Osseous Surgeries in Periodontics

Classification

1. Additive (Regenerative) Osseous Surgery

2. Subtractive (Resective) Osseous Surgery

Resective Osseous Surgery - Core Procedures

Bony Architecture Concepts

• Positive architecture - Normal/ideal; interproximal bone coronal to facial/lingual bone
• Negative (reverse) architecture - Facial/lingual bone coronal to interproximal bone; abnormal
• Flat architecture - Interproximal and facial/lingual bone at the same level

Classification of Bony (Osseous) Defects

Indications for Osseous Surgery

• Residual pocketing (>4 mm) after completion of non-surgical therapy (scaling and root planing)
• Shallow to moderate bone loss (2-3 mm)
• Infrabony pockets with 1 or 2 bony walls
• Moderate-length root trunks
• Furcation defects (Class I/II) amenable to resection
• Elimination of bony exostoses, ledges, and irregular contours

• Deep localized bone defects (>3 mm) - regenerative surgery preferred
• Anterior maxilla - avoided due to esthetic concerns (gingival recession)
• Advanced attachment loss with deep intrabony defects
• Patients where tooth extraction is the better option

Surgical Technique (Resective Osseous Surgery)

1. Flap reflection - Full-thickness mucoperiosteal flap raised (alternatively, split-thickness flap in fiber retention osseous surgery)
2. Root debridement - Thorough scaling and root planing
3. Soft tissue removal from defects using curettes, ultrasonic scalers, or small burs
4. Osteoplasty first - Bony ledges, shelves, and exostoses removed with round surgical burs
5. Ostectomy - Using end-cutting burs, bone removed toward the lingual side to the depth of interproximal defect
6. Contouring - Establish positive architecture on mid-facial and mid-lingual aspects
7. Flap closure - Sutured at or slightly apical to the crest of bone

Variant: Fiber Retention Osseous Resective Surgery (FROSS)

• Similar pocket depth reduction compared to conventional osseous surgery
• Less gingival recession
• Less dentinal hypersensitivity

Additive Osseous Surgery - Regenerative Procedures

Bone Grafts

Guided Tissue Regeneration (GTR)

• Uses a membrane (resorbable or non-resorbable) to exclude epithelium and connective tissue
• Allows selective repopulation of the root surface by periodontal ligament cells
• Best for 3-wall and combined defects
• Non-resorbable membranes (e.g., PTFE/ePTFE) require a second surgery for removal
• Resorbable membranes (collagen, polylactic acid) eliminate second surgery

Biologics

• Enamel matrix derivatives (EMD) - Emdogain; promotes cementum regeneration
• Platelet-rich plasma/fibrin (PRP/PRF) - Autologous growth factors
• rhPDGF-BB (GEM 21S) - Recombinant human PDGF with beta-TCP scaffold

Selection of Treatment Technique

• 1-wall angular defects - Resective recontouring
• 3-wall narrow deep defects - Regenerative (best outcome)
• 2-wall angular defects - Either method based on depth, width, configuration
• Interproximal craters (2-wall) - Resection effective for shallow defects; regeneration for deeper ones
• Wide shallow defects - Resective surgery

Expected Outcomes

• Significant pocket depth reduction in pockets >4 mm
• Mean attachment loss circumferentially: ~0.6 mm (properly applied)
• Gingival recession is an expected consequence
• High long-term predictability when patient selection is appropriate

• Variable bone fill (best in 3-wall defects)
• Clinical attachment level gain
• Improved long-term tooth prognosis in deep intrabony defects

Summary Table

Latest Clinical Guidelines: Resective vs. Regenerative Osseous Surgery

1. The Overarching Framework (EFP S3-Level Guidelines)

• Step 1-2 (non-surgical therapy): Scaling and root planing + behavioral modification
• Re-evaluation at 8-12 weeks: Assess residual pocketing and bleeding on probing
• Surgical threshold: Sites with probing depth >5 mm with bleeding on probing after non-surgical therapy are candidates for surgery
• For residual deep pockets with complex defects, the guideline supports flap surgery + regenerative procedures for deep intrabony defects, with regenerative therapy (GTR or enamel matrix derivatives) recommended when an adequate RCT base exists

2. Primary Decision Driver: Defect Morphology

Defect Depth

• Greater initial defect depth predicts more radiographic bone gain after regenerative surgery
• Narrower defect angle and more bony walls both independently improve CAL gain and bone fill at 12 months
• These associations held irrespective of the biomaterial used - defect anatomy matters more than the choice of graft or membrane

Wall Count and Geometry

• Number of walls
• Defect depth
• Extension to buccal/lingual surfaces

3. Defect Depth Threshold

• Intrabony component ≤3 mm - resective approach appropriate; small defect can be flattened by osteoplasty without unacceptable bone sacrifice
• Intrabony component >3 mm - resective surgery alone is not recommended; regenerative surgery or extraction should be considered
• Infrabony pockets with deep narrow defects - regenerative surgery achieves the best long-term tooth survival

4. Furcation Involvement

5. Esthetic Zone Considerations

• Resective surgery in the anterior maxilla is generally avoided due to inevitable gingival recession exposing root surfaces with poor esthetic outcomes
• In esthetic zones, regenerative surgery or conservative flap debridement is strongly preferred
• The EFP guideline states regenerative procedures should be performed by clinicians with advanced training given technical complexity (MDPI Advances in Regenerative Therapies)

6. Patient-Level Factors

7. FibReORS - The Modern Hybrid Option (2025 Update)

• Uses a split-thickness flap to preserve supracrestal connective tissue fibers
• Allows more coronal positioning of the base of the defect
• Reduces supporting bone removal compared to traditional ostectomy
• Achieves similar pocket depth reduction with less recession and less dentinal hypersensitivity
• Represents a paradigm shift treating the mineralized and unmineralized connective tissue complex as a unit

8. Synthesized Decision Algorithm (Current Evidence)

Residual pocket after non-surgical therapy
            │
    ┌───────▼────────┐
    │ Defect type?   │
    └───────┬────────┘
            │
    ┌───────▼──────────────────────────────────┐
    │ Suprabony (horizontal bone loss)?         │──► Resective (osteoplasty/ostectomy)
    └───────┬──────────────────────────────────┘
            │ Infrabony
    ┌───────▼────────────────────────────┐
    │ Wall count and depth?              │
    └───────┬────────────────────────────┘
            │
    1-wall or 2-wall shallow (<3 mm) ──────────► Resective
    2-wall deep (>3 mm) + narrow angle ────────► Regenerative preferred
    3-wall narrow deep ────────────────────────► Regenerative (best outcomes)
    Furcation Class I-II (accessible) ─────────► Resective or regenerative
    Furcation Class III ────────────────────────► Resective/extraction
            │
    + Overlay patient factors (smoking, compliance, esthetics, strategic value)

Key Evidence Summary

Peri-Implantitis: Management Strategies

2025 Landmark Guideline: AO/AAP Consensus

Risk Factors and Etiology

• History of periodontitis (strongest risk factor)
• Smoking
• Uncontrolled diabetes
• Poor biofilm/plaque control
• Obesity

• Implant malposition
• Unfavorable prosthetic factors (overhangs, subgingival cement excess)
• Suboptimal peri-implant soft tissue phenotype (thin/deficient keratinized mucosa)
• Lack of regular maintenance

Classification of Peri-Implant Bone Defects

Stepwise Management Framework

STEP 1 - Risk Factor Modification and Patient Education

• Smoking cessation counseling
• Glycemic control in diabetics
• Oral hygiene instruction and reinforcement
• Correction of prosthetic risk factors (removal of subgingival cement, prosthesis redesign if needed)

STEP 2 - Non-Surgical Treatment

• Titanium or carbon fiber curettes (avoid scratching the implant surface with steel instruments)
• Ultrasonic devices with plastic/PEEK tips
• Air-polishing with glycine or erythritol powder (soft, non-abrasive)
• Ti-brushes for mechanical scrubbing of implant threads

• Local antiseptics: chlorhexidine chips/gel placed subgingivally
• Photodynamic therapy (PDT) as an adjunct to mechanical debridement
• Local antibiotic delivery (minocycline microspheres)

• A systematic review and meta-analysis (Wang et al., 2022, PMID: 35476853) found adjunctive systemic antibiotics yield statistically greater probing depth reduction (0.56 mm at 3 months, 0.92 mm at 12 months) and radiographic bone gain vs. debridement alone
• However, the Frontiers of Oral and Maxillofacial Medicine 2025 review notes two meta-analyses and an RCT show NO consistent benefit for systemic antibiotics post-operatively
• Current position: Antibiotics considered for acute inflammatory presentations or peri-implant abscesses; routine systemic use is not recommended

• Disease stabilization achieved in only ~40% of peri-implantitis cases (Meyle & Fischer-Wasels, BDJ, 2024, PMID: 39572812)
• The inaccessibility of implant threads and fixture geometry limits thoroughness
• Non-surgical therapy is an essential preparatory step but rarely definitive for peri-implantitis

STEP 3 - Surgical Treatment

A. Flap for Access (Open Flap Debridement - OFD)

• Full-thickness flap reflected for direct visualization and debridement
• Thorough root/implant surface decontamination
• No bone modification
• Indicated when pockets are accessible and bone loss is minimal
• Represents the baseline surgical approach

B. Resective Surgery

• Suprabony defects / horizontal bone loss
• Facial dehiscence-type defects
• Non-contained defects with 1-2 walls
• Areas where esthetics are not a primary concern (posterior regions)
• Shallow, wide defects unfavorable for regeneration

• Bone recontouring (osteoplasty) to eliminate ledges and create physiologic architecture
• Implantoplasty: Mechanical reduction of exposed implant threads using rotary instruments (carbide burs, diamond burs). This smooths the rough implant surface to reduce bacterial adhesion
  • A 2023 systematic review (Dasgupta et al., PMID: 37929359) supports implantoplasty's efficacy in peri-implantitis management
  • A 2025 RCT (Cruz et al., PMID: 40419076) confirms benefits at 24 months
  • Concerns: Generates titanium particles, reduces implant wall thickness and fracture resistance - should be reserved for appropriate cases
• Apical repositioning of flap to eliminate residual pockets
• Expected outcome: Effective pocket elimination; post-operative mucosal recession is expected and should be discussed with patients pre-operatively

C. Reconstructive (Regenerative) Surgery

• Contained circumferential defects (3-wall or deep semi-circumferential)
• Deep defects with multiple remaining bony walls
• Cases where implant re-osseointegration is the goal
• Esthetic zones where recession must be minimized

• Bone grafts: Autogenous bone, allografts (DFDBA/FDBA), xenografts (bovine hydroxyapatite/Bio-Oss), alloplasts (beta-TCP, bioactive glass)
• Barrier membranes (GTR): Resorbable (collagen) or non-resorbable (ePTFE/titanium-reinforced) to exclude epithelium and guide bone regeneration
• Biologics: Enamel matrix derivatives, PRP/PRF, rhPDGF-BB

• Chemical: citric acid, EDTA, H₂O₂, tetracycline
• Mechanical: Ti-brushes, air-polishing, ultrasonic
• Laser-assisted (Er:YAG): evidence supporting decontamination without thermal damage

D. Soft Tissue Augmentation

• Indicated when thin/deficient keratinized mucosa contributes to peri-implant instability
• Free gingival graft or connective tissue graft to increase soft tissue thickness and keratinized band
• Improves peri-implant phenotype and resistance to disease recurrence

Surgical Decision Algorithm

Peri-implantitis confirmed (BOP + bone loss)
           │
     ┌─────▼──────────────────────────────────────┐
     │ Step 1: Risk factor control + hygiene       │
     └─────┬──────────────────────────────────────┘
           │
     ┌─────▼──────────────────────────────────────┐
     │ Step 2: Non-surgical debridement ± adjuncts │
     └─────┬──────────────────────────────────────┘
           │ Re-evaluate 6-12 weeks
     ┌─────▼───────────────────┐
     │ Disease resolved?        │──► YES → Supportive maintenance
     └─────┬───────────────────┘
           │ NO
     ┌─────▼──────────────────────────────────────────────────┐
     │ Assess defect morphology (CBCT/clinical/radiographic)   │
     └─────┬──────────────────────────────────────────────────┘
           │
    Suprabony / horizontal  ──────────────────► Resective ± implantoplasty
    Semi-circumferential    ──────────────────► Resective or combined
    Contained circumferential (≥3 walls)  ────► Regenerative
    Thin keratinized mucosa  ─────────────────► Soft tissue augmentation
    Disease uncontrollable / failed     ──────► Implant removal

Supportive Peri-Implant Maintenance (SPIM)

• 3-month recall intervals initially; extend based on stability
• Probing, radiographic monitoring, BOP assessment at every visit
• Repeated professional debridement
• Reinforced home care with implant-specific brushes and interdental aids
• Adjunctive use of chlorhexidine rinse in high-risk patients

Summary: Treatment Selection at a Glance

Bone Grafts and Bone Substitutes in Periodontics

Biological Mechanisms: The Triad of Bone Regeneration

• Osteopromotion - Enhancement of osteoinduction without independent osteoinductive property (e.g., enamel matrix derivatives enhance the osteoinductive effect of DFDBA but cannot stimulate bone alone)

Classification of Bone Grafts

Based on Source (Primary Classification)

BONE GRAFTS
├── 1. AUTOGRAFT (Autogenous)
├── 2. ALLOGRAFT
├── 3. XENOGRAFT
└── 4. ALLOPLAST (Synthetic)

1. Autograft (Autogenous Bone Graft)

• Healing extraction sockets
• Edentulous ridges
• Mandibular symphysis (chin)
• Mandibular ramus / retromolar area
• Maxillary tuberosity
• Tori (when present)

• Iliac crest (most common extraoral)
• Calvarium
• Tibia
• Radius

• Cancellous: High surface area, rapid revascularization, high osteogenic/osteoinductive/osteoconductive potential. Poor mechanical strength. Remodels faster.
• Cortical: Provides structural support and mechanical stability. Lower biological activity. Takes longer to remodel.
• Corticocancellous: Combination - provides both structural support and biological activity.

• All three bone-regenerative properties
• Fully biocompatible, no immune reaction
• No disease transmission risk
• Fastest incorporation

• Requires a second surgical site (donor site morbidity)
• Limited quantity available
• Donor site pain, scarring, bleeding
• Unpredictable and sometimes rapid resorption
• Rapid reappearance of defects reported

2. Allograft

• Most widely used allograft in periodontics
• Demineralization exposes bone morphogenetic proteins (BMPs), particularly BMP-2 and BMP-7
• Osteoinductive potential is highly variable between products and donors
• Available as putty, injectable gel, paste, powder, strips
• Can be mixed with carriers: glycerol, calcium sulfate, sodium hyaluronate, gelatin
• Significant inter-batch variability is a clinical limitation

• No donor site morbidity
• Available in larger quantities
• Long shelf life (FDBA/DFDBA)
• Well-documented clinical use in periodontics

• No viable cells (no osteogenesis)
• Variable osteoinductive strength
• Risk of immune response (minimal but present)
• Rare risk of disease transmission
• Compromised mechanical strength vs. autograft

3. Xenograft

• Bovine (most common): Deproteinized bovine bone matrix (DBBM) - e.g., Bio-Oss® (Geistlich, Switzerland) - the most widely used and documented xenograft in clinical dentistry
• Porcine: Processed similarly; gaining use
• Equine
• Coralline hydroxyapatite: Derived from coral skeleton; naturally porous

• Osteoconductive only - provides scaffold for bone ingrowth
• No osteogenesis, no osteoinduction
• Excellent biocompatibility
• Structural similarity to native bone mineral
• Very slow resorption (long-term volume maintenance - a clinical advantage for ridge preservation)
• Excellent track record in socket preservation and sinus floor elevation

• Alveolar socket preservation post-extraction
• Sinus floor elevation (sinus lift)
• Ridge augmentation
• Combined with membranes (GBR) for contained defects

• No donor site surgery
• Abundant supply
• Excellent dimensional stability
• Long-term volume maintenance
• Well-documented safety and efficacy

• Osteoconductive only (no osteoinduction or osteogenesis)
• Slow resorption (sometimes persists long-term in tissues)
• Theoretical (very low) infection/prion risk
• Religious/cultural concerns for bovine/porcine sources

4. Alloplast (Synthetic Bone Substitutes)

A. Calcium Phosphate Ceramics

B. Bioactive Glass (Bioglass)

• Silica-based material; forms a biologically active carbonate apatite layer on contact with body fluids
• Bonds directly to both bone AND soft tissue
• Osteoconductive and somewhat osteostimulative
• Releases ions (Si, Ca, P, Na) that upregulate osteogenic genes
• Example: PerioGlas® (45S5 Bioglass) - specifically designed for periodontal defects

C. Calcium Sulfate

• Rapidly resorbing osteoconductive scaffold
• Used as a space maintainer and carrier for other materials
• Often used with DFDBA to enhance handling characteristics
• Example: Capset®, OsteoSet®

D. Polymer-based Substitutes

• Biodegradable polymers (PLA, PGA, PLGA) used as scaffolds
• Can be combined with growth factors or cells
• Mostly experimental/emerging in periodontics

• Osteoconductive only (no osteogenesis or osteoinduction)
• No risk of disease transmission
• Unlimited supply, consistent composition
• Controlled manufacturing allows customization of porosity, particle size, resorption rate
• Good dimensional stability
• Lower biological activity than biological grafts

Classification by Laurencin et al. (Bone Graft Substitute System)

Biologics and Growth Factors (Adjuncts to Bone Grafts)

Comparison Summary Table

Ideal Bone Graft Material Properties (Criteria)

1. Abundant supply without donor site harm
2. Osteogenic, osteoinductive, and osteoconductive potential
3. No immune reaction from the host
4. Rapid revascularization capacity
5. Resorbable and replaceable by native bone
6. Mechanical properties comparable to native bone
7. No risk of infection or disease transmission
8. Easy handling and application

Emerging Technologies (2024-2025)

• 3D-printed patient-specific ceramic scaffolds - customized geometry matching exact defect anatomy; an RCT in 2024 (Kim et al.) showed favorable outcomes
• Nanotechnology-enabled delivery systems - nanocrystalline HA and nano-HA/collagen composites with superior cell adhesion
• Growth factor-loaded scaffolds - controlled release of BMPs, PDGF embedded within scaffold architecture
• Polydopamine-modified surfaces - enhances osseointegration and antibacterial performance
• Cell-sheet engineering - periodontal ligament cell sheets for true periodontal regeneration

Clinical Applications in Periodontics

Bone Graft Selection for Peri-Implantitis: Latest Clinical Guidelines

Foundational Principle: Is Reconstructive Surgery Even Indicated?

Reconstructive/regenerative therapy is indicated only for CONTAINED peri-implant bone defects - specifically intrabony (angular) defects ≥3 mm deep with at least 2-3 remaining bony walls.

The Critical 2025 Evidence: Does Adding a Bone Graft Help?

Landmark 3-Year RCT (Alibegovic et al., 2025)

• Control: Access flap surgery alone
• Test: Access flap surgery + bone substitute material

• Both groups showed 3.2-3.5 mm probing depth reduction
• Marginal bone level gain of 1.1-1.3 mm in both groups
• Primary composite outcome achieved at only 14% of implants in both groups
• Disease resolution in only 39% overall
• Conclusion: Bone substitute did NOT show clear benefit over access flap alone at 3 years

7-Year RCT Follow-up (Isler et al., 2025)

• Xenogenic bone graft + either concentrated growth factor (CGF) or collagen membrane (CM)
• Treatment success at 7 years: only 23-31% of patients
• Disease recurrence in 31-35%
• Collagen membrane group had more favorable outcomes for probing depth and defect depth than CGF at 7 years
• Baseline suppuration was the only significant predictor of treatment failure (OR = 15.45)
• Conclusion: Long-term success is limited and failure rates increase over time regardless of biologic adjunct used

Systematic Review + Meta-Analysis (Donos et al., 2023)

• 7 RCTs comparing reconstructive surgery vs. access flap alone
• No significant difference in PPD change between groups at 12 months (-0.387 mm, p=0.325)
• No clear hierarchy of efficacy established among different biomaterials
• Conclusion: It was not possible to establish one biomaterial as superior over others for peri-implantitis

Material-by-Material Evidence Summary (2024-2025)

1. Xenografts (e.g., Bio-Oss® - Deproteinized Bovine Bone)

• Low resorption rate is an advantage in peri-implantitis - maintains volume longer while re-osseointegration is attempted
• Current evidence indicates bone substitutes with LOW resorption rates tend to yield more favorable outcomes compared to rapidly-resorbing materials and autogenous bone
• Most of the published RCTs on reconstructive peri-implantitis therapy have used xenografts (especially bovine-derived DBBM)
• Bio-Oss granules remain the most documented graft for this indication

2. Autogenous Bone

• Despite being the gold standard in other settings, rapidly resorbing behavior is a disadvantage in peri-implantitis
• Ramanauskaite et al. 2025 explicitly state that autogenous bone yields less favorable outcomes compared to bone substitutes with low resorption rates
• Mechanism: autograft resorbs before adequate re-osseointegration can be established on the contaminated implant surface
• May still have a role as a supplemental component in a "sandwich" or combined technique

3. Alloplasts (β-TCP, BCP, Bioactive Glass)

• β-TCP and BCP are resorbable, which may be disadvantageous for the same reasons as autograft
• Bioactive glass (e.g., PerioGlas) has some supporting case series data but limited RCT-level evidence for peri-implantitis specifically
• BCP (HA + β-TCP) represents a middle ground - tunable resorption rate by adjusting HA:TCP ratio
• Evidence base is weaker than for xenografts in this specific indication

4. Allografts (FDBA / DFDBA)

• Moderate resorption rate
• Some osteoinductive potential (DFDBA)
• Limited RCT data specifically for peri-implantitis reconstruction
• More commonly used in periodontal intrabony defects than peri-implantitis
• May serve as an alternative when xenograft is not available or acceptable to patient

5. "Sandwich" / Combination Technique

• Layers different graft materials to mimic natural bone composition
• E.g., autograft (inner layer for osteogenesis) + xenograft (outer layer for volume maintenance)
• Recent human histological studies show promising outcomes
• Leverages unique properties of each material
• Currently investigational; requires further RCT validation

Barrier Membranes: Do They Add Value?

"Comparative studies have not demonstrated clear clinical advantages from the adjunctive use of barrier membranes."

• Collagen membrane (CM) produced more favorable 7-year outcomes than CGF alone for probing depth and defect depth
• This suggests membranes may have a role, especially for long-term stability

Biologics as Adjuncts

"Current evidence does not support definitive conclusions regarding the benefits of adding biologics to reconstructive treatments."

Implant Surface Decontamination: The Real Non-Negotiable

• Mechanical: titanium brushes, curettes, air-polishing (glycine/erythritol)
• Chemical: citric acid, EDTA, saline irrigation, H₂O₂
• Laser-assisted (Er:YAG): decontamination without thermal damage

Graft Selection Decision Algorithm (Current Best Evidence)

Peri-implantitis confirmed → Non-surgical therapy → Re-evaluate
                                      │
              Residual pocketing / bone loss persists
                                      │
                         ASSESS DEFECT MORPHOLOGY
                                      │
    ┌─────────────────────────────────┼──────────────────────────────────┐
    │                                 │                                  │
Suprabony /              Intrabony contained               Mixed /
horizontal               ≥3 mm, ≥2 walls                 borderline
    │                                 │                                  │
Access flap            RECONSTRUCTIVE SURGERY               Access flap
± resective         Thorough decontamination first          (consider
  surgery               ↓                                   case-by-case)
No graft          GRAFT SELECTION:
                  1st choice: Xenograft (low-resorption DBBM)
                  Alternative: Allograft (FDBA/DFDBA)
                  Avoid: Rapidly resorbing materials
                  Add membrane? Resorbable collagen preferred
                  Biologics: No strong evidence to mandate
                       │
               PREDICTORS OF FAILURE:
               Baseline suppuration (strongest)
               Poor plaque control
               Smoking
               Shallow defects (<3 mm)
                       │
              Supportive peri-implant maintenance
              (3-month intervals - MANDATORY)

Summary: What the Guidelines Currently Say

Key Evidence References