PRE-PROSTHETIC PERIODONTAL SURGERIES

Postgraduate Theory Examination Answer (50 Marks)

INTRODUCTION

RATIONALE FOR PRE-PROSTHETIC PERIODONTAL SURGERY

1. Establishment of stable gingival margins - Non-inflamed, healthy tissues are less likely to change (shrink) as a result of subgingival restorative treatment or post-restoration periodontal care.
2. Adequate tooth length for retention - Certain periodontal procedures provide adequate tooth length for retention, access for tooth preparation, impression making, and placement of restorative margins.
3. Anticipating tissue changes - Periodontal therapy should precede restorative care because resolution of inflammation may result in tooth repositioning or soft tissue changes that interfere with prosthetic designs.
4. Protection of periodontium - Traumatic forces on teeth with ongoing periodontitis may increase mobility and attachment loss.
5. Esthetic and implant procedures - Successful esthetic and implant procedures may be difficult or impossible without specialized periodontal procedures.

SEQUENCE OF TREATMENT

• Emergency treatment
• Extraction of hopeless teeth
• Oral hygiene instructions (OHI)
• Scaling and root planing (SRP)
• Reevaluation
• Periodontal surgery
• Adjunctive orthodontic therapy

1. Management of mucogingival problems
2. Preservation of ridge morphology after tooth extraction
3. Crown-lengthening procedures
4. Alveolar ridge reconstruction

ENUMERATION OF PRE-PROSTHETIC PERIODONTAL SURGERIES

I. MANAGEMENT OF MUCOGINGIVAL PROBLEMS

• Widening of attached gingiva
• Deepening of shallow vestibules
• Resection of aberrant frena

A. PROCEDURES FOR WIDENING ATTACHED GINGIVA

• Prior to placement of subgingival restorations in areas with thin marginal tissue
• Around teeth serving as abutments for fixed or removable partial dentures (RPD)
• Around dental implants with inadequate keratinized mucosa causing patient discomfort during oral hygiene
• Before orthodontic movement of teeth when alveolar bone dehiscence is anticipated
• To facilitate proper prosthetic flange extensions in complete dentures

1. FREE GINGIVAL GRAFT (FGG)

1. Preparation of recipient site: A partial-thickness (split-thickness) flap is dissected in the area of insufficient gingiva. A periosteal bed free from muscle attachment and of sufficient size is prepared by sharp dissection. The partial-thickness flap is displaced apically and sutured.
2. Harvesting the graft: A foil template of the recipient site is produced and transferred to the palatal mucosa (premolar region). A graft approximately 1.5-2 mm thick is dissected from the palate using a scalpel. Sutures are placed in the graft before it is completely freed to facilitate transfer.
3. Graft transfer and stabilization: The graft is immediately transferred to the recipient bed and anchored with sutures to periosteum or adjacent attached gingiva. Firm pressure is applied for 5 minutes to eliminate blood/exudate and establish "plasmatic circulation."
4. The palatal donor wound is protected with a periodontal dressing and acrylic stent. Sutures and dressing are removed after 1-2 weeks.

• Phase 1 - Initial phase (0-3 days): Avascular plasmatic circulation; graft epithelium degenerates. Close adaptation to recipient bed is essential.
• Phase 2 - Revascularization phase (2-11 days): Anastomoses established between graft and recipient bed vessels; fibrous union begins; re-epithelialization occurs.
• Phase 3 - Tissue maturation phase (11-42 days): Vascular system normalizes; keratinized epithelium with keratin layer forms.

2. SUBEPITHELIAL CONNECTIVE TISSUE GRAFT (SECTG / CTG)

• Root coverage for gingival recession (Miller Class I and II)
• Augmenting the width of attached gingiva, especially when esthetics are a concern
• Increasing tissue thickness before subgingival restorations
• Ridge augmentation (soft tissue component)

1. A coronally advanced flap (CAF) or double papilla flap is prepared at the recipient site using split-thickness dissection.
2. The connective tissue graft is harvested from the palate using the "trap-door" approach: a primary horizontal incision 3 mm apical to the gingival margin, followed by a split incision within the palatal mucosa to free the connective tissue from bone, leaving the outer epithelial collar intact.
3. The graft is transferred to the recipient site, placed at a distance from the CEJ (cemento-enamel junction) equal to the height of KG apical to the recession, and secured with mattress sutures.
4. The coronally advanced flap is positioned 1-2 mm coronal to the CEJ and sutured.

3. PEDICLE SOFT TISSUE GRAFTS

• Laterally sliding flap (Grupe and Warren, 1956): A full-thickness or split-thickness flap is reflected adjacent to a localized recession and laterally displaced to cover the exposed root. Indicated for isolated single-tooth recession with adequate donor tissue adjacent to the defect.
• Double papilla flap (Cohen and Ross, 1968): Papillae from both sides of a recession are mobilized and sutured together to cover an exposed root.
• Oblique rotated flap: A variant where the flap is rotated obliquely to cover the defect.

• Coronally advanced flap (CAF): Apically divergent vertical releasing incisions are made at the mesial and distal line angles of the tooth. A split-thickness flap is prepared mesial and distal to the recession, with a full-thickness elevation apical to the recession. After periosteal scoring to release muscle tension, the mobilized flap is advanced coronally to cover the exposed root surface 1-2 mm coronal to the CEJ. The inter-dental papillae are de-epithelialized to create connective tissue beds for flap anchorage. Recommended for multiple adjacent recessions (Zucchelli and De Sanctis, 2000).
• Semilunar coronally repositioned flap (Tarnow, 1986): A semilunar incision is placed apical to the recession. A split-thickness dissection frees the mid-facial soft tissue, which is then coronally repositioned without sutures. Indicated for shallow localized recessions.

B. DEEPENING OF SHALLOW VESTIBULE (VESTIBULOPLASTY)

• Minimal vestibular depth jeopardizes proper oral hygiene (sulcular brushing technique cannot be applied)
• Inadequate vestibular depth compromises the fit, retention, and stability of removable prostheses (complete dentures and RPDs)
• If minimum attached gingiva is present with no vestibular depth, mucogingival correction is usually needed

1. Denudation technique (Ochsenbein, 1960): All soft tissue removed from gingival margin to apical to the MGJ (mucogingival junction), leaving alveolar bone exposed. Results in widened keratinized zone but significant bone resorption. Not used today.
2. Split-flap / periosteal retention technique (Staffileno et al., 1962): Only the superficial mucosa is removed, leaving bone covered by periosteum. Less bone resorption than denudation but still unpredictable. Historical interest only.
3. Apically repositioned flap (Friedman, 1962): Soft tissue flaps are elevated and displaced apically during suturing. Associated with bone exposure in the coronal portion and bone resorption. Currently, the same flap is used in a more conservative way for crown lengthening.

• Shallow vestibule prevents adequate flange extension for complete denture
• Mandibular vestibuloplasty deepens the labial/buccal vestibule to create room for the denture flange
• Surgical techniques now focus on inferiorly positioned incisions in the mandible, and the use of skin grafts was more common historically (now largely replaced by implant therapy)

C. FRENECTOMY / FRENOTOMY (CORRECTION OF ABERRANT FRENUM)

• Frenectomy: Complete excision of the frenum, including its attachment to the underlying bone.
• Frenotomy: Incision and repositioning of the frenum.

1. High frenal attachment pulls on the gingival margin, interfering with plaque removal and opening the sulcus
2. Labial or buccal frenae that become prominent after alveolar ridge resorption may interfere with complete denture flanges and sealing
3. Upper labial frenum with strong band of fibrous connective tissue that limits optimal extension of the denture flange
4. Frena causing dislodgement of the prosthesis
5. Mandibular labial and lingual frena interfering with denture stability

1. The frenum is grasped with a hemostat, and two incisions are made on each side of the hemostat.
2. The intervening tissue is excised.
3. The wound is closed with interrupted sutures, or the frenectomy can be combined with a free gingival graft when attached gingiva is deficient.

II. PRESERVATION OF RIDGE MORPHOLOGY AFTER TOOTH EXTRACTION

• In anticipation of future dental implant placement
• In cases where a pontic (bridge tooth replacement) will be constructed and unaided healing would produce an unesthetic deformity
• Where vestibular osseous plate fracture occurred during extraction

1. Atraumatic extraction technique and maintenance of surrounding anatomic integrity
2. Ovate pontic placement immediately post-extraction to support surrounding soft tissues (Carranza Ch. 71 - Figure 71-5)
3. Flap elevation for complete soft tissue closure of the extraction site (Borghetti and Glise, 2000)
4. Connective tissue grafts placed over extraction sites (Nevins and Mellonig, 1998)
5. Bone grafts in the socket (Becker et al., 1994) - e.g., combination of deproteinized bovine bone and calcium sulfate
6. Barrier membranes (Lekovic et al., 1997) - socket preservation with GTR (guided tissue regeneration) membranes

III. CROWN-LENGTHENING PROCEDURES

1. Provide retention form for proper tooth preparation and restoration
2. Allow placement of restorative margins
3. Adjust gingival levels for esthetics
4. Expose subgingival caries or tooth fractures

A. BIOLOGIC WIDTH - The Fundamental Concept

• Connective tissue attachment: ~1.07 mm
• Junctional epithelial attachment: ~0.97 mm
• Total biologic width: ~2 mm (±30%)
• Healthy gingival sulcus depth: average 0.69 mm
• Minimum recommended distance from restoration margin to bone crest: 3 mm (to accommodate biologic width + 0.5 mm margin placement within sulcus)

B. INDICATIONS FOR CROWN LENGTHENING (Carranza Ch. 71; Lindhe Ch. 46)

C. CROWN-LENGTHENING TECHNIQUES

1. GINGIVECTOMY (Soft Tissue Crown Lengthening)

• External bevel (externally beveled gingivectomy): Removes pigmented tissue; creates pink gingival tissue upon healing. Must be extended bilaterally past the midline to avoid color mismatch (Lindhe Ch. 46).
• Internal bevel (internal gingivectomy): Maintains tissue pigmentation. An internally beveled path of incision creates mini-flaps at the papillae (Lindhe Ch. 46 - Figure 46-63).

2. FLAP PROCEDURE WITH OSSEOUS RECONTOURING (Apically Positioned Flap - APF)

1. Internally beveled flap or apically positioned flap is elevated.
2. Osseous recontouring (osteoplasty and ostectomy) performed to establish proper bone level and create biological width.
3. Flap is apically positioned and sutured with vertical mattress sutures.
4. Bone recontouring done from second premolar to second premolar for esthetic cases.

3. FORCED TOOTH ERUPTION (ORTHODONTIC EXTRUSION)

• Crown lengthening at sites where removal of attachment and bone from adjacent teeth must be avoided (isolated subgingival fractures, cervical caries)
• Reducing pocket depth at sites with angular bony defects

• Orthodontic brackets bonded to the problem tooth and adjacent anchor teeth; power elastic applied.
• In cases with significant crown loss, root canal therapy (RCT) and post placement are required, and the power elastic is attached to the post/hook.
• The tooth is extruded to a position where, after subsequent osseous recontouring, adequate crown structure is exposed.

4. FORCED TOOTH ERUPTION WITH FIBEROTOMY

• Fiberotomy is performed using a scalpel at 7-10 day intervals during the forced eruption procedure.
• This severs the supracrestal connective tissue fibers, preventing the crestal bone from following the root in a coronal direction.
• After stabilization (6 weeks), a full-thickness flap is elevated and bone recontouring performed to expose sound root structure.

IV. ALVEOLAR RIDGE RECONSTRUCTION

• Construction of an esthetic fixed partial denture (FPD) pontic
• Placement of dental implants in optimal prosthetically driven position

• Class I: Loss of buccolingual width but normal apicocoronal height (horizontal deficiency)
• Class II: Loss of apicocoronal height but normal buccolingual width (vertical deficiency)
• Class III: Combined loss of both height and width

• Provisional restoration should be made prior to surgery as a reference and template for shaping augmented tissue
• Pontic shape should be an exact prototype of the final prosthesis
• Restoration margins should not contact the graft during early healing

A. SOFT TISSUE AUGMENTATION

1. ROLL FLAP PROCEDURE (Pedicle graft procedure)

1. Palatal epithelium in the donor area is removed by sharp dissection.
2. A maximum amount of supraperiosteal connective tissue pedicle is raised from the palate.
3. A subperiosteal pouch is created in the connective tissue on the facial surface of the ridge.
4. The pedicle is tucked into the pouch and stabilized with a resorbable suture near the mucobuccal fold.
5. The provisional bridge is relined with autopolymerizing resin to conform to the new ridge contour.

2. POUCH GRAFT PROCEDURE (Free graft - submerged)

• The pouch is prepared coronoapically (horizontal incision on palatal side, dissection carried apically) or apicocoronally (incision high in vestibule, dissection carried coronally).
• A free connective tissue graft is harvested from the palate using the "trap-door" approach.
• The graft is placed, positioned, and the entrance incision closed with sutures.

3. INTERPOSITIONAL GRAFT PROCEDURE

• A labial partial-thickness flap is elevated to create a pouch.
• A free epithelium-connective tissue graft (wedge-shaped) is excised from the palate.
• The epithelial surface is placed flush with the surrounding epithelium (for Class I) or partially above it (for Class II).
• The graft is sutured circumferentially to the surrounding tissues.

4. ONLAY GRAFT PROCEDURE

1. The recipient site is de-epithelialized with short saw-like scalpel strokes, removing minimal connective tissue.
2. An epithelialized graft of appropriate size (a few mm wider and longer than needed to compensate for contraction) is harvested from the premolar region of the palate (major palatine artery must be avoided in the 2nd-3rd molar region).
3. The graft is sutured with interrupted sutures along its borders.
4. Postoperative swelling helps sculpt tissue into the desired contour around the pontic.
5. Gingivoplasty is performed 2-3 months post-surgery to finalize tissue form and create pontic receptacle sites for ovate pontics.

5. COMBINED ONLAY-INTERPOSITIONAL GRAFT PROCEDURE

• The submerged connective tissue (interpositional) section aids revascularization of the onlay section, resulting in greater graft take
• Smaller open wound at palatal donor site
• Greater latitude to control both buccolingual and apicocoronal augmentation
• Vestibular depth not decreased, eliminating need for corrective follow-up procedures

B. HARD TISSUE AUGMENTATION (Guided Bone Regeneration / GBR)

• Soft tissue augmentation alone is insufficient (large defects)
• Implant placement requires adequate bone volume (minimum 2 mm on buccal side of implant)
• After extraction resulting in significant bone loss

1. Primary wound closure - Tension-free primary closure is essential; provides undisturbed healing environment
2. Angiogenesis and cell differentiation - Perforations of cortical plate (the RAP - regional acceleratory phenomenon) release growth factors to facilitate osteogenic cell migration
3. Space maintenance - Barrier membranes exclude epithelial and connective tissue cells; titanium-reinforced membranes maintain space in cases of severe bone loss
4. Wound stability - Membrane stabilizes the blood clot; cytokines (IL-1, IL-8, TNF - tumor necrosis factor, PDGF - platelet-derived growth factor, IGF-1 - insulin-like growth factor-1, FGF-2 - fibroblast growth factor-2) in blood clot recruit osteogenic cells

1. Barrier membranes:
   • Non-resorbable: expanded polytetrafluoroethylene (e-PTFE); titanium-reinforced for space maintenance; requires second surgery for removal
   • Resorbable: collagen, polyglactin, polylactic acid membranes; no second surgery required but may not maintain space as effectively
2. Bone grafts and bone substitutes:
   • Autogenous bone (gold standard): intraoral (symphysis, ramus, tuberosity) or extraoral (iliac crest) donor sites; provides osteogenic, osteoinductive, and osteoconductive properties
   • Allografts: DFDBA (demineralized freeze-dried bone allograft) - osteoinductive; FDBA (freeze-dried bone allograft) - osteoconductive
   • Xenografts: Deproteinized bovine bone (DBB - e.g., Bio-Oss); osteoconductive; slow resorption
   • Alloplastic materials: Hydroxyapatite (HA), tricalcium phosphate (TCP), bioactive glass; osteoconductive only
3. Ridge splitting/expansion: Indicated for narrow but sufficiently tall ridges (horizontal Class I deficiency). A piezoelectric saw creates osteotomies through which the ridge is expanded. Implants are often placed simultaneously.
4. Growth factors and emerging technologies (Lindhe Ch. 50):
   • PDGF (platelet-derived growth factor), BMP (bone morphogenetic protein), rhBMP-2 (recombinant human bone morphogenetic protein-2): enhance osteogenic differentiation
   • PRP (platelet-rich plasma) and PRF (platelet-rich fibrin): concentrate autologous growth factors
   • Cell therapy and scaffolding matrices

• KTW (keratinized tissue width): 3.4 ± 0.6 mm vs. 1.1 ± 0.3 mm (P <0.001)
• MBL (marginal bone loss): 0.35 ± 0.15 mm vs. 0.78 ± 0.25 mm (P <0.001)
• BOP (bleeding on probing): 12.5% vs. 30% (P = 0.03)
• Peri-implant mucositis: 5.3% vs. 18.9% (P = 0.04)
• Patient satisfaction (OHIP-14 - Oral Health Impact Profile-14 score lower; VAS - visual analog scale higher in test group)
• Implant survival comparable: 97.4% vs. 94.6% (P = 0.61)

V. ADDITIONAL PRE-PROSTHETIC SURGERIES FOR EDENTULOUS PATIENTS

A. CORRECTION OF HYPERPLASTIC TISSUE / EPULIS FISSURATUM / PAPILLOMATOSIS

B. REMOVAL OF BONY PROMINENCES, UNDERCUTS, AND TORI

• Mandibular tori: Conspicuous mandibular tori that prevent adequate denture flange extension or cause painful impingement must be surgically excised under a mucoperiosteal flap (Zarb Ch. 8 - Figure 8-7).
• Maxillary tori: Rarely removed if a satisfactory denture can be constructed over them by careful palatal relief. Indications for removal include: the sheer bulk prevents conventional palatal coverage; interfere with prosthesis construction; are deeply cleft and cannot be adequately cleaned; fracture under prosthetic forces.
• Mylohyoid ridge: Sharp mylohyoid ridges causing pain under denture flanges may need surgical smoothing.
• Mental foramen prominence: Resorbed mandibular ridges where bone apical/anterior to the foramen is more dense may cause the mental foramen margins to extend above the surrounding bone. Surgical relief may be required.
• Superior genial tubercle: When prominent and painful, may require excision when the residual ridge has resorbed to the level of the genial tubercle.

C. REDUCTION OF PENDULOUS MAXILLARY TUBEROSITIES

VI. HEALING AND TIMING

CONCLUSION

ABBREVIATIONS

KEY REFERENCES

1. Melnick PR. Preparation of the Periodontium for Restorative Dentistry. In: Newman MG, Takei HH, Klokkevold PR, Carranza FA. Carranza's Clinical Periodontology, 10th ed. Chapter 71. Elsevier, 2006.
2. Takei HH, Azzi RR, Han TJ. Periodontal Plastic and Esthetic Surgery. In: Carranza's Clinical Periodontology, Chapter 69.
3. Wennström JL, Zucchelli G. Mucogingival Therapy: Periodontal Plastic Surgery. In: Lang NP, Lindhe J. Clinical Periodontology and Implant Dentistry, 6th ed. Chapter 46. Wiley-Blackwell, 2015.
4. Rios HF, Vignoletti F, Giannobile WV, Sanz M. Ridge Augmentation Procedures. In: Lang NP, Lindhe J. Clinical Periodontology and Implant Dentistry, 6th ed. Chapter 50. Wiley-Blackwell, 2015.
5. Zarb GA, Bryant SR. Pre-prosthetic Surgery: Improving the Patient's Denture-Bearing Areas and Ridge Relations. In: Prosthodontic Treatment for Edentulous Patients, Chapter 8.
6. Parihar AS, Sultana R, Gubrellay P, et al. Influence of Pre-prosthetic Periodontal Surgery on the Stability of Peri-Implant Tissues and Prosthetic Success: A Randomized Controlled Trial. J Pharm Bioall Sci 2025;17:S2707-10.
7. Seibert JS. Reconstruction of deformed, partially edentulous ridges, using full thickness onlay grafts. Compend Contin Educ Dent 1983;4:437-453.
8. Ingber JS. Forced eruption: Part I and II. J Periodontol 1974, 1976.
9. Pontoriero R, Celenza F, Ricci G, Carnevale M. Rapid extrusion with fiber resection: A combined orthodontic-periodontic treatment modality. Int J Periodont Restor Dent 1987;5:30-43.

Summary of Coverage

I. Management of Mucogingival Problems

• A. Widening of attached gingiva: Free Gingival Graft (FGG) with 3-phase healing; Subepithelial Connective Tissue Graft (CTG/SECTG); Pedicle grafts - laterally sliding flap, double papilla flap, coronally advanced flap (CAF), semilunar flap
• B. Vestibuloplasty: Historical techniques (denudation, split-flap, APF) and current FGG-based approach; indications for edentulous patients from Zarb
• C. Frenectomy/Frenotomy: Indications in prosthetic context, technique

II. Preservation of Ridge Morphology After Extraction

• Socket preservation strategies, ovate pontic placement, barrier membranes, bone grafts

III. Crown-Lengthening Procedures

• Biologic width concept (2 mm; minimum 3 mm bone-to-margin distance)
• Gingivectomy (external and internal bevel)
• Apically positioned flap (APF) with osseous recontouring
• Forced tooth eruption
• Forced tooth eruption with fiberotomy (7-10 day intervals)

IV. Alveolar Ridge Reconstruction

• Soft tissue: Roll flap, pouch graft, interpositional graft, onlay graft, combined onlay-interpositional graft with Seibert's Class I/II/III classification
• Hard tissue (GBR): 4 surgical principles, defect classification, regenerative materials (barrier membranes, autografts, allografts, xenografts, alloplasts, growth factors)

V. Additional Edentulous Pre-Prosthetic Surgery (Zarb)

• Epulis fissuratum excision, tori removal, tuberosity reduction, mylohyoid ridge, genial tubercle, mental foramen relief

VI. Healing Timelines & Abbreviation Table

• Complete table of all abbreviations with full forms