I. Introducción
6 Características del segmento de procesamiento y distribución de productos
Data for this study was obtained from the electronic claims and enrollment database of Delta Dental of Wisconsin. Claims analysis was based on claims data
representing 13,329,249 patient encounters between January 1, 2000 and December 31, 2013. Dental insurance claims were searched for CDT procedure codes D3310, D3320, and D3330 which were considered to be triggering events. The end of study period and loss of continuous dental insurance coverage were treated as censoring events. This query produced 487,476 initial NSRCT procedures performed over the 14-year time period. For each of these procedures, information regarding provider type/specialty status and tooth number was collected. The title of endodontist was given only to clinicians who had completed an American Dental Association accredited U.S.
endodontic residency program. It was decided to include all non-endodontic specialists into the broader category of other providers. As with Lazarski et al, success was determined by the absence of untoward events (39). Cases were followed and considered successful until either enrollment was broken, or until CDT codes
representing extraction, retreatment, or apical surgery were encountered. Once a case met either of these two criteria, the case was eliminated from the sample. Cases were further subdivided into 1, 5, and 10 year follow up intervals to aid in the comparison of survival over time.
Analysis
Insurance claims analysis was completed by the Biostatistics department at the Medical College of Wisconsin. Survival estimates were computed for provider type and tooth location. Kaplan-Meier survival estimates were calculated for 1, 5, and 10-year survival of endodontically treated teeth. Hazard ratios for provider type and tooth type
were calculated using the Cox proportional hazards model. Analyses were performed using SAS 9.4 (Cary, NC).
Results
Of the 487,476 procedures, endodontists completed 153,315 cases (31.5% of the total). These cases consisted of 15,832 anteriors (10.3%), 27978 premolars (18.2%), and 109,505 molars (71.4%). Other-providers completed 334,161 cases (68.55% of the total). These cases consisted of 68,600 anteriors (20.5%), 107,279 premolars (32.1%), and 158,282 molars (47.3%). The survival/absence of untoward events for all teeth collectively was 98% at one year, 92% at five years, and 86% at ten years. The median follow-up time for all cases was 2.43 years
At the one-year interval, no significant difference in survival was noted between providers or for tooth type. Anterior teeth treated by both endodontists and other providers had 98% survival, premolars had 99% survival, and molars survived at a rate of 98% (Table 1).
At the five-year interval, no significant differences in survival were found between treated anterior teeth and premolars. Anterior teeth and premolars treated by both endodontists and other providers had a survival rate of 95%. A significant
difference in molar survival was discovered. Molars treated by other providers survived at a rate of 91%, while molars treated by endodontists had a 93% survival rate (p<.0001) (Table 1).
Time Interval
Group
(years) Tooth type Provider Type
Time (years) Cases Survival Distribution Function Estimate Lower 95% Confidence Limit Upper 95% Confidence Limit 1
Anterior Other Provider 1.00 48986 0.98 0.98 0.99 Endodontist 1.00 11354 0.98 0.98 0.98 Premolar Other Provider 1.00 77670 0.99 0.99 0.99 Endodontist 1.00 20225 0.99 0.98 0.99 Molar Other Provider 1.00 113742 0.98 0.98 0.98 Endodontist 1.00 79649 0.98 0.98 0.98 5
Anterior Other Provider 5.00 16424 0.95 0.95 0.95 Endodontist 4.90 3582 0.95 0.94 0.95 Premolar Other Provider 5.00 27044 0.95 0.94 0.95 Endodontist 4.99 6698 0.95 0.94 0.95 Molar Other Provider 5.00 38358 0.91 0.91 0.91 Endodontist 5.00 25712 0.93 0.93 0.94 10
Anterior Other Provider 9.88 3066 0.91 0.90 0.91 Endodontist 9.62 596 0.92 0.91 0.93 Premolar Other Provider 9.99 5475 0.91 0.90 0.91 Endodontist 9.89 1222 0.90 0.89 0.91 Molar Other Provider 9.98 7406 0.84 0.84 0.85 Endodontist 9.99 4605 0.89 0.89 0.89
Table 1: Summary of survival estimates for endontically treated teeth based on provider type and tooth type.
At the ten-year interval, significant differences were found for all tooth types. Anterior teeth treated by other providers survived at 91% while anterior teeth treated by endodontist survived at a rate of 92% (p<.0001). Premolar survival was 91% for other providers and 90% for endodontists (p<.0001). Molar Survival was 84% for other providers and 89% for endodontists (p<.0001) (Table 1). Figure 1 graphically portrays the 1, 5, and 10-year product limit survival estimates for each tooth and provider type. Cox model analysis found the only significant relationship between tooth type and provider type existed for molars at ten years. A hazard ratio of 1.394 was found when 10-year molar survival of teeth treated by other providers was compared with the same subset of teeth treated by endodontists (p<.0001)
Figure 1: Product limit survival estimates of endodontically treated of different tooth type treated by endodontists and other providers
Discussion
Survival trends of endodontically treated teeth are of considerable interest to providers, patients, and third party payers. Endodontic therapy has proven to be a very predictable and conservative method of retaining natural teeth. Large epidemiological studies provide a method for assessing the outcomes of the dental health system as a whole (39). No studies to date have directly compared long term survival rates of endodontically treated teeth as it relates to provider type and tooth type. The aim of this study was to explore this relationship.
The percentage of treatments provided by endodontists (31.45%) and treatments provided by other-providers (68.55%) in this study closely parallel ratios seen in previous observations of 28%:72% and 33.9%:66.1% (39, 83). The population studied was
stratified to include only those patients with dental insurance. This is an important consideration because an insured patient population may present differing dental care access and expectations when compared with populations of uninsured patients. This would likely have an effect on outcomes, but to what extent is unknown. These results, therefore, should only be interpreted with respect to this population.
Use of insurance information on a scale such as that used for this project conveniently serves to minimize many potential sources of potential bias. At the same time however, data on such a scale makes important diagnostic/prognostic predictors of individual cases impossible (39). There is no way to reliably determine pre-procedural diagnosis as it relates to both the pulpal and periodontal condition of the treated patient. Restorability of the treated tooth and medical conditions that may predispose a person to endodontic failure are also not available. Final restoration and dental dam use have
proven to be vitally important in the long term success of endodontic treatment (22, 40, 66, 79). Such nuances are important to the planning, delivery, and long-term success of a selected treatment.
Despite the limitations of this study, the high long-term survival rates of
endodontically treated teeth reconfirm the predictability of endodontic treatment provided by the dental health system as a whole. 1, 5, and 10-year survival rates of 96%, 92%, and 86% represent survival rates similar to those of previous studies (15, 16, 39). It is
important to bear in mind that basing failure on untoward events yields a higher percentage of overall failure than what is actually present. The incorporation of non- surgical retreatment and apical surgery into the criteria for failure generates a higher number of failed cases, even though these teeth are receiving adjunctive therapies which may ultimately result in tooth retention and function. With the high success rates of these additional modalities, the true survival rate of our sample is likely higher than we are able to present. To what extent is impossible to determine using claims data
The large nature of the sample size in this study allowed for very small differences in survival to be determined as statistically significant between the two provider categories. Although several significant differences of 1-2% were discovered, these small differences could be considered by some as being clinically inconsequential.
A desirable finding in this study would have been to find identical survival rates between initial endodontic therapy provided by endodontists and other providers. This would indicate that the two groupings provide treatment of equivalent quality, and that practitioners practicing within the category of other providers are effectively referring
cases beyond their clinical ability. This result would indicate an effective system of endodontic care under the current dental health system.
This study’s finding of similar survival rates between other providers and
endodontic specialists at the 1 and 5 year post-procedural periods indicates that providers of all varieties provide effective short and medium-term endodontic outcomes. At ten years, anterior teeth and premolar teeth have similar survival rates among provider types as well. Molars treated by endodontists however, show the largest difference in survival when comparing the two groups (84% other providers vs. 89% endodontists). At 10 years, primary endodontic therapy provided by other providers when compared to endodontists is associated with a hazard ratio of 1.394 (95% CI. p<0001). This equates to a 39.4% higher hazard risk within this tooth population.
Endodontists on average treat teeth of all types that are of higher clinical
difficulty than what is typically treated in other practice settings. To have similar or even higher success when completing cases of higher complexity is true testament to their additional training and skill. A more complete understanding of chemomechanical debridement, shaping, and obturation of intricate canal systems may lead to improved long term survival rates of highly difficult cases compared to other providers.
Conclusion
The dental health delivery system is highly effective at providing favorable endodontic outcomes. This study has shown that endodontists and other providers have similar 1, 5, and 10-year survival rates for anterior and premolar teeth. Long term survival of molars is higher when these teeth are treated by endodontists. With the
patient’s best long term prognosis in mind, this finding may inspire non-endodontists to carefully re-examine their referral patterns related to the endodontic treatment of molars.
Future areas of research could include an evaluation of the time from completed endodontic therapy to final restoration, and whether this time period has any correlation to failure rate.
BIBLIOGRAPHY
1. Ørstavik D, Pitt Ford TR. Prevention and Treatment of Apical Periodontitis. Essential Endodontology, 2nd ed. Oxford, UK: Blackwell Munksgaard Ltd; 2008.
2. Figdor D. Apical periodontitis: a very prevalent problem. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94(6):651-652.
3. Eriksen H. Epidemiology of apical periodontitis. In: Ørstavik D, Pitt Ford T, editors. Essential Endodontology. London: Blackwell Science; 1998.
4. Pak JG, Fayazi S, White SN. Prevalence of periapical radiolucency and root canal treatment: a systematic review of cross-sectional studies. J Endod
2012;38(9):1170-1176.
5. Kakehashi S, Stanley H, Fitzgerald R. The effects of surgical exposure of dental pulps in germ-free and conventional laboratory rats. . Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1965;20:340-349.
6. Möller A, Fabricius L, Dahlén G, Heyden G. Influence on periapical tissues of indigenous oral bacteria and necrotic pulp tissue in monkeys. Scand J Dent Res 1981;89(6):475-484.
7. Sundqvist G. Bacteriological studies of necrotic dental pulps. (Odontological Dissertation no.7). Umea, Sweden: University of Umea 1976.
8. Schilder H. Cleaning and shaping the root canal. Dent Clin North Am 1974;18(2):269- 296.
9. Schilder H. Filling root canals in three dimensions. 1967. J Endod 2006;32(4):281- 290.
10. de Chevigny C, Dao TT, Basrani BR, Marquis V, Farzaneh M, Friedman S.
Treatment outcome in endodontics: the Toronto study--phase 4: initial treatment. J Endod 2008;34(3):258-263.
11. Seltzer S, Bender I, Turkenkopf S. Factors affecing successful repair after root canal therapy. Journal of the American Dental Association 1963;67:651-662.
12. Ricucci D, Siqueira JF, Jr., Bate AL, Pitt Ford TR. Histologic investigation of root canal-treated teeth with apical periodontitis: a retrospective study from twenty- four patients. J Endod 2009;35(4):493-502.
13. Kvist T. Endodontic retreatment. Aspects of decision making and clinical outcome. Swed Dent J 2001;(Suppl 144):1-57.
14. Bergenholtz G. Controversies in Endodontics. Crit Rev Oral Biol Med 2004;15(2):99-114.
15. Friedman S. Prognosis Of Initial Endodontic Therapy Endodontic Topics 2002(2):59-88.
16. Friedman S, Mor C. The Success of Endodontic Therapy - Healing and
Functionality. Journal of the California Dental Association 2004;32(6):493-503. 17. Friedman SM, C. Friedman S. Considerations and concepts of case selection in the
management of post-treatment endodontic disease (treatment failure). Endodontic Topics 2002;1:54-78.
18. Strindberg L. The dependence of the results of pulp therapy on certain factors. An analytic study based on radiographic and clinical follow-up examinations. Acta Odontologica Scandinavica 1956;14(Suppl 21).
19. Bystrom A, Happonen R, Sjogren U, Sundqvist G. Healing of periapical lesions of pulpless teeth after endodontic treatment with controlled asepsis. Dental
Traumatology 1987;3(2):58-63.
20. Stockhausen R, Aseltine R, Jr., Matthews JG, Kaufman B. The perceived prognosis of endodontic treatment and implant therapy among dental practitioners. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111(2):e42-47.
21. Vire D. Failure of Endodontically Treated Teeth: Classification and Evaluation. Journal of Endodontics 1991;17(7):338-342.
22. Gillen BM, Looney SW, Gu LS, Loushine BA, Weller RN, Loushine RJ, et al. Impact of the quality of coronal restoration versus the quality of root canal fillings on success of root canal treatment: a systematic review and meta-analysis. J Endod 2011;37(7):895-902.
23. Wu MK, Wesselink P, Shemesh H. New terms for categorizing the outcome of root canal treatment. Int Endod J 2011;44(11):1079-1080.
24. Ørstavik D. Time-course and risk analyses of the development and healing of chronic apical periodontitis in man. Int Endod J 1996;29(3):150-155.
25. Reit G. Decision strategies in endodontics: on the design of a recall program. Dental Traumatology 1987;3(5):233-239.
26. Endodontology ESo. Consensus report of the European Society of Endodontology on quality guidelines for endodontic treatment. Int Endod J 1994;27:115-124.
27. Sjogren U, Hagglund B, Sundqvist G, Wing K. Factors Affecting the Long-term Results of Endodontic Treatment. Journal of Endodontics 1990;16(10):498-504. 28. Smith C, Setchell D, Harty F. Factors influencing success of conventional root canal
therapy-a five year retrospective study. Int Endod J 1993;26:321-333. 29. Imura N, Pinheiro ET, Gomes BP, Zaia AA, Ferraz CC, Souza-Filho FJ. The
outcome of endodontic treatment: a retrospective study of 2000 cases performed by a specialist. J Endod 2007;33(11):1278-1282.
30. Cheung GSP. Survival of first-time nonsurgical root canal treatment performed in a dental teaching hospital. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 2002;93(5):596-604.
31. Molven O, Halse A, Fristad I, MacDonald-Jankowski D. Periapical changess
following root-canal treatment observed 20-27 years postoperatively. Int Endod J 2002;35(9):784-790.
32. Goldman M, Pearson A, Darzenta N. Reliability of radiographic interpretations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1974;38(2):287-293.
33. Brynolf I. Roentgenologic periapical diagnosis. IV. When is one roentgenogram not sufficient? Sven Tandlak Tidskr 1970;63(6):415-423.
34. Ørstavik D, Kereke K, Eriksen H. The periapical index: A scoring system for radiographic assessment of apical periodontitis. dental Traumatology 1986;2(1):20-34.
35. Penick E. Periapical repair by dense fibrous connective tissue following conservative endodontic therapy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod
1961;14:239-242.
36. Bender I, Seltzer S. Roentgenographic and directobservation of experimental lesions in bone: part I. Journal of the American Dental Association 1961;62:152-160. 37. Patel S, Dawood A, Mannocci F, Wilson R, Pitt Ford T. Detection of periapical bone
defects in human jaws using cone beam computed tomography and intraoral radiography. Int Endod J 2009;42(6):507-515.
38. Wu MK, Shemesh H, Wesselink PR. Limitations of previously published systematic reviews evaluating the outcome of endodontic treatment. Int Endod J
2009;42(8):656-666.
39. Lazarski MP, Walker WA, 3rd, Flores CM, Schindler WG, Hargreaves KM.
Epidemiological evaluation of the outcomes of nonsurgical root canal treatment in a large cohort of insured dental patients. J Endod 2001;27(12):791-796.
40. Salehrabi R, Rotstein I. Endodontic Treatment Outcomes in a Large Patient Population in the USA: An Epidemiological Study. Journal of Endodontics 2004;30(12):846-850.
41. Chen SC, Chueh LH, Hsiao CK, Wu HP, Chiang CP. First untoward events and reasons for tooth extraction after nonsurgical endodontic treatment in Taiwan. J Endod 2008;34(6):671-674.
42. Chen SC, Chueh LH, Hsiao CK, Tsai MY, Ho SC, Chiang CP. An epidemiologic study of tooth retention after nonsurgical endodontic treatment in a large population in Taiwan. J Endod 2007;33(3):226-229.
43. Stoll R, Betke K, Stachniss V. The Influence of Different Factors on the Survival of Root Canal Fillings: A 10-Year Retrospective Study. Journal of Endodontics 2005;31(11):783-790.
44. Landys Boren D, Jonasson P, Kvist T. Long-term survival of endodontically treated teeth at a public dental specialist clinic. J Endod 2015;41(2):176-181.
45. Dammaschke T, Steven D, Kaup M, Ott KH. Long-term survival of root-canal- treated teeth: a retrospective study over 10 years. J Endod 2003;29(10):638-643. 46. Ng YL, Mann V, Gulabivala K. A prospective study of the factors affecting
outcomes of non-surgical root canal treatment: part 2: tooth survival. Int Endod J 2011;44(7):610-625.
47. Christensen G. Implant therapy versus endodontic therapy. Journal of the American Dental Association 2006;137:1440-1443.
48. Brånemark P, Hansson B, Adell R, Breine U, Lindström J, Hallén O, et al.
Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg 1977;16:1-132.
49. Iqbal MK, Kim S. A review of factors influencing treatment planning decisions of single-tooth implants versus preserving natural teeth with nonsurgical endodontic therapy. J Endod 2008;34(5):519-529.
50. Ruskin JD, Morton D, Karayazgan B, Amir J. Failed root canals: the case for extraction and immediate implant placement. J Oral Maxillofac Surg 2005;63(6):829-831.
51. Creugers NHJ, Kreulen CM, A. Snoek PA, de Kanter RJAM. A systematic review of single-tooth restorations supported by implants. Journal of Dentistry
52. Smith D, Zarb G. Criteria for success of osseointegrated endosseous implants J Prosthetic Dent 1989;62(5):562-572.
53. Iqbal M, Kim S. For Teeth Requiring Endodontic Treatment, What Are the
Differences in Outcomes of Restored Endodontically Treated Teeth Compared to Implant-Supported Restorations? Int J Oral Maxillofac Implants 2007;22:96-116. 54. Kim SG, Solomon C. Cost-effectiveness of endodontic molar retreatment compared
with fixed partial dentures and single-tooth implant alternatives. J Endod 2011;37(3):321-325.
55. Alani A, Bishop K, Djemal S. The influence of specialty training, experience, discussion and reflection on decision making in modern restorative treatment planning. Br Dent J 2011;210(4):E4.
56. Doyle SL, Hodges JS, Pesun IJ, Law AS, Bowles WR. Retrospective cross sectional comparison of initial nonsurgical endodontic treatment and single-tooth implants. J Endod 2006;32(9):822-827.
57. Beikler T, Flemmig TF. Implants in the medically compromised patient. Crit Rev Oral Biol Med 2003;14(4):305-316.
58. Strietzel FP, Reichart PA, Kale A, Kulkarni M, Wegner B, Kuchler I. Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta-analysis. J Clin Periodontol 2007;34(6):523-544.
59. Wang G, Gao X, Lo ECM. Public perceptions of dental implants: a qualitative study. 2015(43):798-805.
60. Reese R, Aminoshariae A, Montagnese T, Mickel A. Influence of demographics on patients' receipt of endodontic therapy or implant placement. J Endod
2015;41(4):470-472.
61. Woodmansey KF, Ayik M, Buschang PH, White CA, He J. Differences in masticatory function in patients with endodontically treated teeth and single- implant-supported prostheses: a pilot study. J Endod 2009;35(1):10-14. 62. Fuss Z, Lustig J, Tamse A. Prevalence of vertical root fractures in extracted
endodontically treated teeth. Int Endod J 1999;32:283-286.
63. Zadik Y, Sandler V, Bechor R, Salehrabi R. Analysis of factors related to extraction of endodontically treated teeth. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106(5):e31-35.
64. Toure B, Faye B, Kane AW, Lo CM, Niang B, Boucher Y. Analysis of reasons for extraction of endodontically treated teeth: a prospective study. J Endod
65. Tzimpoulas NE, Alisafis MG, Tzanetakis GN, Kontakiotis EG. A prospective study of the extraction and retention incidence of endodontically treated teeth with uncertain prognosis after endodontic referral. J Endod 2012;38(10):1326-1329. 66. Lin PY, Huang SH, Chang HJ, Chi LY. The effect of rubber dam usage on the
survival rate of teeth receiving initial root canal treatment: a nationwide population-based study. J Endod 2014;40(11):1733-1737.
67. Cochran M, Miller C, Sheldrake M. The efficacy of the rubber dam as a barrier to the spread of microorganisms during dental treatment. Journal of the American Dental Association 1989;119(1):141-144.
68. Anabtawi MF, Gilbert GH, Bauer M, Reams G, Makhija S, Benjamin PL, et al. Rubber dam use during root canal treatment: findings from The Dental Practice- Based Research Network. Journal of the American Dental Association
2013;144(2):179-186.
69. Lawson NC, Gilbert GH, Funkhouser E, Eleazer PD, Benjamin PL, Worley DC, et al. General Dentists' Use of Isolation Techniques during Root Canal Treatment: From the National Dental Practice-based Research Network. J Endod 2015. 70. Kuttler Y. Microscopic investigation of root apexes. Journal of the American Dental
Association 1955;50(544-52).
71. Schaeffer M, White R, Walton R. Determining the Optimal Obturation Length: A Meta-Analysis of Literature. Journal of Endodontics 2005;31(4):271-274. 72. Wu M-K, Wesselink PR, Walton RE. Apical terminus location of root canal
treatment procedures. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 2000;89(1):99-103.
73. Tronstad L, Asbjørnsen K, Døving L, Pedersen I, Eriksen H. Influence of coronal restorations on the periapical health of endodontically treated teeth. Endod Dent Traumatol 2000;16(5):218-221.
74. Reeh E, Messer H, William D. Reduction in Tooth Stiffness as a Result of Endodontic and Restorative Procedures. J Endod 1989;15(11):512-516. 75. Lagouvardos P, Sourai P, Douvitsas G. Coronal fractures in posterior teeth.
Operative Dentistry 1989;14(1):28-32.
76. Fedorowicz Z, Carter B, de Souza R, de Andrade Lima Chaves C, Nasser M, Sequeira-Byron P. Single crowns versus conventional fillings for the restoration of root filled teeth In: Cochrane Database of Systematic Reviews. 5/2012 ed.: JohnWiley & Sons, Ltd; 2012. p. 1-24.
77. Hansen E, Asmussen E, Christiansen N. Invivo fractures of endodontically treated posterior teeth restored with amalgam. Endod Dent Traumatol 1990;6:49-55. 78. Ng YL, Mann V, Gulabivala K. Tooth survival following non-surgical root canal
treatment: a systematic review of the literature. Int Endod J 2010;43(3):171-189. 79. Aquilino S, Caplan D. Relationship between crown placement and the survival of
endodontically treated teeth. J Prosthetic Dent 2002;87(3):256-263.
80. Caplan D, Weintraub J. Factors Related to Loss of Root Canal Filled Teeth. J Public