A major drawback of implant therapy is the comparatively long healing period involved. Early and immediate loading of dental implants can significantly decrease the treatment time and thus result in an increase in patients' comfort. In this report, 3 cases of placement and immediate loading of the final implants are presented. In 2 of these cases, where preliminary augmentation was necessary, provisional implants were placed after the procedure and immediate provisional dentures were delivered. With the exception of 1 case, in which 1 implant failed, no adverse events were observed. All cases are in function now for 3 to 5 years after implant placement. The observations from this limited number of cases confirm that immediate loading of implants could be a viable treatment option.
Treatment of the fully or partially edentulous dentition with dental implants is a commonly and successfully used modality, showing a reliable long-term prognosis.1–4 Although this type of treatment leads to functionally predictable and esthetically pleasant results, the comparatively long treatment duration resulting from long healing periods is a major drawback. Treatment duration may be further prolonged if augmentation of the area is necessary before treatment.
The currently suggested healing period for dental implants is based on the original protocol suggested by Branemark. Based on early findings on implant treatment, it was reasoned that an abbreviated healing period would lead to implant failure because of a fibrous encapsulation of the implant.5,6 More recent studies give a more differentiated view of the healing period necessary before successful loading is possible. Successful osseointegration seems to depend not only on the time point of loading but also on the amount of forces applied resulting in movement of the implants and the initial stability of the implant.7,8 Minimizing load on the implant by splinting, reducing the occlusal surface, or taking the crowns out of occlusion has been suggested with different results. Cross-arch splinting of implants seems to be a very promising approach to allow for early or immediate loading of implants.9–22 Different healing periods before loading depending on the surface characteristics of the implant have also been suggested.
In this report, 3 cases of immediate loading of implants using cross-arch fixed partial dentures (FPDs) are presented.
A 71-year-old woman presented in the office asking for a full-mouth rehabilitation. The clinical examination revealed an insufficient prosthodontic treatment of the maxilla and mandible. The FPD in the maxilla showed overhanging filling margins as well as unnecessary splinting of crowns in the interdental areas. Teeth #2 and #14 showed signs of advanced periodontal destruction with a class III furcation involvement. The FPD in the mandibular anterior region was mobile (class III mobility), showing a widened periodontal ligament space and insufficient endodontic treatment on the abutment teeth (Figure 1). The missing teeth in the posterior region had been replaced with a removable partial denture.
The remaining teeth in the mandible were extracted and replaced with an intermediate denture.
The anterior mandibular region was augmented with autologous block grafts and demineralized bovine bone (BioOss spongiosa 0.25–1 mm, 0.25 g, Geistlich Biomaterials, Wolhusen, Switzerland) and covered with 4 titanium foils (FRIOS BoneShield, Friadent, Mannheim, Germany). Lingual and labial fixation of the foils was achieved with titanium screws (Memfix Fixationsschraube Ø 1.2 × 4.5 mm, Straumann, Waldenburg, Switzerland).
To improve the retention of the intermediate denture and to reduce pressure on the surgical areas, 3 provisional implants (immediate provisional implant, 14 mm, Nobel Biocare, Yorba Linda, Calif) were inserted in the area teeth #21, #25, and #27, and the copings (Coping 5 Pkg, Nobel Biocare) were placed into the intermediate denture (Figure 2). The patient was instructed to rinse twice daily with chlorhexidine 0.12% (Chlorhexamed Fluid, Glaxo Smith Kline, Bühl, Germany).
Postoperative checks were performed weekly. Exposure of the membrane was observed 6 weeks after the surgery. The patient was instructed to continue with the chlorhexidine rinses. No further measurements were taken at this time.
After a 4-month healing period, the anterior mandibular region was reentered and the titanium foils and screws as well as the intermediate implants were removed. Six implants (ITI, SLA, solid screw implant, Straumann) were inserted (area teeth #19, #20, #23, #26, #29, and #30). Implants 4.1 mm in diameter and 8 mm in length were used in the molar region, whereas implants 3.1 mm in diameter and 12 mm in length were inserted in the other areas.
An impression was taken after completion of the surgery. The intermediate denture was connected to the implants with the help of “snap-fastener-cylinders” (Straumann). An FPD was delivered 3 days postsurgically.
Six months after insertion of the mandibular denture, the patient came to the office after skipping the recommended regular control-and-maintenance visits. Clinical examination revealed that the denture was loose, resulting in an overload on the implant region #19. The implant was mobile.
It was decided to remove the implant and to provide a new mandibular denture. The existing FPD was shortened and used as an interim prosthesis. The existing restorations in the maxilla were replaced.
The implants were not mobile and showed no signs of mobility at reassessment. The existing FPD was replaced. The patient was placed on a 3-month recall program (Figure 3).
A 70-year-old woman presented in the office asking for a complete renewal of her existing prosthodontic and restorative work and a comprehensive treatment of all other existing conditions.
The FPD in the mandible (areas #22–#28) showed a class III mobility. The remaining dentition had been replaced with a removable partial denture. The maxilla had been treated with combined FPDs and a removable partial denture. Tooth #15 had an insufficient endodontic treatment and a furcation involvement class III as well as a root caries on the palatal side.
Teeth #22, #23, #24, #26, #27, and #28 were extracted. The area was augmented with autologous bone grafts and bovine bone spongiosa (BioOss spongiosa 0.25–1 mm, 0.25 g, Geistlich Biomaterials). The augmented area was covered with 4 titanium foils (FRIOS BoneShield, Friadent) fixated with titanium screws (Memfix fixation screw Ø 1.2 × 4.5 mm, Straumann). To increase denture stability and to reduce pressure on the augmented area, provisional implants were inserted in area teeth #21, #24, and #27 (immediate provisional implant, 14 mm, Nobel Biocare) (Figure 4A). The corresponding copings (Coping 5 Pkg, Nobel Biocare) were inserted into the provisional denture (Figure 5B).
The patient was seen on a weekly basis during the healing period. Exposure of the titanium foils could be observed 6 weeks after the surgery. The patient was instructed to rinse twice daily with chlorhexidinedigluconate 0.1% (Chlorhexamed Fluid, Glaxo Smith Kline). The surgical area was reentered after a 4-month healing period. The titanium foils, screws, and the provisional implants were removed.
Seven implants (ITI, SLA, solid screw implant, Straumann) were inserted into the following positions:
Area #20: 1 solid screw implant, Ø 3.3 × 10.0 mm
Area #22: 1 solid screw implant, Ø 3.3 × 12.0 mm
Area #23: 1 solid screw implant, Ø 3.3 × 12.0 mm
Area #26: 1 solid screw implant, Ø 3.3 × 12.0 mm
Area #27: 1 solid screw implant, Ø 3.3 × 12.0 mm
Area #29: 1 solid screw implant, Ø 3.3 × 12.0 mm
Area #30: 1 solid screw implant, Ø 3.3 × 10.0 mm
Impressions (Impregum Penta, 3M ESPE, Seefeld, Germany) were taken after closure of the surgical site and the provisional denture was connected to the implants (snap-fastener-cylinder, Straumann) (Figure 5A and B). The final partial denture was delivered 3 weeks after implant placement (Figures 6 and 7).
A 57-year-old man presented in the office reporting recurring episodes of gingival bleeding, abscesses, and oral malodor during the past 6 years. No periodontal treatment had been performed during this time period.
Clinical examination revealed generalized probing depth of 6 to 9 mm and localized probing depth of 10 to 12 mm in the molar area. The gingiva was highly inflamed and edematous. Spontaneous bleeding, purulent exudate, and periodontal abscesses could be observed. All teeth were slightly mobile (class I mobility), with tooth #18 showing a class II mobility. The majority of the existing restorations had insufficient margins. Radiographically, horizontal and vertical bone loss of more than 50% could be seen. The maxillary anterior teeth showed a bone loss of more than 90% (Figure 8). Microbiological analysis by using DNA probes revealed significantly elevated levels of Actinobacillus actinomycetemcommitans (3.6%), Porphyromonas gingivalis (25.9%), and Bacteroides forsythus (9.3%).
The patient was informed about the etiology of the disease and was given oral hygiene instructions. Overhanging restoration margins were shortened and polished.
One week later, scaling and root planning was performed in all quadrants. Amoxicillin 500 mg/bid (Ratiopharm GmbH, Ulm/Donautal, Germany) and metronidazol 400 mg/bid (Aventis Pharma, Bad Soden, Germany) were administered for 14 days. Microbiological analysis 10 weeks after the initial treatment still revealed an elevated level of periodontal pathogens (A actinomycetemcommitans [1.8%], P gingivalis [7.2%], B forsythus [4.0%]).
Based on these findings, the decision was made to repeat the scaling and root planing and to again place the patient on an antibiotic treatment for 1 week (Augmentan 1000 mg/d, Augmentan Filmtabletten, Glaxo Smith Kline; metranidazol 800 mg/d, flagyl 400 mg, Aventis Pharma).
The patient refused any type of regenerative treatment in the maxilla. Therefore, only conservative treatment was performed in these quadrants.
The bony defects on teeth #18 and #19 were augmented with a 1:1 mixture of autologous bone from the retromandibular area and demineralized bovine bone spongiosa (BioOss spongiosa granulat, 0.25–1 mm, Geistlich Biomaterials). Teeth #22 to #29 and tooth #31 were extracted and the sockets were filled with demineralized bone (Grafton Putty, Bio Implantat Services, Osteotech, Leide, Netherlands) and covered with a nonresorbable polytetrafluoroehtylene membrane (Cytoplast Regentex GBR-200, 25 × 30 mm, Oraltronics, Bremen, Germany). Doxycyclin 100 mg/bid was administered for 1 week (Doxycyclin STADA 200 mg, STADA Arzneimittel AG, Stadastr. 2–18, Bad Vilbel, Germany). An immediate partial denture was delivered after the extractions. The membranes were removed after 4 weeks.
The patient was seen once weekly during the healing phase. Microbiological analysis at this time revealed no elevated levels of periodontal pathogens.
Implants (ITI, Straumann) were inserted 6 months after the area had been augmented (Figure 9).
Area #21: screw implant SLA, Ø 4.1 × 12 mm
Area #22: screw implant SLA, Ø 4.1 × 12 mm
Area #24: screw implant SLA, Ø 4.1 × 12 mm
Area #26: screw implant SLA, Ø 3.3 × 12 mm
Area #28: screw implant SLA, Ø 3.3 × 12 mm
The final denture and crowns were delivered 4 days after implantation (Figure 10) and the patient was placed on a 3-month supportive periodontal therapy schedule.
A major drawback associated with implant therapy is the comparatively long healing period necessary before the final prosthodontic restoration can be placed. To overcome this problem, immediate or early loading of the implants has been suggested. This treatment approach is a significant deviation from the traditional approach, which suggested a healing period of at least 3 months. These suggestions mainly stem from the original Branemark period, which was based on early findings in implant treatment as well as from the orthopedic field. It was feared that an earlier loading would lead to fibrous encapsulation of the implant, resulting in its failure.5,6
Recent studies give a more differentiated view of the influence of loading on the process of osseointegration of the implant. It is reasoned that it is neither the load itself nor the point of time of loading but rather the resulting movement of the implant that can lead to fibrous encapsulation. In other words, the risk of implant failure is dependent on the amount of force put on the implant and the initial stability of the implant.8 Loads that do not result in excessive movement of the implant may even accelerate the rate of bone formation.7,23
The successful use of immediate or early loading has been demonstrated both clinically and histologically.7–12,14–27 Different approaches to reduce implant movement during the initial healing period have been suggested. These include cross-arch splinting of the implants in completely edentulous patients and reducing or eliminating occlusal contact on immediate single crowns.
Although it could be demonstrated that the treatment of fully edentulous patients with cross-arch FPDs or removable partial dentures on splinted implants leads to a predictable outcome, some controversy still exists about the implementation of immediate loading on single implants.14–16,28–30 Additionally, though taking crowns out of occlusal contact during the healing period may reduce forces on the implant, there is no conclusive evidence that this increases the implant survival rate after immediate loading. Implant placement often necessitates preliminary augmentation of the area of implant placement.
Successful simultaneous augmentation and implant placement has been reported in cases where lateral defects around implants need to be regenerated; however, this technique does not seem to lead to predictable results when augmentation in a horizontal plane is necessary.31–33 Although grafting in a horizontal plane is possible, the initial loss of augmented bone height makes a 2-stage approach more appropriate to obtain predictable results.34 Because of the limited data available, it seems reasonable to follow a 2-stage approach of augmentation and implant placement in the majority of cases of immediate implant loading.
The use of provisional implants together with an intermediate denture can increase patient comfort by restoring function and esthetics during the healing period of the graft.35–37 This approach also protects the grafted area from any excessive forces resulting in movement of the graft and possibly impaired healing. This approach was successfully used in 2 of the cases presented here. In both cases, augmentation of the later implant site was accomplished without any adverse incidents, and implant placement was successful.
In 2 of the 3 cases presented in this report, the implants were immediately provisionalized and the final dentures were delivered 3 weeks later. This allowed for normal function of the dentures while initial healing of the tissue took place before the final dentures were designed. In the third case, the denture was delivered 4 days after implant placement.
Irrespective of the approach used, the cases in this report have been successfully in use for 3 to 5 years. Only 1 of the implants failed. This occurred during the early healing period and was probably due to superstructure loosening, resulting in excessive movement of the implant.
In accordance with previous reports, the observations made in these 3 cases show that early loading of splinted implants can be a successful treatment approach.
Oliver Hoffmann, Dr Med Dent, MS, is an assistant professor in the Department of Periodontics, Loma Linda University, School of Dentistry, Loma Linda, CA 92350 (firstname.lastname@example.org). Address correspondence to Dr Hoffmann.
Christian Beaumont, Dr Med Dent, is an oral surgeon at Blaues Haus Dental Institute, Duesseldorf, Germany.
Gregor-Georg Zafiropoulos, Dr Dent, PhD, is an associate professor in the Department of Operative Dentistry and Periodontology, University of Mainz, Mainz, Germany, and is with Blaues Haus Dental Institute, Duesseldorf, Germany.