Efficient Direct Posterior Composite Restorations

Daniel J. Poticny, DDS


As a doctor, I always want the best for my patients. Therefore, when it comes to placing posterior composites, I have many questions that require answers about choosing from the material options available. Will the materials hold up in the long term? How wear resistant are they? Will the final surface polish and luster be maintained for years to come? How well do they blend with surrounding natural tooth structure?

Though posterior composites today are generally very good materials, they still require significant time and effort to place quality restorations. Compensation for shrinkage through layering, adaptation, and sculpting; sufficient polymerization; and final finishing require a significant amount of effort and time. (Remember that time is a dental practice’s greatest expense!)

Bulk-Fill Composites
Bulk-fill composites are specifically designed to shorten procedural time and to provide a restoration that has a higher fracture resistance than traditional/conventional composites. When I started using Filtek One Bulk Fill Restorative (3M), my general perception of composites changed. I have now concluded that composites can be routinely done while significantly saving time compared to using traditional composites and without compromising the quality outcome desired for our patients.

In the following case, I explain how a patient of mine benefited from my now favorable perception of bulk-fill composites. In addition, the steps taken to ensure a quality restoration are demonstrated.

A 34-year-old female presented with previously placed composite resin restorations in her right first and second mandibular molars. Both restorations were less than 6 years old and needed replacement due to fracture, chipping, and microleakage/recurrent caries.

Figure 1. The preoperative photo. Figure 2. The preparation of the teeth.
Figure 3. Applying the Scotchbond Universal Adhesive (3M). Figure 4. Light-curing the Scotchbond Universal Adhesive using the Elipar S10 Curing Light (3M).
Figure 5. The placement of the Filtek One Bulk Fill Restorative (3M). Figure 6. Contouring and shaping the bulk-fill material.
Figure 7. More contouring and shaping. Figure 8. Restorations after the bulk-fill composite was contoured and light cured.

Adequate Polymerization is Key
Bulk fills are intended to be placed in one increment, unlike conventional composite restorative materials. To make this practical, there needs to be assurance that shrinkage stresses are relieved, along with sufficient depth of cure. Bulk-fill composites have been shown to effectively provide low shrinkage stress. However, the aesthetics for many of these material options could best be described as “blasé,” owing to formulations that lean decidedly toward excessive translucency in an effort to enhance depth of cure.

Manufacturers use proprietary photoinitiators, and there are differences in terms of light responsiveness with respect to intensity, duration, and type of light source. It is important to know what your product specifies, and to use a quality, well-calibrated curing light.

Filtek One Bulk Fill Restorative represents a significant material improvement in both depth of cure and aesthetics. Proprietary technology (researched and developed by 3M) allows for a relatively consistent refractive index (translucence) for the bulk-fill restorative after placement, adaptation, and sculpting. This is the key to allow for a greater depth of cure. What is particularly intriguing with this material is that it permits 5.0-mm bulk fills in the proximal boxes and 4.0 mm in the occlusal areas; however, upon curing, the material becomes noticeably less translucent due to a shift and mismatch of the refractive index that occurs post-cure, which scatters more light and provides higher opacity in the cured composite. The bottom line? These unique material characteristics result in a pleasing aesthetic outcome that is difficult to differentiate from standard posterior composites.

This bulk-fill composite material can be directly dispensed from compules, adapts extremely well, allows for sufficient working time to sculpt anatomy without sticking, and holds its shape nicely, thus greatly reducing instrumentation with a bur later. Most importantly, the majority of restorations can be filled in one increment and, in combination with the ease of delivery and intraoral manipulation/handling, a significant amount of time can be saved. In my hands, using the clinical technique as described below, I have estimated that there is an 20% to 25% time savings for using this restorative procedure.

Clinical Protocol
Before beginning the preparations (Figures 1 and 2), I highly recommend the use of a rubber dam (HandiDam [Aseptico]) or other isolation device (such as the Illuminated Isolation System [Isolite Systems]) that features a combination mouth prop, tongue and cheek retractor, oral evacuator, and operative field illumination. It is difficult to imagine operating without field control that allows the operator to focus on the procedure and enable consistency of the outcome. In my opinion, failure to achieve proper isolation and visualization of the operative field is one reason why many composite resin restorations fail prematurely. And one last thing—this will also save time!

Next, a decision must be made on which adhesive technique to use for placement of the restoration. In this case, I used a selective-etch technique. I recommend a selective-etch using Scotchbond Universal Adhesive (3M), because it has proven to be as effective on dentin as the total-etch, but without the potential risks often associated with the use of phosphoric acid on dentin. However, in order to achieve maximum integrity at the restorative margins, enamel benefits from phosphoric acid with a more aggressive etch pattern than that which would be produced with Scotchbond Universal alone. Scotchbond Universal should be scrubbed into a moist dentin surface for 20 seconds (Figure 3). The adhesive tolerates moisture inconsistencies well, but moist is the optimal condition to achieve optimal adhesive performance. Subsequently, it should be properly thinned with air to evaporate the solvents and provide an optimal hybridization layer that will have an even thickness. Visually, the adhesive will be observed to no longer flow over the dentin surface and the dentin will appear to have a sheen (or shine) to it. At this point, light cure this shiny adhesive interface (Figure 4).

Figure 9. Refinement using 20- to 50-µm diamond burs. (The 50-µm bur is shown here.) Figure 10. Prepolishing using the beige Sof-Lex Pre-Polishing Spiral (3M).
Figure 11. After using the prepolish spiral. Figure 12. Polishing was carried out using the pink Sof-Lex Diamond Polishing Spiral [3M].
Figure 13. The final Filtek One Bulk Fill Restorative restorations. Figure 14. A post-op bite-wing radiograph showing the radiopacity of this material on tooth No. 18 with a Filtek One Bulk Fill Restorative direct restoration and tooth No. 19 with a Lava Ultimate (3M) lab-fabricated restoration. (Editor’s Note: This radiograph is from a different clinical case than the one described in this article’s case report.)

Next, the restoration is placed. The material can be dispensed in one increment, subject to the depth maximums and locations as previously stated (Figure 5). Then the material is adapted to the walls and box floors (where present), suceeded by sculpting that follows the contours of the tooth’s morphologic form (Figure 6). A variety of instruments can be used for this (subject to your preferences). I prefer ball and egg shapes along with pointed, v-shaped contouring instruments (Figure 7), and I suggest that you dim the operatory light or, if using a headlamp, flip on the orange-blue light filter. I have found that I can do this in about 60 seconds with the material still in a plastic state. At this point, depending upon your light source, thoroughly cure the composite per the manufacturer’s instructions. For clinicians using LEDs, this would be 20 seconds, and for halogen lights, it’ll be 40 seconds. Keep the light as close to the surface as possible, and recognize that the size and consistency of your focal spot can be a deal breaker if not assessed properly. I would also recommend light curing from the buccal and lingual directions. In this case, an Elipar S10 Curing Light (3M) was used, which fulfills the stated requirements. Once the curing process is completed, make adjustments/equilibrations using a 50- or 20-µm diamond bur (FG Microcopy NeoDiamond 1920 Football finishing No. 173-0800 [50 µm] or Kerr NTI No. 018 4.5 Superfine [not shown]) (Figures 8 and 9).

Finally, for the polishing steps, I use the Sof-Lex Diamond Polishing System (3M), which is, in my opinion, one of the best polishing products on the market (Figures 10 and 11). This 2-step system uses proprietary abrasives that are incorporated into a unique spiral wheel. This polisher design will very efficiently reach every area of the restoration with minimal effort and will, once again, save time (Figure 12). This polishing system, in conjunction with the polishing characteristics inherent in this bulk-fill composite material, will result in a brilliant shine that can be achieved in less than a minute. Just remember to use a light and intermittent touch at 15,000 to 20,000 rpm with an intermittent, light water spray applied by your assistant (Figure 13).

It should also be noted that this composite material has excellent radiopacity, as seen in Figure 14, which shows a post-op bite-wing radiograph from a different case.

After using the materials and technique described herein on my own patients, I have the highest degree of confidence that Filtek One Bulk Fill Restorative can be used routinely in cases to provide impressive functional and aesthetic outcomes with significantly less time and effort than those associated with the traditional posterior composites. Shortened procedure times with nice results are definitely a win-win for doctors and patients alike!

Dr. Poticny is an adjunct clinical associate professor at the University of Michigan School of Dentistry (Ann Arbor) in the department of cariology, restorative sciences, and endodontics. He also has a full-time practice in Dallas, Texas. Dr. Poticny is a member of the ADA, AGD, the International Association for Dental Research, and the International Society of Computerized Dentistry and is a Fellow of the Academy of CAD/CAM Dentistry. He is a widely published scientific researcher and international lecturer. His lecture topics include digital dentistry and materials, adhesives and cements, and restorative dentistry. He serves as a consultant and advisor to various dental manufacturers and also serves as an editorial board member for multiple dental journals. Dr. Poticny can be reached by phone at (972) 641-9888 or via email at djpoticny@earthlink.net.

Disclosure: Dr. Poticny has received honorarium from various manufacturers, including 3M.

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