Vol. 104 No. 5 November 2007

EDITORIAL

Who cares about the dental pulp?

Modern endodontic therapy originated in the early 20thcentury with pioneers like W. C. Davis and C. J. Grovedescribing successful ways of treating the vital pulp.1,2

As time passed and the profession overcame the scareof “focal infection,” successful treatment of teeth withan infected pulp space became a predictable proce-dure.3 In the middle of the 20th century the technique tostudy the dental pulp was refined, allowing consider-able improvement in our understanding of healing pro-cesses of pulp tissues.4-7 The clinical procedures re-quired for optimal healing after superficial pulp surgerywere well outlined more than 30 years ago.8-11 Duringthe last 10-15 years, attempts to enhance pulp healingwith osteogenic proteins and growth factors have beenmade with modest success.12 There have recently beensuggestions of regrowing pulp space tissue throughtissue engineering.13 However, this idea is 30-40 yearsold14,15 and little progress has been shown since.

Endodontology is the science that deals with theendodontium. An endodontist is supposed to be anexpert on diseases of the endodontium as well as able totreat the diseases thereof. Presently, however, the mostcommon therapy for the exposed and/or diseased pulpis a total amputation. This crude therapy is unfortunate,because today there are restorative materials that rarelyrequire post retention for large restorations, i.e., the rootcanal could still harbor a vital pulp if treated properly.

Pulp capping, in the way it is commonly practiced,has a low rate of success. This is despite the fact thatpast research has clearly outlined how it should opti-mally be done to result in a high rate of success.8-11

This performance problem can often be tracked back tolack of basic training in pulp biology and insufficienttreatment experience in dental school. When dentalstudents have the rare opportunity to perform a super-ficial pulp surgical procedure, it is rarely supervised ortaught by someone who has a solid understanding ofpulp biology. Worse yet, the endodontic teaching fac-

ulty are rarely involved. As a matter of fact, I am not

sure myself if I dare whisper the term “pulp capping”and still be considered an endodontist.

Superficial pulp surgery on permanent teeth, al-though an endodontic procedure, is most frequentlydone in a general practice setting. Much research stillremains to be done with this therapy to achieve a highlevel of success and predictability. This treatment ap-pears to be of little interest, however, to endodonticorganizations on any continent. The International As-sociation for Dental Research Pulp Biology group hasalso shown little interest in the clinical application oftheir basic science research efforts. This leaves animportant form of therapy without any active and pro-gressive interest group behind it. This is a pity, becausethe tooth is probably better off with a functioning pulpthat is healed by hard tissues rather than a root canalimplant. That would also relieve some of the existinghigh anxiety concerning the effect of coronal leakage.Furthermore, we are still unaware of why the pulptissue is among the most densely innervated tissues inthe body, and proprioceptive functions, protecting thetooth from overload, cannot be ruled out.

During the last couple of years, much endodonticresearch has focused on implants and pulpal stem cells.A substantial amount of money is spent on theseprojects with little visible return for the endodonticpatient with a diseased or injured endodontium.

Endodontists are today infatuated by implants, andan undeserving amount of effort has been diverted frombiologic endodontic research. We have been led tobelieve by implant proponents that the success rate ofimplants greatly surpasses the success of endodontictreatment. That has without doubt jolted the profession.Recent available literature does not support that con-clusion, however. We often tend to compare the reten-tion rate of implants with endodontic treatment success.This is comparing apples to oranges. Success for im-plant procedures is vaguely defined. Therefore, the term“retention” is commonly used when outcome is dis-

cussed. Implant retention does not exclude disease con-

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ditions. Recent studies clearly show that many retainedimplants experience progressive bone loss, inflamma-tion, and infection. Retention rate for time periodsbeyond 5 years never exceed 92%. Comparable end-odontic data of retained teeth can be gleaned frominsurance data showing an endodontic retention rate of96%-97% after 8 years, which is substantially betterthan implant data. In my opinion, the endodontist needsto be well informed about these issues and assurehim/herself that the endodontic treatment provided isoptimal and offers better outcome than implant replace-ment for restorable teeth. In addition, the endodontistneeds to be less concerned about implants, which havetheir role in prostodontics. Instead, they should broadentheir role in pulpal diagnosis and the treatment of thedentin and the dental pulp. This would lead to newenhanced treatment options for the vital pulp beyondorgan amputation. The intellectual component of end-odontic practice would also be significantly improvedby such changes.

Stem cell research and scaffolding are nowbuzzwords in basic science pulp research. However,scaffolding for tissue growth into the pulp space are oldideas, and much can be learned from earlier stud-ies.14,15 Unfortunately, many computer search enginesdo not return older studies, resulting in time-consumingreinventions of the wheel. What is more important toremember, however, is the fact that in most cases whereendodontic procedures are done after pulp exposure, afully developed pulp already exists. Instead of ampu-tating the organ and then rebuilding it, a better ideawould be to treat and heal the diseased pulp that isalready established. In the world of contemporary mo-lecular biology and pharmacology, it ought to be pos-sible to save major parts of the endodontium.

The endodontic community needs to enhance itsclinical understanding of the vital pulp and dentin andembrace its treatment. Endodontic postgraduate stu-dents need vastly more education in this area to supporttheir future practices and to function as future leaders ofpulp biology in their dental communities. This field of

endodontology needs drastically more support both in

specialist knowledge and research grant support. This isan area the American Association of EndodontistsFoundation ought to focus on as high priority. It may beexciting to attempt to build connective tissue inside theroot canal but it is exceedingly more valuable to thepatient to preserve a real pulp, which is already there.

Larz S. W. Spångberg, DDS, PhDSection Editor, Endodontology

doi:10.1016/j.tripleo.2007.08.033

REFERENCES1. Davis WC. Pulpotomy vs. pulp-extirpation. Dent Items Interest

1922;44:81-101.2. Grove CJ. Nature’s method of making perfect root fillings fol-

lowing pulp removal, with a brief consideration of the develop-ment of secondary dentin. Dent Cosmos 1921;63:968-82.

3. Strindberg LZ. The dependence of the result of pulp therapy oncertain factors. Acta Odont Scand 1956;14(Suppl):21.

4. Zander HA. Reaction of the pulp to calcium hydroxide. J DentRes 1939;18:373-9.

5. Glass RL, Zander HA. Pulp healing. J Dent Res 1949;28:97-107.6. Nyborg H. Healing Processes in the pulp on capping. Acta Odont

Scand 1955;13(Suppl):16.7. Nyborg H. Capping of the pulp. The processes involved and their

outcome. Odont T 1958;66:296-364.8. Granath LE, Hagman G. Experimental pulpotomy in human

bicuspids with reference to cutting technique. Acta Odont Scand1971;29:155-63.

9. Schröder U, Granath LE. Early reactions of intact human teeth tocalcium hydroxide following experimental pulpotomy and itssignificance to the development of hard tissue barrier. OdontRevy 1971;22:379-96.

10. Schröder U. Evaluation of healing following experimental pulp-otomy of intact human teeth and capping with calcium hydrox-ide. Odont Revy 1972;23:329-40.

11. Cvek M. A clinical report on partial pulpotomy and capping withcalcium hydroxide in permanent incisors with complicatedcrown fracture. J Endod 1978;4:232-7.

12. Rutherford B, Fitzgerald M. A new biological approach to vitalpulp therapy. Crit Rev Oral Biol Med 1995;6:218-29.

13. Murray PE, Garcia-Godoy F, Hargreaves KM. Regenerativeendodontics: a review of current status and a call for action. JEndod 2007;33:377-90.

14. Nevins AJ, Finkelstein F, Borden BG, Laporta R. Revitalizationof pulpless open apex teeth in rhesus monkeys, using collagen-calcium phosphate gel. J Endod 1976;2:159-65.

15. Nygaard-Østby B. The role of the blood clot in endodontic

therapy. An experimental histologic study. Acta Odont Scand1961;19:323-53.