EndoImplantology: Part 2, Surgical Classifications

In part 1 of this 2-part series, the EndoImplantology concepts, their rationale and field of application, were described as part of a new philosophy and way to approach the endodontic-implant connection.1 EndoImplantology2 is rooted in endodontic therapy, and inspired by the practice of comprehensive endodontics—also named EndoSphere for its global approach. EndoSphere3 promotes the inclusion of build-ups and crown lengthening procedures as an integral part of the treatment plan involving root canal therapy for challenging cases.
A challenging endodontic case is one that has a level of predictability that is not recognized if classic endodontic treatment modality were to be applied, therefore affecting the long-term prognosis (LTP). The challenge expands beyond the projected difficulty at the level of root canal system negotiation because we must consider 3 distinct entities: the root canal system, the attachment apparatus, and the crown. Additionally, and more holistically, we are taking into account the larger picture by analyzing the extrinsic value of the challenged tooth within the quadrant, the arch, or the entire mouth. (This larger concept will be developed in a future article in Dentistry Today.4)

Figure 1a. A 60-year-old man was referred for AAA for tooth No. 13.

Figure 1b. Should this 10- to-15-year-old crown presenting with gum recession be removed for retreatment, or drilled through? Is apicoectomy a better indication? Should tooth No. 13 should be extracted?

Figure 1c. Does the PFM with the (partial) metal occlusal surface need upgrading? What are the chances of finding recurrent decay underneath?

When such cases are recognized (Figures 1a to 2b), the elements of the challenges are noted on a blank piece of paper along with the treatment possibilities. This process is referred to as EndoImplantology Case Interception (EICI), and is taking place during the Consult Intake (CI).5

CASES 1 AND 2

Figure 2a. This 84-year-old female was initially referred for extraction and implant placement after the buccal cusp fractured.

Figure 2b. The general dentist had placed a composite filling prior to referring the patient to the oral surgeon.

In 2 recent cases presented here: Case 1 (Figures 1a to 1c) was referred for apicoectomy; Case 2, (Figures 2a and 2b) was rerouted to our practice for reevaluation after the patient was initially scheduled for an extraction and implant placement. These 2 cases exemplify clinical entities classified as Endodontal Failing Site (EFS). They both evoke the possible need of therapy beyond classical endodontics, therefore opening the field of investigation to include: possible extraction followed (or not) by immediate grafting; or immediate implant placement with bone grafting, and soft tissue manipulation. Timing becomes the central issue of importance in properly managing the case and in achieving an optimal outcome.

TO SAVE OR NOT TO SAVE
The ultimate question, when taking into account the multifactorial aspect of the decision-making process is, “Shall we, or shall we not, save the tooth?” Now, if, the tooth is not to be saved, what should be done next? The pros and cons of both protocols are weighed against the better and more predictable LTP. One must remember that saving the tooth remains the primary objective, and that preserving the site for successful implant placement is also a consideration.
In today’s article, we are focusing on the cerebration taking place after the what-if-the-tooth-cannot-be-saved scenario.

ENDOIMPLANTOLOGY SURGICAL PROTOCOL CLASSIFICATION
Once the option of not saving is raised, then thinking of what to do next with the site should become our main focus.
The essence of the EFS entity is the origin of the challenges from extensive decay, loss of attachment, and recession, to large abscess or cystic lesions. The EndoImplantology Surgical Protocol classification utilizes the alphabet as a morphic field representing the level of intention projected or achievement obtained, respectively, before and after surgery.

CASE 3

Figures 3a and 3b: The A-Z Protocol: tooth No. 7 was accidentally fractured (3a); tooth No. 7 after implementation of the A-Z protocol (3b).

In this case (Figure 3a), a patient, in attempting to open the seal of a jar with her front teeth, fractures tooth No. 7. The tooth was previously treated and presented with recurrent cervical decay under an extensive composite resin restoration. Radiographic examination also revealed previous root canal therapy, as well as cervical root resorption.
During presentation to the patient (EICI), the Decision Making Process led to the decision of immediate placement of a Biomet 3i implant and temporization using a PreFormance (Biomet 3i) abutment (unfortunately not radiopaque), followed by an immediate temporary crown left out of occlusion (Figure 3b).

Table 1. EndoImplantology Surgical Classification: Once the Decision to Extract the Tooth has Been Made
Extraction followed by:
A-G
A-X
A-Y
A-Z
immediate grafting
X
and immediate implant placement
X
and immediate loading
X
and immediate temporization
X

In this case, we had projected and successfully implemented the A-Z protocol. The A-Z (Figures 3a and 3b) sounds just like it is, the most complete clinical result that can be currently obtained. The tooth is extracted and immediately replace by an implant integrating both bone grafting and soft tissue manipulation. The implant is then temporized using a temporary implant abutment and crown. At the next appointment (an appropriate number of months later) an impression for crown fabrication is taken. The A-Z surgical protocol, which presents an inherent risk of jeopardizing osseointegration and bone regeneration through unintentional mastication, is reserved for the anterior segment for aesthetic reasons.

CASE 4

Figures 4a and 4b: The A-Y Protocol: tooth No. 19 was vertically fractured while playing rugby (4a); tooth No. 19 after implementation of the A-Y protocol (4b).

A-Y (Figures 4a and 4b), represents a lesser and different degree of challenge; it stops short of temporizing the crown and applies mostly to the posterior quadrants. Nonetheless, the implant is considered “loaded” since a gingival former or gingival healer is placed atop the implant (Figure 4b). In this case as well, the next appointment (again several months later) is the impression phase of the implant rehabilitation.
In this case, the father of patient receiving root canal therapy walks in the office after a collision playing rugby. Clinical examination revealed a coronal fracture of tooth No. 19 (Figure 4a). After evaluation of all the options, and taking into consideration that the patient desired a solution with a predictable long-term prognosis, tooth No. 19 would be extracted for the immediate placement of an implant with a gingival healer, as well as immediate bone grafting and soft tissue manipulation (STM). In the second appointment, after osseointegration and bone regeneration, an impression will be taken for crown fabrication. The A-Z and A-Y could be perceived as “one-shot endo” equivalents.
In the concept of EndoImplantology, the uncertainty of obtaining a secure primary stability is built into the surgical protocol. One of the departures from classic implantology, as described by Brånemark,6,7 is the intention to harvest a predictably limited contact between the socket and the implant (primary stability) and then to graft/manipulate the hard-soft residual socket environment. This is done in a way that will facilitate the growth of bone to the implant at horizontal distances that can exceed 4 mm in the horizontal/occlusal plane (mesiodistal and buccolingual/ palatal direction) around the prosthetic platform, and 12 mm in the vertical plan (apicocervical direction).
The challenge is accentuated for the lower and upper molars presenting 2- or 3-sockets, as well as sinus proximity in the case of upper molars. The level of risk-for-failure must be in constant assessment during the course of the surgery, and a planned A-Y or A-Z protocol may be retrograded to an A-X, or even A-G.

CASE 5

Figures 5a and 5b: The A-X Protocol: No. 15 endodontically treated and crowned presents a vertical fracture (5a) and No. 15 after the A-X protocol (5b).

In this next case (Figures 5a and 5b), tooth No. 2 presented with an AAA. Dental history revealed years of complications, retreatment, as well as an episode of severe sinus infection that led to hospitalization. Clinical examination suggested a vertical root fracture. In accordance with the patient desire to eliminate the issue once for all, an immediate implant (Frialit 2 [Friadent]) placement requiring simultaneous sinus lift was chosen for this patient. The primary stability is minimal, and to decrease the risk of inadvertent traumatic occlusal contact, the very low profile healing screw was chosen over the intentionally bulkier gingival former. This was done with the understanding that this choice would lead to the need of a stage II surgery for gingival former/healer placement. During the EICI, and the subsequent treatment plan presentation to the patient, it was explained that our intention was to go as far as possible in the A-Z protocol. However, realistically, we were looking at an A-Y or A-X at best, if not an A-G (Table 1). The A-G level of achievement will lead to the necessity to embark 4 to 6 months after, in an H-X, Y or Z protocol.
In summary, the A-X protocol (Figures 5a and 5b) substitutes the gingival former for the healing screw (a simple flat cover screw obstructing the implant well), therefore eliminating most of the risk for occlusal interference. This “submerging” of the implant implies a need for a second surgery (often referred as stage II surgery) after the osseointegration period, during which the gingival former or a temporization can be done. The impression phase typically would take place 8 to 10 weeks after the stage II.

CASE 6

Figures 6a and 6b. The A-G Protocol: tooth No. 31 dental history revealed multiple endodontic attempts (6a; see patient history in part 1 of this article). Site No. 31 was immediately grafted after extraction (6b).
Figure 7. The H-X Protocol: The implant was placed with additional cervical grafting.

In some cases (Figures 6a and 6b), even a minimum primary stability cannot be generated. Or sometimes, the intended atraumatic/flapless extraction of an endo-treated tooth, especially when fractured, turns into a much bigger challenge affecting the primary stability and soft tissue envelop. Therefore, in that situation, the procedure would become limited to bone grafting (A-G) (Figures 6a and 6b) with a healing period of 4 to 6 months or more, depending on the mass and kind of grating material utilized. This procedure would typically be followed by the placement of an implant with a gingival former (H-Y). In case of questionable bone density or height achieved, the implant may be submerge (H-X) (Figure 7) leading to the need of a stage II surgery. For the anterior segment, the H-Z protocol (including temporization), as an intended nonfunctional loading, would be chosen (Table 2).

Table 1. EndoImplantology Surgical Classification When Only Grafting was Done, A-G Will Be Followed by:
H-X
Implant placement with healing screw (Submerged)
H-Y
Implant placement with gingival healer (Loading)
H-Z
Implant placement with temporary crown (None functional)

Illustrated below is the A-G followed by H-X (Figures 6 and 7):
Tooth No. 31 was referred for retreatment (Figure 6a). After reviewing the dental history of multiple endodontic attempts (including apical surgery), and understanding the patient’s desire for a more definitive long-term solution, it was decided that tooth No. 31 would be extracted. Because of socket shape and proximity of the mandibular nerve, no primary stability could be generated, so the site was grafted using a demineralized freeze-dried bone (DFDB [Pacific Coast Tissue Bank]) (nonradiopaque) (Figure 6b).
In the second phase (after bone regeneration), the implant (Frialit 2) is placed. In this case, secondary grafting was also done to increase the vertical dimension of bone around the head of the implant again using DFDB. A healing screw, rather than a gingival healer, was placed.
The impact of an endodontic lesion or fenestration, along with the STM addressing complications like gingival recession, will be addressed in a later article.

ENDOIMPLANTOLOGY: GLOBAL APPROACH
The built-in ability to change direction in the “middle of an action” as described above, is an important component of the EndoImplantology protocol and Informed Consent. No investigative technology or clinical foresight can replace the in vivo appreciation of a challenging reality. Hence, the concept of “exploratory surgery” was implemented in the mid-1990s into our practice. As practitioners, we do not know everything about a case, nor do we need to pretend to know it all. In fact, patients appreciate the genuine concern of doing the right thing at the right time. Sometimes, a treatment will take a drastic turn for the better, and a tooth that was scheduled to be replaced by an implant will see its “life” spared. In contrast, a treatment plan that started with the intention to conserve the tooth through classic retreatment might end up as an extraction with bone grafting.

CASE 7

Figures 8a and 8b. Initial intention was to extract tooth No. 7, understanding the patient’s desire to attempt to save it. There was a suspicion of a cracked root (8a); the lost crown/post shows minimal ferrule (8b).

Take for example, the patient who walked into our office with a crown and post in his hand (Figures 8a and 8b). Clinical evaluation revealed recurrent decay and a possible vertical root fracture. The tooth was considered hopeless, but the patient still expressed a desire to save the tooth if possible.
The operatory was set up for an immediate implant placement, but instead of flapless extraction, exploratory surgery started the process. A vertical fracture could no be confirmed and the procedure was rerouted to a classic endodontic retreatment after minor bone remodeling. Tooth No. 7 later received a cast post and core and a crown. The possible long-term failure due to a possible crack was explained to the patient and noted on the consent form. At some point in the future, the patient will understand that an implant may be the only choice.

CASE 8

Figures 9a and 9b. Initial retreatment attempt is rerouted to the A-G protocol: this 78-year-old male fractured tooth No. 30 (9a), and to satisfy the patient’s desire, an initial retreatment was initiated (9b).

Case 8, demonstrates a different scenario to Case 7 above. Tooth No. 30 (Figures 9a and 9b) is referred for exploratory retreatment. A consultation was done with the referring doctor in order to address the subject of restorability. The patient, a medically compromised 70-year-old male, expressed an interest in saving his tooth if possible. He came into the office with his spouse and she was also in agreement with any attempt to save the tooth. During the CI, all possibilities, including extraction and implant placement, were covered. There was no interest on the part of the couple regarding an implant, but they understood that if the tooth simply had to be extracted, it would be wiser to graft, especially if a partial denture would be chosen in the future.)
Both surgical and endodontic operatories were prepared. During the classic retreatment exploration, a furcal communication was discovered. Considering the additional distal vertical defect and the apparent lack of tooth structure for an adequate ferrule, the retreatment process was aborted and an extraction with bone grating was done.
We were ready on paper (Consent Form and Financial Agreement) as well as in the operatories for possible changes in direction and implemented them as the veil of the clinical reality was lifted.

SUMMARY
The morphic classification developed is a silver lining enabling projection, as well as retraction, for complex surgical approaches where ultimate decisions may have to be taken extemporaneously as the surgical case develops. From both a consent form and clinical standpoint, this approach brings clarity to the patient avoiding surprises and disappointment. It also guides the practitioner whose best clinician intention may not alway materialize and guaranty the best and most reasonable possible achievement.


REFERENCES

  1. Stroumza JH. Endoimplantology: A retrospective of the paradigm shift in endodontic therapy. Dent Today. Aug 2009;28:98-102.
  2. Stroumza JH. RSS: The origin of EndoImplantology and Mission Statement. www.endoimplantology.com
  3. Stroumza JH. RSS: EndoSphere is a global approach to root canal therapy at www.endosphere.com
  4. Stroumza JH. Treatment planning in endoimplantology: from case selection to site specific decision-making process. Dent Today. April 2010. In Press.
  5. Stroumza JH. RSS: Consult Intake and EndoImplantology Case Interception. www.endoimplantology.com
  6. Brånemark P-I, Zarb GA, Albrektsson T (ed). Tissue-Integrated Prostheses: Osseointegration in Clinical Dentistry. 1st ed. March 1985; Chicago, Ill: Quintessence Publishing Co.
  7. Albretsson T, Zarb GA (ed). The Brånemark Osseointegrated Implant. 1st ed. April 1989; Chicago, Ill: Quintessence Publishing Co.

Dr. Stroumza received his DDS degree from the Garancière Dental School, University of Paris VII, with emphases in endodontics, periodontics, oral surgery, and radiology. After practicing and teaching in Paris, he completed further training at UCLA and received a Masters of Science in Oral Biology, doing research in growth factors and the extraction and testing of bone morphogenic protein, discovered by Professor Urist. He then received his endodontic specialty and his Doctorate in Science for his research on human osteoblastic cell migration and the impact of endotoxins in healing of lesions of endodontic origin at Boston University. Since teaching at University of California in San Francisco, he maintains a full-time practice in San Francisco and lectures nationally and internationally. He can be reached at (415) 221-6301 (Clinic) or (415) 221-4-525 (teaching institution), e-mail at ei2doc@gmail.com, or visit his Web sites at endoimplantology.com or endosphere.com for lectures and hands-on course schedules.

 

Disclosure: All rights reserved. EndoImplantology and EndoSphere are registered United States trademarks held by Dr. Stroumza.

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