BIOCERAMICS IN DENTISTRY – A PARADIGM SHIFT

Abstract

The desideratum of any dentist / endodontist should be to preserve the pulpal vitality, according to the principle witch says that the best canal filling is the dental pulp itself. In daily practice we must be guided by the postulate of Hippocrates: “Primum non nocere.” Several maintain that the pulp cannot sustain any insult, while others are convinced that because it is very resistant any attempt to preserve it is justified [1]. It was once thought that only pinpoint exposures could be pulp capped, however more recent research would suggest that the size of exposure has no bearing on clinical outcome [2,3,4]. The issue of age is also difficult, as there is no clear cut-off when a direct pulp cap should no longer be considered. The ageing process is gradual and with increased age the pulp tissue becomes more fibrous with a reduction in pulp volume as a result of physiological secondary dentine formation and reactionary dentine due to external stimuli such as trauma, caries and tooth wear. The blood supply to the dental pulp is critical to its health and regenerative capacity, and as this decreases with age so does its capacity to respond to a direct pulp cap [5]. Finally the location of the exposure is important as there should be no pulp tissue coronal to the exposure. Exposure in a cervical cavity would lead to reactionary dentine formation which would restrict the blood supply to the tissue more coronal to it, leading to necrosis and failure. These teeth should therefore be root treated [6]. As Barchall states:” More than 15 years ago, the treatment demarcation for a pulpotomy and/or pulp-capping procedure versus performing a pulpectomy was fairly straightforward. A pulpotomy or pulp-capping procedure was a temporary treatment of the pulp until a full rooth canal treatment could be scheduled. Advancements in technology and materials in the field of endodontics have led to a paradigm shift in vital pulp therapy over the past years. With the arrival of modern method of endodontic treatment, rotary endodontic instruments, apex locator, endodontic micromotors, vertical warm condensing systems, pulpectomies became the treatment of choice over pulp-capping and pulpotomies on a vital pulp. This was because the clinician was now able to effectively and efficiently perform root canal treatment with rotary endodontic files as compared to using all hand-file instrumentation as previously. Specifically, these advancements are the clinician’s ability to histologically assess a carious-involved pulp and the advent of bioceramic materials. Up to a few years ago, the prevailing thought was that if a carious lesion encroached the pulp and the pretreatment pulpal diagnosis was a normal pulp or reversible pulpitis, the entire pulp tissue was considered inflamed and would require a pulpectomy “[7]. Ricucci et al found that clinical pulpal diagnosis of a normal pulp or reversible pulpitis had a 96.6% histological match to the normal pulp tissue in a tooth [7, 8] This study also showed that, in this type of case scenario, pulpal inflammation was localized to the area of the caries alone and the rest of the pulp tissue was observed to be normal. Consequently, the therapy of vital pulp is the treatment of choice if the pulp is exposed during the removal of caries, followed by the placement of a permanent restoration.