One of the most popular current debates covered by dental associations is the comparison of the endodontics retreatment's outcome with that of the implant treatment's, taking into account the patient's best interest. With the advent of new endodontics' technologies and the struggling of implant innovations to achieve and maintain high search results rankings, Data analysts are facing more difficulties when performing meaningful cross-study comparison. Accordingly, this literature review aims to answer one of the principal questions addressed by risk-benefit analysis of two long term treatments, that is “How safe, is safe enough?”

Keywords: implant, root canal, retreatment, success rate, NiTi, study, evolution

"There are living systems; there is no living matter", Jacques Monod.¹ Dental practice system is a framework that is based on the belief that teeth's ultimate treatment can be best chosen in the context of intervening relationships between themselves and between them and other systems, such as the periodontal system and the facial system, rather than in isolation. The question that keeps on bursting is: which is the best to choose between root canal retreatment and implants without misleading the patients? In this paper, an attempt is made to answer this query. Many previous studies have been carried out, and various authors, mostly endodontists (Cohen et al. 2005), reported that the survival rate of implant and endodontic retreatment are both the same.^2,3 However, the latest findings, related to this subject, were mainly directed to the consideration of patient needs and clinical expectations.⁴

Implants v/s retreatment

In today's world, implants have become a complex biomedical system that includes, not only research, design, and crafts, but also manufacturing, marketing, and measuring. If most of their studies show an evidence of easy treatment procedures with high success rate, how wouldn't it be not complex?!⁵ By the same token, Implant innovations with sophisticated 3-D imaging and "virtual treatment planning" software have been crushing dreams , providing the easiest treatment with the best outcome a patient can get. “All-on-4” technique enables a patient to receive an entire row of teeth all in the same day. Above all, every clinician, regardless of gender, age and medical history, could be an implant candidate (Moss 2015).⁶ Thus, these new clinical techniques had assisted in increasing the precision and maintaining the dental implant success rate.⁷ Many authors just as Lazzara et al.,⁸ Schnitman et al.,⁹ Romanos et al.¹⁰ and Simonis et al.¹¹ reported subsequently that the survival rate for implants, whether immediate or delayed, has an average of 93%.¹² Several retrospective articles appraised the survival rate of implants performed on a variety of candidates, including smokers, diabetic participants and some representing periapical lesions as well.¹³⁻¹⁵ The only conclusion that was revealed is that an insignificant percentage difference was detected when comparing those patients to the healthy ones. Admittedly, the profit and the high success rate of implant’s treatment wouldn’t influence the decision of an implantologist. From their perspective, the decision to replace a root-canal-treated tooth, or teeth, with dental implants will depend on many factors, including the reason for failure, the integrity of the tooth and its roots, and the patient’s overall health, both oral and general—and, importantly, what may be involved in a root canal re-treatment. Saving a tooth was always a target for implantologists.³ As an illustration, a decision-making chart was introduced by Avila et al in 2009.¹⁶ To help clinicians make a better choice, the color-based chart was divided into six levels including the factors and variables that can influence the final decision to save or extract a tooth:

1. Initial assessment such as patient expectation and Esthetics
2. Periodontal disease severity (Mobility)
3. Furcation involvement
4. Etiologic factors
5. Restorative factors
6. Other determinants.

The decision of the treatment plan is attempted by a sort of calculation (Figure 1), (Figure 2), (Figure 3) & (Figure 4)

Figure 1 Fractured instrument.

Figure 2 Excessive bone resorption.

Figure 3 Bone resorption.

Figure 4 Tooth with huge bone resorption and large post cannot be saved. Replacing the tooth with an implant would be the perfect treatment choice.

Nevertheless, new technologies (NiTi instruments, Irrigation modalities) were introduced to a conservative section of dentistry, which led to a fast significant evolution of root canal retreatment.¹⁷ This latter stimulated the transition from the world of macro-dentistry to detailed world of micro-dentistry inducing a revolution in the endodontic history such as "microscope".¹⁸ Markedly, Carr and Castellucci (1992) Stated that the increased magnification and the coaxial illumination provided by the microscope have enhanced the treatment possibilities in non-surgical and surgical endodontics. Treatments that were not possible in the past have become reliable and predictable.²⁰ Equally important, the launch of Laser in endodontic treatment improved the quality of canal preparation and enhanced the bacterial elimination.^18,19 Numerous studies reveal the importance of this latter by reflecting his capability to eradicate the resistant bacteria in root canals the "E. Faecalis" that may be tougher than previously thought.²¹⁻²⁴ Traditional mechanical-chemical enlargement lead to Bacterial reduction, however, a recent discover forces us to reevaluate this simple picture; surprisingly, chemicals used in root canal treatment “RCT” (Chloroxedine, Sodium hypochlorite...), which allow the adherence of E. Faecalis to collagen, may be the direct reason for this resistance.²⁵ Gradually, The innovation of “MTA" (Dental root repair material) was able to turn what was known as impossible, to possible. Celikten et al.,²⁶ showed that MTA suggested a good long-term outcome when used in root-fractured and luxated teeth (Complicated cases that might be considered as contra indication of root canal treatment).²⁷ A literature review of Brett Gilbert (2012), proclaimed that this latter, whether with or without periapical lesion, ranged between 85%-93%.²⁸ His work was referred to 112 prospective studies over 5 years done by endodontist such as Sjogren et al.;²⁹ Farzaneh et al.³⁰ Consequently, in front of such similarity and regardless of patient's need the most profitable easy treatment is to be chosen. This statement has been validated by David Corless-Smith, of the Dental Law Partnership claiming:" The irony is that dentists have opted for replacing damaged teeth with implants because they saw this as being “Cautious".³¹ In fact, some papers³² have often involved reporting misinterpretations of the treatment plan, and misapplications of implant techniques by general practitioners, without consideration of patient's sake. The risks of this approach may appear eventually when dentists start to make continuous unjustified and potentially misleading diagnosis as well as misinformed decisions about how and even whether to proceed to other treatments. In the dental field, treatment varies depending on the condition of tooth and the characteristics of the patients. Matching treatment settings, interventions, and services to an individual’s particular problems and needs is critical but potential in order to re-give the oral cavity its normal functioning and its esthetic aspect. Hence, dentist should reach all the information needed to think twice before sacrificing a tooth for their interests.³³ According to the periodontologist Froum et al.,³⁴ the worst case scenario witnessed in endodontic retreatment is the occurrence of reversible injuries of the mandibular nerve. Yet, this barricade is considered minor when being compared to the ones resulting from different procedures. From this point, it is concluded that the RCT is a safe mode for treatment of damaged tooth unconcerned about patient medical condition.³⁴ In spite of all of that, a lack of long-term papers discussing the metal-related complications of NiTi alloy has undermined the reliability of these biomaterials, and set inevitably usage limits for general practitioners.³⁵ Furthermore, while some researchers have focused only on the quantitative part, other work has sought to discuss the high value of existing teeth. Chandki et al.³⁶ & Harrison et al.,³⁷ all argued that finding methods to preserve natural teeth is the first step a dentist must take. From another perspective, the way you look affects the way you feel. For this reason, many papers have emphasized the psychological consequences of tooth loss such as embarrassment and other social impacts.³⁸⁻⁴⁰ On the other hand, few studies was conducted for the investigation of the importance of teeth’s periodontal ligaments. The results were clear that it is very useful, functionally and technically speaking, to preserve natural teeth as a better oral tactile element due to the existence of proprioceptive receptors.^41,42 Researchers are carried out with the goal to clone the periodontal ligaments through tissue cell engineering for a better implant integration.⁴³⁻⁴⁵ Preserving a damaged tooth must be preceded by a case evaluation.^46,47 According to The Endo blog (2012), dentist should consider many factors before deciding a retreatment like: The quality of the initial treatment, the possibility to be performed under microscope, the restorability of the tooth functionally and aesthetically, and the level of expertise of the clinician. If these things can be improved upon with retreatment, then Dentist can proceed the Treatment plan blindfolded.⁴⁸ All of the stated data is summarized in the Table 1 inserted below

When choosing the right treatment for the patients, the options available to them depend on Dentist liability. That's why it is quiet important to realize that preserving a natural tooth is periodontologists' choice as well (mentioned in the table above). Henceforth, dentistry fields are not to compete, but to complete. Correspondingly, the moral duty constrain the dentists to act in ways that aim to maximize patients' satisfaction and to minimize their deception.⁴⁹ To sum it all up, dental implants are modern dentistry's best option for replacing missing or restorable teeth but not damaged ones.⁵⁰ Preserving a natural tooth must be and always will remain a dentist's priority. With all the new endodontic innovations and aesthetic techniques, root canal retreatment should be a dentist’s first choice for saving what we called a “vital organ”.

None.

The author declares that there is no conflict of interest.

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