DETERMINANTS IN SALVAGING A TOOTH VERSUS EXTRACTION AND REPLACEMENT

PREAMBLE / CONCEPTUAL FRAMEWORK

"Periodontal treatment requires long-range planning. Its value to the patient is measured in years of healthy functioning of the entire dentition and not by the number of teeth retained at the time of treatment. Treatment is directed to establishing and maintaining the health of the periodontium throughout the mouth rather than attempting spectacular efforts to 'tighten loose teeth.'" - Newman & Carranza's Clinical Periodontology and Implantology, 14th Ed., Chapter 42

"Implant replacement of missing teeth has become a predictable course of therapy. Therefore, attempts to save questionable teeth may jeopardize adjacent teeth and may lead to the loss of bone needed for implant therapy." - Newman & Carranza 14th Ed., Chapter 42

SECTION 1: PERIODONTAL PROGNOSIS - THE FOUNDATION OF THE DECISION

1.1 Definition and Role of Prognosis

• The periodontal prognosis plays a pivotal role in therapy, as treatment decisions are made based on prognosis and to improve prognosis.
• Teeth with a hopeless prognosis are extracted, whereas teeth with other prognosis categories are treated.
• Prognosis is dynamic and bound to change over time; therefore, the care provider should assess and update the prognosis of teeth on a consistent basis. (Newman & Carranza 14th Ed., Chapter 41)

1.2 Classification of Prognosis - Individual Tooth Prognosis

SCHEME 1 (McGuire & Nunn - tooth mortality based): (Newman & Carranza 14th Ed., Chapter 41)

"It should be recognized that this classification was developed to assign prognosis to individual tooth, and good, fair, and hopeless prognostic categories in this classification system can be established with a reasonable degree of accuracy. However, poor and questionable prognoses are likely to change to other categories because they depend on a large number of factors." - Newman & Carranza 14th Ed., Chapter 41

"...approximately 80% of the teeth that were initially assigned to questionable prognosis ended up with better prognosis, after 5 years of periodontal supportive therapy." - Newman & Carranza 14th Ed., Chapter 41

SCHEME 2 (Kwok & Caton - probability of periodontal stability based): (Newman & Carranza 14th Ed., Chapter 41)

"A prognosis based on whether periodontal stability can be achieved with periodontal therapy and maintenance is as follows: favorable—likely, questionable—maybe, unfavorable—unlikely, hopeless—impossible." - Newman & Carranza 14th Ed., Chapter 41

SCHEME 3 (Essentials - Reddy): (Essentials of Clinical Periodontology and Periodontics, Chapter 30)

SECTION 2: FACTORS TO CONSIDER WHEN DETERMINING PROGNOSIS

2.1 Overall Clinical Factors

• Patient age
• Disease severity
• Biofilm control
• Patient compliance

2.2 Systemic and Environmental Factors

• Smoking
• Systemic disease or condition
• Genetic factors
• Stress

2.3 Local Factors

• Biofilm and calculus
• Anatomic factors:
  • Short, tapered roots
  • Cervical enamel projections
  • Enamel pearls
  • Bifurcation ridges
  • Root concavities
  • Developmental grooves
  • Root proximity
• Furcation invasion
• Tooth mobility
• Caries
• Tooth vitality
• Root resorption

2.4 Prosthetic and Restorative Factors

• Subgingival restorations
• Tooth-supported prosthesis

SECTION 3: SPECIFIC DETERMINANTS - POINT-BY-POINT ANALYSIS

3.1 Bone Loss and Attachment Loss

• In cases with clinical attachment loss and bone loss that are slight to moderate (Stage I or II periodontitis) with slow or moderate progression rate (Grade A or B), prognosis is generally favorable, provided inflammation can be controlled through good oral hygiene and removal of local biofilm-retentive factors.
• In patients with more severe disease (Stage III or IV), as evidenced by bone loss extending to the middle third of root and beyond, furcation invasion, vertical defect, and multiple tooth loss due to periodontitis, with rapid progression rate (Grade C), the prognosis may be questionable, unfavorable, or even hopeless for some teeth. (Newman & Carranza 14th Ed., Chapter 41)
• Advanced bone loss with an unfavorable crown-to-root ratio is listed as a contraindication to root resection, implying extraction is preferred. (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 24)

3.2 Crown-to-Root Ratio

• As bone loss progresses and the bone level drops, the crown-to-root ratio becomes less favorable. By aligning the crowns of the teeth and disregarding the bone level, one perpetuates tooth mobility by maintaining an unfavorable crown-to-root ratio. (Periodontics: Medicine, Surgery and Implants - Rose)
• For fractured teeth requiring forced eruption: "The crown-to-root ratio should be about 1:1. If the ratio is greater than 1:1, too little root may remain in the bone for stability. In this situation, it may be more prudent to extract the root and place a fixed partial denture or implant." (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 28)
• Poor crown-to-root ratio is listed as a factor for questionable prognosis (McGuire & Nunn classification). (Newman & Carranza 14th Ed., Chapter 41)

3.3 Furcation Involvement

• Grade I furcation invasion (location and depth allow proper maintenance) = Fair prognosis - tooth retainable.
• Grade II furcation invasion (location and depth make maintenance possible but difficult) = Poor prognosis - tooth retainable with difficulty.
• Grade II furcation invasion (location and depth make access difficult) or Grade III furcation invasion = Questionable prognosis. (Newman & Carranza 14th Ed., Chapter 41)
• Advanced periodontal disease may be addressed with extraction of questionable abutments more frequently than in the past, provided the resulting edentulous area offers sufficient bone for predictable endosteal implant placement.
• "A first molar furcation entrance cannot be accessed with hand instruments 58% of the time."
• A maxillary molar that has lost bone to the furcation has lost almost 30% of the root surface area of support.
• Mandibular molars with grade I furcation involvement often are placed in the 5- to 10-year prognosis category.
• Maxillary molars are at higher risk of furca complications and are lost 33% of the time within 5 years.
• Mandibular molars have a 20% failure at this same reference time.
• After the molar has a grade II or higher furca, it has a greater risk of failure and may be placed in the 0- to 5-year category. (Misch's Contemporary Implant Dentistry 4th Ed., Chapter 21)
• Herodontics are discouraged when the prognosis is poor or failure of treatment may result in inadequate bone for implant placement. (Misch 4th Ed., Chapter 21)

3.4 Tooth Mobility

• Mobility no. 2 or no. 3 = Questionable prognosis.
• The prognosis of mobility is assessed as unfavorable or hopeless depending on the degree of mobility and its etiology. (Newman & Carranza 14th Ed., Chapter 41)
• Traumatic forces placed on teeth with ongoing periodontitis may increase tooth mobility, discomfort, and possibly the rate of attachment loss. Restorations constructed on teeth free of periodontal inflammation, synchronous with a functionally appropriate occlusion, are more compatible with long-term periodontal stability and comfort. (Carranza's Clinical Periodontology 10th Ed.)

3.5 Periodontal Disease Stage and Grade (2018 Classification - Recent Terminology)

IMPORTANT RECENT TERMINOLOGY CHANGE: Previously, periodontitis was categorized as chronic periodontitis and aggressive periodontitis. Since 2018, both are categorized under the single term "Periodontitis" in the new classification, with a staging and grading system introduced. The previous terminology of aggressive/chronic is no longer recognized in the current classification.

• Staging: Stage I, II, III, or IV (reflects severity and complexity)
• Grading: Grade A, B, or C (reflects rate of progression)
• The higher the Stage and/or Grade of periodontitis, the poorer the individual and overall prognoses will be. (Newman & Carranza 14th Ed., Chapter 41)

3.6 Systemic Factors

• When rapid progression rate is present and associated with systemic factors (e.g., uncontrolled diabetes) and smoking history, the host response might be altered and these patients usually do not respond well to conventional nonsurgical or surgical periodontal therapy, making prognosis poorer. (Newman & Carranza 14th Ed., Chapter 41)
• Systemic conditions should be carefully evaluated, because they may require special precautions during the course of periodontal treatment. The tissue response to treatment procedures may be affected, or the preservation of periodontal health may be compromised. (Newman & Carranza 14th Ed., Chapter 42)

3.7 Patient Compliance and Oral Hygiene

• The long-term success of debridement procedures is ultimately dependent on access for plaque removal and the patient's willingness to perform daily oral hygiene procedures. (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 24)
• Decreased stability in patients with poor plaque control and compliance, and increased stability in patients exhibiting the converse behavior. The difficulty is that patient compliance is hard to maintain. (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 25)
• If hygiene is poor with patients with a high caries index or with grade II or grade III furca involvement in molars, the tooth most often is considered in the 0- to 5-year category and is considered for extraction, especially when other teeth in the same quadrant are missing or hopeless. (Misch 4th Ed., Chapter 21)

3.8 Smoking as a Determinant

• Smoking is a major risk factor not only for disease progression, but also for adverse therapeutic outcomes.
• Smoking has been implicated as having a detrimental effect on periodontal wound healing after surgical procedures.
• It has been linked to impaired healing response to GTR procedures in both intrabony defects and furcation repairs. (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 25)

3.9 Endodontic Status of the Tooth

• "Once a tooth is deemed essential, it is important to assess its endodontic status." Frequently, chronic endodontic-periodontal defects have the same appearance as an advanced intrabony defect.
• Teeth with adequate endodontic therapy appear to respond to regenerative therapy in a way similar to vital teeth without pulpal pathology.
• "Given the expense for endodontic treatment, periodontal regenerative procedures, crown buildup, and the crown - strategic extraction and possible replacement with a prosthesis or a dental implant should be considered." (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 25)
• A nonvital tooth with large periapical pathology has a success rate of 78% (endodontic treatment). A retreatment of an endodontic tooth with a periapical lesion has a reported success rate of 65%. As a result, consideration for extraction and implant replacement may be considered for nonvital teeth with more than 5-mm apical radiolucencies that do not resolve or endodontic retreatment when periapical lesions are present. (Misch 4th Ed., Chapter 21)

3.10 Strategic Importance of the Tooth

• "The critical question to be addressed is whether the involved tooth is strategically important in the final restorative plan." If not, the procedure may not be justified because of its technical difficulty and expense, potential postsurgical complications, and the difficulty in obtaining excellent patient oral hygiene and compliance. (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 25)
• Removal of nonfunctional and diseased teeth and possibly strategic extraction of healthy teeth to facilitate the prosthetic reconstruction of the patient is part of the treatment plan. (Newman & Carranza 14th Ed., Chapter 42)

3.11 Cost and Economic Considerations

• "The natural molar tooth that requires endodontics, root amputation, post and core placement, and nevertheless a compromised root with poor root surface area may be cost prohibitive for the service provided."
• "An implant in the site after tooth extraction is often less expensive and more predictable long term."
• When functional crown lengthening and endodontic post treatment is also required, the fees are usually greater than extraction and implant insertion. Therefore part of the equation of whether to extract or treat a tooth may also relate to the cost of the service provided.
• Traditional methods to save a tooth have increased in cost over the years. Multirooted endodontic therapy now approaches the cost of an implant surgery. (Misch 4th Ed., Chapter 21)

3.12 Bone Availability for Future Implant Placement

• Herodontics are discouraged when the prognosis is poor or failure of treatment may result in inadequate bone for implant placement. The cost of the questionable periodontal treatment may result in the patient's inability to afford the more predictable implant therapy later.
• Unsuccessful periodontal treatment and continual bone loss may render the remaining bone inadequate for extraction and placement of implants. (Misch 4th Ed., Chapter 21)
• "Sometimes, the best management of a periodontal defect may be extraction in lieu of periodontal regeneration or when regenerative efforts have been unsuccessful. Extraction would minimize further bone loss and provide the maximum volume of bone at the future implant healing site." (Newman & Carranza 14th Ed., Chapter 63)

3.13 Defect Morphology and Regenerative Potential

• Defect characteristics such as the overall defect depth, width, and number of walls can influence clinical outcome in response to regenerative surgery.
• Increased depth of the defect is correlated with increased improvement in clinical attachment level and probing depth.
• Increased width of the bony defect has been correlated with decreased bone fill and clinical healing response.
• Intrabony defects characterized by three- or three- and two-walled configurations will generally respond more positively to regenerative procedures. Current regenerative approaches have not been consistently successful in regenerating one- or zero-walled defects. (Periodontics: Medicine, Surgery and Implants - Rose, Chapter 25)
• Should patient-related or clinical determinants be unfavorable for periodontal regeneration, a different, more appropriate, therapy must be selected in place of regeneration. Alternative therapeutic options include long-term maintenance or the removal of the tooth and replacement with a prosthesis, such as a dental implant or another form of prosthesis. (Newman & Carranza 14th Ed., Chapter 63)

SECTION 4: SPECIFIC CONDITIONS FOR EXTRACTION vs. RETENTION

4.1 Absolute Indications for Extraction (Newman & Carranza 14th Ed., Chapter 42)

1. It is so mobile that function becomes painful or if it poses an aspiration (tooth reaching the lungs) risk.
2. It can cause acute abscesses during therapy.
3. There is no use for it in the overall treatment plan.

4.2 Conditions for Temporary (Interim) Retention (Newman & Carranza 14th Ed., Chapter 42)

1. It maintains posterior stops; the tooth can be removed after treatment when it can be replaced by an implant or another type of prosthesis.
2. It maintains posterior stops and may be functional after implant placement in adjacent areas. When the implant is restored, these teeth can be extracted.
3. In the anterior aesthetic zone, a tooth can be retained during periodontal therapy and removed when treatment is completed and a permanent restorative procedure can be performed. The retention of this tooth should not jeopardize the adjacent teeth. This approach avoids the need for temporary appliances in the aesthetic zone during therapy.
4. Extraction of hopeless teeth can be delayed during the nonsurgical periodontal therapy and can be performed during periodontal surgery of the adjacent teeth. This approach reduces the number of appointments needed for surgery in the same area.

SECTION 5: THE MISCH DECISION-MAKING PROTOCOL (0-5-10 YEAR RULE)

"The dentist evaluates the natural teeth for their quality of health with widely used prosthetic, periodontal, and endodontic indexes. After this is accomplished, the dentist obtains an estimate of longevity and decides whether to extract or to treat and maintain the tooth, following a 0-year, 5-year, or 10-year rule." (Misch 4th Ed.)

"However, the recent trend to extract teeth with a good prognosis after endodontic or periodontal treatment is discouraged. Implants are not yet 100% predictable, and implants should not be substituted for natural teeth presenting a good or even fair prognosis." (Misch 4th Ed.)

"Therefore if the practitioner is not sure whether the tooth is in the 0- to 5-year or 5- to 10-year category, the tooth more often should be considered to have the poorer prognosis." (Misch 4th Ed.)

SECTION 6: ROOT RESECTION CONSIDERATIONS - RETAIN OR EXTRACT?

Indications for Root Resection (as an alternative to full extraction):

1. Severe vertical bone loss on one root of a multirooted tooth not amenable to regeneration/reattachment
2. Furcation invasion not correctable by odontoplasty
3. Proximal furcation invasion in combination with root approximation
4. Furcation invasion that is not maintainable
5. Periodontally involved abutment teeth with a hopeless prognosis associated with one root
6. Vertical or horizontal root fracture
7. Uncorrectable root dehiscence
8. When endodontic therapy is impossible on one root of a multirooted tooth

Contraindications to Root Resection (implying extraction of entire tooth):

1. Advanced bone loss with an unfavorable crown-to-root ratio
2. Fused roots that cannot be separated
3. If an endodontically inoperable canal would be retained
4. If the remaining root(s) would be inadequate to serve as a prosthetic abutment
5. If indicated splinting cannot be performed
6. When periodontal support after resection is inadequate to withstand normal occlusal forces
7. Inability to create a good postsurgical gingival environment
8. If socioeconomic conditions preclude necessary treatment procedures

Note on root resection vs. implant (Misch 4th Ed.): "A mandibular first molar with a distal root resection generally has a success rate of 75%. Even when successful, the mesial root requires endodontic treatment, core, and crown and the distal root needs replacement. Therefore an implant or three-unit fixed partial denture is indicated. It is more cost-effective to extract, implant, and fabricate one crown, even when bone grafting is indicated."

SECTION 7: STRATEGIC EXTRACTION

• Strategic extraction is defined as the removal of teeth - sometimes even teeth not severely diseased - to facilitate prosthetic reconstruction or to provide maximum bone volume for future implant placement.
• "Treatment planning in periodontics has also changed dramatically because of the acceptance of dental implants as viable long-term options for replacing missing teeth. With the increased predictability of implants, questions arise regarding when to treat severe periodontal defects with regenerative procedures and when to perform strategic extraction in preparation for implant placement." (Newman & Carranza 14th Ed., Chapter 63)
• "The crucial challenge for the clinician is to assess critically whether a periodontal defect can be corrected with a regenerative approach, or whether it would be better managed with osseous resection for a slight periodontal defect and with strategic extraction for an advanced diseased state." (Newman & Carranza 14th Ed., Chapter 63)
• Should failures due to poor hygiene, uncorrectable tooth anatomy, and undiagnosed endodontic problems be determined at recall, it may be prudent to consider strategic extraction. (Newman & Carranza 14th Ed., Chapter 63)

SECTION 8: IMPLANT VERSUS NATURAL TOOTH - COMPARATIVE ANALYSIS

• "The increasing complications associated with dental implants, such as mechanical failures and peri-implantitis, makes regeneration attractive. In this debate, the patient should be brought into the decision-making process. The medical and dental history of the patient should be considered along with the decision-making for preserving the dentition through regeneration versus strategic extraction with the replacement with implant-supported dentition." (Newman & Carranza 14th Ed., Chapter 63)
• Advanced periodontal disease may be addressed with extraction of questionable abutments more frequently than in the past, provided the resulting edentulous area offers sufficient bone for predictable endosteal implant placement and a predictable prognosis. (Misch 4th Ed., Chapter 21)

Implant Benefits over Questionable Natural Tooth:

• Does not require adjacent tooth preparation
• No risk of caries on implant crown
• No risk of endodontic complications
• Long-term stability when osseointegrated
• "The natural molar tooth that requires endodontics, root amputation, post and core placement... may be cost prohibitive for the service provided. An implant in the site after tooth extraction is often less expensive and more predictable long term." (Misch 4th Ed.)

Natural Tooth Benefits over Implant:

• Periodontal ligament provides proprioceptive feedback and shock absorption
• Reduces stress to adjacent bone
• Reversible - tooth can still be extracted later; implants cannot be reversed
• Implants are not 100% predictable - should not be substituted for teeth with good or fair prognosis (Misch 4th Ed.)

SECTION 9: ROLE OF REGENERATIVE THERAPY AS ALTERNATIVE TO EXTRACTION

Key Finding - Cortellini et al. 2011 RCT (cited in Lang & Lindhe 6th Ed.): "The aim of this randomized, long-term clinical trial was to compare clinical and patient-based outcomes following periodontal regeneration or extraction and replacement of hopeless teeth with attachment loss to or beyond the apex. Twenty-five hopeless teeth were treated with a regenerative strategy... Twenty-three of the 25 regenerated teeth obtained extensive clinical improvements. The average CAL gain was 7.7 ± 2.8 mm, the radiographic bone gain 8.5 ± 3.1 mm, and the PPD reduction 8.8 ± 3 mm... The authors concluded that regenerative therapy can be successfully applied even to hopeless teeth and has the potential to change their prognosis."

• However, "it should be underlined that the reported outcomes were obtained in a carefully selected patient population, and by applying 'state of the art' regenerative therapy by very experienced clinicians, within a high quality program of periodontal and dental therapy and a strict periodontal supportive care program." (Lang & Lindhe 6th Ed.)
• "Case reports also exist demonstrating that 'hopeless' teeth with deep vertical defects, increased tooth mobility or through-and-through furcations can be successfully treated with regenerative periodontal therapy." (Lang & Lindhe 6th Ed.)
• The key point is that the possibility of changing the prognosis of a tooth from 'questionable' or 'hopeless' to 'fair' or 'favorable' would greatly help clinicians and patients in the difficult job of maintaining teeth over time. (Lang & Lindhe 6th Ed.)

SECTION 10: AESTHETIC CONSIDERATIONS

"In addition to the proper function of the dentition, aesthetic considerations play an important role in the formulation of the treatment plan. Different patients value aesthetics differently according to their age, gender, profession, social status, and life experiences. The clinician should carefully evaluate and consider a final aesthetic outcome of treatment that will be acceptable to the patient without jeopardizing the basic need of attaining health." (Newman & Carranza 14th Ed., Chapter 42)

• Aesthetic considerations also form an indication for regenerative periodontal therapy, besides function and long-term prognosis. (Lang & Lindhe 6th Ed., Chapter 45)
• In the anterior aesthetic zone, a tooth can be retained during periodontal therapy and removed when treatment is completed and a permanent restorative procedure can be performed - this approach avoids the need for temporary appliances in the aesthetic zone during therapy. (Newman & Carranza 14th Ed., Chapter 42)

SECTION 11: PROGNOSIS REASSESSMENT - DYNAMIC NATURE

• Prognosis may change as more specific diagnostic information is discovered during the treatment phase - for example, teeth initially determined to be salvageable may be judged "hopeless," thus altering the preconceived treatment scheme.
• During therapy, the patient's motivation and commitment, acknowledged as critical in all forms of periodontal therapy, can be determined, as well as the host response and the healing capacity of the patient.
• "A frank reduction in probing depth and inflammation after therapy indicates a favorable response to treatment and may suggest a better prognosis than previously assumed."
• "The progression of periodontitis generally occurs in an episodic manner, with alternating periods of quiescence and shorter remission or exacerbation. Advanced lesions, if active, may progress rapidly to a hopeless stage, whereas similar lesions in a quiescent stage may be maintainable for long periods."
• "Therefore, the hopeless prognosis must be assigned with caution."

SECTION 12: ERRORS IN PROGNOSIS DETERMINATION

"The treatability of a tooth can be easily skewed by the skills and expertise of the treating clinician, or lack thereof. It is also easier for a clinician to make a diagnosis, determine a prognosis, and create a treatment plan that aligns with his or her expertise. For example, a prosthodontist may assign mandibular incisors with moderate attachment loss and grade 2 mobility a hopeless prognosis and develop a treatment plan that involves replacement of these teeth with a removable partial denture or dental implants. However, a periodontist may assign these teeth a questionable prognosis if the patient is compliant. With the proper periodontal treatment and effective patient biofilm control, the health and function of these mandibular anterior teeth may be restored and maintained for many years."

• "A hopeless prognosis is perhaps the easiest prognosis to assign, because hopeless teeth usually have overt and severe disease. The hopeless prognosis is also perhaps the easiest to be erroneously assigned."

SECTION 13: FLOWCHART - DECISION-MAKING PROCESS

CLINICAL & RADIOGRAPHIC ASSESSMENT OF TOOTH
                    |
                    v
        ASSIGN INDIVIDUAL TOOTH PROGNOSIS
        (Consider: bone loss, furcation, mobility,
         C:R ratio, endodontic status, caries, systemic factors)
                    |
          __________|__________
         |                     |
    FAVORABLE/GOOD            HOPELESS
    (>10 yr expected)    (inadequate attachment;
         |               function/comfort impossible)
         v                     |
  INCLUDE IN                   v
  TREATMENT PLAN           EXTRACT
  (With periodontal            |
   therapy as needed)          v
                      PLAN REPLACEMENT:
                      Implant / FPD / RPD
                           |
         __________________|__________________
        |                                     |
   QUESTIONABLE/POOR                  FAIR/POOR
   (5-10 yr range;                  (Borderline;
    borderline)                      but treatable)
        |                                     |
        v                                     v
  EVALUATE:                         PERIODONTAL
  - Strategic importance            TREATMENT +
  - Bone available for implant      RE-EVALUATE
  - Patient compliance              AT REASSESSMENT
  - Cost
  - Aesthetics
        |
   _____|_____
  |           |
EXTRACT     RETAIN
+IMPLANT    (as "living
             pontic" or
             with implants
             planned around)

SECTION 14: COMPARISON TABLE - VIEWPOINTS ACROSS REFERENCES

SECTION 15: IMPORTANT EXAMINER KEYWORDS (COMPILED)

• Hopeless prognosis
• Questionable prognosis
• Strategic extraction
• Crown-to-root ratio
• Furcation invasion (Grade I, II, III)
• Herodontics (discouraged when prognosis is poor - Misch)
• Living pontic (5-10 yr prognosis tooth acting as interim support - Misch)
• Tooth mortality (basis of McGuire & Nunn classification)
• Probability of periodontal stability (basis of Kwok & Caton classification)
• Episodic progression (quiescence and exacerbation)
• Biofilm-retentive factors
• Root surface area of support
• Edentulous site development
• Peri-implantitis (as counter-argument against extraction/implant)
• Patient-centered decision-making
• Interdisciplinary consultation
• Periodontal supportive therapy (PST) / Supportive periodontal therapy (SPT)
• Reassessment / Re-evaluation of prognosis
• 0-5-10 year rule (Misch protocol)
• Staging and Grading (2018 classification replacing chronic/aggressive terminology)

SECTION 16: RECENT TERMINOLOGY CHANGES

SECTION 17: SEQUENCE OF THERAPY - EXTRACTION IN TREATMENT PLAN

1. Emergency treatment (pain, acute infections)
2. Removal of nonfunctional and diseased teeth and possibly strategic extraction of healthy teeth to facilitate the prosthetic reconstruction of the patient
3. Treatment of periodontal diseases (nonsurgical or surgical)
4. Endodontic therapy (necessary and intentional)
5. Caries removal and placement of temporary and final restorations
6. Occlusal adjustment and orthodontic therapy
7. Replacement of missing teeth with removable or tooth/implant-supported fixed dental prostheses
8. Aesthetic demands
9. Sequence of therapy

"In some cases, extraction may be recommended at any step in treatment when a tooth is given a hopeless prognosis." (Newman & Carranza 14th Ed.)

SUMMARY TABLE - DETERMINANTS FOR SALVAGE vs. EXTRACTION

1. Sections 1-2: The three prognosis classification schemes - McGuire & Nunn (tooth mortality), Kwok & Caton (probability of stability), and Reddy's Essentials scheme - all with criteria tables.
2. Section 3: Point-by-point analysis of each determinant: bone loss, crown-to-root ratio, furcation grade, mobility, 2018 staging/grading, systemic factors, compliance, smoking, endodontic status, strategic value, cost, bone availability for implants, and defect morphology.
3. Sections 4-5: Newman's specific extraction/retention criteria verbatim, followed by Misch's 0-5-10 Year Rule decision protocol including the "living pontic" concept.
4. Section 6: Root resection indications and contraindications from Rose (when root resection itself favors or negates tooth retention).
5. Sections 7-10: Strategic extraction, implant vs. natural tooth comparisons, role of regeneration (including the Cortellini 2011 RCT cited in Lang & Lindhe), and aesthetic considerations.
6. Sections 11-12: Dynamic prognosis reassessment and errors in prognosis determination (the prosthodontist vs. periodontist perspective).
7. Sections 13-17: Flowchart, cross-reference comparison table, examiner keywords, 2018 terminology changes, treatment sequence placement of extraction, and master summary decision table.