Drawbacks and Unfavorable Outcomes of Regenerative
Total Page:16
File Type:pdf, Size:1020Kb
Case Report/Clinical Techniques Drawbacks and Unfavorable Outcomes of Regenerative Endodontic Treatments of Necrotic Immature Teeth: A Literature Review and Report of a Case Ali Nosrat, DDS, MS,* Negar Homayounfar, DDS, MS,† and Kaveh Oloomi, DDS, MS‡ Abstract Introduction: Endodontic treatment of immature reatment of necrotic immature teeth is very challenging in endodontics. Immature necrotic teeth is challenging. Recently a biologically Troots are weak, short, and more susceptible to fracture. It is difficult to perform che- based treatment called regenerative endodontic treat- momechanical debridement and create an effective apical seal by using conventional ment was introduced. Although regenerative en- endodontic treatment methods (1). Historically, multiple-visit apexification was the treat- dodontic treatment causes root development, there ment of choice (2). Although this method was successful (3), it had several disadvantages are several drawbacks and unfavorable outcomes that including long-term treatment, increased root dentin brittleness, and increased risk of should be addressed. This article describes regenerative root fracture because of long-term presence of calcium hydroxide inside the root canal endodontic treatment of 2 maxillary central incisors with space (4). Apical barrier technique was introduced as a replacement for apexification poor root development outcomes. Methods: A healthy with calcium hydroxide (5). In the apical barrier technique a barrier material is placed 14-year-old female patient was referred. The patient at the apex to facilitate obturation procedure. Considering its sealing ability (6),biocom- had history of an impact trauma 6 years before the first patibility (7), hard-tissue induction potential (8), and the ability to set in the presence of visit. Clinical and radiographic examinations revealed moisture (9), mineral trioxide aggregate (MTA) is the material of choice for the apical that maxillary central incisors were immature and barrier technique. Clinical studies have shown high success rates of this method (10). necrotic with symptomatic apical periodontitis. After However, none of the aforementioned methods can promote root development. local anesthesia, rubber dam isolation, and access cavity Recently, a biologically based treatment called regenerative endodontic treatment preparation each tooth was irrigated with 20 mL of was introduced (11). This approach is based on the presence of osteo/odonto progen- NaOCl 5.25% and received triple antibiotic dressing itor stem cells in the apical papilla that are resistant to the infection and necrosis caused (ciprofloxacin, metronidazole, minocycline) for 4 weeks. by proximity to periodontal blood supply (12). In this treatment, the ideal goal is to In the next visit, after eliminating antibiotic dressing, prepare an appropriate environment inside the root canal space (ie, absence of bleeding was induced inside the canals, and then the bacteria and necrotic pulp tissue, presence of a scaffold and a tight coronal seal) coronal thirds of the canals were sealed with mineral that promotes repopulation of these stem cells, regeneration of pulp tissue, and trioxide aggregate. A week later, both teeth were continuation of root development (13). The treatment procedure begins with chemical permanently restored. Results: In clinical and radio- disinfection by copious irrigation of the root canal space with NaOCl (14), combination graphic follow-ups, both teeth were functional, periapi- of NaOCl/chlorhexidine (15, 16) or NaOCl/hydrogen peroxide (17), followed by place- cal lesions were healed, and the apices formed. ment of an intracanal medicament at the first visit. Several medicaments like triple However, the roots were not developed. After 6 years, antibiotic mixture (metronidazole, ciprofloxacin, and minocycline) (18), calcium because of moderate discoloration and caries, both hydroxide (19), and formocresol (20) have been used successfully. At the next visit, teeth received root canal therapy and were permanently which should be at least 1 week after the initial session (21) or more (14), in the restored with casting dowel core and full crown restora- absence of clinical signs of inflammation, the clinician removes the intracanal medica- tions. Conclusions: Criteria for case selection in ment and induces bleeding inside the root canal space by irritating the periradicular regenerative endodontic treatments should be deter- tissue. After clot formation, the clinician seals the root canal space by placing an mined. (J Endod 2012;38:1428–1434) MTA plug over the blood clot (18). There are several case studies that demonstrate successful clinical and radiographic outcome for this treatment approach in single- Key Words rooted (15, 22) and molar teeth (23, 24). Dental trauma, immature teeth, MTA, regenerative However, there are several drawbacks and unfavorable outcomes that are not endodontics, root development, triple antibiotic paste, addressed yet. The purpose of this study was to present these drawbacks and their unfavorable outcome From the *Iranian Center for Endodontic Research, Shahid Beheshti University of Medical Sciences, Tehran, Iran and the Department of Endodontics, Prosthodontics, and Operative Dentistry, School of Dentistry, University of Maryland, Baltimore, Maryland; †Department of Oral Biology, School of Dentistry, University of Washington, Seattle, Washington; and ‡Department of Endodontics, Dental School, Tehran University of Medical Sciences, Tehran, Iran. Address requests for reprints to Dr Negar Homayounfar, Graduate Student, Department of Oral Biology, School of Dentistry, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-7132. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2012 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2012.06.025 1428 Nosrat et al. JOE — Volume 38, Number 10, October 2012 Case Report/Clinical Techniques probable etiologies based on available case reports/series and animal Challenging Histologic Outcomes of Animal studies. These problems are as follows. Studies A few histologic and immmunohistologic studies have been Discoloration performed on the outcome of regenerative endodontic treatments in Discoloration of the tooth after regenerative endodontic treatments, dogs’ teeth (27, 30–33). Histologic evidence of hard-tissue deposition as revealed by Kim et al (25), is a problem mostly related to the use of on the root canal walls (43.9%), apical closure (54.9%), and formation minocycline in the triple antibiotic paste. They demonstrated that the of vital tissue in root canal space (29.3%) was demonstrated by Thibo- main reason for tooth discoloration after treatment was the contact of deau et al (33) in a dog model. They also evaluated the effect of blood minocycline in the triple antibiotic paste with coronal dentinal walls clot and a soluble collagen scaffold on the outcome. Histologic outcome during treatment procedure. A recent study suggested sealing dentinal of the treatment was not different in the presence or absence of blood walls of the access cavity by using dentin bonding agent and composite clot inside the root canal space. In addition, presence of soluble resin before placement of triple antibiotic paste inside the canal (26). collagen scaffold did not improve the results. A histologic study by da On the other hand, Kim et al examined the performance of this prevention Silva et al (27) revealed that the generated tissue inside the root canal technique for tooth discoloration. In this study teeth treated with dentin space after regenerative endodontic treatment was basically ingrowth of bonding were evaluated with naked eye and then with colorimeter. In the periodontal connective tissue instead of pulpal connective tissue. In eye assessment teeth did not have any change in color, but in the color- another study, histologic evaluation of the tissues produced inside the imeter assessment they had. They concluded that using dentin bonding root canal after regenerative endodontic treatment of dogs’ immature agents before placement of the triple antibiotic paste might not completely necrotic teeth revealed 3 types of tissues: cementum-like tissue that prevent tooth discoloration. A practical way to prevent discoloration is was responsible for increase in root length and thickness, bone-like replacing minocycline with an antibiotic that does not stain teeth. Thibo- tissue and periodontal ligament (PDL)–like tissue inside the canal deau and Trope (14) reported a successful regenerative endodontic space (30). There was only one case with partially survived pulp tissue treatment of a maxillary central incisor by using cefaclor instead of min- in which the presence of odontoblasts lining was seen. Formation of ocycline in the antibiotic mixture. Some efforts have been made to omit cemental bridges in different levels inside the canal was also demon- intracanal medication from the treatment procedure. Shin et al (16) pre- strated, which might be related to hard-tissue induction potential of sented a successful single-visit technique of regenerative endodontic MTA (30). In an effort to improve the root thickening and lengthening treatment. The technique used in this study consisted of irrigation of of treated immature necrotic teeth, Yamauchi et al (31) designed and the coronal portion of the root canal space with NaOCl and chlorhexidine evaluated a tissue engineering protocol including use of insoluble gluconate and then MTA placement