How To Repair Denture Base

This article discusses managing a fractured denture base.

Background

Any time a prosthesis is removable by the patient, one of the risks dentists and their patients need to be enlightened of is harm to the prosthesis from being dropped.

Dropping a removable prosthesis may result in chipped or broken teeth but very often results in a fractured denture base. And, while dropping the prosthesis is a mutual cause of fractured denture bases it is non the only cause. As a patient's arches resorb, it is not uncommon to see denture bases fracture due to stress concentrating in areas that haven't resorbed – the maxillary mid-palatal suture, for example.

Equally a result, fractured denture bases are a fairly mutual occurrence with this grouping of patients and, regardless of the crusade, a fractured denture base tin can be an urgent concern for the patient. In many cases, the damaged prosthesis can exist sent to the dental laboratory for repair, simply what if the lab isn't bachelor? In this article I want to share a case presentation for a patient in just this predicament.

Initial situation

A 91-year-old female in practiced general health was referred for urgent repair of her existing lower denture. The patient had implants placed and both arches restored with implant-retained overdentures about vii years prior to this appointment. She is unsure about the last time she had the prostheses evaluated or adapted. She notes they are "fitting loose." Additionally, the patient reports 2 previous attempts past another dentist to repair the broken denture (Figure 1). When asked what she was doing when the denture broke? She is unsure and/or tin can't remember. Upon inspection, the mandibular prosthesis is a 2-implant overdenture that has fractured right through the area of one of the zipper housings.

Clinically, the mandibular arch is significantly resorbed and two implant abutments are present, but the surface appears worn. While you may non recognize these abutments, the blueprint concept with the mandibular prosthesis is the aforementioned as a two-implant Locator overdenture (Effigy 2).

Figure 1. In Figure 1A, fibers from a previous repair are visible. Figure 1B reveals a more complex problem; the prosthesis is an overdenture and the denture base has fractured through the area of one of the housings. — Figure 1. In Figure 1A, fibers from a previous repair are visible. Figure 1B reveals a more complex problem; the prosthesis is an overdenture and the denture base has fractured through the area of i of the housings.

Figure 2. Overdentures with this configuration are usually implant-assisted, meaning support for the prosthesis comes from both the implants and the conventional denture bearing areas. The residual ridges are narrow buccal-lingually and do not appear to have much vertical height; in addition to maintaining/replacing the retentive clips, this scenario requires routine evaluation of the need for relining the prosthesis. — Figure two. Overdentures with this configuration are commonly implant-assisted, pregnant support for the prosthesis comes from both the implants and the conventional denture bearing areas. The rest ridges are narrow buccal-lingually and practice not appear to take much vertical height; in improver to maintaining/replacing the retentive clips, this scenario requires routine evaluation of the demand for relining the prosthesis.

According to both the patient and the referring dentist, both the upper and lower arches were treated approximately seven years prior. Additionally, the patient confesses to wearing both dentures at nighttime to help forestall wrinkles from forming. In the maxilla, two abutments similar to the mandibular abutments are present in the inductive while the posterior two abutments appear to exist angle corrected and custom made Locators (Effigy 3). Despite the historic period of the case and the damage to the lower prosthesis, the maxillary prosthesis has managed to maintain its esthetics (Effigy 4). Neither prosthesis has whatever type of metallic reinforcement.

Figure 3. (left) The maxilla was restored with an overdenture at the same time the mandible was initially restored. (right) In the maxilla, the anterior abutments appear similar to the mandibular abutments, but the posterior abutments appear to be angle-correcting custom locators. — Figure 3. (left) The maxilla was restored with an overdenture at the aforementioned fourth dimension the mandible was initially restored. (right) In the maxilla, the anterior abutments appear similar to the mandibular abutments, simply the posterior abutments appear to exist angle-correcting custom locators.

Figure 4. Despite the age of the prostheses, the esthetics of the maxillary overdenture does not appear to have been negatively affected. — *Effigy 4. Despite the age of the prostheses, the esthetics of the maxillary overdenture does not announced to take been negatively afflicted.*

Looking occlusally at the maxillary prosthesis, significant vesture to the denture teeth is present. At seven years, this finding is non unexpected for conventional dentures and certainly to be expected with implant-retained overdentures (Effigy 5 left, Figure 6). Interestingly, the maxillary overdenture had lost one of the retentive elements entirely and the remaining three retentive clips are not providing much retentive value (Figure v right).

Figure 5. The occlusal view of the existing maxillary prosthesis shows significant but not unexpected wear of the articulating surfaces of the denture teeth. The intaglio view shows retentive elements that differ between the anterior abutments and the posterior abutments. Additionally, the left anterior retentive clip is missing. Neither the upper nor the lower prosthesis are reinforced with a metal framework. — Figure 5. The occlusal view of the existing maxillary prosthesis shows significant but not unexpected article of clothing of the articulating surfaces of the denture teeth. The intaglio view shows retentive elements that differ betwixt the inductive abutments and the posterior abutments. Additionally, the left anterior retentive clip is missing. Neither the upper nor the lower prosthesis are reinforced with a metallic framework.

Figure 6. A close up view of the maxillary anterior acrylic denture tooth wear. It is not unusual for denture teeth to separate from the denture base or fracture under these conditions. Hats off to the technician! — Figure vi. A close up view of the maxillary anterior acrylic denture tooth habiliment. It is not unusual for denture teeth to carve up from the denture base or fracture under these conditions. Hats off to the technician!

Treatment planning

From a treatment planning perspective, this patient presents with 2 challenges. The first challenge is how to manage the urgent problem of the fractured denture base of operations. The second challenge is determining options for her definitive care. Understandably, additional data will exist required to come up with the definitive plan, but the patient is unwilling to get without a lower prosthesis while that plan is developed. In lodge to motility forward, it is important for the patient to know that the repair to the lower overdenture will go out the denture weaker than it was originally and whatever factors that contributed to the denture base fracturing, such as stress concentration effectually the implant abutments, could compromise the weakened denture farther.

Prosthetic procedures

In this case, the patient desires strongly to accept the lower denture repaired. For this particular repair, there are two distinct parts. Part one is to repair the fractured denture base and part 2 is to connect the attachment to the repaired denture base. The first step is to accurately reposition the denture base fragments (Figures 7 and eight). This pace is critical as an error here could create issues with fit of the denture base to the ridge and occlusal discrepancies.

Figure 7. The first step in this repair is repositioning the remaining fragments. In this case, the fragments are held together with sticky wax but cyanoacrylate could be another option. — *Figure 7. The first stride in this repair is repositioning the remaining fragments. In this case, the fragments are held together with gluey wax only cyanoacrylate could be another option.*

Figure 8. The fragments appear to be well positioned but there is a missing piece on the lingual. — *Figure 8. The fragments announced to be well positioned just there is a missing piece on the lingual.*

The side by side step is to fabricate some sort of a matrix to maintain the orientation of the fragments while the repair is existence made. In this case, a remount cast is made for this purpose (Figures 9 and 10).

Figure 9. Although the cast fabrication took additional time, it provides the benefit of a stable base for this repair and a subsequent repair should it be necessary. In addition, if an error is introduced during the repair procedure, the stone cast will serve as a control and will allow for a more efficient clinical remount to manage the occlusion. — Effigy 9. Although the cast fabrication took additional time, information technology provides the benefit of a stable base for this repair and a subsequent repair should it be necessary. In addition, if an error is introduced during the repair procedure, the stone cast volition serve as a command and will permit for a more efficient clinical remount to manage the apoplexy.

Figure 10. The remount cast has been fabricated in such a way as to leave the denture borders contacting the stone. This rigid contact will have no rocking or bouncing, ensuring accuracy and repeatability in the positioning of the fragments. The laboratory silicone component of the remount cast has been removed from the distal extensions (Figure 10A) to avoid interfering with seating of the denture base (Figure 10B). The anterior portion of the silicone has been left in place to help prevent repair material from flowing excessively into the denture base intaglio (Figure 10C). — Figure 10. The remount cast has been fabricated in such a way as to leave the denture borders contacting the stone. This rigid contact will take no rocking or billowy, ensuring accuracy and repeatability in the positioning of the fragments. The laboratory silicone component of the remount cast has been removed from the distal extensions (Figure 10A) to avoid interfering with seating of the denture base (Effigy 10B). The anterior portion of the silicone has been left in identify to help foreclose repair cloth from flowing excessively into the denture base intaglio (Figure 10C).

With the remount bandage fabricated, the mandibular prosthesis is so carefully removed and the surface prepared for the repair cloth. In this example, the repair material selected is an autopolymerizing acrylic resin (Jet Acrylic, Lang) so the surface is roughened with a carbide bur and air abraded with 50 micron particles of aluminum oxide. (Figures xi, 12 and 13).

Figure 11. (left) Following fabrication of the remount cast with the luted denture base, the fragments are removed from the cast and the surfaces prepared for the repair material. In this case the repair material is an autopolymerizing PMMA ( — Figure 11. (left) Following fabrication of the remount bandage with the luted denture base, the fragments are removed from the cast and the surfaces prepared for the repair material. In this case the repair material is an autopolymerizing PMMA ("cold-cure acrylic"). The gap at the fracture was kept as minimal as possible with a bevel abroad from the gap and the surfaces to be repaired air abraded with l-micron aluminum oxide. (right) The repair acrylic has been added to the cameo surface of the lower prosthesis. Post-obit application to this surface, the prosthesis was moved to a force per unit area pot and the repair fabric allowed to cure.

Figure 12. Now the prosthesis can be carefully removed from the remount cast (left) and additional material applied to the intaglio (right). The prosthesis is returned to the pressure pot and the repair PMMA allowed to polymerize. — Figure 12. Now the prosthesis can be carefully removed from the remount cast (left) and additional textile applied to the intaglio (right). The prosthesis is returned to the pressure level pot and the repair PMMA immune to polymerize.

Figure 13. The flash has been removed and the repair finished to allow for chairside pick-up of the attachment housing. One option would have been to use the existing housing and retentive clip, but since this abutment shares most of its geometry with the classic Locator, new Locator (extended range) components were utilized. The color difference between the repair material and the original denture base allowed for efficient flash visualization and removal. — Figure 13. The wink has been removed and the repair finished to let for chairside pick-up of the zipper housing. One choice would accept been to use the existing housing and retentive clip, only since this abutment shares most of its geometry with the classic Locator, new Locator (extended range) components were utilized. The color difference between the repair material and the original denture base of operations immune for efficient flash visualization and removal.

With the denture base repaired, office two of the procedure is fix to brainstorm; the chairside choice up (Figures fourteen and fifteen).

Figure 14. In preparation of the chairside pick-up, a vent has been created in the denture base (left) and the attachment housing picked up in the usual fashion (right). Rather than the tooth-colored PMMA used for the repair, an injectable autopolymerizing pick-up material was used. — Effigy 14. In preparation of the chairside pick-upward, a vent has been created in the denture base (left) and the attachment housing picked up in the usual manner (correct). Rather than the molar-colored PMMA used for the repair, an injectable autopolymerizing choice-up fabric was used.

Figure 15. The new housing is attached to the repaired denture base. — *Figure 15. The new housing is attached to the repaired denture base of operations.*

Final result

The prosthesis is finished with carbide burs and polished using flour of pumice and denture smooth on a rag bicycle and lathe (Figure 16). Alternatively, a silicone polishing organisation could take been utilized.

The last result is then inserted (Figure 17).

Figure 16. Denture base repair and chairside pick-up completed. Note the pink material filling the vent from the pick-up (left) and the tooth-colored repair on the facial surface (left) and the larger repaired area on the lingual (right). — Figure 16. Denture base repair and chairside option-upwards completed. Note the pinkish material filling the vent from the choice-up (left) and the tooth-colored repair on the facial surface (left) and the larger repaired area on the lingual (right).

*Figure 17. A "scar" from the repair procedure is visible with the lips retracted. Fortunately, there was no need to perform a clinical remount and equilibration with this case.*

Determination

Denture base fracture is not an uncommon occurrence in practices who treat edentulous patients. While sending the prosthesis to the dental laboratory for repair is ofttimes a bang-up option, there may be clinical circumstances that won't allow that to occur in a timely mode. In this commodity I've demonstrated one way to solve this problem, but there are countless other variations. I hope this helps next time you encounter this clinical problem.

References

Gad M, Rahoma A, Abualsaud R, Al‐Thobity A, Fouda Southward. Effect of Repair Gap Width on the Strength of Denture Repair: An In Vitro Comparative Study. Journal of Prosthodontics. 2022;28(6):684-691. doi:10.1111/jopr.13091
Kumar A, Badiyani B, Deb S et al. Impact of Surface Treatment with Unlike Repair Acrylic Resin on the Flexural Strength of Denture Base Resin: An In Vitro Study. J Contemp Dent Pract. 2022;21(10):1137-1140. doi:10.5005/jp-journals-10024-2892
Abushowmi T, AlZaher Z, Almaskin D et al. Comparative Effect of Drinking glass Fiber and Nano‐Filler Addition on Denture Repair Strength. Periodical of Prosthodontics. 2022;29(iii):261-268. doi:10.1111/jopr.13124