Full upper metal-acrylic fixed bridge using Axiom PX- Bone Level Implants and Multi Unit Abutments
Featured Products Promotional FeaturesPosted by: Dental Design 6th December 2022
A 75-year-old retired lady was referred to The Park Dental Practice for the restoration of her missing maxillary dentition with dental implants. She had reluctantly been wearing a full removable upper denture for 9 months following extraction of all her upper teeth.
Due to a slightly exaggerated gag reflex, the patient could not tolerate a full palate prosthesis. She presented with a ‘horse-shoe’ shaped removable upper acrylic denture, which she used primarily for aesthetic reasons, as it was unstable during chewing.
She was however happy and comfortable with her lower removable partial cobalt-chromium denture.
Her medical history was clear and she was fit and healthy.
The patient requested fixed teeth in her upper jaw to improve function, aesthetics and her self-confidence.
Assessment
Intra-oral clinical examination was undertaken, which showed the upper alveolar ridge had ample keratinised mucosa, but there had been loss of bone volume (Figure 1). The remaining lower anterior teeth were sound with a healthy periodontal condition and there was no other pathology.
A CBCT scan of the upper jaw was taken to accurately assess the anatomy of the maxilla (Figure 2). The scan confirmed just adequate bone volume in the anterior maxilla, the density of the trabecular bone was adequate to allow for good initial primary stability for the implants (Figures 3).
The CBCT scan also confirmed inadequate bone volume beneath the maxillary sinuses. The patient was very reluctant to undergo any maxillary sinus grafting procedures and it was decided to place the implants anterior to the maxillary sinuses.
An extra-oral facial assessment including patient’s profile and lip support was carried out with a diagnostic wax-setup (Figure 4) to determine the exact design and tooth position of the final fixed bridgework and to get the patient’s approval and consent (Figure 5). This diagnostic was also be used to construct a simple surgical stent.
Implant placement
Anthogyr Axiom® PX BL (Bone Level) implants were placed in the 12, 13, 15 and 22, 23, 25 regions. Six 3.4 mm diameter/ 8 mm length, implants were used.
All implants were placed in healthy bone using the simple drilling sequence of the Anthogyr implant system (Figure 6). The implants were submerged to allow for undisturbed healing for 4 months. Her old full upper denture was relined with soft lining following suturing of the mucosa.
4 months following healing the implants were exposed and healing collars attached with a torque of 10 Ncm (Figure 7).
Following 6 weeks of soft tissue healing (Figure 8), the healing collars were removed and Multi Unit Abutments (MUA) were secured to the implants with a torque of 25 Ncm (Figures 9 and 10).
Three 1.5mm gingival height and 30-degree and three 1.5mm gingival height and 18-degree Non-indexed Regular Multi-Unit Abutments were secured to the implants with a torque of 25 Ncm.
The Multi-Unit abutments have 2 platform widths, Regular 4.8mm in diameter and Narrow 4mm in diameter. The 4.8 mm platforms have a 2.5mm coronal height and the 4mm platform have a 1.5mm coronal height. These narrow abutments are ideal for those multi-unit screw retained restorations in patients with a small inter-implant distance
The 20-degree taper on the platforms allows for a further angular correction of the axial implant position, so that the screw access hole can be located in an ideal position on the final fixed bridgework.
The multi-unit abutments have a selection of gingival heights to allow for varying depths at which the implants are placed and different thicknesses of the gingivae. These range from 0.75mm-4.5mm in height.
The straight multi-unit abutments are tightened to a torque of 25 Ncm directly into the implants.
The angled multi-unit abutments come with a M1.6 screw, which is tightened to a torque of 25 Ncm to secure the abutment into the implant, once the angled multi-unit abutments have been seated in the desired position.
The prosthesis is tightened onto the multi-unit abutment to a torque of 15Ncm with M1.4 screws using the ball ended driver.
The regular (4.8mm) platform multi-unit abutments come in 18 degree and 30 degree angulations. The narrow (4mm) multi-unit platform are only straight abutments, with no angled abutments available.
The angled multi-unit abutments are either indexed or non-indexed. I used the non-indexed as it allowed me the freedom to secure them in any position, within 360 degrees, rather than restricting to only 3 positions as determined by the index of the implant.
Transfer copings were attached to the multi-unit abutments. The transfer copings were linked together with GC Pattern Resin to prevent any positional distortion during impression removal and casting (Figure 11).
Impressions were taken using a special tray (Figures 12 and 13) with a silicone impression material and jaw relationships confirmed.
CAD-CAM design of the proposed titanium metalwork was produced and milled by SIMEDA once approved my me (Figure 14).
My dental technician then completed the acrylic teeth and gingival set-up on the titanium metal sub-structure (Figure 15).
The fixed metal-acrylic bridge was secured to the multi-unit abutment with a torque of 15 Ncm (Figures 17,18 and 19).
A post fit OPG taken at this final stage (Figure 20).
The patient was very satisfied with the final result and was able to enjoy chewing food again. She was very happy with the final aesthetics of the bridgework and her self-confidence had improved.
Axiom® PX Bone Level® is a very user-friendly implant. The implant surgical kit, and the steps involved during the surgery, are straightforward, resulting in minimum trauma to the bone and osteotomy site. The implants afford excellent primary stability due to the thread design, even in soft bone. The prosthetic kit is also easy to use and sterilise.
Maintenance of the final Prosthesis
The patient can easily clean with normal brushing and interdental aids the entire bridgework and the gingivae around the multi-unit abutments. The use of a Waterpick is also recommended and it is very useful and requires less manual dexterity. The use of multi-unit abutments allows for easy removal of the prosthesis for maintenance, without disrupting the soft and hard tissue attachments around the implant neck.
| Figure | Thumbnail | Description |
| 1 | 
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Edentulous ridge |
| 2 | 
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CBCT Scan |
| 3 | 
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CBCT
Scan of anterior maxilla |
| 4 | 
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Diagnostic wax set-up |
| 5 | 
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Wax Try-in |
| 6 | 
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Implants placed in healthy bone |
| 7 | 
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Implants exposed and attach healing collars |
| 8 | 
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Soft tissue healing after 6 weeks |
| 9 | 
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Attach MUA |
| 10 | 
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MUA in situ |
| 11 | 
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Transfer copings linked with Pattern Resin |
| 12 | 
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Special Tray |
| 13 | 
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Transfer impression |
| 14 | 
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CAD-CAM design of proposed fixed prosthesis, indicating position of the screw access holes. |
| 15 | 
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Titanium metalwork from SIMEDA |
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Final acrylic application to metal substructure | |
| 16 | 
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Acrylic bonded to Titanium bridgework |
| 17 | 
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Bridgework immediately after placement |
| 18 | 
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Profile and lip support |
| 19 | 
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Labial view |
| 20 | 
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OPG following fit of prosthesis. |
For more details, please visit www.straumann.com/anthogyr/en/home/implant-system
Dr Waseem Noordin MSc ImpDent (Lond), BDS, DipImpDent RCS (Eng) (Adv cert), LDS RCS (Eng), MFGDP (UK).
Dr Waseem Noordin has over 35 years of experience in all aspects of surgical and restorative implant dentistry. He regularly lectures and runs courses in this field. Waseem provides assistance to colleagues in planning cases and one-to-one mentoring in all aspects of implant treatment.
Dr Noordin is a Fellow of the International College of Dentists. He was a tutor, lecturer, cohort director and examiner of the FGDP Diploma in Implant Dentistry at the Royal College of Surgeons of England for ten years. He was a board member of the FGDP (UK) for nine years and director of the Central London Division.
The Park Dental Practice
166 Whitchurch Lane
Edgware
Middlesex HA8 6QL
Tel: 020 8905 6324
Email: theparkdentalpractice@gmail.com
