Modern Day Treatment Planning Dilemmas; Natural Tooth Versus Implants

Fig. 5.1

Mobile crown, recurrent caries, nonrestorable tooth #8 resulting in extraction and implant placement
Some experts are reconsidering osseointegration, which has been traditionally defined as the anchorage of an implant by direct bony contact (Brånemark et al. 1977; Albrektsson et al. 1981; Zarb and Albrektsson 1991; Albrektsson and Johansson 2001). Reevaluation of the osteointegrative process by several experts may help to explain marginal bone loss and implant failures. They are considering that osseointegration is a foreign body reaction and foreign body equilibrium response whose clinical function depends on the tissue equilibrium in the patient (Albrektsson et al. 2013; Chrcanovic et al. 2014). This equilibrium could easily change depending on the patient’s medical and clinical situation in the future. Conservative treatment planning and preserving the tooth should be the first consideration, not knowing when in the patient’s future health or life a change could tip the balance of this equilibrium away from implant survival or success. Implant success and long-term survival are not 100 % guaranteed.
Compromised teeth that will require root canal treatment may also require adjunctive therapy to include periodontal therapy, orthodontic extrusion, post and core, and a final crown (Doyle 2015). When extensive treatment is required, the patient must consider the cost and time commitment of preserving the tooth and returning it to normal form and function as compared to the cost and time commitment of the implant placement and restoration (Goodacre 2016).
Differentiating the cutoff in deciding when a tooth with multiple risk factors should be deemed to have a hopeless prognosis, with extraction as the best possible treatment, is difficult to determine. But the dental practitioner must carefully determine the limit that preserving the tooth will result in short-term failure. One publication differentiates a “compromised” tooth from an “end-stage” failing tooth. The compromised tooth is a “complex, clinical situation” where the tooth is in a structural or pathologic condition that impairs its ability to function without some type of restoration (Iqbal and Kim 2008, p. 520). Tooth pathology requires the removal of enamel and dentin, possibly the surgical removal of the pulp, and/or periodontal treatment. The end-stage failing tooth is one that “is in a pathological or structural deficient state that cannot be successfully repaired with reconstructive therapies, including root canal treatment and/or retreatment and continues to exhibit progressive pathologic changes and clinical dysfunction of the tooth” (Iqbal and Kim 2008, p. 521). The strategies for definitive treatment of “end-stage” tooth failure include extraction and restoring form and function with an implant or a fixed or removable partial denture (Fig. 5.2). Studies have recommended that both RCT teeth and ISC have higher survival rates as compared to fixed partial dental prosthesis (Torabinejad et al. 2007; Scurria et al. 1995, 1998).

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Fig. 5.2

Reconstructive aspects in treatment planning (Zitzmann et al. 2009)
Critically important is that for a compromised tooth to be restorable with reasonably predictable long-term success with little or no risk of failure, enough tooth structure (enamel and/or dentin) must be available for a minimal, uniform, 2 mm ferrule, 360° around the tooth (Jotkowitz and Samet 2010; Zhi-Yue and Yu-Zing 2003; Tan et al. 2005) (Fig. 5.3). A caries risk assessment should be completed for the patient as part of the decision making process (Featherstone 2007). Jotkowitz and Samet show the anticipated risk for a tooth with varying amounts of tooth structure is available to retain the final restoration following endodontic treatment and the loads under which those teeth are placed. Taking into account this defined risk assists the dentist in determining the reasonable restorability of the tooth. Determining the reasonable restorability of the tooth should be the first consideration the dentist has in making a treatment decision for the compromised tooth.

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Fig. 5.3

Risk assessment analysis (Reprinted by permission from Macmillan Publishers Ltd. [British Dental Journal] (Jotkowitz and Samet 2010) copyright (2010))
Treating a diseased tooth can be influenced by the dental practitioner’s background and training. Bader and Shugars (1993) examined the treatment of approximately 1200 teeth in 43 patients and found 62 % of the practitioners agreed on the treatment plan for individual teeth that were to be treated for the first time but much less agreement for previously restored teeth (Bader and Shugars 1993). The recommendation in this paper was to develop objective criteria for treating teeth with previous restorations. Iqbal and Kim (2008) have also suggested the development of evidence-based guidelines so that patients have sufficient information to select the optimal treatment plan for their situation and not one based on the experience, skills, and interests of the dentist since other members of the dental team can provide specialized care. The best treatment plan for the patient uses the best evidence and specific case factors as well as the patient’s desires and needs. This chapter continues with evaluating the best evidence.

5.2 Survival Versus Success

Dentists should know current evidence-based success rates of the treatment they are recommending for the patient to respond to patients’ questions. There have been a number of meta-analyses and systematic reviews in the literature comparing long-term endodontically treated tooth and implant survival rates that can assist the dental practitioner in making decisions (Levin and Halperin-Sternfeld 2013; Torabinejad et al. 2007; Tomasi et al. 2008; Holm-Pedersen et al. 2007; Jung et al. 2012). Endodontic success rates on teeth without periapical pathology have been reported to be 92–98 % but range from 73 to 90 % with periapical lesions that heal following RCT (Torabinejad et al. 2005 ). When considering endodontic re-treatment and apical surgery, the success rates are even lower and range from 74 to 86 % and 37 to 74 % (Ng et al. 2010, 2011; Gulabivala, Iceland, Freedman, AAC Dallas, 2005) Reviews of trials and studies on the success of implant single crowns range from 57.5 to 100 % (Papaspyridakos et al. 2012). A recent review from the Journal of the American Dental Association (2013) concluded that implant survival rates do not exceed the rates of adequately treated and maintained compromised teeth. (This supports the concept that extracting a tooth and placing an implant should be made based on patient-specific factors and the prognosis of the tooth.) The practical implication from the review was that even though a compromised tooth may require additional treatment for maintenance, implant treatment may also require adjunctive treatment or subsequent revisions from later complications that would pose additional risks. Tooth extraction and replacement may be done at anytime in the treatment and should be carefully considered since it is irreversible.
Other meta-analysis reviews have been performed that compare treatment outcomes of compromised teeth. One systematic review (Torabinejad et al. 2007) concluded that both root canal treatment with a restoration and implant-supported single crowns had higher long-term survival rates as compared to fixed partial dental prosthesis. Additionally, the research stated that extraction without replacement had poorer psychosocial outcomes as compared to the alternative treatment offered. Another systematic review found difficulty in making comparisons between RCT and implant treatment due to the heterogeneity in the findings (Tomasi et al. 2008). A systematic review comparing natural untreated teeth, compromised treated natural teeth, and implant treatment concluded that “oral implants when evaluated after 10 years of service do not surpass the longevity of even compromised but successful root canaltreated natural teeth” (Holm-Pedersen et al. 2007).
It is important when reviewing evidence for treatment recommendations that the reader ensures that the authors of the reviews make similar comparisons. Much of the implant literature considers survival rates in reporting outcomes, and the endodontic literature reports statistics in terms of success and survival (Norton 2001; Gotfredsen 2004; Gibbard and Zarb 2002; Morris et al. 2001). Only recently have reviews been conducted to evaluate criteria for implant success (Papaspyridakos et al. 2012) to include evaluating the “long-term primary outcome of the implant prosthetic complex as a whole” (p 247 Papaspyridakos). Survival rates will typically be higher than success rates. So when these meta-analyses are compared, the studies that are used need to be comparable, and survival levels are used since very few implant studies report success rates.
Root canal therapy and implant placement are “complementary treatment options for the appropriate patient situation” (Doyle, p. 2, 2015). There can be many complicating factors depending on the patient that need to be considered in each case. But simply stated, root canal treatment should be the primary consideration in general for restorable, periodontally healthy teeth that have irreversible pulpitis and/or periapical periodontitis (Doyle 2015; Iqbal and Kim 2008; Zitzmann et al. 2009). Implant placement should be considered in general for nonrestorable teeth and/or teeth with severe periodontal unhealthy conditions. To preserve the endodontically treated tooth successfully, there must be enough sound tooth structure to place a core or a post and core and to have an adequate ferrule for the crown margin of 2 mm surrounding the natural sound tooth structure (Sorensen and Engelman 1990; Libman and Nicholls 1995; Isidor et al. 1999). This situation would make the tooth clinically restorable. The presence of multiple risk factors though can jeopardize the compromised tooth and may weigh the decision toward extraction and implant placement or maintain the decision for RCT and final restoration. These other risk factors that must be considered include outcomes assessment, systemic conditions, tooth and periodontium factors, and patient-specific considerations (Torabinejad and Goodacre 2006; Salinas and Eckert 2007; Torabinejad et al. 2014).

5.3 Outcomes Assessment and Prognosis

Studies analyzing outcomes of RCT and ISC can be conflicting (Stockhausen et al. 2011), yet patients want to know whether a procedure that is recommended will be successful. It has been recommended that guidelines be in place so that these decisions can be made by the dentist to appropriately inform the patient. While both RCT and ISC have been found to be successful, studies predicting long-term outcomes concerning RCT have traditionally used “success and failure” as outcomes measures, while implant studies have used survival as outcome measures, making direct comparisons challenging. Long-term survival levels are comparable for both treatments. However, other factors must be taken into consideration.

5.3.1 Systemic Factors

Systemic factors are important to consider when recommending RCT or extraction and an implant for a patient. Table 5.1 outlines contraindications to implant placement from the National Institutes of Health Consensus Conference (NIHC 1988) that include both systemic factors and patient factors. In these situations, the recommended treatment option would weigh more in favor of RCT.

Table 5.1

Contraindications to implant placement
Contraindications to implant placement (National Institutes of Health Consensus Conference)
 1. Acute illness
 2. Terminal illness
 3. Pregnancy
 4. Uncontrolled metabolic disease
 5. Tumoricidal irradiation of the implant site
 6. Unrealistic patient expectation
 7. Improper patient motivation
 8. Lack of operator experience
 9. Inability to restore with a prosthesis
Adapted from Rosenstiel et al. (2016); Yilmaz and McGlumphy (2016), VitalBook file, p. 321
The risk factors for periimplantitis and implant failure include systemic disease, genetic traits, chronic drug or alcohol consumption, smoking, periodontal disease, diabetes, osteoporosis, and poor oral hygiene (Doyle 2015; Dawson and Jasper 2015). Systemic risk factors that are associated with lower survival of endodontically treated teeth include smoking, diabetes, systemic steroid therapy, and hypertension (Doyle 2015; Bowles et al. 2010; Ng et al. 2010, 2011; Wang et al. 2011). The use of antiangiogenic or antiresorptive medications affect treatment planning for root canal treatment and implant placement due to the risk of medication-related osteonecrosis of the jaw. Additionally it is recommended for the completion of skeletal and dental growth before implant placement is considered (Mankani et al. 2014). Thus for adolescents or young adults that are continuing to grow, the first consideration for the compromised tooth should be RCT and the definitive restoration. It has been shown that growth continues throughout a lifetime such that vertical steps can occur after anterior implant restorations of implant placement similar to that of adolescents that are actively growing (Bernard et al. 2004) and thus are considered esthetic risk factors for implant placement (Table 5.2).

Table 5.2

Contraindications and increased risk for failure for implant failures
 
Disease
Assessment
Medical contraindications
Acute infectious diseases
Cancer chemotherapy
Systemic bisphosphonate medication (>2 years)
Absolute, but temporarily; wait for recovery
Absolute, but temporarily; reduced immune status
Risk of bisphosphonate induced osteonecrosis (BON)
Renal osteodystrophia
Severe psychosis
Increased risk for infection, reduced bone density
Absolute; risk of regarding the implant as foreign body and requesting removal despite of successful osseointegration
 
Depression
Pregnancy
Relative
Absolute, but temporarily; to avoid additional stress and radiation exposure
Unfinished cranial growth with incomplete tooth eruption
Relative, but temporarily; to avoid any harm to the growth plates, to avoid in adequate implant position in relation so the residual dentition; utilize hand wrist radiograph to evaluate end of skeletal growth; single tooth implants in the anterior region not before a 25th year of age
Intraoral contraindications
Pathologic findings at the oral soft- and/or hard tissues
Temporarily; increased risk for infection, wait unit healing is completed
Increased risk for implant failure or complications
History of (aggressive) periodontitis
Relative, requires supportive periodontal care; increased risk to develop peri-implantitis
Heavy smoking ≥10 pack-years (particularly in combination with HRT/oestrogen), alcohol and drug abuse
Relative or absolute, indicates cessation protocol; would healing problems, locally reduced vascularisation, impaired immunity, reduced bone turn over
Insufficient oral hygiene
Uncontrolled parafunctions
Post head and neck radiation therapy
Absolute; wound healing problems, infection
Relative; increased risk for technical complications
Absolute, but temporarily; reduced bone remodelling, risk of osteoradionecrosis, implant placement 6–8 weeks before or ≥1 year after radiotheraphy
Osteoporosis
Relative; reduced bone-to-implant contact; consider calcium substitution, prolong healing period and avoid high torque levels for abutment screw fication
Uncontrolled diabetes
Relative, requires medical treatment; wound healing problems (impaired immunity, microvascular diseases)
Status post chemotherapy, immune-suppressants or steroid long-term medication, uncontrolled HIV infection
Absolute, but temporarily; wound healing problems, medical advice required (consider corticosteroid cover)
With permission Zitzmann et al. (2009)

5.3.2 Site-Specific Factors

In the endodontic literature, the factors that must be considered are preexisting factors that include severe periodontal disease or post-endodontic factors such as recurrent caries, inadequate restoration, and reinfection or fracture (Iqbal and Kim 2007; Aquilino and Caplan 2002). Since these are factors that are listed as ones that contribute to endodontic failures, treatment planning for extraction and implant placement and a single crown should be the treatment plan of choice (Table 5.3).

Table 5.3

Factors influencing endodontic and treatment-planning outcome
 
Initial RCT
Endodontic retreatment
Apical surgery
Implant treatment
Preoperative
+Vital pulp tissue
− Periapical lesion
+ Root canal filling
>2 mm short of the apex
+No periapical lesion
− Large periapical lesion
− Altered root-canal morphology or perforation
− Adequate existing root canal filling
+Orthograde retreatment feasible
+Significant overfill or root canal filling >2 mm short of the apex
− Lesion ≥5 mm
− Persisting lesion despite satisfactory root canal filling
− Combined endo-perio lesion
− Previous surgical treatment
− Insufficient bone volume
− Specific anatomic findings
− History of periodontitis
− Previous implant failure
− Insufficient oral hygiene and smoking (see also Table 5.3)
Intraoperative
+ Root canal filling with no voids extending to 2 mm within apex (radiographically)
+ Sufficient coronal restoration
− Missed canals and inadequate cleaning
− Errors such as ledging, instrument fracture, root perforations
− Inadequate obturation
− Root canal filling >2 mm short of the apex or overfill
+ Addressing previous technical shortcomings
+ Adequate root canal filling feasible
+ Root-end filling
− Poor accessibility
+/− Type of implant and surface
+/− Type of bone
− Fenestration, bone defects
− Specific anatomic findings
− Bone augmentation
− Immediate implant placement
Postoperative
− Restoration failure (coronal leakage)
− Restoration failure (coronal leakage, no cuspal coverage)
+/− No obvious influence by antibiotics
− Wound healing problems
− Iatrogenic factors (e.g., excess cement)

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Dec 11, 2016 | Posted by in General Dentistry | Comments Off on Modern Day Treatment Planning Dilemmas; Natural Tooth Versus Implants
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