Indications:

WELCOME TO WEEKLY SCIENTIFIC SEMINER

CHAIRPERSON

DR. MD. MAHABUBUR RAHMAN BDS,DDS,PhD

ASSOCIATE PROFESSOR & CHAIRMAN

DEPARTMENT OF PROSTHODONTICSBSMMU,DHAKA

CO-ORDINATOR

DR. MD. MASUDUR RAHMAN BDS,MS,FCPS

ASSOCIATE PROFESSORDEPARTMENT OF PROSTHODONTICSBSMMU,DHAKA

PRESENTER

Dr. A. K. M. Rashedul AlamFCPS Part-2 traineeDepartment of ProsthodonticsFaculty of Dentistry, BSMMU

Metal free Inlay retained fixed partial dentureMetal free Inlay retained fixed partial dentureIts a newer technique in the field of Prosthodontics.

It is highly technical & material selective procedure.Why should we choose metal-free inlay retained FPD ?Due to-

the advantage of preservation of tooth structure excellent esthetics entirely fabricated by tooth color materials a high degree of light transmission outstanding corrosion resistance less plaque accumulation- so less caries & less periodontitis

Generally-Metal-reinforced system are the material of choice for fabricating posterior FPDs because of their-ReliabilityDurablityBut this prosthesis characterized by certain basic disadvantages-May have a negative effect on adjacent soft tissueMay induce caries in adjacent teethThe unattractive opaque & darkish appearance mainly in the abutment teeth portion.So, we can overcome the limitations of MetalReinforced system by metal free inlayretained fixed partial denture.Indications short span FPDs residual dentition exhibits low caries activities parallel alignment of abutment teeth immobility of abutment teeth minimum height of abutment teeth > 5mm good oral hygiene

Possible indication for a metal-free inlay retained FPD.

Contraindications:Severe parafunctionsShort clinical crownPoor oral hygiene with unhealthy periodontiumContinue-Existing therapy resistant periodontopathologic complaints Any allergy to the components of dentine adhesive or luting composite

So, the factors should be carried out before planning inlay retained all ceramic FPDs -Thorough intraoral examinationRadiographs of the designated abutment teeth(proximal caries, periodontium )Model analysis of both jawContinue-position of the antagonistic contact Existing hyper balancesThe length of clinical crownPontic spanAlignment of abutment teeth

Continue-Generalized wear facetsIn addition, canine guidance must be ensured to protect the inlay retained all ceramic FPDs from torsional stress.

Materials used for metal free inlay retained FPDs-1.High strength pressed ceramic

Continue-2.Fibre-reinforced composite(FRC)

Preparation of the abutment teeth for inlay retained all ceramic FPDs-2-mm occlusal preparation depth (floor of the isthmus to central groove) 1.5 mm preparation depth of proximal box

Continue-Isthmus width of 1.5- 2mm in premolars and 2.5-3 mm in molarsProximal angle of the internal cavity surface to the enamel surface 100 to 120 degrees

Minimum dimensions of connectors: 4mm x 5mm

Continue- Abutment teeth with a wide bucco-oral defect as well as devitalized abutment teeth; inclusion of cusps in the preparation

Divergence angle of the cavity of approximately 6 degrees

Impression and provisional restorationA one step technique using elastic materials is recommended for impression taking(eg- permadyne, ESPE)The provisional restoration is fabricated using transparent, reusable polyethylene-based vacuum-formed templates and a bis-GMA resin(eg- protemp 2, ESPE

Insertion The restoration must be inserted according to the adhesive technique exclusively in conjunction with absolute isolation using a rubber damProvisional cement residues are removed using pumice paste ; the use of H2O2 is contraindicated-as nascent oxygen may inhibit the polymerization of the luting composite

Continue-Then, in case of high strength pressed ceramic, the contact surface of inlays are etched with a buffered hydrofluoric acid for 20 seconds.

Continue-But, in case of FRC materials the surfaces of restoration must be conditioned according to modified procedure

Continue-Following the drying, a bonding agent (silane) is applied to the conditioned contact surfaces of the restoration

Continue-The prepared tooth is thoroughly cleaned and dried

The enamel margin of the cavity are selectively etched with 37% orthophosphoric cid for approximately 30 seconds.

Continue-The dentine surface are wetted with bonding agent (dual bonding agent)

The bonding agent is also to be applied to the conditioned inlay contact surfaceDuring the following treatment, neither the inlay-retained FPD nor the prepared tooth should be directly exposed to the operatory lights to prevent premature polymerization The bonding agent is blown to a thin layer with a gentle stream of air after the reaction time(20 sec)

Following enamel and dentine conditioning, the cavities are filled with a highly viscous, purely light curing composite materials.

Luting composite are available in a variety of shades

The inlay-retained FPD is placed on the abutment teeth and seated in the cavities using an ultrasonic tip.

Once the restoration is correctly place, excess composite is removed with resin pellets and dental tape.

Subsequently, a glycerin gel is applied to the tooth-restoration interface to prevent the formation of an oxygen-inhibited layer.

Initial curing period- 10-20 sec which turns the composite into a jelly like state. At this stage, excess can be removed near the sulcus with the help of a scalar.

The final curing must be conducted very carefully. The abutment teeth are exposed to a high performance curing light from all sides, each side is exposed for 120 seconds.

Because of the limited curing depth associated with inlay-retained FPDs featuring framework of more than 3mm in thickness- dual cure (eg, Variolink-2,Vivadent) or self-curing(eg, Panavia 21 TC,Kuraray) luting composites are recommended. Preparation of an FRC FPD which has been prepared for a partial crown retainerCompleted FRC FPD prior to the adhesive placement with low viscous dual cure luting composite

Glycerin gel applied to the tooth-restoration interface after removal of excess resinPermanently placed FRC FPD after finishing and polishing.

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