Scaling and Root Debridement: Principles and Re-evaluation

Core Review

Terminology Evolution

The term "root planing" historically implied intentional removal of cementum to achieve a smooth, glass-like root surface. Current evidence has shifted this paradigm:

• Historical concept: Remove all cementum (which was thought to be "contaminated" with endotoxin) to create a biologically acceptable root surface
• Current evidence: Endotoxin (lipopolysaccharide/LPS) is loosely adherent to the root surface and can be removed without aggressive cementum removal. Cementum removal is unnecessary and may cause dentinal hypersensitivity
• Current goal: Disrupt and remove the subgingival biofilm and calculus deposits while preserving tooth structure. The endpoint is a biologically compatible root surface, not necessarily a glass-smooth surface

Current accepted terminology: "Scaling and root debridement" (SRD) or "non-surgical periodontal therapy" is preferred over "scaling and root planing." The NBDHE may use both terms, but the concept tested is biofilm disruption with minimal cementum removal.

Goals of Scaling and Root Debridement

SRD has specific, measurable goals:

1. Disruption and removal of subgingival biofilm — the primary etiologic factor
2. Removal of supragingival and subgingival calculus — a secondary contributing factor that harbors biofilm
3. Elimination or reduction of inflammation — measured by reduction in BOP
4. Reduction in probing depths — tissue shrinkage and reattachment
5. Gain in clinical attachment — formation of long junctional epithelium
6. Arrest of disease progression — stabilization of CAL over time
7. Creation of an environment the patient can maintain — smooth root surfaces and shallow pockets are easier to clean

The Healing Response

After SRD, the periodontium goes through a predictable healing sequence:

Week 1: Initial healing

• Clot formation in the pocket
• Acute inflammatory response
• Epithelial migration begins from the wound margins

Weeks 1-2: Early healing

• Granulation tissue formation
• Epithelial cells migrate apically along the root surface
• New connective tissue begins forming

Weeks 2-4: Intermediate healing

• Collagen deposition and maturation
• Epithelial attachment (long junctional epithelium) forms
• Probing depths begin to decrease as tissue tightens
• BOP decreases as inflammation resolves

Weeks 4-6: Established healing

• Tissue maturation
• The junctional epithelium is firmly attached to the root surface
• Probing depths stabilize
• This is the OPTIMAL TIME for re-evaluation

Beyond 6 weeks:

• Further gains in clinical attachment are unlikely without additional intervention
• If probing depths remain deep (≥5 mm) with BOP at re-evaluation, the response is inadequate

The attachment formed after SRD is a LONG JUNCTIONAL EPITHELIUM, not a new connective tissue attachment. True regeneration (new cementum, periodontal ligament, and bone) requires surgical techniques with biologics (bone grafts, guided tissue regeneration, enamel matrix derivatives).

Re-evaluation Protocol

Re-evaluation is a critical step in the process of care. Key principles:

Timing: 4-6 weeks after completion of SRD. This allows adequate healing time while still permitting timely identification of non-responding sites.

Comprehensive re-evaluation includes:

• Medical history update
• Vital signs
• Review of home care compliance
• Full-mouth probing depths (compare to baseline)
• Full-mouth BOP (compare to baseline)
• Clinical attachment level (compare to baseline)
• Mobility assessment
• Furcation assessment
• Plaque index
• Any persistent signs/symptoms

Re-evaluation outcomes:

1. Adequate response (proceed to maintenance):
   • Significant reduction in probing depths (≥2 mm at most previously deep sites)
   • Significant reduction in BOP (<15-20% of sites)
   • Stabilization or gain in CAL
   • Adequate patient self-care
   • Appropriate continuing care interval (typically 3-4 months initially)

1. Partial response (consider re-treatment or additional therapy):
   • Some sites responded, but others remain with PD ≥5 mm + BOP
   • May benefit from re-instrumentation of non-responding sites
   • May consider local antibiotic delivery (e.g., Arestin/minocycline microspheres, Atridox/doxycycline, PerioChip/chlorhexidine)
   • Re-re-evaluate in 4-6 weeks

1. Inadequate response (refer for periodontal surgical consultation):
   • Persistent PD ≥5 mm with BOP at multiple sites despite adequate SRD
   • Progressive CAL loss
   • Persistent suppuration
   • Furcation involvement not manageable with non-surgical treatment
   • Intrabony defects that may benefit from surgical access and regeneration

Factors Influencing Treatment Response

Favorable prognostic factors:

• Good patient compliance with oral hygiene
• Non-smoker or successful tobacco cessation
• Well-controlled systemic conditions (diabetes with HbA1c <7%)
• Shallow to moderate probing depths (≤6 mm)
• Horizontal bone loss pattern
• Single-rooted teeth
• Non-furcation involved teeth
• Accessible root surfaces

Unfavorable prognostic factors:

• Poor patient compliance
• Current smoker
• Poorly controlled diabetes (HbA1c ≥7%)
• Deep probing depths (≥7 mm)
• Vertical/angular bone defects
• Furcation involvement (Class II or greater)
• Multi-rooted teeth
• Root concavities and grooves
• Thin gingival biotype

Full-Mouth vs. Quadrant Approaches

Quadrant-by-quadrant approach (traditional):

• One quadrant treated per appointment
• Local anesthesia used
• Allows focused, thorough debridement
• Patient comfort during and after procedure
• Total treatment: typically 4 appointments (one per quadrant), completed over 4-6 weeks

Full-mouth disinfection (one-stage):

• All quadrants treated within 24 hours (one or two appointments)
• Rationale: Prevents reinfection of treated sites from untreated sites
• May include use of chlorhexidine for additional chemical disinfection
• More demanding for patient and clinician
• Evidence suggests similar outcomes to quadrant approach in most patients

Full-mouth ultrasonic debridement:

• All quadrants completed in a single appointment using primarily ultrasonic instrumentation
• Less operator fatigue
• Similar clinical outcomes to quadrant-by-quadrant with hand instruments

The NBDHE recognizes that all approaches have evidence support and that the choice depends on patient factors, clinician preference, and practice setting.

Local Anesthesia in SRD

• SRD is inherently uncomfortable due to instrumentation of inflamed, sensitive subgingival tissues
• Local anesthesia is the standard of care for SRD
• Allows thorough debridement without modifying technique due to patient discomfort
• Topical anesthesia alone is insufficient for subgingival instrumentation
• Patients should be informed that post-treatment sensitivity and mild discomfort are common for 24-72 hours

Post-Treatment Instructions

Patients should be counseled on:

• Mild discomfort and sensitivity to cold for 24-72 hours (normal)
• Warm salt water rinses (1/2 teaspoon salt in 8 oz warm water) 2-3 times daily for comfort
• Continue gentle brushing and flossing (avoid treated areas if significantly tender for first 24 hours)
• Avoid extremely hot, cold, or hard foods for 24 hours
• Use desensitizing toothpaste if sensitivity persists beyond a few days
• Report unusual bleeding, severe pain, or signs of infection

Clinical Application

A 52-year-old patient with Stage III, Grade B generalized periodontitis completes quadrant SRD over 4 appointments. At 5-week re-evaluation:

• Responding sites: Probing depths decreased from 5-6 mm to 3-4 mm; BOP reduced from 65% to 15%
• Non-responding sites: Tooth #19 mesial: PD 7 mm (was 7 mm pre-treatment), BOP present. Tooth #30 buccal furcation: PD 6 mm with BOP, Class II furcation

Plan:

• Overall response is favorable — most sites responded well
• Non-responding sites require additional therapy
• Re-instrumentation of #19 mesial and #30 buccal; consider local antibiotic delivery in the deep, non-responding pocket
• Re-evaluate #19 and #30 specifically in 4 weeks
• If still non-responsive, refer for periodontal surgical consultation
• Patient enters 3-month continuing care for responding sites

Common Traps

• TRAP: Thinking SRD requires removal of all cementum. Current evidence says endotoxin is surface-associated and easily removed without aggressive cementum removal.
• TRAP: Re-evaluating too early (before 4 weeks). Insufficient healing time yields misleading results.
• TRAP: Assuming that probing depth reduction = attachment gain. If recession increases as probing depth decreases, CAL may be unchanged.
• TRAP: Not re-evaluating at all. SRD is not the endpoint; re-evaluation determines the next phase of treatment.
• TRAP: Performing SRD without local anesthesia. This compromises thoroughness and patient comfort.