Abstract
Each condition deserves the right treatment and prognosis that is dependent on the cause and the correct diagnosis. It is therefore vital to provide evidence for diagnosis and prognosis when seeking dental treatment. This urgency for the high predictability of dental implants has resulted in the paradigm shift of treatment planning. The dental research has been aimed at identifying the best treatment, either extraction or placement of extracts in salvaging the periodontally involved teeth. This article looks at some of the factors put into consideration when planning on the treatment to be undertaken and presents the parameters that influence the final treatment decision, on whether to extract or place an implant.
Introduction
The study of clinical aspects of the supporting structures of the teeth, periodontics, is aimed at saving teeth by either restoration or surgical practices. The tools used in these dental procedures have been continuously developed to ensure precision and eliminate the need for trial and error in diagnosis and subsequent treatment. “The periodontal surgical tools range from guided-tissue regeneration and soft-tissue root coverage to tissue engineering and periodontal microsurgery with microscope enhancement”.1 In addition to these, there are nonsurgical tools such as “subgingival antimicrobial therapy, subgingival microscopy, and host-modulated resistance”.2
The paradigm shift is a result of the inclusion of dental implants into periodontics. This has necessitated the requirement for long-term predictability and the heightened importance of evidence-based dentistry. The focus has changed from treatment of the teeth to emphasis on taking care of the bone, due to the requirement by many states to facilitate dental implants in the replacement of teeth. This change is attributed to increased life expectancy, thus demanding the longevity of restorative remedies.3 The preservation of bone in treatment planning serves two purposes: adequate bone in the event of replacement of a tooth, and aesthetic value. Another reason for the paradigm shift is the focus on long—term health of the patient. It has been observed that retaining teeth with complex periodontal disease has detrimental effects on an individual. As a result, remedies requiring the chipping of teeth in their preparation have been abandoned for recuperative solutions like dental implants.4
Bone preservation is one of the requirements of the new paradigm, which has necessitated a transformation in treatment procedures, as observed in the treatment of advanced bone loss by grafting of the socket when extracting it. This procedure preserves the hard and soft tissue, while previous methods would have resulted in damage to the tissue due to the extraction of the tooth. Modifications in treatment planning due to the new paradigm have seen the adoption of extraction and ridge augmentation in the place of socket grafting in the treatment of advanced bone loss, among other changes, in determination “of when to save a tooth, and when to extract it and place an implant”.5
Advanced diagnosis technology
The first step in a dental procedure is a diagnosis of the extent of damage on the tooth or teeth. Initially, this process was based on analysis based on experience, education, and rationale, obtained from observation and treatment for a long period. The previous diagnosis systems were based on 2D images, though advancements in technology allow for 3D systems in Cone Beam Computed Tomography (CBCT). Using the advanced computational software, increases the precision of a diagnosis, leading to advanced patient care, and increased efficiency in the treatment process with minimal risk. The 3D scans, in addition to being ideal for single-tooth dentistry, allow cross-sectional imaging, which is necessary for cases requiring full mouth reconstruction.6
One of the benefits of CBCT 3D systems is their precision, in that only the essential images are captured. This means reduced exposure time to radiation as compared to previously used methods. The panoramic and cephalometric features also improve the efficiency of the systems, though the “ability to first perform complex surgical tasks in three dimensions on a computer model so that unexpected anatomic reality can be anticipated in advance”.7
Factors involved in the treatment planning process
The diagnosis of periodontal disease is followed by careful consideration of all the factors involved in the treatment planning process. Some of these factors have been discussed below.
Decay rate
This is an important attribute in determining the long-term outcomes. The endodontic status of a single tooth is also important when planning on the most appropriate treatment. To preserve a tooth, endodontic re-treatment is necessary in cases of recurrent decay observed in endodontically treated teeth, whereby the “decay reaches the endodontic fill via permeable restitutions, ill-fitting crowns or broken fillings causing re-infection in the root canal system”.8 Higher tooth decay rates can be observed in elderly patients due to xerostomia brought about by the use of certain prescriptions. In such situations, several procedures can be administered including endodontic treatment, surgical crown lengthening, among others.
The cost of an implant is equivalent to that of tooth preservation; though the former is advantageous in that it eliminates chances of “decay, root fracture and endodontic failure in the future”.9 Another advantage of the implant is the possibility of post-treatments such as a core. In addition to this, the possibility of a single surgical process by having the implant being placed right after extraction is quite appealing, compared to the numerous treatments involved in the endodontic and crown-lengthening process.
In cases involving teeth with short roots, bone removal is considered to provide a provision for “3-mm biologic width and approximately 2 mm of ferrule”.10 This would affect the crown-to-root ratio, therefore reducing the long-term projection of the tooth. “Removal of bone from adjacent teeth may result from Osseous recontouring for crown lengthening”.11
To ensure the long-term success of the endodontic treatment, it is important to consider whether the tooth has periapical radiolucency, and use a close-fitting single-tooth crown with sufficient ferrule. “Periapical radiolucencies in teeth decrease the efficiency rate, and radiographic diameter of the periapical lesion above 5 mm further reduces the possibility of success”.12 According to research conducted, the ranking of the various reasons of “failure of endodontically treated teeth are a prosthetic failure (59.4%) and periodontal failure (32%)”.13 This accounts for about 9% of tooth loss. The success rate of a procedure in the long term is quite significant when arriving at an appropriate treatment plan. A tooth with a well-fitting crown and adequate ferrule increases the success rate of endodontic treatment, though consideration of restorative and periodontal factors diminishes the success rate.14
Status of adjacent teeth
The condition of teeth adjacent to the tooth undergoing treatment determines the prognosis. Factors such as a short root or root trunk of an adjacent tooth could result in lingual bone loss, in a fixed bridge treatment or implant. The two treatments are also affected by the variability of fixed bridges and implants, in terms of implant length and amount of bone. To ensure the longevity of an abutment tooth, the treatment should be nonendodontic, if the tooth has been posted, and a ferrule exceeding 2 mm. Surveys conducted after five years on the success rate of three-unit fixed bridges and single-tooth implants showed that the latter was better placed at 94.9% as opposed to 85% of the former. Further studies indicated that the implant was more effective after examinations conducted at least fifteen years from the treatment date, as compared to fixed partial dentures.15
In comparing the durability of fixed bridges based on the number of units, it was noted that units beyond three resulted in reduced longevity of the treatment. When excess units are used, there is an excess strain on one of the units, which could fail the bridge, brought about by root fracture in one of the units or even “furcation involvement with residual endodontic infection”.16
Periodontal status
The periodontal status of both the tooth undergoing treatment as well as the entire dentition is important in determining the treatment plan. When considering periodontal status, there are a few determinants that are considered including:
“pocket depth, age of the patient with the associated amount of clinical attachment loss, smoking status, health factors (e.g., diabetes mellitus, stress levels, immunodeficiency disease), furcation status, crown-to-root ration, occlusal factors (e.g., clenching, bruxing), type of vertical osseous lesion, mobility, and compliance (e.g., oral hygiene, motivation”.17
Research conducted on 500 patients with about 20 years of “maintenance in a single periodontal practice” to determine the teeth treatment trends with regard to tooth position came up with an order of the commonly lost teeth. It was observed that “maxillary molars are the most often lost, followed by mandibular molars”. The research indicated that it is more difficult to lose the anterior teeth as compared to the posterior teeth.17
The research also sought to find out how well the patients maintained their teeth with the view to minimizing the chances of tooth loss. The researchers observed that most patients maintained their teeth well, with only about four in a hundred experiencing extreme cases of tooth loss. Another technique used in the treatment of teeth is guided-tissue regeneration (GTR), especially useful in cases where the tooth has a large vertical osseous lesion. The long-term success rate of this procedure is less than that of implants and endodontic treatment, though the varieties of GTR treatments have differing techniques and materials, making the success rate a variable.
Before undertaking treatment in GTR, there are a few factors that should be considered including:
“defect size (at least 3 mm to 4 mm), number of defect walls (at least two bony walls, but a three-wall defect is the most predictable to treat), furcation status (furcations are less predictable to obtain increased clinical attachment levels), and mobility”.18
Propinquity to crucial structures
This is a vital factor for the clinician to put into consideration before proceeding with the prognosis. Such conditions arise for example when the “bone loss around the maxillary molars is close to the maxillary sinuses or even when the loss of bone in the distal and furcal areas of the tooth are close to the inferior alveolar nerve”.19 One of the common suggestions in cases involving extraction is to opt for it if retention of the damaged teeth is likely to cause harm to the bone, within a distance of “10 mm of critical structures like inferior alveolar nerve or maxillary sinus”.19 To safeguard the maxillary sinus, some procedures boost them. These procedures are observed to be more conventional and of less morbidity than vertical bone augmentation.
Esthetic deliberation
Esthetics is a vital feature for consideration, whereby the paradigm of bone preservation is fused with the present elevated concerns of beauty by the patients. The maintenance of esthetics in treatment is a delicate procedure since even the loss of papillary height could reduce the beauty aspect considerably. To avoid such scenarios, dentists try to avoid treatments that lead up to either facial flap elevation or bone removal, in particular places that are considered esthetic. According to research conducted on treatments that result in recession, it was identified that extraction and placement of a dental implant are much safer as compared to techniques that involved GTR and crown-lengthening. 20
An example of advanced recession can be observed in the figure below, (the tenth tooth) which was treated for the periodontal-endodontic lesion.
The procedure undertaken in the case above involved extraction and the immediate placement of an implant,
A remedy to the situation above involved a coronally move of the facial gingival margin followed by implant placement, as indicated in the two figures above.
Esthetics in the dental treatment is a vital aspect, and this has necessitated new modalities in procedures, such as:
“socket preservation, grafting of the socket right after extraction to reduce post operative shrinking of the ridge both horizontally and vertically and the use of bioabsorbable materials that have no need for surgical flap. This is because flapping the tissue results in additional bone resorption, and the nonresorbable materials lead to decreased native bone available for the implant”.21
Discussion
The patients seeking dental treatment have differing causes, which are to be considered before choosing the most appropriate procedure, either extraction or preservation. Regardless of the situation though, there are guidelines that assist clinicians in choosing the right procedure, even when the implant-supported restoration is a viable choice. Due to the paradigm, there has been a change of the principal treatment preparation objective to bone preservation from tooth preservation, with more emphasis when considering the esthetic aspect. While it is important to save a tooth when it is the logical step to take, it is equally important to outline the long-term result in the dental literature. This has necessitated evidence-based dentistry, and the transformation of the treatment planning paradigm, which demands that the clinician investigates all available options and their success rates.22
From previously conducted research, it can be deduced that “there is a high long-term success rate for endodontic treatment with a well-fitting crown with adequate ferrule”.17 In addition to this, a low long-term success rate for re-treatment, particularly with both apical endodontic surgery and big periapical radiolucency is a common scenario. The long-term prognosis of teeth is considerably reduced by preparing them for restoration, which requires re-consideration when restoring a weakening FPD. The better alternative would involve placing an implant in the edentulous space since restorations are generally weaker progressively.17
Research has indicated that single-unit restorations on teeth or dental implants last longer than three-unit FPD, which in turn last longer than FPD with more than three units. Some suitable options may have the most suitable long-term prognosis, though the consent of the patient has to be given. Such a procedure is the “replacement of a failing three-unit FPD with an implant-supported crown in the edentulous area and two single crowns on the adjacent natural teeth”.23 Single crowns are more durable than fixed denture abutment, while a single unit is more likely to be replaced when compared to a three-unit. In a comparison of abutment teeth, FPD is more durable than the RPD.23
Smokers are observed to be at a disadvantage when it comes to the treatment of teeth defects, especially when the procedure requires either GTR or open-flap curettage, though the latter has a lower success rate. Treatment for abutment that is nonendodontic lasts longer than the alternative, and so does periodontal maintenance, though the highest success rate is observed in “dental implants, making it the standard of care in most states”24. Procedures involving surgical crown lengthening advice against extracting bone that is within “10mm of critical anatomic structures, or furcations”.24 One of the strong recommendations regarding esthetic contemplation is the incorporation of certain practices like socket grafting during extraction. This is aimed at reducing ridge shrinkage in the esthetic zone.25
Conclusion
Following the information provided in the article, it is clear that particular instances require the placement of an implant while others require saving the tooth. The placement of an implant ought to be the option in cases when: saving the tooth would result in serious compromise of esthetics; the chances of GTR treatment success for extensive furcations in the molar teeth are unpredictable; patients with a significant caries rate have recurrent decay; youthful patients have high chances of getting periodontal disease due to large amounts of bone loss from periodontitis; the options available for the patient are minimal, as when the patient is a smoker; and when residual periapical lesion endodontic re-treatment has been performed. Placement of an implant is also done as an effort to salvage a tooth with surgical crown lengthening, which would result in the removal of a significant amount of bone from the adjacent tooth.7
On the other hand, saving a tooth would be appropriate when the grafting of the vertical osseous defects can be carried out predictably, when the patient observes good oral hygiene and is willing to keep his or her teeth after being well informed, and when “endodontic treatment is an option, and allows the tooth to be sealed with a well-fitting single-tooth restoration with adequate ferrule”.19
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