direct restorations. GIC having the worst survival due to the material properties, composite resin and amalgam being ok in Class 1 situations. He made the argument that if more than one surface is involved, the success rate drops off significantly due to the inherent poor bond to primary teeth and the larger size of the restoration. Essentialy, if we are in a class 2 situation for a deciduous molar, the ideal treatment is a crown, especially if there a prolonged period of time till the expected exfoliation of the tooth.  I recall the success rates for stainless steel crowns with the Hall technique was in the high 90%s over 6 years. In contrast, the success rates for direct restoraitons over a couple of years was significantly higher. This means that if a 6 year old has class 2 decay on their posterior tooth and we elect to place a GIC or composite there, it is more than likely that that restoration will need to be redone 2-3 times before the tooth exfoliates. That means multiple appointments, multiple injections, multiple procedures. The only drawback of the stainless steel crown is the aesthetics of them. Which to be fair, when weighed up against the risk of having a higher treatment burden, most parents would be fine with the stainless steel crown (at least in my demographic of patients). 

Since listening to that podcast, I was convinced. I put forward the same arguments to the parents of the kids with caries that I was seeing and unsurprisingly they were all for the treatment. To my surprise, a couple of the clinics that I worked at already had a large stock of stainless steel crowns that were gathering dust in the cupboard. I plopped on my first couple of crowns a few months ago and have almost done a dozen more since then. 

I show this sequence of photos to parents to explain the process of the Hall crown technique. Step 1, place a couple of separators for 1 week. When the patient returns, we can see the space that has been created between the teeth and the cavitated caries is visible. The stainless steel crown is cemented on and there is no need for tooth preparation or local anaesthetic. The crown will be high in occlusion short term but as children's bones are soft they teeth will shuffle and the bite will equalise.

I have had some challenges with the stainless steel crowns mainly with fitting the crowns. When they fit well the procedure is exceedingly simple but when the fit is not good then there is a lot of fiddling trying different sizes, trying to use pliers to bend out the crown to make it fit. Usually I encounter a situation where the tooth is too large for the crown. I have gotten around it by bending the crown margins outwards, the downside of this is that there probably isnt as good of an adaptation at the base of the crown, an "overhang" if you will. Sometimes in this situation, tooth preparation interproximally will make the crown fitting a lot simpler. The other troubleshooting I had had to do is when a separator is lost early. I tell the parents to let us know when a separator comes out but one parent has not told us because the child had very poor compliance and she didn't think he would sit through placement of another separator. As a result we had a nightmare appointment trying to fit the crown. Sometimes parents think they are doing the best thing trying to shield their child from things but end up making things worse. In these situations, there is more resistance to the crown seating. It may also be harder to remove the crown after a try in if you do get it seated. Technically, if you can force a separator in between the teeth, you can probably force a stainless steel crown in with enough force.

Stainless steel crowns have quickly become the main restorative choice for me for primary molars with caries involving more than once surface. All it took was a bit of encouragement and some clinical experience and it became a lot easier to go through the clinical process. Don't be afraid to give it a try, start with a compliant child and get comfortable with the sizing, seating,  bonding and cleanup process and your pediatric appointments will be made much more enjoyable for it.