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FAILURES OF PERIODONTAL THERAPY AND ITS MANAGEMENT

Comprehensive Theory Examination Notes - Postgraduate Periodontology

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SECTION 1: DEFINITION AND CONCEPT OF FAILURE IN PERIODONTAL THERAPY

• Failure of periodontal therapy is recognized clinically when a treated patient exhibits signs of recurrence of periodontal disease - defined as the reappearance or progression of disease following what was considered successful active therapy.
• The 2018 AAP/EFP classification framework introduced the concept of "clinical gingival health on a reduced periodontium in a stable periodontitis patient" as the desired end-point of successful treatment. A patient with less than 10% sites with BOP, all sites with probing depths ≤ 4 mm (with no BOP at 4 mm sites), and presence of attachment loss/bone loss due to periodontitis is considered "successfully treated."

[Newman 14th Ed, Ch. 4/Classification; lines 5450-5498]

• "Depending on their future compliance with home care and maintenance visits, patients may have a recurrence of periodontitis or maintain a healthy but reduced periodontium." [Newman 14th, line 5456]
• A failing case can be recognized by the following (Box, Newman 14th, lines 123116-123122):
  1. Recurring inflammation revealed by gingival changes and bleeding of the sulcus on probing
  2. Increasing depth of sulci, leading to the recurrence of pocket formation
  3. Gradual increases in bone loss, as determined by radiographs
  4. Gradual increases in tooth mobility, as ascertained by clinical examination

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SECTION 2: CLASSIFICATION OF FAILURES

A. By Timing of Failure (as applicable to implant therapy, Essentials Ch. 47)

[Essentials of Clinical Periodontology and Periodontics, Ch. 47, lines 53678-53706]

B. By Etiology of Recurrence (Newman 14th, lines 123098-123115)

[Newman 14th, Ch. 70, lines 123098-123115]

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SECTION 3: CAUSES / RISK FACTORS FOR FAILURE

3.1 Patient-Related Causes

• "Periodontal treatment performed in the absence of plaque control is certain to fail, resulting in disease progression or recurrence." [QuintEssentials, line 497]
• "Without adequate oral hygiene, the benefits of periodontal treatment are not likely to be maintained." [QuintEssentials, line 2352]
• Patients tend to reduce their oral hygiene efforts between appointments. "Knowing that their hygiene will be evaluated motivates them to perform better oral hygiene in anticipation of the appointment." [Newman 14th, lines 122921-122924]

• "It is well known that patients' noncompliance with supportive periodontal therapy (periodontal maintenance) is significantly associated with periodontal disease progression and tooth loss." [Newman 14th, lines 73992-73994]
• "If a patient is unwilling to perform adequate biofilm control and receive the timely periodic maintenance checkups and treatments... the dentist can refuse to accept the patient for treatment." [Newman 14th, lines 73996-73998]

• "Epidemiologic evidence suggests that smoking may be the most important environmental risk factor impacting the development and progression of periodontal disease." [Newman 14th, lines 74004-74006]
• "Patients who smoke do not respond as well to conventional periodontal therapy as patients who have never smoked. There is a dose-response effect - with the more the patient smokes, the more severe the tissue destruction and the poorer the treatment outcome." [Newman 14th, lines 74009-74012]
• "In smokers with severe periodontitis (stage III or stage IV), the prognosis may be unfavorable or hopeless." [Newman 14th, lines 74013-74015]
• "It is widely recognised that smoking is one of the most prevalent risk factors for periodontal diseases. The magnitude of the clinical change following periodontal treatment in smokers is inferior to the clinical outcome in ex-smokers and those who have never smoked." [QuintEssentials, line 424]

• patient motivation
• patient compliance
• medical risk factors
• local risk factors
• genetic predisposition to periodontal disease
• the nature of the bacterial challenge

3.2 Operator/Technical Causes

• "Incomplete calculus removal in areas of difficult access is a common source of problems." [Newman 14th, line 123108]
• "Complex root anatomy will compound the difficulty. These sites usually continue to bleed or suppurate because of the persistent inflammation and infection at the base of the pocket." [QuintEssentials, line 2372]
• "Scaling and root planing are generally not effective at sites with probing depths of 6 mm or greater." [Newman 14th, lines 122869-122870]

• "Inadequate restorations placed after the periodontal treatment was completed." [Newman 14th, line 123109-123110]
• Defective crown margins result in localised gingival inflammation. Positive crown margins result in plaque accumulation. [QuintEssentials, line 1781]
• Bridge pontics that impinge on gingival soft tissues result in plaque accumulation and inflammation. [QuintEssentials, line 1793]

• "If the biologic width is encroached by placing crown margins too far subgingivally, then inflammation and breakdown of periodontal attachment apparatus ensues until the biologic width is reestablished." [QuintEssentials, line 1789]

• "Failure of new attachment surgery" is listed as a specific cause of increased pocket depth with no radiographic change. [Newman 14th, Table 70.2, line 123247]

• Scaling and root planing may not eliminate intragingival bacteria in some areas. "These bacteria may recolonize the pocket and cause recurrent disease." [Newman 14th, lines 122872-122875]

3.3 Disease/Biologic Causes

• "Although pocket debridement suppresses components of the subgingival microflora associated with periodontitis, periodontal pathogens may return to baseline levels within days or months." [Newman 14th, lines 122903-122904]
• "The return of pathogens to pretreatment levels generally occurs in approximately 9 to 11 weeks but can vary dramatically among patients." [Newman 14th, lines 122905-122907]
• "Recolonisation of periodontal pockets with periodontal pathogens occurs rapidly following antimicrobial therapy." [QuintEssentials, line 1885]

• "Inadequate subgingival biofilm control can lead to continued loss of attachment, even without the presence of clinical gingival inflammation." [Newman 14th, lines 122867-122869]

• "Histologic studies have indicated that after periodontal procedures, tissues usually heal by the formation of a long junctional epithelium instead of new connective tissue attachment to root surfaces."
• "It has been speculated that this type of dentogingival unit may be weaker and that inflammation may rapidly separate the long junctional epithelium from the tooth."
• "Thus treated periodontal patients may be predisposed to recurrent pocket formation if maintenance care is not optimal." [Newman 14th, lines 122882-122895]

• "Bacteria associated with periodontitis can be transmitted between spouses and other family members. Patients who appear to be successfully treated can become infected or reinfected with potential pathogens. This is especially likely in patients with remaining pockets." [Newman 14th, lines 122876-122879]

• "Bacteria are present in the gingival tissues in chronic and aggressive periodontitis cases. Eradication of intragingival microorganisms may be necessary for a stable periodontal result. Scaling, root planing, and even flap surgery may not eliminate intragingival bacteria in some areas." [Newman 14th, lines 122871-122874]

• "Presence of some systemic diseases that may affect host resistance to previously acceptable levels of biofilm." [Newman 14th, line 123115]
• "Poorly controlled diabetic patients (Hb A1c >10%) often have a poor response to treatment, with more postoperative complications and less favorable long-term results." [Carranza 10th, lines 42456-42457]

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SECTION 4: CLINICAL INDICATORS / SYMPTOMS OF FAILURE

TABLE: Symptoms and Causes of Recurrence of Disease (Newman 14th, Table 70.2, lines 123204-123254)

[Newman 14th, Ch. 70, Table 70.2]

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SECTION 5: REFRACTORY PERIODONTITIS

5.1 Definition and Significance

• "The existence of refractory periodontitis as a diagnostic consideration indicates that some patients do not respond to conventional therapy, which may include root planing, surgery, or both." [Newman 14th, lines 90692-90694]
• "Both [refractory periodontitis and recurrent periodontitis] tend to result in continued periodontal destruction despite conventional therapy." [QuintEssentials, line 1899]
• "Refractory periodontitis is most likely to be due to a number of host factors, such as smoking, stress or specific immune defects rather than the presence of a particular microflora." [QuintEssentials, line 1899]

5.2 Terminology Change - IMPORTANT EXAMINER NOTE

Recent Terminology Change: The terms "Refractory Periodontitis," "Adult Periodontitis," and "Rapidly Progressive Periodontitis" were terminology used in the older 1989 classification. In the 1999 International Workshop classification, these were reorganized, and terms like "refractory periodontitis" were retained as a separate category. In the 2018 AAP/EFP Classification, "refractory periodontitis" is no longer recognized as a separate disease entity. Instead, cases of continued attachment loss are now evaluated within the Staging and Grading framework - specifically Grade C (rapid rate of progression) may be relevant. [Newman 14th, lines 6031-6032; lines 90692-90697]

5.3 Features of Refractory Periodontitis

• Patients with aggressive periodontitis, refractory periodontitis, and type 1 diabetes mellitus often possess the MØ+ phenotype (macrophage hyper-inflammatory phenotype) - characterized by elevated levels of prostaglandin E2 and IL-1β. [Newman 14th, lines 50291-50294]
• High-risk patient populations (diabetic patients, patients with refractory periodontal disease) have benefited from the systemic administration of MMP inhibitors (e.g., low-dose doxycycline). [Newman 14th, lines 23173-23175]

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SECTION 6: FLOWCHART - CLINICAL PATHWAY FOR MANAGING FAILURE

COMPLETION OF ACTIVE PERIODONTAL THERAPY (Steps 1-3)
              |
              v
PERIODONTAL RE-EVALUATION (4-6 weeks post therapy)
              |
              v
     ┌────────────────────────────────────────┐
     |       ASSESS RESPONSE TO THERAPY       |
     └────────────────────────────────────────┘
              |
     ┌────────┴────────────┐
     v                     v
ADEQUATE RESPONSE       INADEQUATE RESPONSE
(Pockets ≤3mm,          (Residual pockets ≥6mm;
no BOP, CAL stable)     or PD ≥4mm with BOP)
     |                     |
     v                     v
ENROLL IN SPT (Step 4)  ┌──────────────────────────────────┐
(recall every 3 months) | Reassess risk factors:            |
                        | - Plaque control adequate?        |
                        | - Patient compliant?              |
                        | - Risk factors controlled?        |
                        | - Technical errors corrected?     |
                        └──────────────────────────────────┘
                                      |
                         ┌────────────┴───────────────┐
                         v                             v
                  CAUSE IDENTIFIABLE           HOST FACTORS DOMINANT
                  (Calculus, plaque,           (Smoking, systemic disease,
                  defective restoration)        genetic susceptibility,
                         |                       refractory disease)
                         v                             v
                  RETREATMENT:                 MEDICAL MANAGEMENT:
                  - Re-instrumentation         - Smoking cessation
                  - Corrective surgery         - Medical co-management
                  - Restoration replacement    - Sub-antimicrobial dose
                  - Local delivery adjuncts      doxycycline (SDD)
                  - Systemic antibiotics       - Antimicrobials guided by
                    (if specific pathogens)      culture & sensitivity

[Newman 14th Ch. 44, 70; QuintEssentials Ch. 7; Lang & Lindhe 6th Ch. 60]

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SECTION 7: RESIDUAL POCKETS AND THEIR SIGNIFICANCE IN FAILURE

• "The enumeration of residual pockets with a PPD of >4 mm represents, to a certain extent, the degree of success of the periodontal treatment rendered." [Lang & Lindhe 6th, lines 127471-127474]
• "Patients who have residual deep probing depths (≥6 mm) or probing depths ≥4 mm with bleeding on probing may require additional periodontal therapy and should progress to the third step of periodontal therapy [surgical therapy]." [Newman 14th, lines 76061-76063]
• The critical probing depth concept: "The concept of the critical probing depth of 5.4 mm has been advanced to assist in making the determination to proceed to surgical intervention. This is the measurement above which surgical therapy will result in clinical attachment gain and below which it will result in clinical attachment loss." [Newman 14th, lines 75628-75632]
• Adjunctive local delivery agents may be used in maintenance patients with remaining pockets. [Newman 14th, lines 123095-123096]

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SECTION 8: SUPPORTIVE PERIODONTAL THERAPY (SPT) - FAILURE PREVENTION

8.1 Rationale

• "Preservation of the periodontal health of the treated patient requires a supportive program that is just as important as the therapy used to treat the periodontal disease." [Newman 14th, lines 122742-122744]
• "The long-term preservation of the dentition is closely associated with the frequency and quality of recall maintenance." [Newman 14th, lines 122749-122751]
• "Periodic recall visits form the foundation of a meaningful long-term prevention program. The interval between visits is usually set at 3 months but may vary according to the patient's needs." [Newman 14th, lines 122940-122941]

8.2 Components of the SPT Appointment (Newman 14th, Box 70.1)

• Patient greeting, medical history changes, oral pathologic examination
• Oral hygiene status, gingival changes, pocket depth changes
• Radiographic evaluation (see Table below)

• Scaling and root planing as indicated
• Plaque/biofilm control instruction and correction
• Local antimicrobial delivery if indicated

• Schedule for next recall, additional periodontal treatment, or restorative procedures

8.3 Radiographic Protocol During SPT (Newman 14th, Table 70.1)

[Newman 14th, Ch. 70, Table 70.1]

8.4 Goals of Supportive Periodontal Care (SPC) per AAP 1998 (QuintEssentials)

• To prevent or minimise the recurrence and progression of periodontal disease in patients previously treated for gingivitis, periodontitis, and peri-implantitis
• To prevent or reduce the incidence of tooth loss by monitoring the dentition and any prosthetic replacements
• To increase the chance of locating and treating, in a timely manner, other diseases or conditions found within the oral cavity

[QuintEssentials, lines 2250-2256]

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SECTION 9: CLASSIFICATION OF POST-TREATMENT PATIENTS AND RISK ASSESSMENT

9.1 Classification by Disease Severity (Newman 14th, Learning Box 70.7)

[Newman 14th, lines 123430-123432, 123452-123463]

9.2 Periodontal Risk Assessment (PRA) - Lang & Tonetti Model

[Lang & Lindhe 6th, Ch. 60, lines 127045-127062; 127719-127733]

• Low PR: All parameters within low-risk OR at most one in moderate-risk
• Moderate PR: At least two in moderate category, but at most one in high-risk
• High PR: At least two parameters in the high-risk category

[Lang & Lindhe 6th, lines 127726-127733]

9.3 Key Risk Indicators for Recurrence

• Bleeding on Probing (BoP): "A BoP prevalence of 25% was the cut-off point between patients with maintained periodontal stability for 4 years and patients with recurrent disease in the same timeframe (Joss et al. 1994)." [Lang & Lindhe 6th, lines 127449-127453]
• "Individuals with low mean BoP percentages (<10% of the surfaces) may be regarded as patients with a low risk for recurrent disease (Lang et al. 1990), while patients with mean BoP percentages of >25% should be considered to be at high risk for re-infection." [Lang & Lindhe 6th, lines 127465-127469]
• Smoking: "While non-smokers (NS) and former smokers (FS) (>5 years since cessation) have a relatively low risk for recurrence of periodontitis, heavy smokers (HS), as defined by smoking more than one pack per day, are definitely at high risk." [Lang & Lindhe 6th, lines 127711-127714]
• Patients with high-risk profile after active periodontal therapy were more prone to recurrence of periodontitis and to tooth loss than those with moderate- or low-risk profile. (Matuliene et al. 2010; Eickholz et al. 2008) [Lang & Lindhe 6th, lines 127744-127747]

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SECTION 10: DECISION TO RETREAT - TIMING AND CRITERIA

• "The decision to retreat a periodontal patient should not be made at the preventive maintenance appointment but should be postponed for 1 to 2 weeks. Often, the mouth appears improved at that time because of the resolution of edema and the resulting improved tone of the gingiva." [Newman 14th, lines 123123-123127]
• "The first year after periodontal therapy is important in terms of indoctrinating the patient in a recall pattern and reinforcing oral hygiene techniques... some areas may have to be retreated because the results may not be optimal." [Newman 14th, lines 123183-123186]
• "For first-year patients, the recall interval should not be longer than 3 months." [Newman 14th, line 123192]

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SECTION 11: MANAGEMENT OF FAILURE - TREATMENT OPTIONS

11.1 Flowchart - Non-Surgical Re-treatment

FAILED NON-SURGICAL SITE IDENTIFIED
              |
     ┌────────┴──────────────────────────┐
     v                                   v
ACCESSIBLE SITE                    INACCESSIBLE SITE
(shallow/moderate pockets)         (deep pocket ≥6mm; complex anatomy)
     |                                   |
     v                                   v
Re-instrumentation                Periodontal Surgery
(scaling/root planing)            (Access Flap / Modified Widman Flap /
+/- local delivery adjunct        Resective / Regenerative Surgery)

[QuintEssentials, lines 2370-2374; Newman 14th, lines 76065-76110]

11.2 Surgical Management of Failure Sites

[Newman 14th, Ch. 44, lines 76065-76110]

11.3 Adjunctive Antimicrobial Management of Failure

A. Rationale for Systemic Antibiotics in Failure Management

• "Bacteria can invade periodontal tissues, thereby making mechanical therapy alone sometimes ineffective." [Newman 14th, lines 90385-90387]
• "Antibiotic treatment should be reserved for specific subsets of periodontal patients who do not respond to conventional therapy. The selection of specific agents should be guided by the results of cultures and sensitivity tests for subgingival plaque microorganisms." [Newman 14th, lines 90953-90956]

B. Antibiotics Used in Refractory/Failing Cases (Newman 14th)

C. Refractory Periodontitis - Specific Antibiotic Notes

• "Studies of the metronidazole-ciprofloxacin drug combination for the treatment of refractory periodontitis have documented marked clinical improvement. This combination may provide a therapeutic benefit by reducing or eliminating pathogenic organisms and a prophylactic benefit by giving rise to a predominantly streptococcal microflora." [Newman 14th, lines 90948-90951]
• "Clindamycin has demonstrated efficacy in patients with periodontitis that are refractory to tetracycline therapy. Walker and colleagues showed that clindamycin helped stabilize refractory patients." [Newman 14th, lines 90825-90827]
• "Studies investigating adjunctive antibiotics in the treatment of refractory periodontitis have provided conflicting data. There is no clear answer as to whether adjunctive antibiotics are beneficial, or which antibiotic should be used. This is because of the variable nature of the periodontal microflora amongst patients diagnosed with refractory periodontitis, together with the importance of other host factors." [QuintEssentials, lines 1899-1900]

D. Current Evidence-Based Recommendation (Newman 14th, lines 76048-76053)

• "The current body of evidence for the use of systemic antimicrobials only supports the use of specific antimicrobials (amoxicillin and metronidazole) for specific patient categories (stage III or stage IV in a molar incisor pattern or generalized disease in a young patient)."
• "In select cases where the combination of amoxicillin and metronidazole were utilized, there was a significant reduction in probing depth when used as an adjunct to mechanical therapy with significant pocket closure, reduction in BOP, and CAL gain at 6 and 12 months."

E. Local Delivery Systems in Failure Management

• Localised recurrent pockets in a patient in supportive phase of periodontal care
• Non-responding sites following non-surgical periodontal therapy
• Peri-implantitis
• Localised suppurating pockets

11.4 Host Modulation Therapy in Failure

• Sub-antimicrobial dose doxycycline (SDD): 20 mg doxycycline twice daily for up to 9 months. "At this dose, doxycycline has no detectable antimicrobial efficacy... a 20mg dose appears to exert its therapeutic effect not as an antibiotic, but as a collagenase inhibitor." Collagenases (MMPs) are produced in elevated quantities in periodontitis and are responsible for breakdown of periodontal structures. [QuintEssentials, lines 1961-1963]
• MMP inhibitors (low-dose doxycycline) used in combination with scaling and root planing or surgical therapy in refractory/high-risk patients (e.g., diabetic patients). [Newman 14th, lines 23170-23175]
• Bisphosphonates (e.g., alendronate) - inhibit osteoclast activity and significantly reduce bone resorption in periodontitis. "Research in this subject is at an early stage." [QuintEssentials, lines 1965-1967]

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SECTION 12: ANTIBIOTIC RESISTANCE AS A CAUSE OF FAILURE

• "The emergence of resistant pathogens is of concern not only in medicine, but also in dentistry as it may be one reason for treatment failure." [Antibiotics and Antiseptics in Periodontal Therapy, line 1316]
• "The level of resistance varies between countries, which can be attributed to the different use of antibiotics." [Antibiotics text, lines 1323-1324]
• "Bacterial resistance in subgingival plaque samples from adult periodontitis patients against a number of common antibiotics was higher in Spain than in the Netherlands for penicillin, amoxicillin, metronidazole, clindamycin, and tetracycline." [Antibiotics text, lines 1325-1328]
• "An overall increased frequency of tetracycline resistance has been recently reported... especially in countries with unrestricted antimicrobial use, and it is suggested that bacteriostatic drugs may not be suitable for treating biofilm infections. This may be one of the causes of treatment failure of periodontitis when using this drug." [Antibiotics text, lines 8179-8185]
• "The common and indiscriminate use of antibiotics worldwide has contributed to increasing numbers of resistant bacterial strains since the late 1990s." [Newman 14th, lines 90425-90426]
• "At least one Antibiotic Resistance Gene (ARG) has been identified in a majority of the population in a cross-sectional study, and the disease sites exhibited a further increase in prevalence of these ARGs." [Newman 14th, lines 90432-90433]

Mechanisms of Tetracycline Resistance (Antibiotics text):

1. Efflux pump: Actively removes the drug from the bacterial cell - "common mechanism for the conveyance of resistance to tetracycline and, to a lesser extent, to doxycycline"
2. Ribosome protection: Tetracycline antibiotics are not removed from the bacterial cell but are prevented from binding to the 30S ribosomal subunit - "generally conveys resistance equally to all tetracyclines"

[Antibiotics text, lines 8170-8178]

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SECTION 13: FAILURE IN SPECIFIC DISEASE CONDITIONS

13.1 Refractory Periodontitis - Comprehensive Management Flowchart

PATIENT WITH CONTINUED ATTACHMENT LOSS DESPITE CONVENTIONAL THERAPY
                          |
             ┌────────────┴─────────────┐
             v                          v
   RE-EVALUATE THOROUGHLY         EXCLUDE INADEQUATE:
   (Clinical + radiographic)      - Compliance
                                  - Plaque control
                                  - Incomplete treatment
                                  - Systemic disease control
                          |
                          v
        ASSESS MICROBIOLOGICAL PROFILE
        (Subgingival cultures + sensitivity tests)
                          |
             ┌────────────┴──────────────┐
             v                           v
   SPECIFIC PATHOGEN                HOST-FACTOR DOMINANT
   IDENTIFIED                       (smoking, stress, immune defect)
        |                                |
        v                                v
   TARGETED ANTIBIOTIC              MANAGE HOST FACTORS:
   THERAPY:                         - Smoking cessation
   - Metronidazole + Amoxicillin    - Stress management
   - Metronidazole + Ciprofloxacin  - SDD (low-dose doxycycline)
   - Clindamycin (if tetracycline   - MMP inhibitors
     resistant)                     - Immunomodulation (future)

[Newman 14th, Ch. 53; QuintEssentials Ch. 7]

13.2 Chronic Periodontitis Failing Therapy

• "Systemic antibiotics are not indicated in the management of cases of chronic periodontitis. Studies have not established with any certainty whether RSI and systemic antibiotics result in any treatment benefit compared to RSI alone." [QuintEssentials, line 1885]

13.3 Aggressive Periodontitis - Tendency to Fail

• Aa (A. actinomycetemcomitans) invades the gingival soft tissues - "Invasion of the tissues affords the organism a degree of protection from root surface instrumentation (RSI) and allows for rapid recolonisation of the instrumented root surface." [QuintEssentials, line 1893]
• "The recent development of tetracycline-resistant strains of Aa has led some researchers to switch to an antibiotic regimen of metronidazole (400 mg 3x/day) and amoxicillin (250 mg 3x/day) for 7 days as an adjunct to full mouth RSI." [QuintEssentials, line 1893]
• "The metronidazole-amoxicillin and metronidazole-Augmentin combinations provided excellent elimination of many organisms in adults with LAP who had been treated unsuccessfully with tetracyclines and mechanical debridement." [Newman 14th, lines 90935-90937]
• "Although 50% of patients who were treated with this [metronidazole + amoxicillin] regimen harbored A. actinomycetemcomitans 1 year later." [Newman 14th, lines 90940-90942]

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SECTION 14: COMPARISON TABLE - DIFFERENT REFERENCE VIEWPOINTS

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SECTION 15: REFERRAL CRITERIA - WHEN TO REFER TO SPECIALIST

1. Pockets of 5 mm or more as measured from the CEJ - these teeth may have a questionable prognosis
2. Teeth with furcation invasions even when more than 50% of bone support remains
3. Patients with strategically important teeth with moderate to severe attachment loss or furcation invasions
4. Extent and severity of the disease process - amount of bone loss even in localized areas
5. Root length - short-rooted teeth are jeopardized to a greater extent by the 5-mm CAL criterion
6. Periodontal surgery indicated but not performed for medical, psychological, or financial reasons
7. Many teeth with less than 50% of alveolar bone support
8. Condition too far advanced to be improved by periodontal surgery
9. Smoking / positive family history or genetic test

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SECTION 16: RECENT TERMINOLOGY CHANGES - EXAMINER ALERT

[Newman 14th, lines 5467-5473; 6031; QuintEssentials, line 1887]

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SECTION 17: ADDITIONAL EXAMINER-IMPORTANT POINTS

1. "Periodontal treatment performed in the absence of plaque control is certain to fail, resulting in disease progression or recurrence." [QuintEssentials] - a critical examiner statement.
2. Plaque-infected dentitions will yield recurrence in multiple locations, while dentitions under plaque control and regular supportive care maintain periodontal stability for many years. (Rosling et al. 1976; Axelsson & Lindhe 1981) [Lang & Lindhe 6th]
3. Combination antibiotics (serial vs. simultaneous): "Antibiotics that are bacteriostatic (e.g., tetracycline) generally require rapidly dividing microorganisms to be effective. They do not function well if a bactericidal antibiotic (e.g., amoxicillin) is given concurrently. When both types of drugs are required, they are best given serially rather than in combination." [Newman 14th, lines 90927-90931]
4. Subgingival scaling alters microflora temporarily: "Reported alterations included a decrease in the proportion of motile rods for 1 week, a marked elevation in the proportion of coccoid cells for 21 days, and a marked reduction in the proportion of spirochetes for 7 weeks." [Newman 14th, lines 122898-122901]
5. Antibiotic-resistance gene (ARG) concern: The overuse, misuse, and widespread prophylactic application of anti-infective drugs are some of the factors that have led to the emergence of resistant microorganisms. Increasing levels of resistance of subgingival microflora to antibiotics have been correlated with the increased use of antibiotics in individual countries. [Newman 14th, lines 90427-90431]
6. "Surgery should not be undertaken unless the patient participates in disease prevention and demonstrates proficiency in plaque/biofilm control." [Newman 14th, line 123103]
7. An ideal antibiotic for periodontal use should be: specific for periodontal pathogens, allogenic, nontoxic, substantive, not in general use for the treatment of other diseases, and inexpensive. "Currently, however, an ideal antibiotic for the treatment of periodontal disease does not exist." [Newman 14th, lines 90403-90407]
8. Biofilm resistance to antibiotics: "Bacterial species residing in biofilms are much more resistant to antibiotics than the same species in a planktonic state." [Antibiotics text, lines 1301-1302]

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SECTION 18: SUMMARY - KEY POINTS FOR EXAMINATION

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• Newman MG, Takei HH, Klokkevold PR, Carranza FA. Newman and Carranza's Clinical Periodontology and Implantology. 14th ed. Elsevier, 2023.
• Newman MG, Takei HH, Carranza FA. Carranza's Clinical Periodontology. 10th ed. Saunders, 2006.
• Lang NP, Lindhe J. Clinical Periodontology and Implant Dentistry. 6th ed. Wiley-Blackwell, 2015.
• Heasman PA, Preshaw PM, Robertson P. Successful Periodontal Therapy: A Non-Surgical Approach. Quintessentials of Dental Practice, 2004.
• Reddy S. Essentials of Clinical Periodontology and Periodontics. 4th ed. Jaypee, 2017.
• Rose LF et al. Periodontics: Medicine, Surgery, and Implants. Mosby, 2004.
• Herrera D, Matesanz P, Martín C, Oud V, Feres M, Teughels W. Antibiotics and Antiseptics in Periodontal Therapy. 2020.