Direct and indirect stamp techniques for composite restorations - Sealing the uniqueness of a tooth: A case series.

Composite resin restorations using the incremental technique are time-consuming and technique sensitive requiring excellent hand dexterity of the clinician for achieving good contacts and contours. "Stamp technique" for posterior composite restoration is a novel method for duplicating occlusal anatomy with near perfection. This technique is indicated when the preoperative anatomy of the tooth is intact. An indirect technique can be used in cases where the occlusal surface is cavitated due to caries. The purpose of this article is to demonstrate the direct and indirect technique of stamp fabrication and restoration using different materials, emphasizing the fact that it is reliable and predictable and, when performed correctly, helps the practitioner to a great extent. Copyright:

INTRODUCTION

Dental caries is a multifactorial disease leading to demineralization and destruction of inorganic and organic components of the teeth.[1] Gradually, the morphology of the carious lesions has changed, leading to lesions with intact enamel surfaces.[2] A restoration that rehabilitates the carious lesions should not only aim to replace the lost tooth structure but also should re-establish its ideal form and function which is the “ultimate goal” of restorative dentistry.[3]

Restorations can be direct or indirect. Unlike indirect restorations, where contact, contour, and occlusion are well achieved, direct restorations are technique sensitive, time-consuming, and may not reproduce optimal form and occlusion. Direct restorative materials include dental amalgams, glass-ionomer cement (GIC), and composites. Given the drawbacks of dental amalgam and GIC, composite resin restorations, owing to their excellent mechanical properties, esthetics, and biocompatibility, have become the new norm.[4]

Direct composites carry the burden of polymerization shrinkage, a time-consuming procedure requiring excellent operators’ skills to achieve a harmonious occlusal and cusp–fossa relationship. The time required to finish a composite restoration is double compared to amalgam restoration.[56] However, the surface finish obtained with abrasives is not as smooth as that under a matrix.[4] Matrices help achieve good contour of proximal surfaces, but they are not useful for occlusal surfaces, thereby posing a risk of over/under restored surfaces.[57]

Proposed by Dr. Waseem Riaz, a London-based practitioner, the “stamp technique” for direct composite resin restorations helps attain precise occlusal topography.[8] Stamp is an index that replicates the anatomy of the unprepared tooth.[89] After stamp fabrication on an unprepared occlusal surface, the cavity is prepared, and the prepared stamp is pressed against the final composite increment before curing.[810]

Stamp technique is indicated where the occlusal surface is intact before restoration, including Class I and Class II preparations.[9] For proximal lesions, contouring middle or cervical thirds requires matricing, followed by placement of an occlusal stamp.[1] In cavitated lesions, cavities are blocked with wax and carved to desired morphology. It allows accurate reproduction of original occlusal anatomy, minimal finishing, polishing, and voids with optimal polymerization due to exclusion of air during stamp pressing.[11]

Various materials used for the occlusal replicas include light-cured composite, self-cured acrylic resin, polyvinylsiloxane bite registration material, liquid dam material, transparent silicone molds, and occlusal transfer devices.[11213]

In this case series, composite restorations using direct stamp technique using liquid dam material, flowable composite, and indirect method using self-cure acrylic resin material were performed.

CASE REPORTS

Case 1

A 26-year-old male patient came with a complaint of blackening of the lower right back tooth. Clinical examination showed Class 1 carious lesion in 46 with an intact occlusal surface [Figure 1a]. Radiographic examination revealed a radiolucent area in the crown of 46, suggesting dentinal caries with no pulp involvement.

Figure 1

(a) Preoperative image of 46 in case 1 (b) Stamp prepared using flowable composite in 46 in case 1 (c) Prepared cavity in 46 in case 1 (d) Pulp protection done in 46 in case 1 (e) Prepared stamp placed over the Teflon tape coated final composite increment in 46 in case 1 (f) Postoperative image of 46 in case 1 (g) Preoperative image of 26 in case 2 (h) Stamp prepared using liquid dam material in 26 in case 2 (i) Prepared cavity in 26 in case 2 (j) Pulp protection done in 26 in case 2 (k) Prepared stamp placed over the Teflon tape coated final composite increment in 26 in case 2 (l) Postoperative image of 26 in case 2

The occlusal surface was unscathed, so we suggested composite restoration with occlusal stamp technique using flowable composite material. The patient consent was obtained. After shade selection as A2 using Vita classical shade guide and isolation with a rubber dam, the occlusal stamp was prepared using flowable composite material (Te-Econom Flow, Ivoclar Vivadent, Liechtenstein) and applicator tip [Figure 1b]. Cavity preparation was done with spherical diamond points (BR 46, fine grit 001-012, medium by Mani, Inc., Japan) at high speed [Figure 1c]. Infected dentin was removed with a spoon excavator and round tungsten carbide bur (Fine Grit, no. 4, 25 mm by S. S. White Dental Manufacturing Company, Philadelphia) at a low speed (5000 rpm).

Etching was done with 37% phosphoric acid for 20 s. The cavity was washed and dried. Resin-modified GIC (GC Gold Label 2 LC, GC, Japan) was applied for pulp protection and cured for 30 s [Figure 1d]. Bonding agent (Te-Econom Bond, Ivoclar Vivadent, Liechtenstein) was applied and cured. Composite (Ivoclar Te-Econom Plus, Ivoclar Vivadent, Liechtenstein) was placed in 2-mm increments and light-cured for 20 s. Teflon tape was placed, and the prepared stamp was pressed over the final increment [Figure 1e] before curing for 20 s post stamp removal.

Finishing was done using diamond finishing points (TR-25 and EX-2, Extra Fine Grit by Mani, Inc., Japan), and polishing was done using polishing disks (Super-Snap Rainbow Kit, Shofu Inc., Japan) and polishing cups and cones (Shofu Composite Finishing Kit, Shofu Inc., Japan). Postoperative evaluation was done after 3 months [Figure 1f].

Case 2

A 32-year-old female patient came with a complaint of blackening of the upper left back tooth. Clinical examination showed Class 1 carious lesion in 26 with mild cavitation [Figure 1g]. Radiographic examination revealed a radiolucent area in the crown of 26, suggesting dentinal caries with no pulp involvement. The occlusal surface was unscathed, so we suggested composite restoration with occlusal stamp technique using liquid dam material.

The patient consent was obtained. After shade selection as A1 using Vita classical shade guide and isolation with a rubber dam, the occlusal stamp was prepared using liquid dam material (Pola Office, SDI Limited, Australia) and applicator tip [Figure 1h]. Cavity preparation [Figure 1i], infected dentin removal, pulp protection [Figure 1j], and composite restoration were done as described in case 1. Teflon tape was placed, and the prepared stamp was pressed over the final increment [Figure 1k] before curing for 20 s post stamp removal.

Finishing and polishing were done as described in case 1. Postoperative evaluation was done after 3 months [Figure 1l].

Case 3

A 35-year-old female patient came with a complaint of food lodgment in the lower right back teeth. Clinical examination presented Class 2 carious lesions in 44.45 with cavitation in the mesial surfaces and intact occlusal surfaces [Figure 2a]. Radiographic examination revealed a radiolucent area in the crowns of 44.45, suggestive of enamel caries in 45 and dentinal caries in 44 with no pulp involvement.

Figure 2

(a) Preoperative image of 44 and 45 in case 3 (b) Stamps prepared using flowable composite in case 3 (c) Prepared cavities in 44 and 45 in case 3 (d) Pulp protection done in 44 in case 3 (e) Prepared stamp placed over the Teflon tape coated final composite increment in case 3 (f) Postoperative image of 44 and 45 in case 3 (g) Preoperative image of 36 and 37 in case 4 (h) Preoperative image of 46 and 47 in case 4 (i) Modelling Wax filled in cavities in the casts and carved in case 4 (j) finished and polished cold cure acrylic resin stamps in case 4 (k) Prepared cavities in 36 and 37 in case 4 (l) Prepared stamps placed over the Teflon tape coated final composite increment in 36 and 37 in case 4 (m) Prepared cavities in 46 and 47 in case 4 (n) Prepared stamps placed over the Teflon tape coated final composite increment in 46 and 47 in case 4 (o) Postoperative image of 36 and 37 in case 4 (p) Postoperative image of 46 and 47 in case 4

The occlusal surface was unscathed, so we suggested composite restoration with occlusal stamp technique using flowable composite material. The patient consent was obtained. After shade selection as A2 using Vita classical shade guide and isolation using cotton rolls, occlusal stamps were prepared using flowable composite material (Te-Econom Flow, Ivoclar Vivadent, Liechtenstein) and applicator tip [Figure 2b]. Cavity preparation and infected dentin removal were done as described in case 1 [Figure 2c].

Pulp protection was done in 44 using resin-modified GIC (GC Gold Label 2 LC, GC, Japan) and cured for 30 s [Figure 2d]. Matricing was done using Palodent System (Dentsply Sirona Inc., USA). Etching, bonding agent application, and composite restoration were performed as in case 1. Teflon tape was placed, and a prepared stamp was pressed over the final increment (2e) before curing for 20 s after stamp removal.

Finishing and polishing were done as described in case 1. Postoperative evaluation was done after 3 months [Figure 2f].

Case 4

A 25-year-old male patient came with a complaint of food lodgment in the lower right and left-back teeth. Clinical examination presented Class 1 carious lesions in 36, 37, 46, and 47 with deep occlusal cavities [Figure 2g and h]. Radiographic examination revealed radiolucent areas in the crowns of 36, 37, 46, and 47, suggestive of dentinal caries with no pulp involvement.

Occlusal surfaces were cavitated, so we suggested composite restoration using indirect occlusal stamp technique with Cold Cure Clear Acrylic Resin material. The patient consent was obtained. Upper and lower impressions were made with additional silicone putty material (Photosil Soft Putty Impression Material, Dental Products of India, India). Maxillary and mandibular casts were prepared using dental stone and mounted onto an articulator. Modelling Wax No 2 (Hindustan Dental Products, India) was filled in cavities in the casts and desired occlusal anatomy was carved using a Lecron Wax Carver (Hu-Friedy, USA) [Figure 2i]. Cold cure acrylic material (RR Cold Cure Acrylic Resin, Dental Products of India, India) was used to prepare occlusal stamps. They were finished and polished [Figure 2j].

After shade selection as A1 using Vita classical shade guide, cavity preparation and infected dentin removal were done as detailed in case 1 [Figure 2k and m]. Resin-modified GIC (GC Gold Label 2 LC, GC, Japan) was applied for pulp protection and cured for 30 s.

The composite restoration was done as explained in case 1. Teflon tape was placed, and the prepared stamps were pressed over the final increments of composite resin [Figure 2l and n] and light-cured for 20 s post stamp removal. Finishing and polishing were done as detailed in case 1. Postoperative evaluation was done after 3 months [Figure 2o and p].

DISCUSSION

In posterior teeth, carious lesions are usually set in occlusal surfaces that are less cleansable. Orientation of dentinal tubules determines the progression of caries. Thus, occlusal surface caries strides in a triangular shape with apices away from dentin–enamel junction, clarifying the intact superficial enamel but extensive dentin destruction.

Successful restoration denotes restoring proper occlusal and proximal anatomy while maintaining a harmonious relationship with adjacent tissues. The importance of occlusion is paramount for orofacial integrity, which when not reproduced properly might lead to occlusal discrepancies and temporomandibular disorder disorders, altering the entire stomatognathic system.[7]

The occlusal stamp technique allows the re-establishment of proper form, function, and esthetic dental structure, reducing postrestoration adjustments. With the minimal time required for finishing and polishing, it is suitable for a busy practice.[14] Material consumption is minimal.[7] The pressure exerted by the stamp decreases microbubbles and oxygen interferences.[2]

The indirect technique reduces the time taken for restoring multiple teeth in the same quadrant as contouring is eliminated and there will be fewer high points. Hence, it is helpful in patients who cannot open their mouths for a longer period.

In the cases described in this case series, no isolation agent was used before stamp fabrication. However, it is required in deep pits and fissures to prevent fluxing of flowable composite.[13] In these cases, we have used flowable composite, liquid dam material, and clear acrylic resin for fabricating occlusal stamps.

Flowable composite is mostly used due to easy availability and precise detail reproduction. However, the material cost is high. However, stamps can be prepared using expired composites, thus reducing the expense.[13] Liquid dam material has low viscosity for easy flowability. However, its high flexibility requires a bulk of material for proper strength. Furthermore, the material is costly. Transparent acrylic resin, due to its easy handling, low cost, and precision, is a good material.[2] Since it is transparent, it can be retained while curing, but it carries the hitch of creating a rough surface under the stamp.

Alternative to Teflon tape is a cling film that can be retained while curing that protects composite from exposure to ambient light multiple times.[15] Sandwich technique, using liquid chromatography GIC liner for pulp protection, minimizes microleakage.[2] Furthermore, incremental placement avoids polymerization shrinkage.

In Class II restorations, stamps can be prepared using two techniques. First involves fabrication of stamp, like in Class I lesions, and matrix band is removed and the stamp is pressed over the last composite increment and cured. In the second technique, the matrix band is placed earlier, and the stamp is prepared within. Hence, matrix band removal is not required. Here, the first technique was used.[14]

The stamp can be prepared indirectly with PVC material and acrylic material. Indirect technique is indicated in multiple and cavitated lesions. Desired occlusal anatomy can be created by the dentist before laboratory stamp fabrication, making restoration of multiple carious lesions an easy task.

The finish of restoration is pivotal for its overall success. Finish obtained with finishing procedures is different from that after final cure. As functional and nonfunctional adjustments are reduced, the stamp technique helps achieve the best finish.

The stamp technique carries the burden of less clinical efficacy, repeated restoration failures, and inability to recreate deep pits and fissures. The possibility of the stick falling off the stamp poses a threat for aspiration that is overcome by using a rubber dam. It is not cost-effective, as the materials used are expensive.[7] Professionals must stay alert as the incorrect placement will cause distortions.[2]

CONCLUSION

Composite restorations using the stamp technique are convenient and favorable in replicating and restoring the exact anatomy of the teeth with minimal time and resources for finishing and polishing. Although usually indicated only for caries with the intact occlusal surface, the indirect technique can help us restore large cavitated lesions as well.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.