Pulp Debridement Emergency Flashcards
A. What information from the clinical and radio- graphic examination will lead to the diagnosis of pulp necrosis? What clinical presentations can appear?
A tooth with a necrotic pulp can manifest as an emergency in any of the following ways:
1. Acute Apical Periodontitis (AAP) without swelling
2. Acute Apical Abscess (AAA) with fluctuant swell-
ing (draining may or may not be present)
3. Diffuse Facial Swelling with or without drainage
through canal system (Wolcott, Rossman & Hasselgeren 2011).
Upon interviewing a patient experiencing intense
symptoms, our priority should be to determine the chief complaint (CC). In this case, the CC was pain. Secondly, the history and nature of said pain needs to be evaluated. A tooth with pulp necrosis will not respond to cold testing, except in cases of liquefac- tion necrosis or necrobiosis (partial necrosis) in multi‐rooted teeth. Percussion will be positive, signifying the spread of inflammation to the per- iradicular tissues. Palpation will also likely be positive, as will examination with a bite stick.
The nature of pain associated with a necrotic tooth presenting as an emergency will involve constant moderate to severe pain. It could be spontaneously produced, or triggered by stimula- tion, such as percussion or mastication. Supination could aggravate symptomatology, while the pain could have throbbing characteristics.
The pain could be localized in the specific tooth, or be diffuse, involving an entire quadrant, and even refer to other anatomical areas (ear, throat, eye) (Glick 1962).
The radiographic findings can present a wide range, depending on the duration of necrosis and stage of inflammation. A necrotic tooth can present with a normal periapical area, a widened or obscure PDL or a clear radiolucent area. It can also manifest with condensing osteitis or resorption of the root structure.
The extra‐oral exam can reveal facial swelling with asymmetry and swollen nodes in the affected area. During the intra‐oral exam, the clinical crown can present with an existing restoration, caries, traumatic pulpal exposure or fracture. Soft tissues can present with or without swelling.The presence of a sinus tract depends on the duration and intensity of the disease.
B. Which microorganisms have been found to cause infection in necrotic cases?
A tooth presenting with pulp necrosis that has never been accessed before will fall under the category of primary intraradicular infection. In primary infections, the necrotic pulp tissue becomes colonized by a mix of 10–30 taxa of microorganisms (Siqueira & Rocas 2005).
It has been noted that the larger the size of peri- apical destruction, the greater the bacterial diversity. The bacteria dominating the infected canals are primarily Gram‐negative anaerobes, particularly rods, such as Tannerella, Porphyromonas, Prevotella, Fusobacterium and Treponema (spirochetes). Some Gram‐positive anaerobes, such as certain cocci (Streptococcus, Peptostreptococcus, Enterococcus) and rods (Actinomyces, Propionibacterium, Lactobacillus) can also be found in primary infec- tions, as can facultative or microaerophilic strepto- cocci. Certain viruses (HIV, HSV) and fungi (Candida) have also been found in primary endodontic infections (Sedgley 2011).
Some Gram‐negative anaerobic species have been linked to symptomatic cases; however, data suggests that these species can also be found in asymptomatic cases.
C. What is the first line of defense to treating an emergency stemming from a necrotic pulp?
It has been established that acute apical peri- odontitis (AAP) and acute apical abscesses (AAA) are caused by microorganisms and their byproducts egressing the infected root canal system, and communicating with the periodontal tissues.The first line of defense in treating cases presenting with AAP is the removal of these microbes, as well as their byproducts, from the canal system. By effec- tively debriding the canal system, the stimuli caus- ing apical periodontitis are removed and the inflammatory process can begin to shut down (Peters & Peters 2011).
Microbial elimination in cases with necrotic pulp can be achieved through mechanical instrumenta- tion (debridement), irrigation with disinfecting solutions (NaOCl, CHX, EDTA) and placement of intracanal medications (Ca(OH)2) (Law & Messer 2004; Sathorn, Parashos & Messer 2007). Canal debridement is considered the first line of defense in these cases, as instrumentation alone, even without disinfectants, reduces the existing flora by up to 90% (Dalton et al. 1980). According to recent studies, debridement results in a statistically signifi- cant reduction in post‐operative pain, when com- pared to the sole prescription of medication without clinical intervention.
While most microbes in an intraradicular infec- tion can be found in a fluid phase, some microor- ganisms form biofilms that penetrate the dentinal tubules and extend to varying depths into dentin. Files that engage the dentinal walls literally “scrape” and disrupt the microbial biofilm, and remove necrotic pulp tissue, thus eliminating the cause of disease (Love, McMillan & Jenkinson 1997).
The material of the instruments used to clean and shape the canal system has not been found to affect total microbial reduction. Rather, the final shape of the canal is important with regards to the number of remaining bacteria (Card et al. 2002).
D. What are the basic objectives and principles in cleaning and shaping a canal?
The basic objectives in cleaning and shaping are:
• Removal of infected soft and hard tissue
• Granting apical access to medicaments and
disinfecting solutions
• Creation of space for obturation
• Retention of integrity of radicular structure,
preventing vertical fractures (Peters & Peters 2011) A multitude of files can be used for the debride-
ment of the canal system.These include, but are not limited to: K‐files, reamers, Hedstrom files, broaches, C+ files, Gates Glidden drills, Peeso reamers, NiTi, stainless steel (SS) files, M wire files, controlled memory files.Traditionally, hand files have been used to establish a glide path at the beginning of treatment. Rotaries can be used on a canal‐specific basis, utilizing their strengths. Larger taper rotaries are typically used for orifice shaping, whereas less tapered files offer more flexibility, respect the anatomy of the canals and deliver safe apical enlargement. Rotary files can be used in a continuous rotary or a reciprocating mode.
Although the removal of all infected dentin is not currently feasible, as all root canal surfaces cannot be mechanically prepared, there are multiple tech- niques to help overcome this limitation.
Most commonly preferred techniques involve some method of coronal enlargement, followed by different middle and apical third preparation sequences and sizes/ tapers. Special attention needs to be paid to the apical area as the larger the apex, the more volume of disinfectant delivered (Card et al. 2002; Souza 2006).
Each clinician needs to address individually the specific needs of each canal system, trying to respect and maintain the original anatomy, remaining mindful of the vast anatomic variations, not only between different individuals, but among different teeth and even different roots and canals.
E. Should a tooth be left open?
Historically, leaving a tooth open between visits, for the purpose of drainage, was common practice (Torabinejad et al. 1988). Based on current studies, this practice is no longer recommended, as it can lead to more complications and inferior success rates in the long‐term prognosis of treatment (Simon, Chimenti & Mintz 1982). If a tooth is left open, foreign objects can gain entry to the periapi- cal tissues, and opportunistic bacteria, hereto without access to the canal system, can colonize the radicular dentin.This can lead to a secondary intraradicular infection and reduce chances of successful elimination of microbial flora.
