Basing materials (materials Basing materials (materials used to protect pulp): role, used to protect pulp): role, classification, indications.classification, indications.

ObjectivesObjectives::Cavity preparation is relationship with pulpCavity preparation is relationship with pulp

Explain the protecting the pulp with cavityExplain the protecting the pulp with cavity

Describe the purpose of using cavity liners, Describe the purpose of using cavity liners, list the type of materials that can be used list the type of materials that can be used and explain the placement procedureand explain the placement procedure

Describe the purpose of using cement base. Describe the purpose of using cement base. List types of materials and placement List types of materials and placement procedureprocedure

Introduction:Introduction:

Should be familiar preparation of the cavity Should be familiar preparation of the cavity with the amount of enamel and dentin with the amount of enamel and dentin removed and how near the preparation is to removed and how near the preparation is to the pulp the pulp

Should understand the pulp protection Should understand the pulp protection theory that the depth of cavity preparations theory that the depth of cavity preparations and pulpal relationand pulpal relation

Cavity preparation/Pulp Cavity preparation/Pulp protection theoryprotection theory

The cavity preparation for a restoration The cavity preparation for a restoration depends on the amount of decay, the depends on the amount of decay, the location of the decay, and the type of location of the decay, and the type of materials used to restore the toothmaterials used to restore the tooth

Should examine the cavity preparation to Should examine the cavity preparation to assess pulpal involvement and then place assess pulpal involvement and then place the liners, base, or warnish the liners, base, or warnish

Treatment of cavity preparationsTreatment of cavity preparations

1.1. Treatment of the ideal cavity preparationTreatment of the ideal cavity preparation

2.2. Treatment of the beyond – ideal cavity Treatment of the beyond – ideal cavity

preparationpreparation

3. Treatment of the near – exposure cavity 3. Treatment of the near – exposure cavity preparationpreparation

Treatment of the ideal cavity Treatment of the ideal cavity preparation:preparation:

A base is not required because only a minimal A base is not required because only a minimal amount of enamel and dentin has been removedamount of enamel and dentin has been removed

Some dentists place only the restoration, while Some dentists place only the restoration, while other prefer to place a fluoride –releasing linerother prefer to place a fluoride –releasing liner

If an amalgam restoration is going to be placed, If an amalgam restoration is going to be placed, two thin layers of cavity varnish are often placed two thin layers of cavity varnish are often placed over the dentinover the dentinIf a composite restoration is going to be used, a If a composite restoration is going to be used, a glass ionomer liner or calcium hydroxide is placed glass ionomer liner or calcium hydroxide is placed over the exposed dentin over the exposed dentin

Treatment of the beyond – ideal Treatment of the beyond – ideal cavity preparationcavity preparation

With a beyond –ideal preparation , the With a beyond –ideal preparation , the level of the dentin is restored with a level of the dentin is restored with a cement base cement base

With an amalgam restoration, there are With an amalgam restoration, there are several options. One option is to placetwo several options. One option is to placetwo thin layers of varnish to seal the dentin thin layers of varnish to seal the dentin tubules and then place a layer of a cement tubules and then place a layer of a cement base, such as zinc phosphate base, such as zinc phosphate

Another option is a reinforced ZOE base Another option is a reinforced ZOE base which has a soothing effect on the pulp. which has a soothing effect on the pulp. Varnish is not used with this materialVarnish is not used with this material

Other options include polycarboxylate or Other options include polycarboxylate or glass ionomer base, which also do not glass ionomer base, which also do not require varnishrequire varnish

Under composite restorative materials, Under composite restorative materials, use a glass ionomer base or calcium use a glass ionomer base or calcium hydroxide hydroxide

Treatment of the near – exposure Treatment of the near – exposure cavity preparation:cavity preparation:

The nearer the cavity preparation comes The nearer the cavity preparation comes to the pulp, the more precautions are to the pulp, the more precautions are needed. There are also several options of needed. There are also several options of treatment of the near-exposure treatment of the near-exposure preparationpreparation

Cavity which going to restore with Cavity which going to restore with amalgam, a liner of calcium hydroxide , amalgam, a liner of calcium hydroxide , glass ionomer , or ZOE is placed first , glass ionomer , or ZOE is placed first , then a layer of cement base such as Zinc then a layer of cement base such as Zinc phosphate, polycarboxylate, or glass phosphate, polycarboxylate, or glass ionomer cements ionomer cements

Another option for amalgam restoration is to Another option for amalgam restoration is to place a liner, then a layer of reinforced ZOE, place a liner, then a layer of reinforced ZOE, polycarboxylate, or glass ionomer cement. This polycarboxylate, or glass ionomer cement. This is then sealed with cavity varnish , although is then sealed with cavity varnish , although some dentist do not place cavity varnishsome dentist do not place cavity varnish

Restore with composite, a liner is placed first, Restore with composite, a liner is placed first, then place a layer of either polycarboxylate or then place a layer of either polycarboxylate or glass ionomer cementglass ionomer cement

A cavity liner is placed on a near exposure, the A cavity liner is placed on a near exposure, the procedure is often referred to as an indirect pulp procedure is often referred to as an indirect pulp capping capping

Treatment of the exposed- pulp Treatment of the exposed- pulp cavity preparation:cavity preparation:

In an exposed pulp, should be decided In an exposed pulp, should be decided whether endodontic treatment is indicated whether endodontic treatment is indicated or should save the vitality of the tooth.or should save the vitality of the tooth.

If the treatment of choice is to save the If the treatment of choice is to save the pulp, a procedure called a pulp, a procedure called a direct pulpdirect pulp cappingcapping is performed is performed

Cavity linersCavity liners Cavity liners are placed in the deepest Cavity liners are placed in the deepest portion of the cavity preparation on the portion of the cavity preparation on the axial walls or pulpal walls axial walls or pulpal walls When the liners are hardened, they form When the liners are hardened, they form as a cement layer with minimum strengthas a cement layer with minimum strengthLiners are protect the pulp from chemical Liners are protect the pulp from chemical irritations and also provide a therapeutic irritations and also provide a therapeutic effect to the tooth effect to the tooth Liners are calcium hydroxide, zinc oxide Liners are calcium hydroxide, zinc oxide eugenol, and glass ionomer cementeugenol, and glass ionomer cementLiners also called low-strength base Liners also called low-strength base

On this direct pulp capping treatment, place the On this direct pulp capping treatment, place the calcium hydroxide or glass ionomer liner and calcium hydroxide or glass ionomer liner and then reinforced ZOE as a temporary restoration . then reinforced ZOE as a temporary restoration . This gives to the dentist time to see whether the This gives to the dentist time to see whether the pulp is going to heal pulp is going to heal

Another treatment involves the placement of a Another treatment involves the placement of a liner, a layer of ZOE cement, two thin layers of liner, a layer of ZOE cement, two thin layers of varnish, and cement basevarnish, and cement base

Some dentist prefer to place a liner and then a Some dentist prefer to place a liner and then a layer of polycarboxylate or glass ionomer layer of polycarboxylate or glass ionomer cement base cement base

Placement of cavity liner in Placement of cavity liner in preparationpreparation

Cavity varnishCavity varnish Cavity varnish is used to seal the dentine Cavity varnish is used to seal the dentine tubules to protect acids, saliva and debris tubules to protect acids, saliva and debris from the pulp from the pulp

It is used under amalgam restorations to It is used under amalgam restorations to prevent microleakageand under zinc prevent microleakageand under zinc phosphate cement to prevent penetration phosphate cement to prevent penetration of acid to the pulpof acid to the pulp

If cavity liners or medicated based are If cavity liners or medicated based are used,varnish is placed after or on top of used,varnish is placed after or on top of these materials these materials

Placement of cavity varnishPlacement of cavity varnish

Cement basesCement bases

Cement bases are mixed to a thick putty Cement bases are mixed to a thick putty and placed in the cavity to protect the pulp and placed in the cavity to protect the pulp and provide mechanical support for the and provide mechanical support for the restoration restoration

These cement bases are placed on the These cement bases are placed on the floor of the cavity floor of the cavity

Cement bases are glass ionomers, hybrid Cement bases are glass ionomers, hybrid ionomers, reinforced zinc oxideionomers, reinforced zinc oxide

Placement of cement basesPlacement of cement bases