Immediate Rehabilitation of Edentulous Maxilla with a Definitive ProsthesisUtilizing an Intraorally Welded Titanium Framework

Introduction

Several studies have reported successful treatment outcomes with prosthesis.^1,2 Numerous protocols have been proposed for the immediate implant loading, which enables immediate provisionalization with a fixed prosthesis. The reported procedures are consistent and are aimed at simplifying the treatment protocol and reducing healing time.^3,4

A protocol was published in 2006 to create a customized metal-reinforced provisional prosthesis to implant abutments directly in the oral cavity, which can be further utilized for a definitive restoration.^5,6 Hence, the present case report showcases a technique for the immediate provisionalization of an edentulous maxilla with an intraorally welded titanium framework following immediate implant placement.

Case Report

A 46-year-old male patient presented at the clinic with periodontally weakened dentition. The patient’s chief complaint was poor aesthetics and lack of masticatory capability arising from the mobile teeth (Figure 1a). On examination, 13, 12, 11, 21, 22, 23 were found to be mobile (grade III), requiring an extraction (Figure 1b).

A panoramic radiograph and Cone Beam Computed Tomography (CBCT) images were captured, and viable treatment alternatives were explained to the patient (Figure 2). The patient chose the treatment option of implant supported fixed prosthesis with immediate implant placement following extraction of the teeth. The patient’s medical and dental history was noncontributory. The patient also did not reveal any positive drug history.

After obtaining diagnostic impressions, vertical dimension was estimated for the fabrication of provisional complete dentures. The diagnostic casts were then mounted in an articulator, and a diagnostic wax-up was made. The occlusion, aesthetic parameters, and relation between the teeth and alveolar ridge were evaluated in the diagnostic wax-up. An immediate provisional prosthesis was fabricated with heat cure acrylic resin. The bone width and height were estimated with the CBCT images, and the appropriate number of implants, size and location were determined.

The patient was prepared for the implant surgery by administering local anesthesia (2% lignocaine/ adrenaline, 1:100,000). Traumatic extractions were carried out for the mobile teeth.

Following this, a mucoperiosteal flap was raised for the subsequent implant placement (Figure 1b). The fabricated provisional complete denture was used as a stent for the placement of the implants. Sequential osteotomies were performed and five implants of the dimension 3.5 x 11 mm were placed (two in the molar region, two in the cuspid region and one in the anterior). The implants were then torqued with a range of 20N–40N (Figure 1c).

In order to improve the cross-arch stability of the implants, a 2-mm titanium wire (commercially pure titanium grade 2) was molded and shaped according to the arch form to form a passive framework and connect the implants. The welding abutment was then attached to each abutment using a long pin screw. The titanium bar was then welded on to the welding abutments starting from the distal most abutments followed by the other abutments with an intraoral welding unit (Figure 1d). To ensure retrieval of the framework after welding, twopart welding abutments were used.

An opaquer (crea.lign, Bredent) was then applied to the titanium framework to mask the metallic shade. Following this, a light cure composite (combo.lign, Bredent) was injected on to the individual abutments and cured intraorally. To ensure complete curing of the composite, the framework was unscrewed and cured again in the laboratory. Subsequently, the framework was placed back onto the implants and the provisional prosthesis loaded with relining composite (combo.lign, Bredent) was pressed on to the framework (Figure 1e).

The provisional prosthesis was then removed along with the picked-up framework, following which it was finished and polished. A soft liner was then injected on to the intaglio surface of the prosthesis with the incorporated framework. Try in trial was done for the provisional prosthesis and it was then finished and polished for the final insertion (Figure 1f).

The patient was recalled after a period of one month and three months for observation. Radiographs were made to check the bone levels. A marginal bone loss of 0.3 mm was observed, which was well within the normal range (Figure 1g).

Discussion

The evolution of implant treatment, regardless of whether it is performed in the mandible or the maxilla, strives to shorten the period from implant placement to implant loading. Due to aesthetic, economic, and psychological reasons, patients may prefer avoiding a long transitional interval from wearing a removable prosthesis to a fixed, definitive one. Immediate loading of implants with definitive dentures have demonstrated long-term success and high predictability.^2,6 Indeed several studies do confirm successful oral rehabilitation of edentulous maxilla and mandible with a fixed definitive restoration supported by an intraorally welded titanium wire on the same day of implant placement surgery.⁷

According to Brunski et al., immediate, or early loading of implants can be carried out only if the micro-movement can be restricted to 100 µm during the healing phase.⁸ The intra-oral welding technique allows rigid splinting of multiple implants for immediate loading on the same day, resulting in a predictable fixation of implants in the healing period with a significant reduction in the micro-movements. The welded framework resists forces in all directions, thus allowing the osseointegration to occur safely. Additionally, intraoral welding enables the creation of a precise and passive framework, without the need for any other additional components or luting agents as with the other frameworks. It also shortens the treatment time and is cost-effective.

A case series published by Degidi et al., in 2008 demonstrated the success of rehabilitating the edentulous maxilla by immediate loading with a definitive restoration supported by an intraorally welded titanium framework. The mean marginal bone loss observed in the study at the end of a 12-month follow-up period was 0.57 mm.⁹ Another case report by Degidi et al., demonstrated the successful rehabilitation of edentulous mandible with an immediately loaded definitive prosthesis using intraoral welding. The two-year follow-up demonstrated a 100% implant survival rate and minimal bone loss.¹⁰

In the present study, the same technique was utilized, and a welded framework was fabricated to minimize the micro-movements and improve the prognosis and longterm success of the prosthesis. The mean marginal bone loss observed after follow-up was negligible. Avvanzo et al., demonstrated that intraoral welding of implant abutments with a titanium bar allows immediate loading of implants with a provisional or definitive restoration during the healing period, without any micro-movements and implants loss.4 The welded titanium framework technique gives the opportunity to provide patients with hopeless dentition with a definitive prosthesis, with good aesthetic outcomes, on the same day as implant placement. The definitive prostheses provide exceptional aesthetics and function and improves the patient compliance.

One of the limitations of the above-mentioned procedure is its technique sensitivity. It is critical to have total contact between the welding abutment and the titanium bar during the welding procedure and a firm and constant pressure must be applied to achieve a perfect joint. Another major concern is the endurance of the welding joint and the stability of the titanium-framework. Further investigations with a longer follow-up period must be carried out to assess the bone-loss pattern and the stability of the welded framework to better determine the long-term success of this approach.

Conclusion

This case report demonstrates a method of successfully rehabilitating an edentulous maxillary arch with a fixed restoration utilizing an intraorally welded titanium framework on the same day of implant placement, without jeopardizing the osseointegration and subsequently the success of the implant. The prosthesis supported by the welded titanium framework not only minimized the micro-movements of the implants but also provided good aesthetics and function, increasing the patient compliance.