Periodontal healing: attachment, reattachment, new attachment and bone healing

Periodontal healing: attachment, reattachment, new attachment and bone healing.

1. Introduction:

The goal of reconstructive periodontal therapy is the restoration of tissues destroyed by the disease, i.e. the formation of new cementum, new periodontal ligament and new alveolar bone. This ideal result seems difficult to achieve, but it is thanks to the remarkable healing abilities of periodontal tissues that the treatment can be effective, and knowledge of the healing process allows the practitioner to make a judicious choice of surgical techniques. 

2. definition of healing:

Healing is the set of biological phenomena which lead to the repair of damaged tissue, achieving its continuity, with morphological and functional restitution of the tissue concerned.  

3. Terminology:

In order to clearly describe the different types of healing, it is appropriate to recall the following definitions:

1. The reattachment: 

Is the reunion of connective tissue on the surface of a dental root on which physiologically viable periodontal tissue remains, the biological repair process then reconstitutes the structural and functional integrity of the tissue concerned.

2. The new attachment: 

Is the union of connective tissue with a root surface deprived of its original attachment system, i.e. the periodontal ligament; this process occurs by the insertion of collagen fibers within a neocementum.

3. The repair: 

Is the healing of a wound by tissues which do not completely restore the initial architecture or function (long junctional epithelium)

4. Regeneration: is the original reconstitution of lost or injured elements.
5. Periodontal regeneration: 

It is the reconstruction of the attachment apparatus of cement, ligament and alveolar bone, around a tooth whose periodontium has been damaged.

4. Reminder on inflammation:

The acute inflammatory reaction constitutes the first ^line of tissue defense occurring after irritation or aggression.

The chronic inflammatory response can be considered as the second line of defense.

      ⎧ Aggression (B, chemical)

       ⎢ ↓

       ⎢ Inflammation  

      ⎨ ↓ ↓

       ⎢ Vascular reaction Cellular reaction

       ⎢ ⇒ Isolation of the injured site → elimination of the causative agent and the damaged tissue         

      ⎩ → healing.

      ⎧ Repeated aggression (Ag presence) 

       ⎢ ↓

       ⎢ Chronic inflammation 

       ⎢ ↓ ↓

      ⎨ Immune reaction Non-specific reaction 

      ⎪ ↓ ↓ ↓

      ⎪ Lymphokines Ac Accumulation of 

      ⎪ Monocytes and macrophages

• ⇒ Identification → isolation → elimination of the causal agent → healing

Wound healing is the final phase of the acute inflammatory response, it occurs when the agent triggering the inflammatory response has been eliminated or partially inactivated, the main objective of the local inflammatory reaction is to protect the exposed tissue against the penetration of harmful substances as well as to establish favorable conditions for tissue regeneration or repair.

5. Classification:

KRAMER classification: It classifies periodontal surgery:

• Depending on the tissues involved 
• Depending on the type of surgery
• Depending on the surgery
• Depending on the therapeutic chronology
• Depending on the type of healing:
• Reattach by repair:

• Long junctional epithelium → epithelial or connective tissue adhesion 
• No neo-cement
• No neo-ligament 
• Could be new bone formation 
• SGD a little deeper than normal 
• New attachment by regeneration:  

• Short junctional epithelium
• Neo-cement
• Neo-ligament
• New bone 
• SGD short

6. Goals of healing:

The goal of periodontal healing is to obtain a periodontal attachment system consisting of an epithelium and connective tissue to achieve absolute hermeticity.

Find the same attachment position as before the intervention but often this attachment is more apical. 

7. Different types of fasteners:

The type of attachment will be conditioned by the cellular supply during healing.

1. Epithelial-connective tissue reattachment:

Identical to healthy gingival epithelium, it can extend up to or apically to the bone crest. Adhesion to the root surface is via hemi-desmosomes.

2. Connective adhesion:

Connective fibers parallel to the tooth apically to the junctional epithelium and coronally to the bony crest.

This attachment may be associated with a short or long junctional epithelium.

3. Fibrous bypass:

Union of the connective fibers of the flap with the endings of the collagen fibers of the root surface.

Biochemically, this healing would be the result of a depolymerization of pre-existing collagen molecules followed by their reorganization; these reorganized fibers would serve as a link between the connective tissue and the root surface.

4. New epithelial-connective tissue attachment:

It corresponds to a regeneration, that is to say a restoration of the four periodontal tissues with reestablishment of function (Stahl, 1979). In periodontics, regeneration remains exceptional even if surgical techniques have attempted to achieve it.

8. Biological bases of healing:

8.1. Wounds and healing:

• The wound: 

Is formed by the rupture of the anatomical and functional continuity of living tissues (KRAWCZYLE 1978)

Wounds can originate from pathological destruction, chemical, physical or thermal aggression or from a surgical incision.

• Healing: 

Induces healing of a wound, it is represented by restoration in the form of reattachment or new attachment.

• Periodontal healing: 

It has particularities, because the periodontal wound is specific. The clot separates two kinds of tissues; the root surface on the one hand, the connective tissue, the epithelium and the alveolar bone on the other hand.

⮞ The root surface is rigid, acellular, avascular, it does not have the ability to move towards the other bank of the wound; it is therefore the set of soft tissues which performs a migration movement towards this bank.

2. Physiology of healing:
   1. The preparatory phase (detersion phase):

The immediate sequence of the injury is a hemorrhage, the blood coagulates quickly, the fibrin network that forms fills the gap between the edges of the wound and brings them together. This bridge is fragile but creates a framework on which the granulation tissue can be built.

2. The production phase (repair phase):

The construction of the repair tissue begins with the multiplication of fibroblasts in the edges and in the bottom of the wound, when the inflammatory manifestations are attenuated this productive phase allows the formation of a dense and regular connective tissue.

9. Healing modalities of the different periodontal tissues:
10. Ephithelio-conjunctival healing:

• By 1st ^intention : healing by 1st ^intention is carried out in the presence of a surgical incision. It includes two aspects:
• Connective repair: is done in three phases: 

→ Inflammation or latency phase: during which vasoconstriction occurs, followed by rapid vasodilation leading to the formation of a fibrin clot     

→ Granulation tissue formation phase or cellular repair phase: occurs after 3 days, there is capillary neovascularization leading to the formation of a dense network of vessels in the connective tissue and significant fibroblastic activity reinforcing the repair.

→ Tissue maturation phase: occurs after 7 days, the vascular system is established, there are no more inflammatory cells, on the other hand we observe the formation of a collagen matrix with a functional remodeling of the tissues.

Periodontal healing: attachment, reattachment, new attachment and bone healing

• Epithelial repair: 

It is characterized by 3 phenomena: differentiation, proliferation and cell migration.

• Healing by secondary intention:

It occurs after a loss of substance, a wound due to an ulceration or open wound or after destruction resulting from periodontal disease.

• Suppurative detersion: Is the prerequisite for healing, it eliminates all necrotic tissues and anything that hinders budding.
• Closure: To achieve wound closure, the body will call upon new tissues called granulation tissues. 

The more exposed the wound is, the more debris there will be to remove and the longer the healing will take.

2. Bone healing:

4 main phases occur in bone wound healing:

• Filling phase:

It begins with an inflammatory reaction according to the same process occurring at the level of the mucous membrane.

• resorption phase: from the 4th ^to the 7th ^day ; ensured by osteoclasts.
• Osteoblastic phase: from the 7th ^to the ^28th day

Formation of young bone in forming Haversian systems.

• Maturation phase:

It continues from the 28th ^to the 126th ^day , and even continues for a year.

3. the periosteum:

The inner layer of the periosteum consists of resting cells that can be reactivated into osteogenic cells by a stimulus.

10. Periodontal surgery and healing:
    1. Root curettage and planing:

There is repair of epithelial cells and connective tissue by new attachment, with the formation of a long junctional epithelium more apically and a new connective tissue attachment.

2. Gingivectomy and gingivoplasty:

Clinical healing occurs after 3 weeks, with epithelialization completing after 35 days.

3. Flap surgery:

a- Full thickness flap: The speed of healing depends on the thickness of the clot, it can last between 4 and 5 weeks.

b- Partial thickness flap: The phenomenon of apposition resorption exists, but in this case there is a certain bone economy during healing.

4. Grafts:

a- Epithelial-connective tissue grafts: In this type of intervention, during healing, there is direct contact between the connective tissue of the graft and the periosteum; this is healing by first intention. 

b- Healing by RTG: The reconstitution of periodontal tissues remains the main objective in periodontics.

5. Vestibular deepening: Healing is done by secondary intention. 
6. Frenectomy and frenotomy:  

Healing is rapid by first ^intention at the bottom of the vestibule, this is known as “closed wound” healing. 

Epithelialization occurs within a week.

Periodontal healing: attachment, reattachment, new attachment and bone healing

11. Factors influencing healing:

For healing to take place in the best conditions and achieve its goals, a generally beneficial local environment is necessary.

1. Local factors:

a- Delaying or inhibiting factors: 

• Irritation not from plaque microorganisms.
• Excessive handling of tissues during treatment .
• Repeated therapeutic procedures that disrupt the body’s inflammatory action during the healing process.
• Pulp damage.
• Thick blood clot.
• Occlusal trauma.
• Exogenous toxic factors; tobacco.

b- Accelerating factors:

• Sometimes elimination of necrotic elements.
• Smallest clot.
• Immobilization of the wound during healing.
• Good sutures (perfect application of flaps)
• Healthy pulp condition.

2. General factors:

In the same species, the progress of the scarring process varies from one individual to another.

a- Delaying factors:

• Age: the scarring process is more active in young people because cell multiplication occurs more easily. 
• Nutritional factors: The intense cellular activity involved in healing requires sufficient protein and vitamin (vitamin C and A) intake. 
• Hormonal factors: Glucocorticoids slow healing by decreasing collagenesis and neovascularization.
• Toxic factors: toxic role of alcohol and tobacco.
• Hematological diseases: hemorrhage (disorganization of the clot) 

b- Favoring factors:

• Hormonal factors: progesterone 
• Vitamin A
• Antibiotic (allow healing to take place without microorganisms)

12. Conclusion :

The regenerative or reconstructive therapeutic techniques used to date result in the formation of a long epithelial attachment with or without bone filling rather than the formation of a new connective tissue attachment.  

Periodontal healing: attachment, reattachment, new attachment and bone healing

  Sensitive teeth react to hot, cold or sweet.
Sensitive teeth react to hot, cold or sweet.
Ceramic crowns perfectly imitate the appearance of natural teeth.
Regular dental care reduces the risk of serious problems.
Impacted teeth can cause pain and require intervention.
Antiseptic mouthwashes help reduce plaque.
Fractured teeth can be repaired with modern techniques.
A balanced diet promotes healthy teeth and gums.
 

Periodontal healing: attachment, reattachment, new attachment and bone healing