5-year Results Comparing Mineral Trioxide Aggregate and Adhesive Resin Composite for Root-end Sealing in Apical Surgery

5-year Results Comparing Mineral Trioxide Aggregate and Adhesive Resin Composite for Root-end Sealing in Apical Surgery

Clinical Research 5-year Results Comparing Mineral Trioxide Aggregate and Adhesive Resin Composite for Root-end Sealing in Apical Surgery Thomas von ...

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Clinical Research

5-year Results Comparing Mineral Trioxide Aggregate and Adhesive Resin Composite for Root-end Sealing in Apical Surgery Thomas von Arx, Prof Dr med dent,* Stefan H€ anni, Dr med dent,†‡ and Simon Storg ard Jensen, DDS*§ Abstract Introduction: Recent meta-analyses of the outcome of apical surgery using modern techniques including microsurgical principles and high-power magnification have yielded higher rates of healing. However, the information is mainly based on 1- to 2-year follow-up data. The present prospective study was designed to reexamine a large sample of teeth treated with apical surgery after 5 years. Methods: Patients were recalled 5 years after apical surgery, and treated teeth were classified as healed or not healed based on clinical and radiographic examination. (The latter was performed independently by 3 observers). Two different methods of root-end preparation and filling (primary study parameters) were to be compared (mineral trioxide aggregate [MTA] vs adhesive resin composite [COMP]) without randomization. Results: A total of 271 patients and teeth from a 1-year follow-up sample of 339 could be re-examined after 5 years (dropout rate = 20.1%). The overall rate of healed cases was 84.5% with a significant difference (P = .0003) when comparing MTA (92.5%) and COMP (76.6%). The evaluation of secondary study parameters yielded no significant difference for healing outcome when comparing subcategories (ie, sex, age, type of tooth treated, post/screw, type of surgery). Conclusions: The results from this prospective nonrandomized clinical study with a 5-year follow-up of 271 teeth indicate that MTA exhibited a higher healing rate than COMP in the longitudinal prognosis of rootend sealing. (J Endod 2014;40:1077–1081)

Key Words Apical surgery, clinical comparative study, long-term follow-up, root-end filling

A

pical surgery is a continuation of care in endodontics to maintain endodontically treated teeth with post-treatment apical periodontitis in which conventional endodontic retreatment is not possible, is associated with risks, or is denied by the patient (1, 2). Modern apical microsurgery includes the use of microsurgical principles and high-power magnification (surgical microscope and/or endoscope). Recent meta-analyses have documented the following: 1. The use of microsurgical techniques is superior in predictably achieving high success rates for root-end surgery when compared with traditional techniques (3). 2. The probability for success of endodontic surgery using high-power magnification rendered by the dental operating microscope or the endoscope proved to be significantly greater than the probability for success of endodontic surgery performed with loupes or no visualization aids (4, 5). 3. Endodontic surgery using mineral trioxide aggregate (MTA) was significantly associated with better treatment outcome compared with other retrofilling materials (5). The 3 meta-analyses pooled the data and calculated weighted success rates of 94% (9 studies qualified for the assessment by Setzer et al [3, 4]) and 89% (18 studies qualified for the assessment by Tsesis et al [5]), respectively, for the modern techniques using high-power magnification. However, 8 of the included 9 studies in the metaanalyses by Setzer et al (3, 4) had a follow-up limited to between 12 and 24 months, and 66% of the cases of the remaining study (6) also had a follow-up of #2 years. In the meta-analysis by Tsesis et al (5), only the 12-month data were extracted from studies that presented 1- to 3-year follow-up results. Consequently, the conclusions drawn by the previously mentioned meta-analyses are valid for a follow-up period of 1–2 years only. To date, only 1 study using high-power magnification and the microsurgical technique has prospectively evaluated the long-term (5-year) outcome of apical surgery (7). Other ‘‘long-term’’ studies had inhomogeneous follow-up periods ranging from 4 months to 6 years (8), the observation periods extended from 1–16 years (9), or surveys of $5 years only re-examined cases classified as successful after 1 year (10, 11). There is a need for long-term documentation of cases treated with modern endodontic surgery and for re-examination including all teeth after $5 years rather than the subset of successful cases after 1 year. The objective of the present study was to prospectively assess the outcome of apical surgery after 5 years, compare it with the 1-year results, and differentiate the data for 2 different modalities of root-end preparation and sealing (primary study parameters).

From the *Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland; †Department of Preventive, Pediatric, and Restorative Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland; ‡Private Practice limited to Endodontology, Bern, Switzerland; and §Department of Oral and Maxillofacial Surgery, Copenhagen University Hospital, Denmark. Address requests for reprints to Prof Thomas von Arx, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010 Bern, Switzerland. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2014 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2014.04.009

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Clinical Research The outcome was further evaluated with respect to secondary study parameters (ie, age, sex, type of tooth treated, post/screw, and type of surgery).

Materials and Methods Patient Selection The present study is a 5-year follow-up assessment of a previously evaluated 1-year follow-up cohort of 339 patients with the same number of treated teeth (12). Patients were originally enrolled consecutively in a prospective clinical study comparing 2 different methods of root-end cavity preparation and root-end sealing without randomization. For statistical reasons, only 1 tooth was evaluated per patient when multiple teeth had been treated in the same patient (QuickCalc; GraphPad Software Inc, La Jolla, CA). Furthermore, teeth presenting through-andthrough lesions, apicomarginal lesions, or root perforations were excluded from the analysis. All patients were fully informed about the treatment and alternative methods, and each patient signed a consent form according to the Declaration of Helsinki. Surgical Treatment Details of the surgical technique and medication were presented in the 1-year follow-up article (12); therefore, only a brief summary of the procedure is repeated. All patients were treated with local anesthesia in an operating room using a surgical microscope. After flap elevation, osteotomy, root-end resection, and hemostasis, the cut root faces were inspected with an endoscope. Root-end cavities were prepared and filled with MTA (ProRoot; Dentsply Tulsa Dental, Tulsa, OK) or a dentin-bonded adhesive resin composite (COMP) (Retroplast; Retroplast Trading, Rorvig, Denmark) was placed in a shallow and concave root-end preparation. 5-year Follow-up All patients presenting to the 1-year follow-up examination were recalled 4 years later by written notice to attend the 5-year follow-up. Patients who did not respond were contacted by telephone without an offer of reimbursement. All subjects who could not be contacted or declined re-examination at 5 years were considered dropouts (Table 1). In addition, all teeth that had been extracted in the period between the 1- and 5-year follow-up examinations for unknown reasons or for reasons not directly related to apical surgery were also considered lost to follow-up. Cases that had been reoperated after the 1-year follow-up control were considered as not healed at the 5-year follow-up with regard to the initial apical surgery. Outcome Assessment At the 5-year follow-up, the same criteria were used for the assessment of healing as at the 1-year follow-up (12). The outcome was categorized as healed or not healed based on clinical and radiographic findings. Three observers independently evaluated the radiographs according to the criteria established by Rud et al (13) and Molven et al (14); radiographic periapical healing was classified as complete, incomplete (scar tissue formation), uncertain, or unsatisfactory. A specific healing category was selected when 2 examiners agreed on the same healing category. A case to be classified as healed had to be without clinical signs and symptoms and had to present complete or incomplete (scar tissue) radiographic healing. In multirooted teeth, the tooth (and not a single root) was the unit of assessment, and the condition of the least favorable root determined the healing classification of the tooth. 1078

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Healing was assessed per treatment modality (MTA or COMP [primary study parameters]) regarding several secondary study parameters including age group (<45 years or $45 years), sex, type of tooth treated (maxillary anterior, premolar, and molar or mandibular anterior, premolar, and molar), presence or absence of post/screw, and type of surgery (first-time surgery or repeat surgery). Furthermore, changes of the healing classifications (overall and radiographic) from the 1-year control to the 5-year control were evaluated per treatment modality.

Statistics All data were first analyzed descriptively. The subsets of ‘‘extractions’’ among dropouts were analyzed with the binomial test. For the statistical analysis of healed rates when comparing MTA and COMP or subcategories, respectively, Fisher exact tests were used. For the parameter ‘‘type of tooth’’ with multiple subcategories, the chi-square test was applied. Cohen kappa values were calculated to assess the inter-rater agreement (15, 16). Because of the great number of statistical tests, no correction for multiple testing was applied. As a consequence, P values <.05 should be interpreted as a tendency rather than a significance. For statistical analysis, the Internet-based R software package (R 2.15.1; http:www.R-project.org, Vienna, Austria) and the extension packages exactRankTests and nparLD were used.

Results A total of 271 patients with the same number of treated teeth attended the 5-year follow-up. The loss of 68 of the 339 teeth re-examined after 1 year amounted to a dropout rate of 20.1% (Table 1). Dropout rates of MTA and COMP were not significantly different (P = .28). The mean age of the patients (45.4% males and 54.6% females) re-examined at 5 years was 49.2 years (range, 11–80 years). The overall rate of healed cases was 84.5% (Table 2). Teeth treated with MTA were assessed as healed in 92.5% of cases, and teeth treated with COMP were rated as healed in 76.6% (P = .0003). The breakdown of healed and not healed cases at the 1-year and 5-year follow-ups for the 2 different treatment methods is shown in Figure 1. The predictive value of the 1-year healed MTA and COMP cases remaining healed after 5 years was high for both modalities (96.7% and 90.7%, respectively [P = .09]). In contrast, only 24.1% of COMP-treated teeth rated as not healed after 1 year were rated as healed after 5 years compared with 53.8% of MTA-treated teeth (P = .08). Regarding the radiographic assessment of healing, the inter-rater concordance showed kappa values varying between 0.41 (moderate) and 0.69 (substantial). The comparison of the radiographic judgment of the 3 observers with the final consensus judgment showed high agreement ranging from 84.3%–97.0%. TABLE 1. Reasons for Patient Dropouts MTA COMP All Patient cohorts after 1 year* (n = 173) (n = 166) (N = 339) Patient did not respond 10 6 Patient refused 5-y follow-up 7 11 Tooth had been extracted 22 11 before 5-y follow-up Patient sustained trauma — 1 to treated tooth shortly before 5-y follow-up Total (% of dropouts) 39 (22.5) 29 (17.5) Patient cohorts after 5 years* 134 137

16 18 33 1 68 (20.1) 271

COMP, adhesive resin composite; MTA, mineral trioxide aggregate. *Patient numbers are identical to tooth numbers.

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Clinical Research TABLE 2. Healed Cases per Treatment Modality Regarding Secondary Study Parameters MTA (n = 134) Secondary study parameters All Sex Age Tooth

Post/screw Surgery

COMP (n = 137)

All (N = 271)

Subcategories

No. of healed/ no. of group

%

No. of healed/ no. of group

%

No. of healed/ no. of group

%

Male Female <45 y $45 y Maxillary anterior Maxillary premolar Maxillary molar Mandibular anterior Mandibular premolar Mandibular molar Yes No First-time surgery Repeat surgery

124/134 59/61 65/73 49/52 75/82 44/47 15/18 24/25 3/3 10/10 28/31 57/61 67/73 110/118 14/16

92.5 96.7 89.0 94.2 91.5 93.6 83.3 96.0 100 100 90.3 93.4 91.8 93.2 87.5

105/137 46/62 59/75 34/44 71/93 28/37 27/30 17/21 2/2 6/7 25/40 60/79 45/58 94/122 11/15

76.6 74.2 78.7 77.3 76.3 75.7 90.0 81.0 100 85.7 62.5 75.9 77.6 77.0 73.3

229/271 105/123 124/148 83/96 146/175 72/84 42/48 41/46 5/5 16/17 53/71 117/140 112/131 204/240 25/31

84.5 85.4 83.8 86.5 83.4 85.7 87.5 89.1 100 94.1 74.6 83.6 85.5 85.0 80.6

COMP, adhesive resin composite; MTA, mineral trioxide aggregate.

After 5 years, significantly (P = .0005) more MTA-treated teeth (88.1%) were classified as ‘‘complete radiographic healing’’ compared with COMP-treated teeth (70.8%) (Tables 3 and 4). In contrast, COMP-treated teeth (10.9%) were significantly (P = .002) more frequently categorized as ‘‘uncertain radiographic healing’’ compared with MTA-treated teeth (1.5%). Regarding the ‘‘unsatisfactory radiographic healing’’ category, the difference be-

tween MTA- (5.2%) and COMP-treated teeth (12.4%) was borderline statistically significant (P = .053), and no significant difference was found for teeth classified as ‘‘incomplete radiographic healing’’ (MTA 5.2% vs COMP 5.8%). Changes in the radiographic healing resulting in changes in the healing classification from the 1-year control to the 5-year control are presented in Tables 3 and 4. Again, high proportions of cases assessed as completely healed after 1 year remained so after 5 years (92.9% for MTA and 83.8% for COMP [P = .054]). On the other hand, 62.5% of MTA-treated teeth radiographically assessed as uncertain at 1 year were found to show complete radiographic healing after 5 years, but only 21.7% of COMP-treated teeth did so (P = .07). The data with regard to age, sex, type of tooth treated, presence or absence of post/screw, and type of surgery (first time vs repeat surgery) are listed in Table 2. Comparing the subcategories of the secondary study parameters, no significant differences were found for the calculated rates of healed teeth (age: P = .60; sex: P = .74; type of tooth treated: P = .13; post/screw: P = .74; and type of surgery: P = .60) irrespective of the treatment modality.

Discussion The present study prospectively evaluated the long-term prognosis of 271 teeth treated with apical surgery and compared 2 different root-end treatment modalities: MTA and adhesive resin composite. The strengths of the study are based on the following facts: 1. The number of treated cases (n = 271). 2. A nearly identical number of cases per group (134 and 137) could be reassessed after 5 years. 3. All cases were treated by the same surgeon. 4. All cases were strictly re-examined after 5 years. 5. The dropout rate (20.1%) recorded after 5 years was low.

Figure 1. Changes in the clinical healing resulting in changes in the healing classification from 1–5 years for MTA-treated and COMP-treated cases.

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On the other hand, the weaknesses of the study are that treatment methods were not randomly assigned and that only a single observer (the surgeon) assessed the clinical healing. Regarding dropouts, the difference between the number of extracted MTA-treated teeth (n = 22) and COMP-treated teeth (n = 11) was not statistically different (P = .08). Also, the rate of teeth extracted because of root fractures did not differ significantly (P = .08) between the 2 treatment modalities (12 MTA- vs 5 COMP-treated teeth).

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Clinical Research TABLE 3. Change of Radiographic Healing Category from 1- to 5-year Follow-up for Cases Treated with MTA (N = 134) 5-year follow-up, n (%) 1-year follow-up

Complete

Incomplete

Uncertain

Unsatisfactory

Complete (n = 112) Incomplete (n = 9) Uncertain (n = 8) Unsatisfactory (n = 5) Total (N = 134)

104 (92.9) 8 (88.9) 5 (62.5) 1 (20) 118 (88.1)

5 (4.5) 1 (11.1) 1 (12.5) — 7 (5.2)

1 (0.9) — 1 (12.5) — 2 (1.5)

2 (1.8) — 1 (12.5) 4 (80) 7 (5.2)

MTA, mineral trioxide aggregate.

Comparison of Rates of Healed Cases The overall rate (84.5%) of healed cases after 5 years was slightly higher than the rate (75.9%) in a previous 5-year longitudinal study (7). However, the latter study included a subsample of teeth treated with SuperEBA (Staident International, Staines, UK) that showed the lowest rate (67.3%) of healed teeth after 5 years among 3 different root-end filling materials. Comparing the rates of healed teeth per treatment technique in the present study (MTA: 92.5%, COMP: 76.6%) with previous long-term studies, the following observation can be made: teeth treated with MTA as root-end filling material consistently show high success rates of healing. In a retrospective study with a followup period of 1–16 years, a subset of 36 of 43 (83.7%) MTA-treated teeth were classified as successful (9). In a prospective study with MTA as the only material tested, 245 of 271 (88.8%) teeth were rated successful. Although that study evaluated twice as many MTA-treated teeth (271) than the present study (134), the mean follow-up was only 18 months (range, 4–72 months) (8). In a prospective 2-year follow-up study, MTA proved successful in 56 of 61 (91.8%) of reexamined teeth (17). Although a recent long-term study (follow-up of 6–10 years) of successful cases of a prior short-term study showed an overall success rate of 93.3%, no information was provided by type of retrofilling when 3 different materials (MTA, SuperEBA, IRM [Caulk Dentsply; Milford, DE]) were used for root-end sealing (11). The results of that study were further flawed by a very high dropout rate of 39.5% (present study = 20.1% dropout rate). In a study with an identical methodology to the present one, MTA had the highest rate of healed teeth (38/44 [86.4%]) after 5 years among 3 different retrograde filling materials (7). Regarding the COMP, the present study found a rate of healed teeth in 76.6% after 5 years. This rate is nearly identical to the rate of 75.3% of healed teeth treated with the same material in the 5-year follow-up study by von Arx et al (7) and 78% of successfully rated teeth treated with the same composite material in a long-term study (mean followup = 8 years; range, 6.5–9 years) by Yazdi et al (18). Rud et al (19), the developer of the adhesive resin composite (the material used in the other studies mentioned previously), reported a success rate of 92% in 834 mandibular molar roots treated with that material after a follow-up ranging from 6 months to 12.5 years. The given

outcome should be cautiously interpreted because the success rate was calculated per root and not per tooth. Furthermore, no dropout rate was provided, and 744 of 834 roots (89.2%) had a follow-up period of only 6–18 months.

Change in Rates of Healed Teeth over Time In the present study, the overall rate of healed teeth after 1 year was 85.5% (n = 339), and after 5 years, it was 84.5% (n = 271). The reduction of 1% was mainly accounted for by teeth treated with COMP in which the rate of healed teeth dropped from 79.5% to 76.6%. In contrast, teeth treated with MTA had a rate of healed teeth of 91.3% after 1 year and 92.5% after 5 years. Chong et al (17) similarly reported an improving success rate for MTA-treated teeth from 84% after 1 year to 92% after 2 years. In our previous study with a smaller subsample of teeth treated with MTA, the rate of healed teeth after 1 and 5 years was 90.2% and 86.4%, respectively, which is a drop of 3.8% (7). In that study, a marked reduction (9.4%) of rates of healed teeth was observed for teeth treated with COMP from 84.7% after 1 year to 75.3% after 5 years. On the other hand, Yazdi et al (18) reported a success rate of 78% after 6.5–9 years compared with a success rate of 73% after 1 year for the same cohort of teeth treated with COMP (20). Predictive Value of 1-year Results Although the predictive value of the short-term results for the long-term prognosis is only applicable for the subset of teeth with the same initial healing classification, it has no meaning for the predictability of the overall success rate. Earlier studies (using traditional methods of apical surgery) have shown that the 1-year control provides a valid diagnosis for the majority of cases regarding the long-term outcome, in particular for cases classified as successful at the 1-year examination (21, 22). In fact, the present study showed that cases rated as healed after 1 year remained so in 93.9% of cases after 5 years, and the values for MTA and COMP were 96.7% and 90.7%, respectively. Comparing the radiographic healing assessment after 1 and 5 years showed that cases classified as completely healed remained so in 88.5% (MTA = 92.9%, COMP = 83.8%) of cases. The main difference between the 2 materials was observed in the category ‘‘uncertain radiographic healing,’’ with 62.5% of MTA cases rated as

TABLE 4. Change of Radiographic Healing Category from 1- to 5-year Follow-up for Cases Treated with COMP (N = 137) 5-year follow-up, n (%) 1-year follow-up

Complete

Incomplete

Uncertain

Unsatisfactory

Complete (n = 105) Incomplete (n = 4) Uncertain (n = 23) Unsatisfactory (n = 5) Total (N = 137)

88 (83.8) 3 (75) 5 (21.7) 1 (20) 97 (70.8)

6 (5.7) 1 (25) 1 (4.3) — 8 (5.8)

4 (3.8) — 11 (47.8) — 15 (10.9)

7 (6.7) — 6 (26.1) 4 (80) 17 (12.4)

COMP, adhesive resin composite.

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Clinical Research uncertain after 1 year presenting as completely healed after 5 years. However, only 21.7% of COMP-treated teeth showed such improvement. This is in contrast to the study by Yazdi et al (18). Their data showed that 46.7% of COMP-treated roots (not teeth) rated as uncertain after 1 year were rated as completely healed after 5 years. The present study and the study by Halse et al (21) found that the category ‘‘uncertain radiographic healing’’ after 1 year exhibited the greatest diversity after 5 years. As a consequence, the larger the proportion of cases rated as uncertain after 1 year with only few of those teeth improving to a better radiographic healing category (complete or incomplete healing), the more likely a reduction of the success rate is to be expected.

Secondary Study Parameters In the present study, sex, age group, type of tooth treated, post/ screw, and first-time versus repeat surgery showed no significant effects on the rates of healed teeth after 5 years irrespective of the treatment modality. The lowest rate of healed teeth (62.5%) among all subcategories was found in COMP-treated mandibular molars. Inadequate isolation or contamination during root-end conditioning and placement of the adhesive resin in mandibular molars may be important factors explaining the low success rate in COMP-treated inferior molars (19). The category ‘‘tooth’’ was also the category showing the greatest variability in rates of healed teeth, but it was not statistically significant. Previous meta-analyses evaluating prognostic factors of apical surgery have corroborated lower success rates in mandibular molars compared with other teeth (5, 23).

Conclusion The data of the present study show a good long-term (5-year) outcome of apical surgery with a rate of 84.5% of healed cases but with a marked difference with respect to the retrograde sealing material (92.5% for MTA-treated teeth vs 76.6% for COMP-treated teeth). However, this difference must be interpreted with caution because of the nonrandomized nature of the study. Age, sex, type of tooth treated, presence of post/screw, and type of surgery (first-time vs repeat surgery) had no effect on the longitudinal prognosis of apical surgery in the present study.

Acknowledgments The statistical evaluation by Mr Lukas Martig, Institute of Mathematical Statistics and Actuarial Sciences, University of Bern, Bern, Switzerland, is gratefully acknowledged. The authors deny any conflicts of interest related to this study.

References 1. Friedman S. Considerations and concepts of case selection in the management of posttreatment endodontic disease (treatment failure). Endod Topics 2002;1:54–78.

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2. Kim S, Kratchman S. Modern endodontic surgery concepts and practice: a review. J Endod 2006;32:601–23. 3. Setzer FC, Shah SB, Kohli MR, et al. Outcome of endodontic surgery: a meta-analysis of the literature—part 1: comparison of traditional root-end surgery and endodontic microsurgery. J Endod 2010;36:1757–65. 4. Setzer FC, Kohli MR, Shah SB, et al. Outcome of endodontic surgery: a metaanalysis of the literature—part 2: comparison of endodontic microsurgical techniques with and without the use of higher magnification. J Endod 2012; 38:1–10. 5. Tsesis I, Rosen E, Taschieri S, et al. Outcomes of surgical endodontic treatment performed by a modern technique: an updated meta-analysis of the literature. J Endod 2013;39:332–9. 6. Kim E, Song JS, Jung IY, et al. Prospective clinical study evaluating endodontic microsurgery outcomes for cases with lesions of endodontic origin compared with cases with lesions of combined periodontal-endodontic origin. J Endod 2008;34:546–51. 7. von Arx T, Jensen SS, H€anni S, Friedman S. Five-year longitudinal assessment of the prognosis of apical microsurgery. J Endod 2012;38:570–9. 8. Saunders WP. A prospective clinical study of periradicular surgery using mineral trioxide aggregate as a root-end filling. J Endod 2008;34:660–5. 9. Villa-Machado PA, Botero-Ramirez X, Tobon-Arroyave SI. Retrospective follow-up assessment of prognostic variables associated with the outcome of periradicular surgery. Int Endod J 2013;46:1063–76. 10. Rubinstein RA, Kim S. Long-term follow-up of cases considered healed one year after apical microsurgery. J Endod 2002;28:378–83. 11. Song M, Chung W, Lee SJ, Kim E. Long-term outcome of the cases classified as successes based on short-term follow-up in endodontic microsurgery. J Endod 2012;38:1192–6. 12. von Arx T, H€anni S, Jensen SS. Clinical results of two different methods of root-end preparation and filling in apical surgery: mineral trioxide aggregate and adhesive resin composite. J Endod 2010;36:1122–9. 13. Rud J, Andreasen JO, Jensen JE. Radiographic criteria for the assessment of healing after endodontic surgery. Int J Oral Surg 1972;1:195–214. 14. Molven O, Halse A, Grung B. Observer strategy and the radiographic classification of healing after endodontic surgery. Int J Oral Maxillofac Surg 1987;16: 432–9. 15. Cohen J. A coefficient of agreement for nominal scales. Educ Psychol Meas 1960;20: 37–46. 16. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–74. 17. Chong BS, Pitt Ford TR, Hudson MB. A prospective clinical study of mineral trioxide aggregate and IRM when used as root-end filling materials in endodontic surgery. Int Endod J 2003;36:520–6. 18. Yazdi PM, Schou S, Jensen SS, et al. Sewerin. Dentine-bonded resin composite (Retroplast) for root-end filling: a prospective clinical and radiographic study with a mean follow-up period of 8 years. Int Endod J 2007;40: 493–503. 19. Rud J, Rud V, Munksgaard EC. Periapical healing of mandibular molars after root-end sealing with dentine-bonded composite. Int Endod J 2001;34:285–92. 20. Jensen SS, Nattestad A, Egdo P, et al. A prospective, randomized, comparative clinical study of resin composite and glass ionomer cement for retrograde root filling. Clin Oral Invest 2002;6:236–43. 21. Halse A, Molven O, Grung B. Follow-up after periapical surgery: the value of the one-year control. Endod Dent Traumatol 1991;7:246–50. 22. Jesslen P, Zetterqvist L, Heimdahl A. Long-term results of amalgam versus glass ionomer cement as apical sealant after apicectomy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:101–3. 23. von Arx T, Penarrocha M, Jensen SS. Prognostic factors in apical surgery with root-end filling: a meta-analysis. J Endod 2010;36:957–73.

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