Assalamaa aleh kum

Relining and Rebasing of Relining and Rebasing of Removable Partial DenturesRemovable Partial Dentures

Prof. Dr. S. Venugopal.

Indications for relining a distal Indications for relining a distal extension RPDextension RPD

• Loss of tissue support that causes rotation Loss of tissue support that causes rotation and settling of the distal extension base.and settling of the distal extension base.

• Loss of occlusal contact causing difficulty in Loss of occlusal contact causing difficulty in mastication mastication

The need for relining a distal extension The need for relining a distal extension

base is detected bybase is detected by • By applying pressure on the extreme distal end of By applying pressure on the extreme distal end of

the denture base and watching the anterior the denture base and watching the anterior indirect retainer as it lifts off.indirect retainer as it lifts off.

• Loss of occlusal contact is detected by having the Loss of occlusal contact is detected by having the patient close on two strips of blue casting wax. If patient close on two strips of blue casting wax. If the occlusal contact between the artificial dentition the occlusal contact between the artificial dentition is weak or lacking; while natural teeth in is weak or lacking; while natural teeth in opposition are making firm contact, then the RPD opposition are making firm contact, then the RPD needs relining.needs relining.

The need for relining a bounded case of a The need for relining a bounded case of a RPD is detected byRPD is detected by

• Unpleasant appearance, due to space Unpleasant appearance, due to space that may develop between the denture that may develop between the denture base and underlying tissues.base and underlying tissues.

• Lack of tissue contact and patient’s Lack of tissue contact and patient’s discomfort.discomfort.

• Entrapment of food debris. Entrapment of food debris.

I. Laboratory ReliningI. Laboratory Relining

• Closed mouth technique: Closed mouth technique: in bounded in bounded cases cases

• Open mouth techniqueOpen mouth technique : : in distal in distal extension casesextension cases

Closed mouth techniqueClosed mouth technique

Procedure:Procedure:• The tissue surface of the denture base is relieved to The tissue surface of the denture base is relieved to

accommodate the impression material.accommodate the impression material.• The impression material is mixed and applied to the tissue The impression material is mixed and applied to the tissue

surface and the PD is seated in the patient’s mouth making surface and the PD is seated in the patient’s mouth making sure that the impression material is kept away from the sure that the impression material is kept away from the occlusal rests.occlusal rests.

• The patient is asked to close in centric occlusion until The patient is asked to close in centric occlusion until complete setting of the material.complete setting of the material.

• An overall alginate impression is made, cast poured, then An overall alginate impression is made, cast poured, then the RPD is flasked, processed and reline material is added.the RPD is flasked, processed and reline material is added.

Open mouth techniqueOpen mouth technique

• functional reline impression functional reline impression technique technique

II. Intra-oral (chair side) reliningII. Intra-oral (chair side) relining

AdvantagesAdvantages• Saves time.Saves time.• The patient does not leave his denture.The patient does not leave his denture.N.B.N.B. • After relining occlusal corrections should be done. If After relining occlusal corrections should be done. If

minor adjustments are required it could be carried minor adjustments are required it could be carried out intraorally. However, occlusal adjustments for out intraorally. However, occlusal adjustments for distal extension PDs may be accomplished more distal extension PDs may be accomplished more accurately by remounting procedures.accurately by remounting procedures.

Removable Partial Removable Partial OverdenturesOverdentures

Prof. Dr. S. Venugopal.

DefinitionDefinition

• It is a removable prosthesis that is retained It is a removable prosthesis that is retained and supported by some of the natural teeth and supported by some of the natural teeth or roots under its base. If the natural roots or roots under its base. If the natural roots or teeth are replaced by an implant it is or teeth are replaced by an implant it is called an implant supported partial denture called an implant supported partial denture

IndicationsIndications

1.1. In cases where the chosen abutment teeth show improper In cases where the chosen abutment teeth show improper crown/root ratio, so reduction of the natural crown is crown/root ratio, so reduction of the natural crown is done to improve the C/R ratio.done to improve the C/R ratio.

2.2. In cases that provide poor prognosis if restored by In cases that provide poor prognosis if restored by conventional removable partial denture; for example:conventional removable partial denture; for example:

• Flat ridge Flat ridge • Few remaining natural teeth.Few remaining natural teeth.• Remaining healthy roots.Remaining healthy roots.• Long span, edentulous ridge.Long span, edentulous ridge.• A case contra-indicated for fixed partial dentureA case contra-indicated for fixed partial denture

IndicationsIndications

3.3. Excessive wear of the teeth, which may result Excessive wear of the teeth, which may result from erosion, abrasion or attritionfrom erosion, abrasion or attrition

4.4. Loose teeth that can be devitalized and reduced Loose teeth that can be devitalized and reduced in favor of C/R ratio and their presence in favor of C/R ratio and their presence maintain the level of alveolar bone.maintain the level of alveolar bone.

5.5. Patients with congenital defects are cosmetically Patients with congenital defects are cosmetically and functionally inadequate as regards dental and functionally inadequate as regards dental and alveolar arch relationships. Removable and alveolar arch relationships. Removable partial overdenture gives excellent (superb) partial overdenture gives excellent (superb) results.results.

ContraindicationsContraindications

• When other prosthesis give and provide When other prosthesis give and provide superior and efficient and more superior and efficient and more beneficial results.beneficial results.

• In cases of bad oral hygiene, where the In cases of bad oral hygiene, where the patient can't afford the least routine patient can't afford the least routine ways, that keeps and maintains the ways, that keeps and maintains the health of the remaining natural teeth. health of the remaining natural teeth.

• When the interarch space is insufficient.When the interarch space is insufficient.

AdvantagesAdvantages

• Good stability as its support is mainly from the teeth Good stability as its support is mainly from the teeth rather than the edentulous ridge.rather than the edentulous ridge.

• Provides more load distribution, which minimizes the Provides more load distribution, which minimizes the trauma of soft tissues and bone resorption.trauma of soft tissues and bone resorption.

• It needs minimum adjustment and modification, as it is It needs minimum adjustment and modification, as it is highly supported and stable.highly supported and stable.

• Preservation of proprioceptors in the periodontal Preservation of proprioceptors in the periodontal membrane of the remaining roots, so the jaw relation will membrane of the remaining roots, so the jaw relation will be easily recorded.be easily recorded.

• Easily accepted and used, so the patient is satisfied and Easily accepted and used, so the patient is satisfied and feels normal especially during mastication.feels normal especially during mastication.

DisadvantagesDisadvantages

• It can interfere with the inter-arch space, as it It can interfere with the inter-arch space, as it is more bulky (especially if not perfectly is more bulky (especially if not perfectly constructed).constructed).

• More time consuming and more expensive.More time consuming and more expensive.

• Needs more clinical and laboratory steps.Needs more clinical and laboratory steps.

Attachments in Attachments in Removable partial overdenturesRemovable partial overdentures

• Increases retention, stability and support.Increases retention, stability and support.

• Distribution of masticatory load between Distribution of masticatory load between abutment and tissues.abutment and tissues.

• Caries control.Caries control.

• Splinting of questionable abutments Splinting of questionable abutments

Implant supported Implant supported Removable partial OverdenturesRemovable partial Overdentures

IndicationsIndications

• Partially edentulous cases with unilateral or Partially edentulous cases with unilateral or bilateral free end saddle cases.bilateral free end saddle cases.

• Long span cases with few remaining teeth.Long span cases with few remaining teeth.

• To help periodontally involved teeth.To help periodontally involved teeth.

• In cases of resected mandible.In cases of resected mandible.

Repair of Repair of Removable Partial DenturesRemovable Partial Dentures

Prof. Dr. S. Venugopal.

Broken clasp armBroken clasp arm

• It may be replaced by wrought wire clasp It may be replaced by wrought wire clasp embedded in the resin or attached to the embedded in the resin or attached to the metal base by soldering.metal base by soldering.

• In cases where a rigid clasp is needed a new In cases where a rigid clasp is needed a new clasp assembly may be cast and attached to clasp assembly may be cast and attached to the framework by solderingthe framework by soldering

Broken occlusal restBroken occlusal rest

• A new clasp assembly is made and A new clasp assembly is made and soldered to the denture framework. soldered to the denture framework.

Addition of a new toothAddition of a new tooth

In cases where the last tooth is an abutment In cases where the last tooth is an abutment supporting a clasp armsupporting a clasp arm::

• Cut off the clasp arm and prepare the Cut off the clasp arm and prepare the adjacent tooth to receive the new clasp. Cast adjacent tooth to receive the new clasp. Cast the new clasp and attach it to the the new clasp and attach it to the framework by soldering, then add the framework by soldering, then add the artificial tooth to replace the lost natural artificial tooth to replace the lost natural toothtooth..

Addition of a new toothAddition of a new tooth

If the lost tooth is not the main abutmentIf the lost tooth is not the main abutment::

• If the denture base is resin simply make If the denture base is resin simply make retentive means in the acrylic resin and add retentive means in the acrylic resin and add the tooth. If the denture base is metal, this the tooth. If the denture base is metal, this necessitates both casting a new component necessitates both casting a new component and attaching it by soldering or creating and attaching it by soldering or creating retentive means for the attachment of an retentive means for the attachment of an acrylic resin extension.acrylic resin extension.

THANK YOUTHANK YOU

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