Levels of Evidence for the Outcome of Endodontic Retreatment
Stephen Paik, DDS, Christopher Sechrist, DDS, Mahmoud Torabinejad, DMD, MSD, PhD
Treatment Outcome in Endodontics—The Toronto Study. Phases I and II: Apical Surgery
Nancy Wang, DDS, Keith Knight, PhD, Thuan Dao, DDS, PhD, Shimon Friedman, DMD
Evaluation of Periapical Lesion Healing by Correction of Gray Values
Jean Camps, DCD, PhD, Ludovic Pommel, DCD, and Frédéric Bukiet, DCD
Expression of Insulin-Like Growth Factor-1 Receptor in Human Pulp Tissue
Javier Caviedes-Bucheli, MSc, DDS,* Hugo Roberto Muñoz, DDS,† Carlos Eduardo Rodríguez, DDS,† Tania Carolina Lorenzana, DDS,† Gloria Cristina Moreno, MSc,* Nelson Lombana, MSc*
Substance P Enhances Expression of Lipopolysaccharide-induced Inflammatory Factors in Dental Pulp Cells
Masayuki Tokuda, DDS, PhD, Rie Miyamoto, DDS, Shigetaka Nagaoka, DDS, PhD, and Mitsuo Torii, DDS, PhD
A Comparison of the In vitro Retentive Strength of Glass-Ionomer Cement, Zinc-Phosphate Cement, and Mineral Trioxide Aggregate for the Retention of Prefabricated Posts in Bovine Incisors
Joseph W. Vargas, DDS, Frederick R. Liewehr, DDS, MS, Anthony P. Joyce, DDS, and Royce R. Runner
Antimicrobial Effect of Ozonated Water on Bacteria Invading Dentinal Tubules
Masato Nagayoshi, DDS, Chiaki Kitamura, DDS, PhD, Takaki Fukuizumi, DDS, PhD, Tatsuji Nishihara, DDS, PhD, and Masamichi Terashita, DDS, PhD
Bacterial Leakage with Mineral Trioxide Aggregate or a Resin-Modified Glass Ionomer Used as a Coronal Barrier
Marat Tselnik, DDS, J. Craig Baumgartner, DDS, PhD, and J. Gordon Marshall, DMD
Soft Tissue Dissolution Capacity of Currently Used and Potential Endodontic Irrigants
Nadja Naenni, cand DMD, Kaya Thoma, DMD, and Matthias Zehnder, DMD
Effect of 2% Chlorhexidine Gel as an Intracanal Medication on the Apical Seal of the Root-Canal System
Rolf M. W. Wuerch, DDS, Michael J. Apicella, DDS, Pete Mines, DDS, Peter J. Yancich, DDS, and David H. Pashley, DMD, PhD
Evaluation of the Effect of Endodontic Irrigation Solutions on the Microhardness and the Roughness of Root Canal Dentin
Hale Ari, DDS, PhD, Ali Erdemir, DDS, PhD, and Sema Belli, DDS, PhD
Treatment of Periapical Inflammatory Lesion with the Combination of Platelet-Rich Plasma and Tricalcium Phosphate: A Case Report
Burak Demiralp, Hu¨ seyin Gencay Kec¸ eli, Mehmet Muhtarog˘ ulları, Ahmet Serper, Bahtiyar Demiralp, and Kenan Eratalay
Levels of Evidence for the Outcome of Endodontic Retreatment
Stephen Paik, DDS, Christopher Sechrist, DDS, Mahmoud Torabinejad, DMD, MSD, PhD
The purpose of this investigation was 2-fold: (a) to complete a thorough search of published literature related to clinical studies on the success and failure of nonsurgical retreatment, and (b) to assign levels of evidence to these publications. Clinical studies related to success and failure of retreatment since 1970 were identified using both electronic and manual literature searches. After identification of pertinent literature, each article received a level of evidence (LOE) from one (high) to five (low). Thirty-one clinical studies and six review articles related to this subject were identified. There was no LOE 1 Randomized Control Trials (RCT). There were three LOE 2 RCTs, one LOE 2 Cohort, and two LOE 3 Case Control Studies. Thirteen Case Series (LOE 4), which comprise the most highly quoted success and failure data, were found. Twelve Case Reports (LOE 5) and six review articles (LOE 5) were found. Based on these findings, it appears that few high level studies have been published in the past 34 yr related to the success and failure of endodontic retreatment.
Treatment Outcome in Endodontics—The Toronto Study. Phases I and II: Apical Surgery
Nancy Wang, DDS, Keith Knight, PhD, Thuan Dao, DDS, PhD, Shimon Friedman, DMD
This study prospectively assessed the 4 to 8 yr outcome of apical surgery performed by graduate students in phases I and II of the Toronto Study. The study cohort included 155 teeth in 138 patients. Outcome was assessed by a blinded and calibrated examiner. Clinical and radiographic measures were used for a dichotomous outcome: healed (no signs and symptoms, Periapical Index score < 2 or scar), or diseased (presence of signs and symptoms, or Periapical Index score > 3). The recall rate was 85% and the overall healed rate 74%. Healed rate was significantly higher for teeth with small (<5 mm) than larger preoperative lesions (_2, p _ 0.02). Logistic Regression revealed an increased odds of disease persistence for teeth with larger preoperative lesions (OR _ 3.81, CI _ 1.2–12.1), and preoperative rootfilling of adequate length (OR _ 3.7, CI _ 1.1–11.1). Preoperative lesion size and root-filling length were significant predictors of outcome of apical surgery.
Evaluation of Periapical Lesion Healing by Correction of Gray Values
Jean Camps, DCD, PhD, Ludovic Pommel, DCD, and Frédéric Bukiet, DCD
The purpose of this study was to compare two methods for evaluating periapical healing in humans: the periapical index (PAI) and a gray value correction method. Fifty human teeth with a periapical lesion were endodontically treated. Radiographs, with a special aluminum device, were taken postoperatively, after 3 months and after 6 months. The PAI was recorded at each period of time, and a Kruskall and Wallis test was performed to compare the three groups. After scanning, the size of the lesion and its gray value were recorded. The aluminum device allowed the gray values to be equalized. An analysis of variance followed by a Duncan test was performed to compare the three groups. The teeth that showed no sign of healing according to the PAI were separately analyzed by an analysis of variance and a Duncan test. The PAI (n _ 50) showed signs of periapical healing over time (p < 0.01). The analysis of variance, based on gray value evaluation (n _ 50), also showed signs of periapical healing over time (p < 0.002). The analysis of variance of teeth with the same PAI over time (n _ 15 at 3 months, and n _ 5 at 6 months), based on gray value evaluation showed statistically significant differences among the 3 groups (p< 0.02). These results show that the gray level correction method is powerful and may reduce the risks of false negative responses during assessment of treatment results or epidemiological studies.
Expression of Insulin-Like Growth Factor-1 Receptor in Human Pulp Tissue
Javier Caviedes-Bucheli, MSc, DDS,* Hugo Roberto Muñoz, DDS,† Carlos Eduardo Rodríguez, DDS,† Tania Carolina Lorenzana, DDS,† Gloria Cristina Moreno, MSc,* Nelson Lombana, MSc*
Insulin-like growth factor-1 (IGF-1) plays an important role in cell proliferation and differentiation. The purpose of this study was to use a radioreceptor assay to evaluate whether IGF-1 receptors are present in human pulp and to determine whether differences in its expression are found in the pulp tissue of teeth having incomplete or complete root development. Twenty pulps were obtained from freshly extracted human third molars; they were then processed and labeled with 125I-IGF-1. The results showed IGF-1 receptor expression in all human pulp samples. t test revealed statistically significant higher expression in the pulps from teeth having incomplete root development (P<0.005). Given the functions of this growth factor system in other tissues, the present findings are consistent with the hypothesis that IGF-1 contributes toward forming and mineralizing dental tissues as well as in pulp-repairing processes.
Substance P Enhances Expression of Lipopolysaccharide-induced Inflammatory Factors in Dental Pulp Cells
Masayuki Tokuda, DDS, PhD, Rie Miyamoto, DDS, Shigetaka Nagaoka, DDS, PhD, and
Mitsuo Torii, DDS, PhD
To examine how substance P (SP) is related with dental pulp inflammation, we examined the effects of SP on expression of genes for inflammatory factors in human dental pulp cell cultures. Using reverse transcriptase-polymerase chain reaction, we found that Prevotella intermedia lipopolysaccharide (LPS) induced expression of SP and SP-receptor mRNAs, and that somatostatin inhibited the LPS-induced expression of SP mRNA. We also found that SP enhanced LPS-induced stimulation of NF-_B binding activity. In addition, SP induced expression of cyclooxygenase-2 and interleukin-10 receptor mRNAs. In contrast, SP inhibited expression of interferon-gamma receptor mRNA. These results suggest that SP may play a regulatory role in the immunological response of dental pulp tissue to pathogenic bacteria.
A Comparison of the In vitro Retentive Strength of Glass-Ionomer Cement, Zinc-Phosphate Cement, and Mineral Trioxide Aggregate for the Retention of Prefabricated Posts in Bovine Incisors
Joseph W. Vargas, DDS, Frederick R. Liewehr, DDS, MS, Anthony P. Joyce, DDS, and Royce R. Runner
The purpose of this study was to compare the retentive strength of zinc-phosphate cement, glass-ionomer cement, and mineral trioxide aggregate (MTA) cement in the retention of prefabricated posts. The root canals of 60 bovine incisors were prepared and obturated with warm gutta-percha. Post space was prepared, the smear layer removed, and posts were luted with zinc-phosphate cement, glass-ionomer cement, or MTA. The specimens were stored at 37°C and 100% humidity for 2 weeks, and then subjected to increasing axial tensile forces by an Instron machine until bond failure occurred. Data were analyzed by a one-way ANOVA and a Tukey-Kramer multiple comparison test. The retentive strengths of zinc phosphate and glass-ionomer cements were statistically equivalent, and significantly greater than MTA (p < 0.001), which suggests that zinc phosphate or glass-ionomer cement may be superior to MTA when used as luting agents for posts in endodontically treated teeth.
Antimicrobial Effect of Ozonated Water on Bacteria Invading Dentinal Tubules
Masato Nagayoshi, DDS, Chiaki Kitamura, DDS, PhD, Takaki Fukuizumi, DDS, PhD,
Tatsuji Nishihara, DDS, PhD, and Masamichi Terashita, DDS, PhD
Ozone is known to act as a strong antimicrobial agent against bacteria, fungi, and viruses. In the present study, we examined the effect of ozonated water against Enterococcus faecalis and Streptcoccus mutans infections in vitro in bovine dentin. After irrigation with ozonated water, the viability of E. faecalis and S. mutans invading dentinal tubules significantly decreased. Notably, when the specimen was irrigated with sonication, ozonated water had nearly the same antimicrobial activity as 2.5% sodium hypochlorite (NaOCl). We also compared the cytotoxicity against L-929 mouse fibroblasts between ozonated water and NaOCl. The metabolic activity of fibroblasts was high when the cells were treated with ozonated water, whereas that of fibroblasts significantly decreased when the cells were treated with 2.5% NaOCl. These results suggest that ozonated water application may be useful for endodontic therapy.
Bacterial Leakage with Mineral Trioxide Aggregate or a Resin-Modified Glass Ionomer Used as a Coronal Barrier
Marat Tselnik, DDS, J. Craig Baumgartner, DDS, PhD, and J. Gordon Marshall, DMD
The purpose of this study was to evaluate gray mineral trioxide aggregate (MTA), white MTA, and Fuji II LC cement as coronal barriers to bacterial leakage. Seventy-eight, matched, human teeth were obturated with gutta-percha. In group I, 18 pairs received a 3-mm barrier of gray or white MTA. In group II, 18 pairs received a 3-mm barrier of gray MTA or Fuji cement. Three pairs were used as positive (obturated without barrier) and negative (covered with epoxy resin) controls. A dual-chamber leakage model utilizing salivary microbes was used for the evaluation. Leakage was recorded when turbidity was observed. All controls behaved as expected. In group I, three gray MTA and three white MTA samples leaked. In group II, one gray MTA and three Fuji samples leaked. There was no statistically significant difference in leakage between gray and white MTA or gray MTA and Fuji at 30, 60, or 90 days. Gray and white MTA or Fuji II can be recommended as a coronal barrier for up to 3 months.
Soft Tissue Dissolution Capacity of Currently Used and Potential Endodontic Irrigants
Nadja Naenni, cand DMD, Kaya Thoma, DMD, and Matthias Zehnder, DMD
Necrotic soft-tissue remnants in root canals may provide a source of nutrition for surviving microbiota after root-canal therapy. This study assessed the necrotic tissue dissolution capacity of some popular and some potential root-canal irrigants: 1% (wt/vol) sodium hypochlorite (NaOCl), 10% chlorhexidine, 3% and 30% hydrogen peroxide, 10% peracetic acid, 5% dichloroisocyanurate (NaDCC), and 10% citric acid. Standardized necrotic tissue samples obtained from pig palates were incubated in these solutions, and their weight loss was measured over time. None of the test solutions except sodium hypochlorite had any substantial tissue dissolution capacity. It was concluded that this might be important when considering the use of irrigants other than NaOCl.
Effect of 2% Chlorhexidine Gel as an Intracanal Medication on the Apical Seal of the Root-Canal System
Rolf M. W. Wuerch, DDS, Michael J. Apicella, DDS, Pete Mines, DDS, Peter J. Yancich, DDS, and David H. Pashley, DMD, PhD
The purpose of this study was to determine what effect intracanal medications might have on the apical seal of the root-canal system. Forty-two teeth were cleaned and shaped in a crown-down manner to a size #50 K-file. The teeth were divided into three groups: (A) immediate obturation; (B) intracanal placement of calcium hydroxide placed for 14 days; and (C) 2% chlorhexidine gel placed for 14 days. After 14 days, these materials were removed using copious irrigation and obturation was completed on groups B and C. Obturation was performed using the continuous wave of condensation technique using AH Plus sealer in all groups. Leakage was evaluated 60 days after obturation by using a fluid-filtration device. Using the one-way ANOVA test, there was no statistically significant difference in leakage between the three groups. Under the conditions of this study, 2% chlorhexidine gel and calcium hydroxide paste did not adversely affect the apical seal of the root-canal system.
Evaluation of the Effect of Endodontic Irrigation Solutions on the Microhardness and the Roughness of Root Canal Dentin
Hale Ari, DDS, PhD, Ali Erdemir, DDS, PhD, and Sema Belli, DDS, PhD
The purpose of this study was to evaluate the effect of 0.2% chlorhexidine gluconate on the microhardness and roughness of root canal dentin compared with widely used irrigation solutions. Ninety, mandibular, anterior teeth extracted for periodontal reasons were used. The crowns of the teeth were removed at the CEJ. The roots were separated longitudinally into two segments, embedded in acrylic resin, and polished. A total of 180 specimens were divided into 6 groups of 30 teeth at random according to the irrigation solution used: group 1: 5.25% NaOCl for 15 min; group 2: 2.5% NaOCl for 15 min; group 3: 3% H2O2 for 15 min; group 4: 17% EDTA for 15 min; group 5: 0.2% chlorhexidine gluconate for 15 min; and group 6: distilled water (control). Each group was then divided into 2 subgroups of 15 specimens: groups 1a, 2a, 3a, 4a, 5a, and 6a were submitted to Vickers microhardness indentation tests; groups 1b, 2b, 3b, 4b, 5b, and 6b were used for determination of the roughness of root dentin. The data were recorded as Vickers numbers and Ra, _m for roughness test. The results were analyzed statistically by using one-way ANOVA and Tukey tests. The results indicated that all the irrigation solutions except chlorhexidine significantly decreased microhardness of root canal dentin (p < 0.05); 3% H2O2 and 0.2% chlorhexidine gluconate had no effect on roughness of the root canal dentin (p > 0.05). Although there are many other factors for irrigation solution preference, according to the results of this study, 0.2% chlorhexidine gluconate seems to be an appropriate endodontic irrigation solutions because of its harmless effect on the microhardness and roughness of root canal dentin.
Treatment of Periapical Inflammatory Lesion with the Combination of Platelet-Rich Plasma and Tricalcium Phosphate: A Case Report
Burak Demiralp, Hu¨ seyin Gencay Kec¸ eli, Mehmet Muhtarog˘ ulları, Ahmet Serper, Bahtiyar Demiralp, and Kenan Eratalay
Periapical surgery is an important treatment alternative in the presence of a periapical inflammatory lesion. To achieve optimal healing and regeneration of the bone, different bone substitutes or barrier membranes can be used after degranulation of the lesion. Tricalcium phosphate (TCP) graft material is one of these substitutes. Platelet Rich Plasma (PRP) preparation is a new biotechnology and can be used in many different surgical procedures. It consists of thrombocyte concentrates and high amounts of growth factors (GFs), especially platelet derived growth factor (PDGF), insulin-like growth factor (IGF-I) and transforming growth factor (TGF-_), which are important in wound healing and regeneration. In this case report, use of platelet gel in conjunction with TCP in the treatment of periapical inflammatory lesion and the results of 12 months has been reported.