By Dr. Ara Nazarian
Advances in clinical techniques and materials continue to revolutionize dentistry, enabling clinicians to practice with a greater degree of predictability and confidence than ever before. Also, with increasingly affordable dental implants, more and more patients are opting for some form of implant therapy whether fixed or removable. Utilizing not only the savings in dental implants, but also advancements in dental materials, clinicians are reporting reduced chair time and increased patient satisfaction when reconstructing patient’s smiles. This article focuses on the sequences involved in the edentulation of the affected dentition, grafting these areas to build the foundation and final implant overdenture reconstruction.
A patient presented to my practice for a consultation wanting to restore her dentition to proper form and function. She complained of generalized discomfort in these teeth due to the gross caries and periodontal disease that was readily apparent (Figure 1). There were several teeth in both arches that were already removed due to gross decay and/or periodontal disease.
A CBCT scan using the CS 8100 3D (Carestream Dental) was taken to accurately capture the information needed to properly treatment plan this case insuring the most ideal outcome, especially since the patient discussed her frustration with previous treatment.
Figure 1: Retracted preoperative view
Figure 2: Maxillary Digital View from CS 3600
Figure 3: Mandibular Digital View from CS3600
Figure 4: Smoothing of bone to eliminate sharp areas
To further develop a treatment plan, digital impressions and bite registration were captured using the CS 3600 (Carestream Dental) intraoral scanner (Figure 2 & 3). In addition to illustrating the current condition to the patient during her case presentation, the digital images were used for further analysis of tooth position, tooth size and arch form for the proposed treatment of full mouth edentulation, leveling and grafting. Immediate dentures for both arches would be delivered on the day of surgery, however in the lower arch four dental implants would be placed to support an overdenture.
Financing options using a third party payment option (Lending Club) were discussed with the patient. This discussion was a very important part of facilitating acceptance of her care, since it made the cost of treatment more feasible.
Starting in the maxillary arch, the teeth were extracted using the Physics Forceps (Goldendent). The Physics Forceps act simply like a class I lever, where only one force is applied with the beak on the lingual aspect of the tooth. Once the beak is placed at the lingual cervical portion, the soft bumper is placed on the buccal alveolar ridge at the approximate location of the muco-gingival junction to balance the beak. The beak grasps the tooth, while the bumper is the fulcrum to provide leverage and stability for the beak. Extraction is accomplished with wrist movement rotation in a buccal direction which is usually accomplished within 30-60 seconds depending on the tooth morphology.
Once the teeth in the maxillary arch were removed, any granulation tissue remaining within the sockets were removed using a curette and any sharp areas of the alveolar crest were leveled with a bone bur (Goldendent) and smoothed with a bone file (Goldendent) (Figure 4).
Immediately after the extractions, carious lesions, remnants of periodontal ligament (PDL) and calculus were removed with a bur, so that the teeth could be used in the Smart Dentin Grinder (KometaBio) as an autologous graft. Once cleaned, the teeth were dried and placed into the sterile chamber (Figure 5) of the Smart Dentin Grinder (KometaBio) for grinding and sorting collecting particles from 300um and 1200um.
The particulate dentin from the drawer was then immersed in basic alcohol for 10 minutes, using a small sterile glass container included with the kit. The basic alcohol cleanser consists of 0.5M of NaOH and 30% alcohol (v/v) which are used for defatting, dissolving all organic debris, bacteria, and toxins of the dentin particulate. After decanting the basic alcohol cleanser, the particulate was washed twice in sterile phosphate-buffered saline (PBS). The PBS was decanted, leaving wet particulate dentin that was placed into freshly extracted sockets and any alveolar bone defects (Figure 6).
Figure 5: Using the Smart Dentin Grinder
Figure 6: Dentin Graft placed into sockets
Figure 7: Removing the lower teeth with Physics Forceps
Figure 8: Lower edentulous ridge before leveling
Figure 9: Engage (OCO Biomedical) dental Implant
Figure 10: Maxillary and Mandibular immediate dentures
After extracting the mandibular teeth (Figures 7 & 8), the ridge was leveled in the same manner as the maxillary arch. However, four 4x12mm Engage (OCO Biomedical) dental implants (Figure 9) were placed in key positions to support overdenture prosthesis. These implants were used because their design offers high initial stability for selective loading options due to their patented Bull Nose Auger™ tip and Mini Cortic-O Thread™. Tall healing caps of 5mm (OCO Biomedical) were placed onto the dental implants so that they would extend through the tissue once sutured and aide in supporting the lower immediate denture.
Any residual areas around the implants or in remaining sockets were grafted with dentin autogenous grafting material from the freshly extracted teeth. Primary closure was achieved by suturing the tissue with resorbable sutures.
The upper and lower immediate dentures were tried in to insure there were no areas binding (Figure 10). Once confirmed, a self-cured silicone based soft reline material (Sofreliner Tough Medium, Tokuyama) was used to line the inner aspects of the immediate dentures (Figure 11).
Approximately 3-4 months later (Figure 12), the healing caps were removed from the Engage (OCO Biomedical) dental implants in the mandibular ridge and Locator RTx (Zest) overdenture attachments placed (Figure 13) and tightened to 30Ncm. Free-standing attachments like the Locator RTx (Zest) used to retain overdentures provide numerous advantages, including enhanced esthetics, phonetics, as well as ease of maintenance and simplified hygiene.
A previously made metal reinforced overdenture with relieved areas for the housings was tried in to confirm comfort and fit. Any interference that was detected between the denture base and attachments and housings was checked and eliminated.
When relining dentures or picking up over-denture attachments directly within the mouth, the patient may experience heat generation that is uncomfortable in addition to a bad taste when using methyl methacrylate. Since Tokuyama Rebase II Hard Denture Chairside Reline and Pickup Material is methyl methacrylate free, it doesn’t have a strong odor or taste as well as minimal heat generation making it a much better experience for the patient.
Figure 11: Injecting Sofreliner (Tokuyama) into immediate denture
Figure 12: Healed maxillary ridge
Figure 13: Locator RTx attachments with housings placed and ready for pick-up
Figure 14: Applying bonding agent
Figure 15: Tokuyama Rebase II Hard Reline and Pick Up material
Figure 16: Mixing the pickup material
The first step was to brush a thin coat of adhesive into the overdenture recesses (Figure 14) to enhance retention between the denture base and the hard reline/pick up material. Petroleum jelly was applied to the surrounding surfaces of the denture to prevent unwanted adherence of excess material. Once mixed, the Tokuyama Rebase II material (Figure 15 & 16) was placed into a plastic dispensing syringe and injected up to two thirds the height of each recess as well as on to the attachments. During seating, the prosthesis was gently held in place by hand. After a total of about 3 minutes, the overdenture with the incorporated retention caps was removed. Any excess material was removed with a trimming bur (Figure 17). At the completion of the prosthetic phase, the patient stated how pleased she was to be able to smile and function without the prosthesis wobbling or falling out (Figure 18). Most importantly from a clinical standpoint, we were pleased to see the areas in the upper and lower arches healthy and infection free.
More and more patients are presenting to dental practices with terminal dentitions requiring full mouth extractions. Overdenture treatment is a very good option for those individuals who may be anatomically, financially or medically compromised. Having the proper armamentarium that allows the dental practitioners the ability to provide efficient yet effective treatment benefits the patient in several ways.
Dr. Nazarian maintains a private practice in Troy, Michigan with an emphasis on comprehensive and restorative care. He is a Diplomate in the International Congress of Oral Implantologists (ICOI) and the director of the Ascend Dental Academy. He has conducted lectures and hands-on workshops on aesthetic materials, grafting and dental implants throughout the United States, Europe, New Zealand and Australia.
Figure 17: Picked up overdenture attachments
Figure 18: Metal reinforced lower overdenture seated
Ara Nazarian DDS, DICOI