Page 20 - DP Vol 19 No 6 pw_Neat

RestoRative section

Minimally Invasive Restorative

Approach With Indirect

Restorations: Case Reports

With Two Materials

Sachindeep Singh

Restorative dentistry has undergone dramatic changes in the past two long term success. The mechanical properties of glass ceramics closely
decades regarding the preservation of the remaining tooth structure. mimic those of enamel, making them a natural choice for replacing the
Now we understand the importance of various aspects of posterior missing enamel.
teeth morphology and its role in maintaining tooth strength against Their ability to be milled makes them well-suited to the digital
masticatory and parafunctional forces. dentistry that is currently practiced.
Minimally invasive restorative techniques approach the restoration The flip side is that in large restorations, especially post endodontic
two ways:- cases where loss of tooth structure is more, a lot of dentin replacement
1. Preparation designs which focus on preserving the maximum tooth is required. Glass ceramics lack the properties matching those of dentin,
structure and the obvious choice of material to replace dentin is composites.
2. Restorative materials and adhesive dentistry which aim to restore So in these cases one has to first replace dentin via composites and
function effectively. then prepare the tooth for an onlay, which is later bonded on to the
This article highlights the utilization of two different materials dentin core and available tooth margins.
through three case reports, emphasizing on indirect restorations.
Indirect CAD/CAM Resins [Edelweiss Blocks]
PREPARATION DESIGNS AND THEIR RATIONALE The edelweiss CAD/CAM BLOCK has a homogenous base material of
Human molars exhibit various morphological design aspects and we, glass (silica) manufactured through a patented process of controlled
as clinicians, must understand their significance. The enamel layer laser sintering technology fusing the glass crystals. The finished product
surrounding the dentin creates a dome effect. Any breach in this layer is characterized by a single glass phase embedded in a hybrid matrix.
considerably reduces the fracture resistance. Transverse ridges play The properties of both particle reinforced and predominately glass
a crucial role in stress strengthening, enabling the tooth structure to ceramics are featured in a single hybrid glass block, having the strength
withstand occlusal loads. Peri-cervical enamel and dentin constitute of reinforced ceramics, the optical properties of predominantly glass
the maximum strength of the tooth against any lateral forces. The ceramics and the flexibility of dentin. Its versatile application, together
preparation design for any indirect restoration aims at the following:- with its time and cost saving procedure makes the edelweiss CAD/
1. Preservation of healthy transverse ridges, marginal ridges and CAM BLOCKs a preferred alternative where the dentin portion to be
oblique ridges. replaced is larger and one can do both layer replacement with indirect
2. Preservation of peri-cervical enamel and dentin. method.
3. Re-establishing the natural dome effect of the two layers The base material of the edelweiss block is glass, in which crystals
4. Creating enamel-dentin complex like structure using Dentin are joined by controlled laser sintering. The edelweiss CAD/CAM
Bonding agents. BLOCK is mainly composed of silica and barium glass with a very
Post-endodontic teeth require cusp coverage to re-establish the small portion of resin, combining the added advantages of ceramic and
dome effect, but care should be taken to preserve the remaining polymer materials into one block.
tooth structure. The cases reported here followed the same rationale,
employing partial onlay designs. CASE 1: PARTIAL ONLAY: EMAX
A 40-year-old male patient underwent endodontic treatment in
MATERIALS FOR INDIRECT RESTORATIONS tooth number 46 (Figures 1, 2). As visible, the tooth still had the
Lithium Disilicate [Emax] mesial marginal ridge intact. The mesial contact is also intact, and
Glass ceramics have been the mainstay in indirect posterior restorations. its configuration is almost impossible to duplicate in a restoration.
Lithium disilicate has been the best material available to us in terms of A partial onlay with glass ceramic was planned. As large amount of
aesthetics, strength, bondability, opposite tooth wear, polishability and dentin loss is seen, the missing dentin was replaced via direct composite

20 Dental Practice I November-December 2023 I Vol 19 No 6