Immediate Loading: Three Cases with up to 38 Months of Clinical Follow-up

Immediate implantation and immediate loading protocols are becoming more common. Immediate loading in the mandibular interforaminal region has been routinely performed for more than a decade and success rates of 90% to 100% have been reported.1 The goal of immediate implantation and immediate loading is to decrease the number of surgical interventions, thereby reducing costs and patient discomfort. Furthermore, such an approach has led to immediate implant placement after tooth extraction and immediate loading of implants with fixed restorations. Studies showing long-term results of these two methods are scarce, and the number of cases is limited.2^,3 This article presents three different immediate loading cases and shows clinical and radiographic status after short-term functional loading.

An 18-year-old female patient was sent by her dentist to the Department of Prosthodontics of the Faculty of Dentistry at Istanbul University for evaluation of her maxillary right central incisor. Clinical and radiographic examinations showed external root resorption (Figures 1a and b), with slight mobility and a negative vitality test. The adjacent left central incisor also showed external root resorption (Figure 1a), but it was still vital. The patient's dental history included orthodontic treatment. Endodontic consultation led to a decision to retain the left central incisor and extract the right one. After atraumatic extraction (Figure 2), a dental implant (4.5 × 13 mm, Astra Tech Osseospeed, Astra Tech AB, Mölndal, Sweden) was placed in the fresh extraction socket in a 3-dimensionally correct position (Figure 3). After primary stability was affirmed, an abutment (Direct Abutment, Astra Tech) was mounted, upon which a temporary acrylic (Dentalon Plus, Heraeus Kulzer GmbH & Co KG, Dormagen, Germany) crown was fabricated chair-side. The marginal fit was finished and controlled on a laboratory analogue and then temporarily cemented (Temp Bond, Kerr Corp, Romulus, Mich) (Figures 4a and b). Occlusal contact was eliminated to protect the provisional crown. A final periapical radiograph was taken to evaluate the marginal fit (Figure 5a). After 3.5 months, minimal bone loss was observed radiographically (Figure 5b). A crown of porcelain fused to zirconium oxide, ZrO₂ (Cercon, Degudent, Hanau, Germany), was fabricated and cemented permanently (Panavia 21, Kuraray, Tokyo, Japan) after a 10-day period of temporary cementation. A 27-month follow-up radiograph (Figure 6a) showed a clinically stable situation around the implant, peri-implant bone resorption appeared comparable to results with delayed loading protocols, and the soft tissue showed excellent pink esthetics (Figure 6b).

A 22-year-old female patient who had lost her maxillary left central incisor in a car accident several months earlier, applied to the Department of Prosthodontics of the Faculty of Dentistry at Istanbul University for evaluation (Figure 7). A dental implant (4.5 × 13 mm, AstraTech Osseospeed) was placed in a 3-dimensionally correct position. After primary stability was affirmed, an abutment (AstraTech) was mounted, upon which a temporary acrylic (Dentalon Plus, Heraeus Kulzer GmbH & Co KG) crown was fabricated chair-side. The marginal fit was finished on a laboratory analogue and then temporarily cemented (Temp Bond, Kerr Corp). The provisional crown was protected from occlusal contact. This was easy to accomplish because the patient had an open bite. Final seating of the crown was verified by a periapical radiograph. The marginal fit was very good, as in case 1. Three months later, the final restoration (a porcelain fused to metal crown) was fabricated and cemented (Figure 8) with polycarboxylate cement (Adhesor Carbofine, SpofaDental, Praha, Czech Republic). Clinical follow-up after 38 months of functional loading showed a stable clinical (Figure 9) and radiographic (Figure 10) outcome.

A 27-year-old male patient who had lost his mandibular right central incisor because of a trauma several months earlier, applied to the Department of Prosthodontics of the Faculty of Dentistry at Istanbul University for evaluation (Figure 11). A dental implant (3.5 × 15 mm, AstraTech) was placed in the missing tooth location in a 3-dimensionally correct position (Figure 12). After primary stability was affirmed, an abutment (AstraTech) was mounted, upon which a temporary acrylic (Dentalon Plus, Heraeus-Kulzer) crown was fabricated chair-side. The marginal fit was finished on a laboratory analogue and then temporarily cemented (Temp Bond, Kerr Corp). The provisional crown was protected from occlusal contact with the opposing teeth. At that time, the patient's adjacent mandibular left central incisor was also prepared and provisionalized. The patient was lost to follow-up but eventually returned for definitive restoration 18 months later. The radiograph taken in this session showed that the crestal bone level had been well maintained (Figure 13).

Since the first reports demonstrating successful implantation into fresh extraction sockets,4 this technique has gained frequent, widespread use.5^,6 Immediate implantation has several advantages, such as reducing the number of surgical interventions and the total treatment time. Furthermore, the alveolar bone at the extraction site may be more resistant to resorption,7,^–9 and the soft tissue esthetics can be better maintained.10 

It has been reported that the buccolingual alveolar crestal width shrinks 5 to 7 mm, which is approximately 50% of the original volume, in the first year after tooth loss; the largest resorption appears within the first 4 months.11^,12 Parallel to that resorption, a vertical bone loss of 2 to 4.5 mm tends to continue simultaneously.13^,14 Extraction of several neighboring teeth may cause an even greater volume loss in the bone.11^,14^,15 

Immediate implantation should be avoided in the following situations: infection at the extraction site,16,^–18 significant discrepancies in a smaller size (ie, diameter) of the implant relative to the alveolar socket, and absence of primary stability of the placed dental implant. Studies with animals have shown that the distance of the implant surface to bone is important for clot stabilization.19,^–22 Distances >2 mm should be covered by a membrane.23,^–26 

If the requirements for immediate loading are met after implantation, this treatment option is valuable for fulfilling the esthetic and functional expectations of patients. A fixed provisional crown is more comfortable and less vulnerable to fracture or loss than a temporary removable denture.

The implant should be positioned 3-dimensionally in the correct position,12^,27,^–29 and primary stability must be obtained. Additionally, the socket walls where the implant will be placed must be intact to warrant later soft tissue esthetics.30 Insufficient bone support and a thin biotype often lead to disastrous results.31,^–36 If bony support is defective or if a dehiscence or a thin biotype is detected before or during the surgery, a grafting procedure that will delay the loading time is indispensable. Another important risk factor is a history of aggressive periodontitis, especially combined with cigarette smoking.37^,38 These cases can show unpredictable soft tissue recession.

The provisional crown is a key factor in the success of immediate loading of single implants, patient satisfaction, and soft tissue and interproximal papilla shaping. The provisional crown should not cause extensive pressure on the gingiva, which could lead to recession. Furthermore, the crown should be fabricated in a manner to avoid contact in laterotrusion or protrusion.

Proper indications, good surgical technique, and the use of a prosthetic protocol are very important for the success of immediate loading and immediate implantation. Patient satisfaction is very high, and difficulties related to the implantation site in late implantations are eliminated. Nevertheless, there are also contraindications for these treatment modalities. If even one of the following patient-related factors, such as poor systemic health, a heavy smoking habit, poor oral hygiene, a thin biotype, or an infection in the extraction region is present, this treatment option should not be considered.

All three cases presented herein showed a relatively good soft tissue response and a physiologically normal crestal bone loss after up to 30 months of functional loading. Periapical radiographs showed clearer and more accurate details than panoramic radiographs.39 

Based on our clinical experience, we suggest that if correct surgical techniques are applied and the indication and planning of the case is done meticulously, good clinical results can be achieved in immediate loading or immediate implantation combined with immediate loading when compared to delayed loading protocols. To be able to draw clinically meaningful conclusions, larger case numbers with longer observation periods must be achieved.