Outcome assessment of apical surgery: A study of 234 teeth

Outcome assessment of apical surgery: A study of 234 teeth

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Journal of the Formosan Medical Association xxx (xxxx) xxx

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Original Article

Outcome assessment of apical surgery: A study of 234 teeth Wan-Chuen Liao a, Yuan-Ling Lee a,g, Yi-Ling Tsai a,g, Hseuh-Jen Lin b, Mei-Chi Chang c,d,***, Shu-Fang Chang e, Shu-Hui Chang f,**, Jiiang-Huei Jeng a,* a Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan b Department of Dentistry, Show Chwan Memorial Hospital, Chang Hua, Taiwan c Chang Gung University of Science and Technology, Kwei-Shan, Taoyuan City, Taiwan d Department of Dentistry, Chang Gung Memorial Hospital, Taipei, Taiwan e Department of Dentistry, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan f Graduate Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan

Received 5 October 2018; received in revised form 24 October 2018; accepted 26 October 2018

KEYWORDS Apical surgery; Healed rate; Clinical characteristics; Lesion size; Follow-up period

Background/Purpose: Apical surgery is an option for management of endodontically-treated tooth with persistent periapical lesions or symptom and sign. The objective of this study was to investigate the correlation between the demography, preoperative, postoperative factors and healed rate of apical surgery. Methods: Subjects were retrospectively collected from patients who received apical surgery/ apicoectomy at the Endodontic Department, National Taiwan University Hospital from January 2013 to June 2015. The standard apical surgery procedures were performed. The demography, preoperative clinical and radiographic examination data as well as postoperative variables were collected. The outcome assessment was carried out after surgery. Statistical analysis was performed by chi square test to evaluate the potential outcome predictors. Results: Total 187 patients and 234 teeth receiving apical surgery were included. 53 male and 134 female patients were collected. The age was ranged between 17 and 89 years old and the mean age was 43.64 years old. Better healed rate with significant differences were observed in female patient (p < 0.05), age 60 years old (p < 0.01), preoperative root canal filling material >2 mm short of apex (p < 0.01), lesion size from 2 mm to 12 mm (p < 0.05) and follow-up period S12 months (p < 0.01) groups.

* Corresponding author. School of Dentistry and Department of Dentistry, National Taiwan University Medical College, Taipei, Taiwan. ** Corresponding author. College of Public Health, National Taiwan University Hospital, No. 1, Chang-Te Street, Taipei 100, Taiwan. *** Corresponding author. Chang-Gung University of Science and Technology, 261, Wen-Hua 1st Road, Kwei-Shan, Taoyuan City, Taiwan. E-mail addresses: [email protected] (M.-C. Chang), [email protected] (J.-H. Jeng). g This author makes an equal contribution to the first author. https://doi.org/10.1016/j.jfma.2018.10.019 0929-6646/Copyright ª 2018, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article as: Liao W-C et al., Outcome assessment of apical surgery: A study of 234 teeth, Journal of the Formosan Medical Association, https://doi.org/10.1016/j.jfma.2018.10.019

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W.-C. Liao et al. Conclusion: Gender, age, preoperative root canal filling material extent, lesion size and follow-up period may affect the outcome of apical surgery. Tooth type, post, prosthesis, and lesion area showed no marked effect on apical healing. These results provide more detailed information for the clinical practitioners to make treatment plans and are important for clinical endodontic practices. Copyright ª 2018, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/).

Introduction Apical surgery is an option for the management of endodontically-treated tooth with persistent periapical lesions or symptom/sign. Several epidemiological studies have suggested that 33e60% of endodontically-treated teeth still presented the pictures of apical periodontitis.1 The possible causes may be persistent primary infection, secondary infection after endodontic therapy,2 vertical root fracture or cemental tears.3,4 Nonsurgical retreatment is preferable as the first choice for management of teeth with symptoms/signs, apical lesions and prior root canal treatment.5,6 However, there were some limitations restricting the possibility of nonsurgical root canal retreatment, e.g., obstructed canal pathway, irretrievable materials within the root canal and persistent symptoms, which could not be resolved even after the meticulous performance of nonsurgical treatment, persistent pain or swelling/sinus tract even after endodontic treatment and re-treatment.7 For above reasons, apical surgery can be conducted to preserve the affected teeth.6 The success rate of apical surgery was reported to range from 37% to 91%.8 Complete apical healing had been observed in 37%e96% of the endodontically-treated teeth after apical surgery.9 The wide range and inconsistency of the results may be attributed to the variation in treatment planning, surgical technique, methodology, and follow-up period.10 Endodontic microsurgery was introduced and recommended in the 1990s with advanced equipment and material. The healed rate of apical lesion was improved to 80e90% of cases after surgery.11 In addition to the advances of surgical instruments and techniques, appropriate case selection is also important for success. The type of root-end filling material was the most commonly studied issue. However, there are still many other potential prognostic factors that would affect the outcome of apical surgery and await further investigation. Several prognostic factors of apical surgery have been proposed. A retrospective study examined 491 teeth and evaluated the outcome of the endodontic microsurgery at least 1 year after the operation. The authors suggest that the potential prognostic factors are gender, tooth position, lesion type, and root-end filling material.6 A prior metaanalysis study has evaluated the prognosis of apical surgery with root-end filling. The prognostic factors are further divided into patient-related, tooth-related, or treatment-related categories. The results concluded that within tooth-related factors, cases without preoperative pain or signs, cases with good density of root canal filling,

and cases with absence or size 5 mm of periapical lesion showed significantly higher healed rates. As for the treatment-related factors, cases treated with the use of an endoscope presented higher healed rates.11 In a prospective cohort study, the 4- to 10-years follow-up of treatment outcome of apical surgery was assessed. Total 134 teeth with 85% recall rate were further examined. The results showed that in subjects >45 years old, teeth with inadequate root-filling length, and crypt size 10 mm presented better clinical outcome.10 The other 5-year longitudinal study evaluated the prognosis of 170e194 teeth 5 years after apical microsurgery. The predictors were also grouped into patient-, tooth-, and treatment-related variables for analysis. The study suggested that outcome of apical surgery was significantly impacted by the interproximal bone levels and the materials used for root-end filling.12 With regard to the previous study, the prognostic factors of the apical surgery still did not meet a consensus. Further studies related to the analysis of prognostic factors are needed for clinician’s reference and to assist the treatment considerations during clinical practice. The objectives of this study were to investigate the correlation between the demography, preoperative, postoperative factors and the healed rate of apical surgery. Patients receiving apical surgery were collected and used for further outcome assessment evaluation and statistical analysis. The outcome-predicting value may provide the clinicians with better evaluation and treatment planning before apical surgery in the future.

Material and methods Case selection By the approval of Ethics Committee, National Taiwan University Hospital, subjects in this study were retrospectively collected from patients who received apical surgery with apicoectomy at the Endodontic Department, National Taiwan University Hospital from January 2013 to June 2015. Teeth with crack or fracture detected during surgical procedures, teeth receiving other endodontic surgery (auto-transplantation, hemi-section, root amputation and intentional replantation . etc.), and re-surgery cases were all excluded.

Treatment protocol The standard apical surgery procedures operated at the Endodontic Department, National Taiwan University

Please cite this article as: Liao W-C et al., Outcome assessment of apical surgery: A study of 234 teeth, Journal of the Formosan Medical Association, https://doi.org/10.1016/j.jfma.2018.10.019

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Factors for the outcome of apical surgery Hospital were described as the followings. Preoperative periapical radiograph was taken using a parallel technique. Local anesthesia was administered and followed by flap elevation. Surgical curette was used to enucleate the pathologic tissue and identify the root apex with/without prior osteotomy. The apical 3 mm of the root was resected perpendicularly to the long axis of the tooth with no or minimal bevel. The root apex and root surfaces before and after root-end resection was carefully inspected and observed under a surgical microscope (Zeiss OPMI Proergo, Surgical microscope, Germany). The root-end cavity was prepared with ultrasonic micro-tips and filled with retrograde materials. Flaps were repositioned and sutured. Periapical radiograph was taken after surgery using the parallel technique. Antibiotics and analgesics medication were prescribed. Follow-up appointments were arranged.

Collection of clinical and radiographic examination data The collected demography, preoperative clinical examination data, preoperative radiographic examination data and postoperative variables were listed as the followings. The rationale of grouping the recorded information was based on several published researches.6,10,12 C Demography - Gender - Age C Preoperative clinical examination data - Tooth type A Maxillary anterior tooth A Maxillary premolar tooth A Maxillary molar tooth A Mandibular anterior tooth A Mandibular premolar tooth A Mandibular molar tooth - Prosthesis status A Present A Absent C Preoperative radiographic examination data - Apical extent of root canal filling A 0e2 mm short of apex A >2 mm short of apex A Beyond apex - Lesion size A 5 mm A >5 mm - Bony destruction pattern A Apical A Apicomarginal - Post status A Present A Absent C Postoperative variable - Follow-up period A <6 months A 6e11 months A 12 months

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Evaluated factors The evaluated factors were divided into demographic, preoperative and postoperative factors. Demographic factors included gender and age of the patients. Preoperative clinical factors included tooth type and prosthesis status. Preoperative radiographic factors included the apical extent of root canal filling, lesion size, bony destruction pattern and the presence or absence of post. Postoperative factor included follow-up period.

Follow-up examination and assessment of outcome The patients were usually followed-up at 1, 3, 6, and 12 months and every 6 months thereafter. Clinical and radiographic examinations were performed at each recall. The outcome assessment was carried out after the surgery. If the evaluated tooth presented with subjective discomfort, swelling, sinus tract formation or loss of function, then the tooth was classified as clinical failure. The radiographic healing pattern was categorized according to the classification proposed by Molven and Rud as followed: complete healing, incomplete healing, uncertain healing, and unsatisfactory healing.13,14 The radiographic evaluation of a multirooted tooth was classified according to the worstappearing root.12 Teeth were grouped under “healed” when presenting with complete or incomplete healing without clinical failure. Teeth were grouped under “not healed” when presenting with uncertain or unsatisfactory healing or with clinical failure despite the radiographic evaluation results. The radiographic interpretation was carried out by 1 endodontic specialist twice with 1 month interval. The agreement of the intraexaminer reliability in evaluating the apical extent of root canal filling, lesion size and postoperative radiograph outcome were calculated and presented. Result conflicts were resolved by discussing and reaching a consensus with another endodontic specialist.

Analyses of data The previous described data were listed in tables and presented with case numbers and percentage. Statistical analysis was performed by the chi square test using the R Studio Version 0.99.902 (The R Foundation for Statistical Computing, Vienna, Austria) to evaluate the potential outcome predictors. Significant difference was at the level of p < 0.05.

Results Total 187 patients and 234 teeth receiving apical surgery were included in this study. Most of the patients were female (71.66%) and aged between 20 and 59 years old (86.11%). Preoperative clinical examinations demonstrated that most of the cases were maxillary teeth (82.91%), maxillary anterior teeth (63.68%) and without prosthesis (51.71%) (Table 1).

Please cite this article as: Liao W-C et al., Outcome assessment of apical surgery: A study of 234 teeth, Journal of the Formosan Medical Association, https://doi.org/10.1016/j.jfma.2018.10.019

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W.-C. Liao et al. Table 1 Distribution of demography, preoperative clinical and radiographic examination data and postoperative variables in this study. Category

Case number

Demography Gender Male 53 Female 134 Age 10e19 3 20e29 30 30e39 47 40e49 40 50e59 44 60e69 13 70e79 7 80e89 3 Preoperative clinical examination Tooth type Maxillary anterior tooth 149 Maxillary premolar tooth 33 Maxillary molar tooth 12 Mandibular anterior tooth 17 Mandibular premolar tooth 8 Mandibular molar tooth 15 Prosthesis Present 113 Absent 121 Preoperative radiographic examination Apical extent of root canal filling 0e2 mm short of apex 135 >2 mm short of apex 82 Beyond apex 17 Lesion size 5 mm 88 >5 mm 146 Bony destruction pattern Apical 229 Apicomarginal 5 Post Present 95 Absent 139 Postoperative evaluation Follow-up period <6 months 38 6e11 months 55 12 months 141

Percentage

28.34% 71.66% 1.60% 16.04% 25.14% 21.40% 23.53% 6.95% 3.74% 1.60%

63.68% 14.10% 5.13% 7.26% 3.42% 6.41% 48.29% 51.71%

57.70% 35.04% 7.26% 37.61% 62.39% 97.86% 2.14% 40.60% 59.40%

16.24% 23.50% 60.26%

Preoperative radiographic examinations showed that most of the cases with the apical extent of root canal filling at the position of 0e2 mm short of apex (57.70%), lesion size >5 mm (62.39%), bony destruction pattern confined within apical area (97.86%) and without post (59.40%). Postoperative follow-up period displayed that most of the patients returned for evaluation after 1 year (12 months, 60.26%). Table 1 listed the detailed distribution of demography, preoperative clinical and radiographic examination data and postoperative variables. The intraexaminer agreement value for the apical extent of root

canal filling, lesion size and postoperative radiograph outcome was ranged from 92% to 96% (Table 2). Table 3 showed the correlation between the demography, preoperative and postoperative features and the healed outcome after apical surgery. With regard to the factors examined, female with 49.70% healed rate (p < 0.05), patients aged 60 years old with 48.79% healed rate (p < 0.01), preoperative root canal filling material >2 mm short of apex with 56.10% healed rate (p < 0.01), lesion size from 2 mm to 12 mm (p < 0.05) and follow-up period S12 months with 63.83% healed rate (p < 0.01) have better outcome after apical surgery, whereas tooth type, post, prosthesis, and bony destruction pattern showed little association with the healing of apical bone fill.

Discussion The effect of demographic factors on apical surgery was not consistent in previous literature. A meta-analysis study reported that age and gender of the patient did not present significant difference in the treatment outcome.11 A retrospective study suggested that younger patients in their 20s showed the highest success rate (6). Another long-term study found a higher success rate with significant difference in patient older than 45 years old.10 The cutoff ages of patients for analysis categories varied in different studies, such as 40, 41 or 45 years old.11 In this study, patient younger than 60 years old presented higher healed rate with statistically significant difference. The actual cause may need further research with biologic basis.10 From the clinical perspective, apical surgery could still be considered as a treatment option also in older patients. It seems that accomplishing a bacterial-tight apical sealed status during apical surgery was more important than advanced age.11 One research proposed that male patient presented poorer success rate, but the differences may be caused by the sample discrepancy.6 In this study, female patients also showed better healed rate with significant difference in the outcome of apical surgery when comparing to male patients. For the preoperative clinical factor, maxillary and mandibular anterior teeth were reported to present higher healed rates, which may reach 85%, and the mandibular molars with a relatively lower healed rate. This results may relate to the access for surgical approach, complexity of root canal anatomy, presence of isthmus, axis of root canal preparation etc.6,11 However, different tooth types did not present significant difference in this study, which may be due to the cases were not equally distributed within the groups and more cases should be analyzed in the future.

Table 2 Intraexaminer reliability in evaluating preoperative and postoperative radiographs outcome. Factors

Agreement (%)

Apical extent of root canal filling Lesion size Postoperative radiograph outcome

92% 96% 96%

Please cite this article as: Liao W-C et al., Outcome assessment of apical surgery: A study of 234 teeth, Journal of the Formosan Medical Association, https://doi.org/10.1016/j.jfma.2018.10.019

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Factors for the outcome of apical surgery

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Table 3 Demography, preoperative and postoperative features and the healed outcome after apical surgery related to potential outcome predictors. Variables

1-year follow-up n

Healed % healed p value

Demography Gender Male 65 22 Female 169 84 Age 40 years old 107 45 >40 years old 127 61 45 years old 128 59 >45 years old 106 47 60 years old 207 101 >60 years old 27 5 Preoperative clinical examination Tooth type Maxillary anterior 149 69 Maxillary premolar 33 14 Maxillary molar 12 6 Mandibular anterior 17 7 Mandibular premolar 8 1 Mandibular molar 15 9 Prosthesis Present 113 56 Absent 121 50 Preoperative radiographic findings Apical extent of root canal filling 0e2 mm short of apex 135 57 >2 mm short of apex 82 46 Beyond apex 17 3 Lesion size 1 mm 10 7 >1 mm 224 99 2 mm 20 15 >2 mm 214 91 12 mm 200 97 >12 mm 34 9 13 mm 214 101 >13 mm 20 5 Bony destruction pattern Apical 229 104 Apicomarginal 5 2 Post Present 95 45 Absent 139 61 Postoperative Follow-up period <6 months 38 2 6e11 months 55 14 12 months 141 90

33.85% 49.70%

0.0417

42.06% 48.03% 46.09% 44.34% 48.79% 18.52%

0.4336

46.31% 42.42% 50.00% 41.18% 12.50% 60.00%

0.3947

49.56% 41.32%

0.2571

42.22% 56.10% 17.65%

0.0081

70.00% 44.20% 75.00% 42.52% 48.50% 26.47% 47.20% 25.00%

0.2008

0.8915 0.0057

0.0106 0.0279 0.0945

45.41% 40.00%

1

47.37% 43.88%

0.6951

5.26% 25.45% 63.83%

<0.01

Bold indicate statistically significant difference between groups (p < 0.05).

For preoperative radiographic factor, root-filling length prior to surgery is suggested to be an outcome predictor as reported in previous literature. Teeth with filling length >2 mm short of apex presented higher

healed rate when compared with the other groups. The surgical procedures could remove the infected portion of the root to achieve successful results.6,10 Another study suggested the length of root canal filling did not show significant difference, but the density of the filling material was found as a significant prognostic factor.11 In this study, the apical extent of root canal filling did present significant difference between the groups. One study indicated that the preoperative radiographs with lesion size smaller than 5 mm showed a significantly higher healed rate when compared with lesion larger than 5 mm. The results may be closely related to the fact that healing time for larger lesion usually takes longer period. Another possible reason may be the smaller lesion required surgical enlargement of the bone cavity, thus thoroughly remove the pathologic tissue with subsequent better outcome. Also, as the fresh osseous wound was created during the surgery, the procedure may activate new bone formation.11 In this study, we found that preoperative lesion size from 2 mm to 12 mm showed a higher healed rate with significant difference. Teeth with apicomarginal defect may have an adverse effect on the outcome of apical surgery and were usually excluded from the assessment.6 In this study, only 5 cases presented apicomarginal defect, so the data may not be sufficient to make a conclusion or to reach significant difference. The presence or absence of a post did not prove to be a significant prognostic factor in a study with total 1273 cases.11,15 In this study, operated tooth with or without post also did not show significant difference in the outcome. According to a meta-analysis and a review study, the length of the post may be more important than the existence of a post. A long post would impede the operator to perform standard root-end resection of 3 mm and root-end filling of 3 mm. Thus, the post length would directly impact the procedure of root-end preparation, which was a crucial step to remove the infected root portion and to achieve a tight apical seal.11,15 Evaluating the outcome of apical surgery at the timing of 1 year after the surgery was commonly adopted in most of the studies.16e20 In a prospective clinical study of comparing the Mineral Trioxide Aggregate and IRM in endodontic surgery, the author suggested that the information of healing result was revealed 1 year after the surgery which was confirmed by longer follow-up period. Thus, the outcome after 1 year could be considered as a predictor for treatment prognosis.21 A long-term study of 5 years followup after apicoectomy reported that assessing the outcome after 1 year was valid in more than 95% of the cases. Most of the 5-year follow-up results could be predicted at the particular time of 1 year after the surgery.22 The short-term outcome of apical surgery did not overestimate the success rate of the surgery.23 The exact success rate of different long-term follow-up studies showed conflicting results. In a study of 477 teeth receiving periapical surgery, the author collected the data from 1 year up to 8 years after the surgery. The results showed that the overall success rate was 87.2%, which was higher than the 80.9% at the 1-year follow-up appointment. Cases with incomplete or uncertain healing 1 year after the surgery may end up with complete or unsatisfactory healing

Please cite this article as: Liao W-C et al., Outcome assessment of apical surgery: A study of 234 teeth, Journal of the Formosan Medical Association, https://doi.org/10.1016/j.jfma.2018.10.019

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6 over time.24 However, the success rate of the apical surgery declined with time in some other studies.22,25e28 The authors concerned that the short follow-up period did not observe the deteriorating of the treated teeth 1e2 years after the surgery.10 The disease may recur in 5%e25% of the healed cases within 4 years after the surgical treatment.22,26e29 Thus, some concluded that the longterm success rate was expected to be reduced when comparing to short-term studies. According to Molven et al., they proposed that cases classified as uncertain after 1 year follow-up might be unpredictable and needed longer recall for final outcome assessment.13,30 The authors suggested that for those uncertain healing cases, another regular follow-up to 3 years was indicated.14,31 In this study, the follow-up period was categorized into three groups. The low healed rate in the 6 months and 6e11 months categories may be resulted from insufficient time for healing. Thus, according to the methodology of other studies and the result of this study, assessing the outcome of the apical surgery at the point of 1 year after the operation might be appropriate.16e20 The limit of this study included that there would be reduced incentive for the patient to return for recall appointment as the symptom and sign subsided after the surgery.23 Thus, the overall healed rate in this study might be underestimated. More cases should be collected and analyzed to know whether different retrofilling materials or grafting with/without GTR may affect the treatment outcome. Moreover, long-time follow-up evaluation results of apical surgery should also be conducted. To sum up, female patient, age 60 years old, preoperative root canal filling material >2 mm short of apex, lesion size from 2 mm to 12 mm and follow-up period S12 months showed a higher healed rate after apical surgery. Tooth type, post, prosthesis, and lesion area did not present marked effect on healing of apical lesion. Although definite conclusions could not be made arbitrarily, this study still provided important and valuable information for the endodontic practice. Additional long-term studies were still important for comparison and provided more reliable treatment considerations.

Conflict of interest The authors denied any conflict of interest for this submission.

Acknowledgments This study is supported by grants from the Ministry of Science and Technology (MOST106-2314-B-002-034-MY2, MOST1062314-B-002-033-MY2, MOST 104-2314-B-255-010-MY3, NSC100-2314-B-002-09, NSC100-2314-B-002-94), Taiwan; National Taiwan University Hospital (NTUH 101-S1862, 102S2180, 103-S2368, 104-S2658, 106-S3467, 106-UN-001) and Chang Gung Memorial Hospital, Taipei, Taiwan (CMRPF1G0101, CMRPF3E0023, CMRPF1F0071, CMRPF3E0021, CMRPF3E0022, NMRPF3C0093, NMRPF3C0062, NMRPF3C0061, NMRPF3C0091, NMRPF3E0041, NMRPF3E0042, NMRPF3E0043).

W.-C. Liao et al.

Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jfma.2018.10.019.

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Please cite this article as: Liao W-C et al., Outcome assessment of apical surgery: A study of 234 teeth, Journal of the Formosan Medical Association, https://doi.org/10.1016/j.jfma.2018.10.019