Written by Bruce J. LeBlanc, DDS Thursday, 08 July 2010 10:40
My journey into what later became a minimally invasive trend in dentistry began shortly after my graduation from dental school in 1977. At that time, porcelain jacket and porcelain-to-metal restorations were the primary solutions available to aesthetically reconstruct teeth seriously damaged by decay or injury. This created a real dilemma, considering that the preparations were necessarily aggressive to accommodate the restorative technique, and the results were often less than desirable aesthetically by today’s standards. PFM crowns were often chosen when optimal restoration strength was required, and these restorations, in order to properly mimic natural teeth, often presented a considerable artistic challenge for the dental ceramist.
In those earlier years of my practice, adhesive direct composite dentistry began to emerge, offering materials and techniques that minimized tooth structure removal while blending tooth-mimicking materials exhibiting physical and optical properties more like the missing tooth structure being replaced. This offered a quantum leap of available options to solve patient aesthetic dilemmas, particularly as more durable bonding adhesives were manufactured along with composites that were stronger and more easily polished. Nanohybrids are the latest generation of composite resins to be introduced. These materials have formulations which incorporate nano-sized glass particle fillers that maximize polishability and long-term surface luster, with larger particles to resist fracture.
This article will share how I used products in this latest generation of composite resins to create long-term solutions. The results obtained from using these materials and techniques are exciting to patients because of their natural appearance, conservation of tooth, one appointment completion, and cost value.
The proper selection and use of products is imperative when offering the available adhesive treatment alternatives to your patients. Dentists are often reluctant to offer direct-bonded composites as a long-term solution due to concerns about postoperative sensitivity issues, margins that may discolor with time, and premature restoration failure. It is my opinion, based on the clinical results that we have observed in our practice, that if adhesive products are chosen and used correctly, we can have tremendous confidence in routinely delivering restorations that are comfortable, aesthetic, conservative, and durable.
To present my bonding protocol, I have chosen a case example that is typical of those found when restoring posterior teeth with direct composite resin restorations. Since my first concern in the protocol is to control the oral environment, I isolate the area to be restored with a rubber dam (Hygienic Medium [Coltène/Whaledent]) when working in the posterior region of the mouth. Placement of the rubber dam should take less than one minute, paying time management dividends while controlling moisture contamination of the replacement materials (Figure 1). I believe that commitment to proper technique will maximize restoration longevity and comfort.
Figure 1. Pretreatment (bonding protocol) of lower left quadrant to be restored with direct resin nanohybrid composite, showing a rubber dam in place.
Figure 2. Teeth have been prepared, removing unsound tooth structure and defective amalgam restoration.
Figure 3. Preparations are etched past the margins with phosphoric acid etchant gel.
Figure 4. After rinsing away the etchant and properly drying, OptiBond FL primer (Kerr) was applied 2 times and then air-dried to evaporate the alcohol solvent.
Figure 5. Following proper application of the primer, OptiBond FL resin component was applied and then light-cured.
Figure 6. Herculite Ultra nanohybrid composite (Kerr) was applied and light-cured in multiple layers, then sculpted and polished, creating a restoration that mimics natural teeth in function and aesthetics.
During preparation, defective materials, decay, and unsound tooth structure are removed to ensure a firm base for bonded materials to adhere to and properly seal the tooth (Figure 2). Phosphoric acid gel (Gel Etchant [Kerr]) is applied to the entire preparation beyond marginal areas to ensure proper adhesion of the bonding agent (Figure 3). After 30 seconds, the etchant is rinsed away with water until the tooth is clean. My personal choice in a bonding agent that I have used with predictable success for nearly 20 years is OptiBond FL (Kerr). It is a 2-component primer/resin system that has an alcohol-water base, allowing a larger window of bonding opportunity when considering how wet/dry the dentin should be after etching. In my protocol, I dry the dentin (not “bone” dry) for about 5 to 10 seconds to remove water after rinsing. The water component of the mixture allows some rewetting of dentin and proper activation of the chemistry. My preference is unidose packaging to ensure the manufactured chemistry ratio for each procedure we perform. The adhesive primer component is applied in 2 separate layers with air drying after each application for 5 to 10 seconds to evaporate the alcohol solvent (Figure 4). It is critical that the alcohol is allowed enough time to evaporate so that the next layer, the bonding resin, can be properly cured. Meticulous technique at this step greatly affects our success in preventing the problems of microleakage and sensitivity. The bonding resin in the second component is brushed over the primer layer on all surfaces past the marginal areas then light-cured for 10 seconds with a Demi LED curing light (Kerr) (Figure 5). After curing the bonding resin, nanohybrid composite (Herculite Ultra [Kerr]) is placed in multiple layers of less than 2 mm and cured to control polymerization shrinkage. After placement and curing of the final layer of the composite, the restoration is sculpted and then polished with carbide finishing burs (H48L-012 and H379-018 [AXIS Dental]) and silicone polishing cups (Kerr Hawe HiLuster [AXIS Dental]) to maximize the final polish. The final restoration should effectively seal the tooth, creating a durable, comfortable, long-term restoration (Figure 6).
CASE REPORT 1
Diagnosis and Treatment Planning
In my opinion, the age group of patients that has benefited the most by the development of durable and highly polishable composites is the pediatric group. Consider this patient: an 8-year-old was referred to our practice with a broken upper incisor (tooth No. 9) that had previous endodontic therapy and a temporary restoration placed (Figure 7). Notice the guarded and strained smile that she displayed when we photographed her presenting condition. The effect these conditions have on the psyche of patients can be emotionally disabling.
Figure 7. Pretreatment photo (Case 1) shows patient with a guarded smile appearance after having previous root canal therapy and a temporary restoration placed in tooth No. 9.
We considered the restorative treatment options available for this patient, knowing the dentition is in the developmental stage with lots of transitioning in the years ahead. It is obvious that this patient would likely endure multiple restorations over a lifetime for this tooth. What could we offer as a choice for the first restoration, and what were our considerations when making that choice? In a pretreatment photographic triage appointment, we consulted with our patient and her parent, showing photographs of the present condition along with photo examples of successes that had been achieved with other patients having similar conditions. This allowed the patient and parent to choose the treatment outcome, building trust in the doctor/patient relationship. In this case, it was decided that a direct bonded nanohybrid composite restoration would offer natural aesthetics to blend with the transitioning dentition while conserving maximum tooth structure while allowing flexibility if faced with future restorative needs.
We removed the temporary restoration along with any unsound tooth structure. The tissue was trimmed to allow proper access to the tooth area to be bonded (Figure 8). My preference for controlling tissue hemorrhaging to prevent contamination of the adhesive materials, and what we consider a must-have in adhesive dentistry, is Expasyl (Kerr). This proprietary putty-based material contains aluminum chloride (a hemostatic agent) which does not cause brown discoloration encountered with some other products used to control bleeding. Expasyl was placed with compression into the bleeding sulcus areas for up to 3 minutes, and then rinsed away. Using an effective hemostasis technique eliminated a great sabotager of long-term success in direct composite bonding and allowed us to proceed with confidence to completion of the restoration. The dentin was then etched with phosphoric acid gel, and the enamel was etched for 30 seconds, well past the anticipated restoration margin. After rinsing the acid etchant off the tooth with water, the tooth was dried and OptiBond FL primer component was applied 2 times and air-dried for 5 to 10 seconds after each application. The OptiBond FL bonding resin component was then painted over the dried primer and light-cured with a Demi LED curing light for 10 seconds. For this case we created an endodontic core and restoration with Premise (Kerr) nanohybrid composite (shade A1). With both Premise and Herculite Ultra, one shade is often sufficient to produce a natural restoration that blends with the surrounding dentition. Multiple applications and curing of composite placed in layers minimizes polymerization shrinkage effects, allowing for properly sealed dentin with margins that should not turn white or brown.
Figure 8. The temporary restoration was removed, the tissue trimmed to create proper crown length appearance, and then Expasyl (Kerr) was applied to stop tissue bleeding.
Figure 9. Photo taken at 4 years postoperatively shows a durable direct composite restoration constructed with Premise (Kerr) (Shade A1) that blends with surrounding natural teeth in appearance. The patient’s psyche was also greatly improved.
Figure 9 shows the completed restoration at a 4-year post-treatment recall appointment. The patient was thrilled with a natural appearance of the restoration that also improved her psyche at a critical time in her emotional development.
CASE REPORT 2
Diagnosis and Treatment Planning
A 16-year-old had previous treatment for a root canal in tooth No. 10 which had considerable microleakage and subsequent bleeding of surrounding tissue (Figure 10).
Figure 10. Pretreatment photo (Case 2) shows restoration discolored due to microleakage on tooth No. 10 with unhealthy gingival tissue.
After consultation using photographs of present conditions, and presentation of restorations that solved similar dilemmas for other patients, the decision was made to restore the tooth with a direct nanohybrid composite restoration similarly to what was described in case report 1.
The existing restoration was removed, and the remaining tooth structure was properly prepared and cleaned. The soft tissue exhibited considerable bleeding, which had to be controlled to prevent the type of staining and microleakage in the future that we were in the process of correcting (Figure 11).
Figure 11. Following bleaching treatment, the defective restoration was removed and the tooth prepared, leaving hemorrhaging gingival tissue.
Figure 12. Expasyl was compressed into the gingival sulcus to arrest bleeding.
|Figure 13. With gingival bleeding arrested, a Greater Curve (Greater Curve) band matrix facilitated the bonding protocol completed with OptiBond FL bonding agent and Premise B1 nanocomposite.||
Figure 14. A full-smile photo, taken one year post-treatment, reveals an aesthetic restoration with healthy surrounding tissue.
Expasyl tissue management paste was placed with compression and allowed to remain for 3 minutes (Figure 12). Following rinsing, tissue bleeding had totally halted, allowing us to proceed with the bonding procedure. The tooth was then acid etched, then rinsed with water and properly dried. The tooth was then encircled with a Greater Curve (Greater Curve) matrix band to control the perimeters as we added adhesive materials (Figure 13). OptiBond FL was applied with 2 primer layers that were appropriately dried to evaporate the alcohol solvent. The OptiBond FL resin layer was then painted over the primer and light cured for 10 seconds. Premise B1 shade composite was sculpted and cured in multiple layers to control polymerization shrinkage. Finishing was completed with carbide finishing burs followed by polishing with silicone cups and polishing brushes.
A photo taken one year postoperatively shows a restoration that blends nicely with the adjacent natural teeth (Figure 14). The gingival tissue surrounding the tooth had returned to normal coloration and contours.
Diagnosis and Treatment Planning
An adult patient who had not received dental care for more than 15 years presented to our office. In our initial consultation appointment, he had indicated that he was embarrassed of his teeth, but that he had recently committed to improving his overall health and was determined to do the same with his mouth.
Figure 15. Preoperative photo (Case 3) shows discolored teeth with heavy calculus buildup. The patient’s smile was guarded due to appearance of his teeth.
Visible in his initial smile photo, taken at the triage consultation appointment, was a lower orthodontic retainer (Figure 15) that was fixated with bands typically used for orthodontic retention prior to the use of adhesive bonded retainers. The facial surfaces of the anterior teeth had previous restorations and defects that he wanted to replace and resurface. Additionally, his teeth showed tetracycline staining and were coated with severe calculus buildup throughout his mouth.
His guarded smile, as seen in the preoperative photo, revealed emotionally what he had indicated verbally in our consultation: that he was not comfortable smiling. Although he was committed to optimizing his overall health, his mouth did not look healthy.
Financial concerns limited treatment possibilities for the final restorations. Nanohybrid direct bonding was chosen to improve the surface defects and tooth coloration on the upper anterior teeth. This allowed for minimal tooth alterations, which was important to this health-aware patient.
Our initial treatment phase included removal and replacement of the banded orthodontic retainer, appropriate procedures to clean the teeth and gums, and tooth bleaching to improve coloration. With the gums returning to normal health and the teeth looking cleaner, the patient was excited about the changes that had already been accomplished (Figure 16) and was ready to begin the restorative treatment phase.
Figure 16. A professional prophylaxis and bleaching created a healthier smile, laying the foundation for final restorative enhancements.
|Figure 17. Postoperative photo shows the teeth after resurfacing with a nanohybrid composite resin (Herculite Ultra XL [Kerr]) to maximize whitening affect to fulfill patient desires. The patient’s smile was then unguarded and relaxed due to improved self esteem.|
At the restorative appointment, we meticulously performed the preparation, etching, and application of bonding as described in the previous cases. Since the patient wanted to maximize lightening the color of the teeth, we chose Herculite Ultra (Kerr) (shade XL), a durable nanohybrid composite that has been shown to maintain a natural polish and appearance over time. The procedure was completed in one appointment.
Until that final appointment the patient displayed a pursed lip, guarded appearance when he smiled. Although the teeth were improved in color and health with the prerestorative work prior to the bonding appointment, he was not emotionally comfortable enough yet to let go when he smiled. That all changed once the composite resin restorations were completed. The photo we took immediately (Figure 17) after his first glance in a mirror reveals a wide, “let go” smile that shows all of his teeth with a comfort that he had not previously experienced. The improvements that we accomplished with cleaning, whitening, and bonding were life changing to him and he verbally expressed this at his final consultation appointment.
We partner in our practice with our patients to prevent and to solve dental health problems. Our photographic triage consultation allows them to make choices according to their preferences. When we provide treatment with superior care, skill, and judgment, then trust is developed within the doctor/patient relationship, which I believe not only potentially creates patients for life, but also reduces stress for the dentist. Ultimately, when we provide solutions that excite our patients and gain their trust, the enjoyment we experience in dentistry can reward us in ways that are spiritual as well as financial.
Although product selection combined with meticulous technique is imperative for predictable adhesive success, it is not difficult. It is simply a matter of committing to a protocol without compromise. The development of adhesive dental technology with aesthetic tooth replacement materials has created an opportunity for us as dentists to offer conservatively prepared, durable, value-priced aesthetic restorations that are exciting to our patients. With many people experiencing financial challenges in uncertain economic times, these procedures can provide cost effective solutions that patients will appreciate.
Disclosure: Dr. LeBlanc has received support from Kerr Dental in the form of product merchandise.
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