IMMEDIATE LOADING PROTOCOL

Prosthetic Success with a Maxillary Immediate-Loading Protocol in the Multiple-Risk Patient

  • Method and materials Inclusion criteria and general requirements
  • Prosthetic procedures The prosthetic procedure followed the pick-up technique
  • DISCUSSION The treatment of high-risk patients with immediately loaded implants might be offered to partially edentulous patients

INTRODUCTION

The application of immediate loading of implants in the edentulous maxilla in multiple-risk patients is presented. Five partially edentulous patients attended with failing prostheses supported by hopeless teeth. An immediate-loading protocol was proposed because the patients rejected provisionalization with a removable prosthesis. Multiple teeth were extracted, and 44 immediately loaded implants were placed, most of them (55.5% to 88.9%) in fresh extraction sites, to support a cross-arch prosthesis that was loaded 3 to 4 days after surgery. The overall implant failure rate was 13.4%; in healed sites it was 20% (2/10) and in fresh extraction sites it was 8.82% (3/34). Prosthetic success was 100%. The overall failure rate was higher than is usually seen with the standard delayed-loading approach. Nevertheless, this immediate-loading protocol was satisfactory for the patients and the practitioner because prosthetic success was maintained during the provisionalization phase. (Int J Periodontics Restorative Dent 2007)

After two decades of extensive experimental and clinical research, the dental community came to recognize that early and immediate-loading protocols might be viable alternatives to the standard delayed-loading protocol.1–3 Clinicians have begun to use immediate loading protocols with occlusal contacts in the edentulous maxilla.4–6 To meet patients’ demands for immediate treatment, some clinicians have placed implants in fresh extraction sockets and loaded them immediately.5–10 Satisfactory results have been obtained in these limited series, fostering confidence and leading some clinicians to treat riskier and more challenging patients with this modality. In some patients the envelope has been pushed too far,5 resulting in more failures. Frequently, immediate replacement of a failing fixed prosthesis with an implant-supported rehabilitation meets the psychologic needs of patients. The prospect of wearing a removable appliance may induce sensations of mutilation and decay, feelings of premature aging, and loss of self-confidence.11 This is particularly true when the maxilla is involved. This emotional distress warrants efforts from practitioners to help patients cope with their ailment. Often, these patients can be treated with multiple extractions followed by immediate implant placement and immediate rehabilitation. However, such implants are at a higher risk of failure, since they are placed in sites of poor bone quality as well as fresh and (perhaps) infected extraction alveoli. In addition, the host may present additional risk factors, such as smoking and bruxing habits. In this environment of cumulative risk factors, both the patient and the practitioner may accept the occurrence of implant failures as long as prosthetic success is achieved during the healing period. The prosthetic success trumps implant failure, because the patient avoids the trauma or upset of wearing a provisional removable prosthesis.

The purpose of this paper is to present a series of five consecutive high-risk patients in whom the risk of implant failure was accepted by both patients and practitioners to achieve successful immediate provisionalization in the maxilla.

Method and materials
Inclusion criteria and general requirements

Inclusion criteria for the present protocol were as follows: (1) patients had to undergo the extraction of multiple teeth, leading to an edentulous maxilla; (2) patients had to refuse to wear a removable prosthesis during the healing period; (3) patients had to provide written, informed consent; and (4) the maxilla had to accommodate at least eight Osseotite (standard, NT, or XP versions; 3i/Implant Innovations) implants at least 11.5 mm long placed with a surgical guide in normal or soft bone.


Implants were distributed in the posterior and anterior regions without distal extensions. Implant primary stability was mandatory; implant seating with 35 to 45 Ncm of torque was required in all bone types. Where soft bone was identified, undersized drills were used to ensure implant primary stability.

The healing abutments were hand-tightened. Within 2 to 5 days, a provisional prosthesis was prepared by the dental technician and was placed on the implants. Abutments were tightened at 20 Ncm. A balanced occlusal scheme was followed with the prostheses. Patients maintained a soft diet for 6 to 8 weeks. The definitive prosthesis was delivered after 6 months of loading.



Patient reports and surgical procedures

Patient 1
A 44-year-old woman with poor hygiene presented with advanced periodontal disease in the maxilla, from the right first molar to the left second molar. In the mandible, teeth from the left first premolar to the right second premolar were present, along with two implant-supported prostheses in the posterior areas. Extraction of multiple teeth was indicated. The patient was scheduled for scaling, hygiene instruction, and extraction. Antibiotics (Augmentin, 500 mg four times daily, SmithKlineGlaxo) were prescribed the day before surgery and maintained for 7 days after implant placement. A crestal flap was raised at the healed sites, and a flapless approach was performed at the extraction sites. Atraumatic and gentle extraction was performed with the aim to maintain the buccal cortical plates. Ten implants were placed between the second premolar areas; eight of these were placed in fresh extraction sites. Seven XP and 3 standard Osseotite implants were placed, with length of 13 and 15 mm. After implant placement, all but two of the implants were expected to be loaded. This patient’s treatment is illustrated in fig 1.

Patient 2
An 82-year-old woman with a bruxing habit and poor hygiene presented with mobility of her maxillary anterior prosthesis, which was supported by six teeth (from canine to canine). The posterior maxilla had been rehabilitated with a removable prosthesis. In the mandible, teeth between the second molars were present. Advanced periodontal disease in the maxilla was the cause of the mobility, and extraction of multiple teeth was indicated. The patient refused a removable prosthesis in the anterior area, and an immediate- loading alternative was proposed. Hygiene, tooth extraction, and antibiotic treatment were scheduled and performed as previously described. Following extraction, eight implants were placed, from first premolar to first premolar; six were placed in fresh extraction sites. Four XP and four standard Osseotite implants were placed; all implants were 13 or 15 mm long. All implants were expected to be loaded.



Patient 3
A 61-year-old woman who was a bruxer and heavy smoker (40 cigarettes/ day) with poor hygiene presented because of mobility of her five remaining maxillary anterior teeth (from right canine to left lateral incisor). The vertical dimension had been lost because of posterior bite collapse. In the mandible, natural teeth were present from the right first molar to the left second premolar. Advanced periodontal disease in the maxilla was the cause of mobility, and extraction of multiple teeth was indicated. The patient wished to maintain the diastema between the central incisors. Placement of a high number of implants was indicated to ensure prosthetic success even if several implants failed. The extraction sites were carefully curetted, and nine standard implants were placed (from second premolar to second premolar); five of these were placed in fresh extraction sockets. Implant length varied from 11.5 to 15 mm; all implants were standard Osseotite. After implant placement, eight of the nine implants were expected to be loaded, and one implant would be left submerged.



Patient 4
A 72-year-old man with a bruxing habit and poor hygiene attended with mobility of his maxillary prosthesis because of advanced periodontal disease. In the mandible, all natural teeth between the second molars were present. The maxillary prosthesis was supported by seven teeth (from the right canine to the left first premolar . All remaining teeth needed to be extracted; nevertheless, the left first and second molars were retained to maintain the vertical dimension. Nine implants were placed, from the right first premolar to the left second premolar, and eight of them were placed in fresh extraction sites. Implants were five standard Osseotite, one XP, and three NT, and they were either 13 or 15 mm long. The NT implants were placed in the large extraction sockets to achieve better primary stability. After implant placement, eight of the nine implants were expected to be loaded.

Patient 5
A 52-year-old woman with poor hygiene presented with mobile maxillary prostheses. In the mandible, natural teeth were present between the second molars. The maxillary prostheses were supported by nine teeth. Advanced periodontal disease on the remaining teeth was the cause of prosthesis mobility. Multiple tooth extraction was indicated. After gentle, atraumatic extraction, 12 implants were placed between the right second molar and the left third molar; 8 of these were placed in fresh extraction sites. One standard Osseotite and 11 Osseotite NT implants were placed, and their length varied between 11.5 and 15 mm. After placement, 9 of the 12 implants were loaded, and 3 implants were left to heal free of loading.



Prosthetic procedures

The prosthetic procedure followed the pick-up technique illustrated for patient 1. Immediately after implants were placed, impression copings were attached to the implants and suturing was performed around the impression copings (see Fig 1d). Adaptation to the implants was checked radiographically. The impression tray was tried in (see Fig 1f), and an impression was made. Subsequently, the healing abutments were screwed back onto the implants (see Fig 1g). The impression was sent to the laboratory to prepare a provisional metal-reinforced acrylic resin prosthesis (see Figs 1h to 1j). Metal reinforcement was not used for the prosthesis of patient 2. All prostheses except that of patient 2 were cement-retained; the latter was screwretained. The healing abutments were removed after 3 days (4 days for patient 1). They were replaced by laboratory- prepared abutments tightened at 20 Ncm. The provisional prosthesis was seated on top of the abutments. Dynamic occlusion was checked carefully, and the prostheses were cemented with Temp Bond (Fuji GC) or hand-screwed. Patients were recalled after 1 week for suture removal and again after 2, 4, 8, 12, and 24 weeks. After 6 months, the provisional prosthesis was removed, and implants, including those that were not loaded, were individually checked for mobility. Impressions were made on all stable implants, and a metal-ceramic definitive prosthesis (see Fig 1k) was prepared according to standard procedures.

Success criteria

Success criteria included (1) absence of clinically detectable implant mobility, (2) absence of pain or any subjective sensation, (3) absence of recurrent periimplant infection, and (4) absence of continuous radiolucency around the implant.



Résults

Patient 1

The healing period during loading was uneventful. At the 6-month recall, the two submerged implants were left as sleeping implants, and the definitive prosthesis was placed as scheduled. This patient completed the 24-month follow-up.

Patient 2
After 3 months of loading, the provisional prosthesis fractured distally to the right lateral incisor. The implants at the right canine and first premolar were clinically mobile. These (XP 4/5 3 13 mm and XP 4/5 3 15 mm) were removed, and two one-stage NT implants (6 313 mm and 5 313 mm) were placed in these sites, respectively. An additional implant was also placed in each tuberosity; all these implants were left to heal in a stress-free fashion. The extension facing the right canine and first premolar sites was maintained. The provisional prosthesis was repaired and left in function for 4 more months. The definitive prosthesis was placed after 6 months as scheduled, including the four previously submerged implants. Despite two failed implants, the fixed prosthesis was successful and the patient avoided the use of a removable appliance during the transition phase. Implant failure was attributed to fracture of the prosthesis, which occurred because of the lack of metal reinforcement. The patient completed the 24-month follow- up.


Patient 3

After 3 months, the provisional prosthesis became loose. The left first premolar implant was clinically mobile (4 3 15 mm) and was removed. A onestage NT implant (5 3 13 mm) was placed to heal in a stress-free way. The unloaded implant in the left canine site was brought into function as the most distal implant. The prosthesis extension was limited to the left first premolar site. The provisional prosthesis was recemented and was left to function for an additional 3 months. The definitive prosthesis was placed after 6 months, as initially scheduled. Despite the implant failure, the provisional fixed prosthesis was successful and the patient avoided the use of a removable appliance. The patient passed the 24- month follow-up.

Patient 4

At 4.5 months, the patient presented with prosthesis mobility. Implant mobility at the left premolar sites was clinically identified. The mobile implants (NT 5 3 13 mm and NT 6 3 13 mm) were removed; in the right first premolar site, a standard one-stage implant of 6 313 mm was placed. An implant in the right canine site that was left transgingival was loaded; it served as the most distal supporting implant. The left first molar, which had been left in situ to maintain the vertical dimension, provided posterior support. The provisional prosthesis was cemented and was kept in function for 6 more months; the definitive prosthesis was placed after 10.5 months. Despite the failure of two implants, the fixed prosthesis was successful and the patient avoided the use of a removable appliance. Implant failure was attributed to the lack of sufficient surrounding bone at the wide NT implants. The patient passed the 24-month follow-up.

Patient 5

The provisional prosthetic period was uneventful. At the 6-month recall, all implants were stable. The patient passed the 24-month follow-up.

Results

A total of 44 implants were immediately loaded, and five implants failed (13.4%). All unloaded implants integrated. All failures were in soft bone; three had been placed into fresh extraction sockets and two had been placed into healed sites. In healed sites, the failure rate was 20% (2 of 10); in fresh extraction sites it was 8.82% (3 of 34). The prosthetic success rate was 100%.



Discussion
Immediate-loading protocols have been developed recently to reduce the number of surgeries and treatment length and to increase acceptance of implant therapy.1,9,12 To be accepted as reasonable alternatives, these protocols should demonstrate high success rates, similar to those seen with conventional delayed-loading treatments. The present failure rate was 13.4%, which is higher than the failure rates seen for conventional13 or early14–16 loading protocols, which approximate 2% to 4%. Nevertheless, this protocol and patient outcomes were considered satisfactory by the patients and the practitioner because, in these conditions, the aim was to ensure success of the implant-supported fixed prosthesis. This was achieved despite the failures that occurred in three of the five patients. It is notable that implant failures were recorded after 3 and 4.5 months, which is within the timeline reported for immediate-loading protocols.1

This high-risk population included patients with poor hygiene, a biotype susceptible to periodontal disease, bruxing habits, smoking, poor bone quality, and/or placement of implants in fresh extraction sites. Despite these demanding conditions, prosthetic success was achieved for all patients. This was probably achieved by: (1) placement of at least eight implants, (2) placement of implants at least 11.5 mm long with a textured surface, (3) primary stability achieved following an insertion torque of 35 to 45 Ncm, (4) adequate splinting, and (5) a balanced occlusal scheme.

Implants placed in healed sites failed more often (20%, 2 of 10) than those placed in fresh extraction sites (8.82%, 3 of 34). This was not anticipated and contrasts with the results of previous studies9,10; the reason for this difference is unknown. Notably, all failed implants were the most distal, while no mesial implants were lost. This observation should be taken into account when planning the number of implants and their spatial distribution. Either a higher number of immediately loaded implants should be placed in the posterior area to more evenly distribute the excessive load in the posterior region, or unloaded implants should be placed distal to the immediately loaded implants to ensure prosthetic function if the latter implants fail. Testori et al12 stressed that immediate loading is technique sensitive and requires a gradual and progressive approach. It is therefore suggested that clinicians treat this category of patients only after having gained experience with immediate loading in the edentulous mandible and the edentulous maxilla.

The treatment of high-risk patients with immediately loaded implants might be offered to partially edentulous patients with a failing fixed prosthesis. A higher failure rate is anticipated because of the combined risk factors. However, placement of a higher number of implants at least 11.5 mm long, inserted with a torque over 35 Ncm, and supporting a metal-reinforced prosthesis with a balanced occlusion delivered within 3 to 4 days can predictably lead to prosthetic success. Despite higher implant failure rates than are commonly accepted for other immediate or delayed loading protocols, application of this protocol can result in prosthetic success that is satisfactory to the patient and the practitioner.


The International Journal of Periodontics & Restorative Dentistry
Volume 27, Number 2, 2007


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Articles implantologie

After two decades of extensive experimental and clinical research, the dental community came to recognize that early and immediate-loading protocols might be viable alternatives to the standard delayed-loading protocol.



AUTHORS


Mithridade Davarpanah, MD, DDS

Private Practice, Paris, France; Head, Oral Rehabilitation Center, American Hospital of Paris, Neuilly sur Seine, France.


Mihaela Caraman, DDS

Private Practice, Paris, France; Oral Rehabilitation Center, American Hospital of Paris, Neuilly sur Seine, France


Boris Jakubowicz-Kohen, DDS

Private Practice, Paris, France; Oral Rehabilitation Center, American Hospital of Paris, Neuilly sur Seine, France


Myriam Kebir-Quelin, DDS

Private Practice, Paris, France


Serge Szmukler-Moncler, DDS, PhD, IEP

Associate Professor, Department of Stomatology and Maxillofacial Surgery, University of Paris 6, Paris, France


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