LPT and TMD – any evidence?
By Jan Tunér, DDS
In 2010 the Swedish Council on Health Technology Assessment (SBU) published an analysis of the available scientific support for performing endodontic therapy. The conclusion was that there was little, if any, scientific support for any endodontic method. The reasons were the technical variations in root canal debridement and widening, rinsing agents, diagnoses and types of fillers. Further to that, the groups were generally small and non-homogenous and follow up periods short. Now, we all know that endodontic methods are reasonably successful and widely used for decades. But when a strict scientific evaluation was performed, no endodontic method had a reasonable support in the scientific literature. This came as a total surprise to most dentists.
In 2011 Petrucci et al. published a literature review on the use of LPT for TMD. The correct conclusion was that there is no scientific support for the use of LPT for this indication. Yet, most users of LPT know that this is a very useful method. However, the available literature is quite non homogeneous. Even though many authors report good results, each author seems to have chosen his own wavelength, energy, dose, mode of application, patient selection, follow up period etc. So there are not two studies of any quality using the same concept. And just as in endodontics, the TMD background is multi-factorial. Consequently, from a strict scientific point of view, there is no support for the treatment modality. Not for LPT for TMD, nor for root fillings. Still, both work.
The above illustrates one of the obstacles for the acceptance of LPT. Not only is the collected scientific documentation distilled by being used for so many indications, the parameters vary a lot, even within a selected indication. And further to that, many authors do not seem to have control over their laser parameters.
Some indications for LPT (e.g. mucositis) have strong scientific evidence, but most have little or hardly any. So scientific work has to accelerate and also improve. In the meantime we sometimes have to rely on indirect evidence. For instance, there is general evidence of pain reduction, reduction of edema and inflammation, all involved in TMD. With this, and the strong evidence for the lack of side effects, LPT for TMD appears to be a promising method. Lack of Cochrane-style scientific evidence is no contraindication in itself - that would exclude many traditional medical methods. Indeed, Cochrane evaluations are rarely overwhelmingly positive – rightfully so.