For restoration to survive long term the periodontium must remain healthy so that teeth are maintained.
For the periodontium to remain healthy restoration must be critically maintained in several area so that they are in harmony with their surrounding periodontal tissue.
To maintain and enhance the patient esthetic appearance the tooth-tissue interface must present a healthy natural appearance with gingival tissue framing a restored teeth in a harmonious manner.
Defective dental restorations and anatomical aberration of the teeth often favour plaque accumulation leading to gingival inflammation.
Hypersensitivity to restorative material
- Sub gingival debris
ESTHETIC CONSIDERATION IN GINGIVAL TISSUE: - Interproximal Embrasure form. - Restorative correction of open gingival Embrasure OCCLUSAL CONSIDERATION ROLE OF DENTAL PROSTHESIS RESTORATION OF ROOT RESECTED TOOTH ANTERIOR ESTHETIC SURGERY
Location, fit and finish of restorative margins are critical factor in the maintenance of peridontal health.
According to the concept of “ extension for prevention” Postulated by G.V. Black, margins of restoration have to be placed on self cleancing regions of teeth.
Restoration with supragingival margin gave the most favourable gingival response.
Restoration with margin placed subgingivally appeared to be most harmful to the periodontium.
Gingival inflammation and loss of attachment with pocket formation have been observed.
Surface roughness of the restoration and tooth- restoration interface favour plaque retention.
Restorative margin should preferably be placed supragingivally.
In case when placement of restorative margin subgingivally is unavoidable due to caries, tooth fracture, previous restoration or aesthetics, it should placed not more then 0.5 mm into the sulcus so that plaque should be achieved.
BIOLOGICAL WIDTH :
The dimension of space that the healthy gingiva tissue occupy above the alveolar bone is identified as Biological Width.
An average length of 1.07mm of connective tissue attachment and 0.97mm of epithelial attachment.
So on an average the biological width measures 2.04mm.
Invasion of this space result in inflammation and crestal resorption of alveolar bone.
Invasion of the biological width should avoided during restoration, in order to prevent attachment loss and persist gingival inflammation.
The more common finding with deep marginal placement is that the bone bevel appears is remain unchanged but gingival inflammation develops and persist.
Evaluation of biological width:
Radiographic interpretation can identify interproximal violation of biological width.
If patient having discomfort when restorative margins level being assessed with a periodontal probe it is a good indication that the margin extends into the attachment and that a biological width violation occurred.
more positive assessment can be made clinically by measuring the distance between the bone and margin.
The probe is pushed through the anaesthetized attachment tissue from the sulcus to the underlying bones.
If the distance is less than 2mm at one or more location, a diagnosis of biological width violation
can be confirmed.
Assessment is completed circumferentially around the tooth.
The biological or attachment , width can be identified for each individual patient by probing under anesthesia to the bone level and subtracting the sulcus depth from the resulting measurement.
this measurement must be performed on teeth with healthy gingiva tissue and should be reapeted more than one tooth for accurate measurement.
The information is obtained is then used to definitive diagnose biological width violation.
1.SURGICALLY: By removing bone away from proximity to the restorative margins. Drawback: High risk of inter papillary recession. 2. ORTHODONTICALLY: By extruding the tooth out of the socket. Correction of Biologic-Width Voilation:
By applying low extrusive forces
By rapid orthodontic extrusion
Why the restoration extended sub-gingivally???
For adequate resistance& retention
To make significant contact & contour
To mask the tooth-restoration interface gingivally.
Too Sub-Gingivally located margins may results…..
Unpredicted bone loss
Gingival tissue recession
Other factors inducing Gingival recesion:
Trauma from restorative procedures
Thickness of gingiva
Gingival Form- scallopedFlat
Overhanging restoration most commonly encountered with amalgam restoration.
Improper placement of matrix band and wedge result in over hanging restoration.
This area are most frequently area of plaque retention.
It also create an enviornment favourable for the growth of pathogenic organism.
Removal of overhangns followed by professional tooth cleaning result in improvement of periodontal tissue.
Marginal fit :
Marginal fit has clearly been implicated in producing an inflammatory response in the peridontium.
The level of gingival inflammation can increase corresponding with the level of marginal opening.
Margins that are significantly open are capable of harboring large number of bacteria and may be responsible for the inflammatory response .
Restoration contour extremely importance of the periodontal health.
Contour provides access for hygiene.
Baker and Wayne described three theories of crown contour, they are
(1) Gingival protection theory
(2) Muscle action theory
(3) Theory of access for oral hygiene.
According to gingival protection theory the contour of the restoration should be designed to protect the marginal gingiva from mechanical injury during mastication.
Over contour of crown leads to plaque retention and marginal gingivitis.
According to muscle action theory believe that the functional movement of lips, cheeks and tongue has cleansing action of teeth.
The crown contour should be designed to facilitate this cleaning action during mastication.
According of access for oral hygiene is based on the concept that periodontal disease is plaque associated.
Over contouring of crown decrease access for oral hygiene.
EFFECT OF DIFFERENT RESTORATIVE DENTAL MATERIAL ON GINGIVA:
Inflammatory gingival response have been reported related to the use of non precious alloy in dental restoration.
Rough dental surface favour plaque accumulation and contribute to periodontal disease.
In class II amalgam restoration polishing of the proximal surface is difficult and surface appear rough as compared to enamel surface.
Three to four year old composite restoration showed greater deterioration with higher plaque.
Composite resins and glass ionomer cement are the material of choice for restoration, where the aesthetics are important.
Porcelain seems to retain plaque than other restorative materials.
The highly polished surface of porcelain inhibit plaque formation and permits its rapid removal too.
Plaque retentive properties of the restorative materials appear to be most important factor responsible for initiation of periodontal disease.
Leaving debris below the tissue during the restorative procedure can cause adverse periodontal ligament Changes.
Cements - Temporary permanent
ESTHETICS COSIDERATION OF GINGIVAL TISSUE
Any change in shape or form of embrassure Change in height & form of the papilla Food impaction, Accumulation of micro-organisms & Plaque accumulation Inter-proximal Embrasure Form
Too Wide Embrasure – Flattened & Blunt Papilla
Too Narrow Embrasure – Inflammed Papilla
Ideal Embrasure – Healthy & pointed Papilla
PROXIMAL CONTACT AND EMBRASURE
Proper proximal contact is essential to prevent food impaction.
Forceful wedging of food into interproximal spaces occur due to the funneling effect of adjacent tooth surface directing food interproximally and into open contact areas.
Opposing cusp which force into the proximal area is called plunger cusp.
The mechanical pressure on the interdental tissue can cause ischemia, inflammation, and necrosis of the interdental tissue.
It favours plaque growth and pocket formation.
The contact point should be placed occlusally and buccally to facilitate access for interdental plaque control.
Ideal interproximal embrasure should house the gingival papilla without impinging on it and also extend the interproximal tooth contact to the top of the papilla so that no excess space exist to trap food .
RESTORATIVE CORRECTION OF OPEN GINGIVAL EMBRASURE
Mainly there are two cause of open gingival embrasure : either the papilla is inadequate in height due to bone loss or interproximal contact is located to high coronally.
If high contact has been dignosed as the cause of the problem ther are two potential reasons either root angulation of tooth diverge or interproximally contact is moved coronally resultig in the open embrasure.
If the root angulation of the tooth diverges -> the interproximal contact is moved coronally -> open embrasure.
If the root are parallel, the papilla form is normal, and open embrasure exists than the problem is related to tooth shape.
Restorative procedure can correct this problem by moving the contact point to the tip of the papilla.
The margins of the restoration must be carried subgingivally 1 to 1.5mm.
And emergence profile of the restoration is designed to move the contact point toward the papilla while blending the contour below the tissue.
The increases in the utilization of the dental implant and nonmetalic cosmetic restoration has resulted with the increases concern with the force management.
The restoration is the more sensitive with occlusal trauma.
For create good occlusion following point should be follow:
(1) There should be even simultaneous contact on all teeth during centric closure. This distributed the force of closure over all teeth instead of few teeth.
(2) When the mandible moves from centric closure some form of canine or anterior guidance is desirable with on posterior tooth contacts.
(3) The anterior guidance needs to be harmony with the patients neuromuscular envelop of function. Relationship is demonstrated by a lack of framitus and lack of mobility of anterior teeth, patient can speak clearly and comfortably.
(4) The occlusion should be created at a verticle dimension that is stable for the patient.
It is generally accepted that the patient existing vertical dimension is an equilibrium between the eruptive force of their teeth and the repetitive contracted length of their elevator muscle.
(5) When managing a pathological occlusion or when restoring a complete occlusion a repeatable condoler reference position is needed.
ROLE OF DENTAL PROSTHESIS
Removal partial dentures prepared without occlusal lag tends to shink into edentulous area causing gingival recession of adjacent tooth .
This can be prevented by providing occlusal lag to the clasp.
Fixed prosthesis should be designed to facilitate mechanical plaque control .
For type of pontic design :
Modified ridge lap pontic with concave gingival surface and open interproximal space. Cleaning the undersurface of pontic is difficult in this case, as the pontic makes a surface contact with gingival tissue buccally and lingually.
Lap facing pinpoint contact pontic with open interproximal space.
The pontic makes only a pinpoint contact with ridge and interproximal space are open so the cleansing is easy.
3. Lap facing pinpoint contact pontic with closed interproximal space. 4. Sanitary pontic Contact between the pontic and alveolar mucosa should be restricted to pinpoint as far as possible plaque control.
Restoration of Root – Resected Tooth
One piece cast or core is indicated.
Development of appropriate contour for hygienic access.
Avoid any excess convexities.
Applied to: Bonded External Appliances Intra Coronal Appliances Indirect Cast Restorations Indication: To prevent mobility
Any inflammation of the periodontal Supporting tissues must be controlled before making a decision for splinting because Inflammation may cause mobility in presence of normal occlusal forces & PDL. Support.
Anterior Aesthetic Surgery
More Imp. in Anterior Region
Gingivectomy, Apically displaced flaps with osseous recontouring & Use of Orthodontics in positioning the gingiva apically or coronally by Extruding or Intruding the teeth.
Computer Imaging for Visual preview
A Stone cast of patient`s own teeth may be used – Composite or Acrylic veneer is constructed on the cast extending gingivally in a correct position.
A defective dental restoration and anatomical aberrations of the teeth often favour plaque accumulation leading to gingival inflammation.
A good knowledge of such factor is essential for prevention of periodontal disease by adapting suitable restorative procedure or correcting the anatomical defect.
REFERENCE : Clinical periodontology - Michael G.Newman - Henry H. Takei - Ferrmin A. Carranza Clinical periodontology and Implant Dentistry -Jan Lindhe