Written by Tony Soileau, DDS Saturday, 31 March 2007 19:00
Restorative options are often limited to the scope of the restoration and the confidence the dentist has in his or her restorative choices. Many procedures that seem complex at first actually become quite simple when they are broken down into stages and modern techniques are employed. Electric handpieces coupled with the latest generation of sintered diamonds make preparing teeth comparatively stress-free. Diode lasers are becoming very affordable, and they generate predictable outcomes with little effort on the part of the dentist. Synthetic grafting materials can prevent compromised results, and their improved delivery systems make them even more practical and easy for the dentist to apply. Porcelain-fused-to-metals such as gold can reduce the level of plaque accumulation in compromised periodontal conditions while providing superior aesthetics.
This article presents a case in which modern technologies were used to enhance the treatment outcome of crown and bridge restorations.
Figures 1 and 2. Preoperative views of failing bridge.
A 55-year-old male presented with a loose bridge from Nos. 27 to 30. The abutment teeth were Nos. 27, 29, and 30. Spacing was noted between Nos. 29 and 30, creating the need for a pontic. The patient cited a history of having both lower and upper wisdom teeth removed as a child. His main complaint was that the bridge “felt loose” when chewing. Digital photographs were taken (Canon 20D with 100-mm Canon macro lens and ring flash [Norman Camera]), and were displayed to the patient with image editing software (Image FX [SciCan, Patterson Dental Supply]; Figures 1 and 2).
Digital radiographs were taken of the entire mouth (Sidexis Digital Radiographic System [Sirona]). It was noted on the radiographs that the distal abutment (No. 30) had completely decayed through the root and was no longer supporting the bridge (Figure 3).
Figure 3. Digital radiograph showing failed abutment.
Figure 4. Abutments and pontic sites immediately after bridge removal.
|Figure 5. Ovate pontic sites created with a diode laser. Note the precise cut and lack of bleeding.||
Figure 6. Uncovering subgingival decay with the diode laser.
The patient and the author discussed at length various treatment options including replacing the bridge, implants, and removable partial dentures. While periodontal measurements were within normal limits, plaque control was less than desirable. Hygiene habits at home would play a major role in the success of any option. After considering the options, the patient decided that a new bridge that included No. 31 as the distal abutment was the treatment of choice. While the patient understood the questionable long-term prognosis of such a long-span bridge, he still favored that option over implants. The author and patient agreed that a new bridge would be constructed along with treatment of the supporting structures, and in the event of failure, implants would be placed.
Once the bridge was removed, the existing width of the ridge would be evaluated for the creation of ovate pontics for the new bridge. Other factors also needed to be addressed, including ridge width, biologic width of abutments, removal of calculus, oral hygiene of the patient, occlusion, etc. The restoration of the bridge would be done in phases, with the total treatment time being dictated by the patient’s oral hygiene and the healing of supportive tissues.
The first appointment would be to remove the bridge, tooth No. 30, and any other failing dental work associated with the restoration of the quadrant. Maintaining the width of the ridge for ovate pontic design would include grafting the socket with synthetic material to promote bone growth and decrease resorption of the ridge. The occlusion discrepancies would be corrected with the provisional restoration and then duplicated with the final bridge. The patient’s oral hygiene instruction and removal of calculus would also be addressed at the first appointment. After the supportive tissues had time to heal and reestablish themselves, the abutments and ridge would be evaluated for biologic width considerations and final pontic design.
The bridge was removed using a diamond bur (GRT010 G-Force Diamond [Garrison Dental Solutions]) and a high-speed electric handpiece (25LPA electric high-speed attachment [KaVo America]). G-Force diamonds, coupled with the increased torque of electric handpieces, easily cut through both the metal and porcelain. Grooves were cut through the facial and occlusal surfaces of each abutment. Care was taken to only slightly penetrate through the metal substructure and not cut too deeply into the existing tooth. The abutments were “torqued” with a hand crown remover until the cement seal was broken, and the bridge was then removed with hemostats using a slight rocking motion. This removal method is atraumatic to the existing teeth and to the patient (Figure 4).
At this point, the initial pontic space was addressed. This was done prior to removing tooth No. 30 and root planing. Both of these procedures result in bleeding, which would obscure the clinician’s view. A 2-watt diode laser was used to sculpt the initial pontic sites (SoftLase 2W [Zap Lasers]). After anesthetizing the tissue, the laser tip was initiated with carbon articulating paper and used to “sculpt” a 1-mm to 2-mm ovate pontic site. The diode laser easily “carves” the tissue with little or no bleeding—it is extremely precise. It is important to maintain the site on the top of the ridge if a cleansable pontic is to be developed. If the tissue is carved off the crest of the ridge, then a “saddle” or “ridge lab” pontic would be created, which is very difficult for patients to clean with floss threaders or electric flossers.
It appeared that a connective tissue graft might be needed on the sites, but that decision would be made at the next appointment. At this point, the author was trying to be as conservative as possible. No decay on the premolar and canine abutments or history of trapping food was noted. These findings gave reason to believe that additional soft-tissue grafts might not be needed (Figure 5).
The crown on tooth No. 31 was then removed. It was removed in the same manner as the bridge, using a diamond bur, high-speed electric handpiece, and hand crown remover. Decay was noted along the facial, mesial, and lingual margins. The diode laser was used to uncover the decayed segments along the original crown margins and the root surface (Figure 6). Due to the extent of the decay, it appeared that crown lengthening with osseous recontouring would probably need to be done. It was not done at this appointment due to its proximity to tooth No. 30, which would be extracted.
Figure 7. Drawing patient’s blood into Bioplant syringe.
Figure 8. Blood being drawn into Bioplant beads.
Figure 9. Graft “paste” being injected into socket.
Figure 10. Site immediately after injection of graft material.
At this point, preserving as much of the ridge as possible was the primary concern. Following the extraction, even with grafting of the socket, some resorption could be expected to occur around the crest of the extraction site. This resorption, however slight, may negate the need for crown lengthening on tooth No. 31.
With the margins of tooth No. 31 cleaned and free from decay, tooth No. 30 could be removed. Care was taken to avoid traumatizing the tissue and bone surrounding the root. Once the root was elevated out of the socket, a hand instrument was used to “scrape” the socket clean of any granulation tissue. A No. 8 round bur with a low-speed electric handpiece and water spray (7LP low-speed attachment [KaVo America]) was used to “punch” through the lamina dura to access the medullary bone. This caused additional bleeding in the extraction site. Blood from the extraction site was drawn up into the grafting syringe (Bioplant bone augmentation material [Kerr Dental]; Figure 7).
Enough blood was drawn into the syringe to mix with the synthetic grafting material to form a paste. After excess blood was expelled, the blood/Bioplant material mixture was allowed to sit for 4 to 5 minutes. The Bioplant beads are negatively charged and create a “scaffolding” effect for the bone to grow into. The material is also bacteriostatic and will reduce the possibility of infection within the extraction site (Figure 8). The plastic cap on the end of the syringe that was used to draw the blood was then removed, and the blood/material mixture was injected back into the extraction site (Figure 9).
Figure 11. Final preparations of abutments, extraction site, and pontic sites.
|Figure 12. Teflon tape is placed over the extraction site prior to smoothing and depressing into the socket.|
Figure 13. Provisional immediately after removing stint and tape.
|Figure 14. Digital radiograph of the extraction site showing placement of synthetic graft.|
Figure 15. Buccal view of bridge showing excellent margin adaptation.
Figure 16. Occlusal view of bridge showing excellent aesthetic characteristics.
|Figure 17. Six-month postoperative radiograph showing integration of Bioplant and preservation of ridge.|
Once the paste was injected into the site, it was pushed farther in with a silicone-tipped composite instrument. The mixture was pushed to the crest of the ridge. The purpose of the mixture is to promote bone formation while preventing tissue growth into the socket. The area below the mixture will fill in with bone in a few months. The beads themselves will slowly resorb and be replaced by bone over the next several years. The excess tissue that the author was careful not to disturb while extracting the tooth, and the provisional, will serve to hold the “graft” in place while the blood clots and the bone begins to regrow (Figure 10).
The crown margins were now finalized, and the ovate sites were checked for proper shape and depth. The tissue held the “graft” in place while margins were refined, so no sutures were used (Figure 11). Teflon tape was now placed over the extraction site. The tape acts as a barrier to prevent the provisional material from contacting the graft. The tape was placed over the site and pushed into the socket to make a smooth pontic site (Figure 12).
The provisional material (A2 Luxatemp Fluorescence [Zenith/DMG]) was injected into a provisional matrix (Siltec [Ivoclar Vivadent]) that was formed over a wax-up of the patient’s bridge. The Luxatemp was allowed to set for 6 minutes after it was seated over the preps. After it was fully set, the stint was removed and the Teflon tape was pulled out from under the provisional. The provisional was then polished and refined at the margins.
The occlusion was adjusted and polished. Once the provisional was finished, the remaining teeth in the quadrant were root planed and polished. A final radiograph was taken to ensure proper placement of the graft into the socket. The patient would return in 1 month for removal of the provisional, refining of the pontic sites with the diode laser, and evaluation of the case for crown lengthening, additional soft-tissue grafts, occlusal harmony, and oral hygiene (Figures 13 and 14).
The final bridge was fabricated with porcelain-fused- to-gold (Captek Dental Arts Laboratory). Gold restorations such as Captek provide exceptional marginal adaptation and reduced plaque accumulation. Due to the warm hue of gold the aesthetics of the bridge is very natural (Figures 15 to 17).
With the use of modern technology such as specialized diamond burs, electric handpieces, diode lasers, synthetic grafting material, provisionals, and porcelain-fused-to-gold restorations, dentists can offer their patients a greater range of restorative options than ever before. What constitutes long-term success is determined by not only the dentist but also by the patient.
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