Full Maxillary Arch Immediate Implant, Immediate Loading with Final Single Restorations: A 7-Year Follow up

Dental News Volume XVIII, Number I, March, 2011

by Dr. Jihad Abdallah
 

Successful implant placement immediately after tooth extraction has been well reported in the literature. In this case report, the immediate implant placement and immediate loading of a full maxillary arch is described.

Although the temporary restoration was a fixed bridge connecting the twelve implants; the final restoration was twelve single crowns and followed up for 87 months in function.

Key Words: dental implants, immediate implant placement, immediate implant loading, locking tapper

Introduction

Recent advances in implant surgery have made it the standard of care and it now provides a simplicity that is demanded by our patients. Loading directly after implant insertion is of clinical interest since this considerably shortens treatment time. However, early excessive micromotion after implantation interferes with local bone healing and predisposes a fibrous tissue interface instead of osseointegration ⁽¹⁾. As the patient was asking for simple implant restorations, this large number of implants connected in one bridge during healing made the procedure more predictable. It is the macromovement of the implants during healing that leads to fibrous encapsulation of the implants due to scar formation instead of regeneration of bone around implants ⁽²⁾. So properly splinted implants prevents destructive lateral forces on solitary implants and will provide the healing environment needed for osseointegration⁽³⁾. Since the implant abutment connection, in this implant system that we are using (Bicon^TM), is a locking taper; single implant restorations could be safely used. Certain implant abutment connections (some screw type) are not secure enough to have single molar restorations, it is recommend to splint 2-3 implants together to prevent the micromotion that might lead to prosthetic failure especially at the weakest point which is the connecting screw ^(4,5) .The only concern that remains is to place an un-splinted implant of enough size to hold masticatory forces especially at the molar area.

Surgical Procedure

A 56-year-old healthy patient came in to the Beirut Implant Dentistry center. The patient presented with failing teeth and mobile fixed restorations in the maxillary arch indicating clearance of remaining tooth structure (figure 1). The patient was missing teeth number 1, 2, 3, 4, 12, 15, 16, 17, 18, 31 and 32, and had chronic marginal periodontitis with class I occlusal angles classification. After signing the informed consent, the patient underwent a maxillary arch restoration with 12 immediately placed and loaded implants, under local anesthesia.

After trial of the vacupress stent and its proper support on the palatal and labial tissues, the patient was draped and local anesthesia was applied. Periotomes were used to luxate remaining teeth to remove them atraumatically. This was followed by the extraction of teeth number 5, 6, 8, 9, 10, 11, 13, 14.  Proper curettage of the sockets ensured that no granulation tissue was left behind (figure 1). Tissue punch was used to expose crestal bone and sites of implants 3, 4, and 12.  After placing the implants in their osteotomies, the shouldered stealth abutments were connected with finger pressure only. The vacupress was placed in the patient’s mouth to check the proper selection of abutment size and angulation. The snap-on abutment covers were then connected to their corresponding abutments (figure 2). The vacu press stent was placed again on top of the connected snap-on acrylic sleeves to make sure that we still have enough space for injecting BIS-GMA around abutments and inside the stent to fabricate the temporary bridge (figure2).  Before the acrylic had set, the stent and temporary bridge were removed, all excess was properly trimmed, and embrasures opened and then balanced occlusion verified with no premature occlusal contact.

The patient was given post-operative instructions and dismissed. The patient was instructed to immediately report to the clinic if and as soon as acrylic bridge instability was detected in order to avoid permanent damage.

Ice packs were applied during the first 24 hours following surgery. Warm saline water baths followed this for the next week. The amoxicillin regimen (2 grams, 1 hour before surgery then 1 gram before bed for 1 week) was maintained for 7 days. Post-operative care also included 600 mg of Ibuprofen until the pain and swelling stopped. Regular check-ups were performed to check for stability and integrity of the temporary acrylic bridge. Check-ups also screened for any fractures that needed immediate repair. 

Fig. 1: Preoperative intra-oral picture, preoperative panoramic x-ray, and intra-oral clinical picture after removal of the failing restorations and intra-oral clinical picture after extraction.

Prosthetic Restoration

      During prosthetic restoration, the acrylic bridge was divided into two sections at the midline between the two central incisors. The right acrylic bridge was removed, as were the stealth abutments. Implant level impression was taken of implants 3, 4, 5, 6, 7, 8 as well as a bite registration all that while keeping the left bridge in place.  The stealth abutments and acrylic bridge were placed back in their original positions. The same procedure was performed on the left side with the right side acting as a reference for Vertical Dimension of occlusion. The cast of the mandibular impression was duplicated by the lab technician so two separate cases could be mounted (left and right). The lab technician also prepared abutments and new temporaries on the final abutments. After transferring the abutments from the cast to the patient’s mouth using the Duralay^{® resin} guide, the final abutments were permanently tapped in place (figure 3). The new acrylic single temporary restorations were tried and occlusion was verified. Any corrections on occlusion or margins were done using cold cure white acrylic at that stage. Again, two impressions were taken for the right and left while keeping the cross arch abutments in thereby maintaining the VDO. The lab technician finalized the single PFM restorations and the main issue at try in was checking contact points and occlusion.

    Fig. 2: Intra-oral clinical pictures of the implants in place, the stealth abutments, the acrylic snap on stealth abutments and the temporary restoration.

As proper margins and embrasures with proper occlusion were respected during the fabrication of the prosthesis, the main concern following prosthetic restoration was proper home care, including brushing and flossing.  As such, the patient received proper instruction in plaque control and management (chlorexhidine mouthwash, dental brushing with anti-plaque toothpaste, inter-dental brushes and dental floss when appropriate). The importance of proxy-brush was explained to the patient after helping him choose the proper size of proxy brush. The patient was asked to visit the office regularly (every 4 months) for scaling and cleaning. A panoramic X-ray was taken every year. 

Fig. 3: Clinical intra-oral pictures of the stealth abutments after healing, temporary restorations on the final abutments, metal try in, and the final ceramic restorations.

Following prosthetic completion, two implants (# 13 and 14) became a little mobile but did not present with pain or any other complications. The percentage of bone to implant may have been insufficient. Both implants were replaced. The replacements remain functioning and in excellent condition as confirmed by the panoramic radiograph and clinical photographs which were taken every year for the past 7 years.

Fig. 4:  Panoramic radiographs with the Stealth abutments after healing ,the final abutments in place, final PFM single crown restorations, clinical intraoral picture with the ceramic restoration 7 years after placement

Fig. 5:  Panoramic radiograph taken right after ceramic restoration placement and the figure on the right is the panoramic radiograph taken 7 years later.

Conclusion

Extraction, immediate placement and loading of dental implants is a successful treatment plan that is well tolerated by patients.  Follow up for 7 years shows the stability of the dental implants, bone and restorations, which was evident by the panoramic radiograph and clinical pictures (figure 4). Placement of single restorations did not affect the longevity of these implant restorations. It should be noted that this treatment option should not be offered to every single patient. Patients with high esthetic demands in the anterior region should be given the option of surgical rehabilitation of the implant site prior to placement of an implant.

References

1- Brunski JB: In vivo Bone Response to Biomechanical Loading at the Bone/Dental Implant Interface. Adv Dent Res 1999; 13:99-119.

2- Szmukler-Moncler S, Salama H, Reingewirtz Y, Dubruille JH: Timing of loading and effect of micromotion on bone-implant interface: A review of experimental literature. J Biomed Mater Res 1998; 43:192-203.

3- Bergkvist G, Sahlholm S, Karlsson U, Nilner K, Lindh C: Immediately loaded implants supporting fixed prostheses in the edentulous maxilla: a preliminary clinical and radiologic report :Int J Oral Maxillofac Implants. 2005 May-Jun; 20(3): 399-405.

4- Isidor F: Loss of osseointegration caused by occlusal load of oral implants. Clin Oral Implant Res 7:143, 1996

5- Rangert B, Jemt T, Jorneus L: Forces and moments on Branemark implants. Int  Oral Maxillofac Implants 4:241, 1998