Matricing and Wedging PDF

Matricing and wedging By: Dr. Doaa Alhelais Consultant Advanced Restorative Dentistry Operative Dentistry Division  Reference: Art and science of operative dentistry 6th edition. An evidence-based review of dental matrix systems Barry M. Owens, DDS ¢ Jeffrey G. Phebus, DDS ...

Matricing and wedging By: Dr. Doaa Alhelais Consultant Advanced Restorative Dentistry Operative Dentistry Division  Reference: Art and science of operative dentistry 6th edition. An evidence-based review of dental matrix systems Barry M. Owens, DDS ¢ Jeffrey G. Phebus, DDS ILOs: Define the Matrix and its Function. Know the different type pf Matrices and the Advantage of each one. Learn the application and Removal Technique for each Type of Matrix. Know the different types of wedges and the application Technique.  OUTLINE:  Matrix (definition, Function , Requirement)  Matrix classification  Circumferential matrices with the application technique for each type.  Sectional Matrices.  Wedging  A matrix is defined as a properly contoured piece of metal or other material used to support and give form to the restoration during its placement and hardening. There is no method to control the placement and contour of restoration without a matrix wall. 1) Establish proper contour and contact. 2) Prevent marginal overhangs 3) Increase density and adaptation of the restoration by pressure application on the material. 4) Provide a smooth surface which is the best condition for biocompatibility with surrounding soft tissues.  Easy to adapt to teeth. Easy to contour. Easy to introduce and remove. With enough rigidity Thin enough not to occupy much space not interfere with the tightness of the contact. Smooth and highly polished Provide proper contouring and contact of the restoration. Compatible with the restorative material  On the basis of material (Metal, Plastic) On the basis of thickness (thick , thin , ultra thin) On the basis of rigidity ( rigid, flexible) On the basis of circumference (circumferential, sectional)  On the basis of circumference: (circumferential, sectional) 1- CIRCUMFERENTIAL MATRIX  A-TOFFLEMIRE MATRIX (UNIVERSAL MATRIX) Probably the most commonly used type of matrix system in the United States is the Tofflemire system. Tofflemire matrix assembly consists of the following: Matrix bands Matrix retainer  1) BAND 2 TYPES: FLAT BAND AND PRE CONTOURED A) Flat bands: Bands for the Tofflemire system come in several shapes and in three thicknesses: 0.0010, 0.0015, and 0.0020 inches. The thicker band is stiffer to resist deformation during condensation. The thinner bands are often used to help ensure a tight contact in Class 2 restorations. Any of the three thicknesses can be used to achieve excellent results, and selection is primarily a matter of operator preference. Flat bands: Because these bands are flat, they should be contoured before or after placement. Before placement: The band is laid on a paper pad or other compressible surface, and the area to be contoured is heavily rubbed with an ovoid burnisher, a beavertail burnisher, the convex back of the blade of a spoon excavator, or a convex After Placement : The area to be contoured is rubbed with the back of the blade of the spoon excavator or with some other thin, convex instrument  Flat bands: 3 Sizes of flat Band: By far the most frequently used shape is the no. 1, or Universal, band. The no. 2 (so-called MOD) band has two extensions projecting at its gingival edge to allow matrix application in teeth with very deep gingival margins in the proximal aspects of the tooth. The no. 3 band (MOD) has projections for deeper gingival margins, but the band is narrower than the no. 2 band. Precontoured bands: Precontoured from the company. When these bands are removed from interproximal contacts, the contour must be considered, and the band must be rotated in such a way that the trailing edge does not break or alter the shape of the marginal ridge as the band is being removed. 2) RETAINER Tighten or loosen the rod Increase or decrease the matrix circumference  TOFFLEMIRE MATRIX (UNIVERSAL MATRIX) 2) RETAINER The open side of the head (Slot) should face gingivally when the band is placed around the tooth.  TOFFLEMIRE MATRIX (UNIVERSAL MATRIX) 2) RETAINER  TOFFLEMIRE MATRIX (UNIVERSAL MATRIX) 2) RETAINER 2) RETAINER There are two types of Tofflemire retainers based on the angulation of the head : Straight and Contra angled. Contrangled used when there is Buccal Cavity or missing Buccal Wall and you need to put the retainer lingually ASSEMBLY AND PLACEMENT: The band should be seated around the tooth such that: 1. The occlusal portion of the band extends 1.5 – 2.0 mm above the marginal ridge of the adjacent tooth. 2. The gingival portion of the band extends 0.5 mm below the gingival margin. ASSEMBLY AND PLACEMENT: INDICATION : 1- Class I compound with buccal or lingual extensions. 2- restoring class II cavities on one or both the proximal surfaces of posterior teeth.  ULTRADENT OMNI MATRIX Preassembled Tofflemire retainer and band that intended for one time use (disposable). The band’s circumference can be easily adjusted simply by twisting the handle and the pivoting head allows it to access any quadrant of the mouth. Once the restoration is complete, the Omni-Matrix band easily releases without disturbing the restorative material. Innovative shape allows superior procedural visibility and patient comfort. Ultra-thin burnishable stainless steel adapts to all preparations. Unique winged and wingless styles meet individual case needs. Disposable design saves you time and money Available in stainless steel and mylar  B- AUTOMATRIX The Automatrix is a retainerless matrix system designed for any tooth regardless of its circumference and height.  B- AUTOMATRIX Components: 1-automatrix band (available in three widths), 2-automate tightening device (adjust loop of band according to circumference of the tooth to be restored), 3-shielded nippers (used to cut auto lock loop, so that band can be separated and removed from the tooth). 3 2 1  Advantages of this system include (1) convenience, (2) improved visibility because of absence of a retainer, (3) ability to place the auto-lock loop on the facial or lingual surface of the tooth. Disadvantages of this system are that (1) The band is flat and difficult to burnish and is sometimes unstable even when wedges are in place. (2) development of proper proximal contours and contacts can be difficult with the Automatrix bands.  C- T-BAND MATRIX Premade T shape brass or SS matrix band. The long arm of T curled to encompass the tooth circumfrentially and overlap the short horizontal arm of T , then it bent over the long arm. II- SECTIONAL MATRIX  A-SECTIONAL MATRIX Studies have shown that use of sectional matrices for composite restorations are on a rise. Sectional matrices do not only result in tighter anatomical contacts but also are dentist friendly. The marginal ridge strength obtained with a contoured sectional matrix is significantly greater than that obtained with a straight, circumferential band.  A-SECTIONAL MATRIX These sectional matrices are relatively easy to use, very thin, and come in different sizes that can be used according to the clinical situation. There are several systems available and selection is based on operator preference These systems may use a bitine ring to (1) aid in stabilizing the matrix band and (2) provide additional tooth separation while the composite is inserted. The primary benefit of these systems is a simpler method for establishing an appropriate composite proximal contour and contact. PALODENT PLUS  B- Anterior matrix 1-Clear polyester matrix (Mylar/ Celluloid): Class III and IV PreContoured or Flat  B- Anterior matrix Cervical Clear Matrix: Used in Class V light-cured tooth colored restorations. Small handle to aid in picking the matrix A curing tip can be placed against this handle to cure through and hold the matrix in place during composite curing.  C- Walser matrix It has different shapes: X-shape for biplane fillings with existing interdental space , O-shape for MOD fillings and single, freestanding teeth, ON-shape for terminal teeth, XF shape for Anterior. X-shape O-shape ON-shape XF-shape  WEDGES Function: 1. used for pre wedging.(promote more conservative preparation and protect adjacent tooth during preparation) 2. Prevent marginal overhangs 3. Maintain adequate temporary teeth separation to compensate for the thickness of the matrix. 4. Assure close adaptability of the band 5. Establish retraction of the rubber dam and gingiva. Types of Wedges: - According to Materials of fabrication: A) Wooden Wedge ( Triangular , Round, Anatomical ) B) Plastic Wedge or light reflecting plastic wedge A) Wooden Wedge: - Available in various sizes, which may be color coded. - They are either straight or anatomically shaped - They absorb water interiorly and swell up, which improves separation. Anatomical or triangular wedges are recommended for deeper and / or wider proximal preparations because its greatest cross-sectional dimension is at its base. B) Plastic wedges : Light reflecting wedges: Transparent plastic wedges with built in light reflecting property help to assess in direction light to inner proximal area during initial stage of class II composite curing Wedge Placement : A wedge should usually be inserted from the side with the widest embrasure. The wedge must be positioned so that its base is also gingival to the gingival margin. Should be tight enough to prevent overhang of restoration (The explorer pressed against the matrix band at gingival margin of the cavity to check tightness of matrix to the margin) THERE IS SPCAE BETWEEN THE MATRIX AND THE TOOTH >> NEED TO USE WEDGE  If wedge is placed more occlusal to the gingival margin, it creates abnormal concavity in the proximal surface of the restoration. If wedge is placed more apical to gingival margin, band will not be held tightly against the gingival margin & creates gingival overhangs in the restorations. Wedge Placement : When rubber dam cannot be used, care should be taken when inserting the wedge because of the susceptibility of the gingiva to bleed upon removal. Wedges cannot be placed in the inflamed gingiva as it can cause bleeding.  -Maxillary 1st premolar -Shallow proximal -Large spacing because of presence of Box with gingival -Wide cavity flutes in root near recession buccolingually gingival area