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Mast Cells and Allergic Reactions

• Mast cells originate from pluripotent cells and mature in tissues such as the lungs
• They are activated by surface receptor-bound IgE encountering an antigen, leading to degranulation and release of inflammatory mediators
• Mast cells are involved in allergic reactions and neuroinflammatory diseases, particularly those worsened by stress
• They can be activated through Fc receptors by immunoglobulins other than IgE, anaphylatoxins, neuropeptides, and cytokines
• Mast cells contain prominent cytoplasmic granules (lysosomes) storing inflammatory mediators such as histamine, eosinophil chemotactic factor, and heparin

Periodontal Disease and Smoking

• Smoking is a major risk factor for the initiation, extent, and severity of periodontal disease
• Smokers have at least twice the risk of periodontal disease than non-smokers
• Long-term smoking increases the risk of periodontal disease
• Smokers often exhibit a poorer response to periodontal therapy, including regenerative procedures, soft-tissue grafting, and dental implants
• Smoking leads to immunosuppression and greater susceptibility to periodontitis

Periodontal Dressings

• Periodontal dressings (packs) provide mechanical protection for the surgical wound, facilitate healing, and support mobile teeth
• They help prevent postoperative bleeding, maintain the position of the flaps, and provide patient comfort
• Characteristics of acceptable dressing materials include being non-toxic, non-irritating, and having good adhesion to the teeth
• Types of dressings include zinc oxide and eugenol-containing (hard) packs and non-eugenol (soft) packs

Gingival Fibers

• Gingival fibers consist mainly of type I collagen, which provides tensile strength to the marginal gingival tissue
• They also contain type VI collagen fibers (argyrophilic reticulum fibers) that are interspersed between the type I collagen fibers
• Gingival fibers hold the marginal gingiva firmly against the tooth, provide rigidity, and link the marginal free gingiva with the adjacent attached gingiva and root cementum
• There are three groups of gingival fibers: gingivodental, circular, and transseptal

Periodontal Abscesses

• Periodontal abscesses are infections located contiguous to the periodontal pocket and may result in the destruction of the periodontal ligament (PDL) and alveolar bone
• They can be classified as acute or chronic
• Acute periodontal abscesses are characterized by constant, severe, dull throbbing pain, while chronic periodontal abscesses are characterized by no or dull pain, slight tooth elevation, and intermittent exudation
• Treatment for an acute periodontal abscess involves providing drainage, instructing the patient to rinse with warm saltwater and chlorhexidine gluconate, and prescribing antibiotics if necessary

Bruxism

• Bruxism is defined as diurnal or nocturnal parafunctional activity that includes clenching, bracing, gnashing, and grinding of the teeth
• It can cause tooth mobility, tooth wear, and fracture, as well as TMJ pain and disorders
• Maxillary or mandibular interocclusal appliances (occlusal splints/night guards) are used to manage bruxism and redistribute occlusal forces
• Night guards are used to modify and control bruxism, stabilize the dentition, and redirect forces into a non-traumatic pattern### Periodontal Disease and Occlusal Forces
• Occlusal forces can cause periodontal changes, but they do not continuously remodel periodontium like bone.
• Periodontal ligament space widens, and the number and width of periodontal ligament fibers increase with increased occlusal forces.
• Direction of occlusal forces affects periodontium, with horizontal and rotational forces causing more injury than vertical forces.
• Duration and frequency of occlusal forces also impact periodontium, with prolonged and constant pressure causing more injury than intermittent forces.

Primary and Secondary Trauma from Occlusion

• Primary trauma from occlusion occurs due to changes in occlusal forces, causing periodontal destruction without changing the level of connective tissue attachment.
• Secondary trauma from occlusion occurs when the adaptive ability of tissues to bear occlusal forces is reduced due to bone loss from marginal inflammation.

Diagnosis and Treatment of Periodontal and Endodontic Lesions

• Differential diagnosis between periodontal and endodontic origin can be established through history, clinical examination, and radiographs.
• Treatment of combined lesions involves treating the endodontic component first, followed by periodontal treatment.

Periodontal Therapeutic Objectives and Prognosis

• Periodontal therapeutic objectives vary with the extent and configuration of the residual periodontal lesion.
• Long-term prognosis for a tooth with a combined lesion is closely related to the extent and configuration of periodontal attachment loss.

Splinting Therapy

• Indications for splinting include mobility of teeth, migration of teeth, and prosthetics where multiple abutments are necessary.
• Before considering splinting, the clinician must identify the etiology of instability and control any inflammation.
• Adequate crown length and space are critical for splinting to avoid impinging on the interdental papilla.

Stains and Oral Irrigators

• Stains can be intrinsic (within the tooth substance) or extrinsic (on the external surface of the tooth).
• Extrinsic stains can be further classified as endogenous (originating from within the tooth) or exogenous (originating from an external source).
• Oral irrigators can be effective in removing non-adherent bacteria and debris, but are not effective in removing biofilm, which requires mechanical removal.
• Water irrigation does not replace brushing and flossing.

Clinical Attachment Loss and Periodontitis

• Clinical attachment loss (CAL) is measured as the distance from the cementoenamel junction (CEJ) to the base of the pocket.
• CAL is a more accurate indicator of periodontal support around a tooth than probing depth alone.
• Severity of periodontitis can be characterized by the amount of clinical attachment loss (CAL).

Doxycycline (Periostat) and Host Modulation

• Doxycycline (Periostat) is a systemic drug approved for host modulation in the treatment of periodontitis.
• It acts as a collagenase inhibitor and has been shown to reduce collagenase activity in the crevicular fluid of patients with adult periodontitis.

Gingival Enlargement and Medications

• Causes of gingival enlargement include inflammatory gingival enlargement, medication-induced gingival enlargement, hereditary gingival fibromatosis, and systemic causes.
• Medications associated with gingival enlargement include phenytoin, calcium channel blockers, and cyclosporine.

Periodontal Maintenance and Recall Intervals

• Periodontal maintenance begins after completion of active periodontal therapy and continues at varying intervals throughout a lifetime.
• Therapeutic goals of maintenance therapy include minimizing the recurrence and progression of periodontal disease, reducing the incidence of tooth loss, and increasing the probability of locating and treating other diseases or conditions.

Clinical and Radiographic Signs of Trauma from Occlusion

• Clinical signs of trauma from occlusion may include mobility, fremitus, occlusal prematurities, wear facets, tooth migration, tooth fracture, thermal sensitivity, and V-shaped gingival recession.

• Radiographic signs of trauma from occlusion may include thickening of the lamina dura, widened periodontal ligament spaces, bone loss, and root resorption.### Subgingival Antibiotics

• FDA approved 10% doxycycline in a gel system using a syringe (ATRidox) for subgingival placement as an adjunct to scaling and root planing.

• FDA approved a new, locally delivered, sustained-release form of minocycline microspheres (ARESTIN) for subgingival placement as an adjunct to scaling and root planing.

• 2% minocycline is encapsulated into bioresorbable microspheres in a gel carrier.

• Chlorhexidine in a gelatin matrix has been tested for subgingival placement with positive clinical results.

• PerioChip is a small chip (4.0 x 5.0 x 0.35 mm) composed of a biodegradable hydrolyzed gelatin matrix, cross-linked with glutaraldehyde and also containing glycerin and water, into which 2.5 mg of chlorhexidine gluconate has been incorporated per chip.

Systemic Administration of Antibiotics

• Tetracyclines are used to treat aggressive forms of periodontitis and have the ability to concentrate in periodontal tissues and inhibit the growth of Aggregatibacter actinomycetemcomitans (Aa).
• Subantimicrobial-dose doxycycline (SDD) is a 20-mg dose of doxycycline (Periostat) that is approved and indicated as an adjunct to scaling and root planing in the treatment of chronic periodontitis.
• Metronidazole is effective against Aa when used in combination with other agents and effective against anaerobes such as Porphyromonas gingivalis and Prevotella intermedia.
• Penicillins (amoxicillin and amoxicillin-clavulanate potassium [Augmentin]) may be useful in the management of aggressive forms of periodontitis (both localized and generalized forms).
• Clindamycin is often used when patients are allergic to penicillin.
• Ciprofloxacin is the only antibiotic in periodontal therapy to which all strains of Aa are susceptible.

Periodontal Ligament

• The periodontal ligament is a vascular and highly cellular connective tissue that surrounds the root of the tooth.
• It transmits occlusal forces to the bone.
• It acts as a shock absorber.
• It safeguards the vascular and nervous structures from injury by mechanical forces.
• It maintains the gingival tissue in its proper relationship to the teeth.

Cementum

• The cementum is a calcified vascular tissue that forms the outer covering of the root.
• It serves as support for the fibers of the periodontal ligament.

Alveolar Process

• The alveolar process is the maxilla and mandibular bone that supports the tooth socket.
• It consists of an outer plate of cortical bone and the alveolar bone proper.
• The outer plate is formed by compact bone lamellae and haversian bone.
• The inner socket wall, called alveolar bone proper, is a thin compact bone with a series of openings for the neurovascular bundles.
• The alveolar bone proper is seen in radiographs as lamina dura.

Gingiva

• The gingiva is divided anatomically into marginal, attached, and interdental areas.
• The marginal gingiva is about 1 mm wide and is the terminal border of the gingiva that embraces the teeth in a collar-like fashion.
• It is an unattached gingiva.
• The attached gingiva lies apically to the marginal gingiva and is firm, resilient, and attached tightly to the periosteum of the alveolar bone.
• The facial aspect of the attached gingiva is continuous with the relatively loose and movable alveolar mucosa; their junction is called mucogingival junction.
• The width of the attached gingiva coincides with the distance between the mucogingival junction and the projection on the external surface of the bottom of the gingival sulcus or the periodontal pocket.

Gingival Fibers

• Gingival fibers are collagen fiber bundles in the connective tissue of the marginal gingiva.
• They are made of type I collagen.
• They firmly hold the marginal gingiva against the tooth.
• They confer rigidity to the gingiva to bear the masticatory forces.
• They join the marginal gingiva with the root cementum and the adjacent attached gingiva.

Gingival Fiber Arrangements

• Gingivodental fibers are present on the facial, lingual, and interproximal surfaces incorporated within the cementum just underneath the epithelium at the base of the gingival sulcus.
• Circular fibers embrace the tooth in a ring-like fashion and course their way through the marginal and interdental gingival connective tissue.
• Transseptal fibers are horizontal fibers that run interproximally between the cementum of the teeth.
• They are situated between the epithelium at the base of the gingival sulcus and the alveolar crest of the adjacent teeth into which they are embedded.