Immediate functional loading of implants in single tooth replacement: a prospective clinical multicenter study

Objectives: The aim of the present study was to evaluate the outcome of immediate functional loading of implants in single-tooth replacement using two different installation procedures.
Material and Methods: One hundred and fifty-one subjects, who required single-tooth rehabilitation in the area of 15–25 and 35–45, were enrolled in eight private clinics in Italy. The implant sites were randomly allocated to one of the following treatment groups. In the control group, in which a standard preparation procedure for implant placement and submerged healing of the implant was used, abutment connection and loading of the implants were performed 3 months after installation. In the test group 1, a standard preparation procedure for the implant placement and immediate functional loading of implant was carried out. In the test 2 group, however, a modified implant installation procedure (osteotome technique) was used followed by immediate functional loading of the implant. Clinical and radiographic examinations were performed at 3 and 12 months of follow-up at all sites.
Results: Three implants (5.5%) from the test 2 group (osteotome preparation) and one (2%) from the test 1 group (conventional drill preparation) failed to integrate and were removed one and three months after implant installation. The mean marginal bone loss assessed at 12 months was 0.31 mm (test 1), 0.25 mm (test 2) and 0.38 mm (control) (no statistically significant differences were found between the three treatment groups.)
Conclusion: It is suggested that immediate functional loading of implants that are placed with a conventional installation technique and with sufficient primary stability may be considered as a valid treatment alternative in a single-tooth replacement.     

Implant-retained mandibular overdentures with immediate loading: a 3- to 8-year prospective study on 328 implants

Purpose: The purpose of this study is to evaluate prospectively survival and success rates of implants placed in the inter‐foraminal area of edentulous mandibles and immediately loaded with an implant‐supported overdenture. Materials and Methods: Eighty‐two patients, 33 males and 49 females, aged between 42 and 87 years (mean age 58.6 yr), presenting edentulous mandibles were rehabilitated with an implant‐supported overdenture in the mandible. Three hundred twenty‐eight screw‐type osseointegrated implants (164 Ha‐Ti, Mathys Dental, Bettlach, Switzerland; 84 ITI Dental Implant System, Straumann Institute, Waldenburg, Switzerland; 40 Brånemark Conical, Nobel Biocare AB, Gothenburg, Sweden; 40 Frialoc, Friatec, AG Mannheiti, Germany), were placed in the intraforaminal area of the mental symphysis (4 implants per patient). Immediately after implant placement, a U‐shaped gold or titanium bar was fabricated and implants were rigidly connected with the bar and immediately loaded with an implant‐retained overdenture. Success rate of implants was evaluated clinically and radiographically every year after the loading of the prostheses according to the following parameters: (1) absence of clinical mobility of implants tested individually after bar removal, (2) absence of periimplant radiolucency evaluated on panoramic radiographs, (3) absence of pain and radiologic or clinical signs of neural lesion, and (4) peri‐implant bone resorption mesial and distal to each implant less than 0.2 mm after the first year of prosthetic load. Results: Of 328 implants placed, 296 were followed up from a minimum of 36 months to a maximum of 96 months, with a mean follow‐up of 62 months. Seven implants in 6 different patients were removed owing to loss of osseointegration, whereas 18 implants, although still osseointegrated, did not fulfill success criteria due to bone resorption > 0.2 mm/year after the first year of loading. Despite implant losses, all patients maintained their bars supporting overdentures, although in 6 patients they were supported by 3 instead of 4 implants. The only patient who lost 2 implants received 2 new implants, which survived normally. Therefore, the absolute success and survival rates were 91.6% and 97.6%, respectively, whereas the cumulative survival and success rates of implants obtained with a life table analysis were 96.1% and 88.2%, respectively. Conclusions: Results of this study seem to demonstrate that survival and success rates of immediately loaded implants placed in the intraforaminal area of the mandible and rigidly connected with a bar through an implant‐supported over‐denture are consistent with those reported in the international literature as far as delayed loading is concerned after 3 years of loading. After longer observation times, this study demonstrated that, while survival rates of implants and bar‐supported overdentures are still consistent with results published in the international literature pertaining to delayed loading, a moderate decrease in success rates of implants was found. Nevertheless, it must be stressed that this decrease (88.8 and 90.4% after a 7‐ to 8‐year observation period for Ha‐Ti and ITI implants) is related only to two implant systems; no data are available for the other two implant systems because of the shorter follow‐up period.     

A 10-year evaluation of implants placed in fresh extraction sockets: a prospective cohort study

Background: The placement of an implant into a fresh extraction socket has been identified as a reliable technique, allowing a reduction in the time needed for prosthetic rehabilitation. This treatment modality is widely reported in the scientific literature; however, the long-term outcomes and the need for guided bone regeneration (GBR) are still topics of debate. The aim of this prospective study is to evaluate the clinical and radiologic findings from the 10-year follow-up of immediately placed implants, with and without the GBR procedure. Methods: A total of 159 implants in 91 patients are included in this study; 101 implants required a GBR procedure simultaneously with placement. All implants were used to support a single crown restoration. The clinical/radiographic measurements were repeated each year up to the 10-year follow-up. At the 10-year follow-up visit, the papilla index and the apico-coronal location of mid-buccal soft tissue positions were recorded. Results: The 10-year cumulative success rate was 91.8% (87.9% in the non-GBR group and 94.1% in the GBR group). The clinical attachment level (CAL) measurements were stable throughout the study, and 82% of the implants showed marginal bone loss (MBL) of 0.6 to 1.5 mm at the 10-year visit; moreover, these two parameters did not show significant differences between the GBR and non-GBR groups. Seventy percent of the implant sites showed acceptable outcomes in terms of interproximal papilla. The facial gingival level was more apical in the non-GBR group than in the GBR group (P <0.05). Conclusions: The present prospective clinical study shows that implants placed in fresh extraction sockets had a high cumulative success rate, namely 91.8% after 10 years. No differences were detected in survival and success rate of implants whether GBR procedures were performed or not. The CAL, MBL, and marginal level of soft tissue measurements were stable throughout the 10-year evaluation.     

Early healing of implants placed into fresh extraction sockets: an experimental study in the beagle dog. III: soft tissue findings

Aim: To describe histologically the early phases of soft tissue healing to implants placed into fresh extraction sockets. Materials and Methods: In 16 beagle dogs, 64 3.25‐mm‐wide cylindrical screw implants were inserted into the distal sockets of the third and fourth lower premolars using a one‐stage trans‐mucosal healing protocol. Biopsies were then taken at 1, 2, 4 and 8 weeks and prepared for histological examination. Results: One‐week specimens showed a junctional epithelium and an underlying loose connective tissue rich in inflammatory cells. At 2 weeks, signs of epithelial proliferation and a more organized connective tissue were observed. At 4 and 8 weeks, inflammation was absent; the epithelium appeared mature and in close contact with the surface of the healing abutment or the implant. The connective tissue was dense in an area close to the implant surface and the fibres were aligned parallel to the implant surface. The soft tissue dimensions at 8 weeks were approximately 5 mm, including about 3–3.5 mm of epithelium and 1–1.5 mm of connective tissue. Conclusion: Soft tissue healing to implants placed in fresh extraction sockets may result in a longer epithelial interface than implants placed in a healed ridge.     

The immediate rehabilitation by means of a ready-made final fixed prosthesis in the edentulous mandible: a 1-year follow-up study on 50 consecutive patients

Although a two-stage procedure with symphyseal oral implants can lead to a long-term (15 years) 99% cumulative survival rate, a one-stage approach with immediate loading via prefabricated elements seems to offer a short-term acceptable outcome with significantly lower costs. A series of 50 consecutive patients, not eliminated for any systemic or smoking condition, received at the department of periodontology three implants in the symphyseal area, connected by a very rigid horse shoe-shaped titanium bar. A final screw retained prosthetic framework was placed on top of it at the department of prosthetic dentistry within 2 days after surgery (44) or after a delay, due to purely external factors, of up to 10 days (6). Forty-five patients were followed for 1 year. In one patient, all three implants failed and another four patients were lost to follow-up. The cumulative failure rates for implants and prostheses at 1 year were, respectively, 7.3% and 5%. The mean marginal bone loss at 1 year was 1.08 mm (SD: 1.62; range -5.68 to +2.55). This study shows that stable marginal bone levels can be maintained around immediately loaded implants in the lower jaw in an average patient population for at least 1 year. The survival rate is, however, lower than for a staged approach.     

Alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification: a three-dimensional microcomputed tomography analysis

Background: Previous studies assessed bone remodeling after a single tooth extraction; however, the effect of multiple contiguous teeth extractions around immediate implant remains unknown. The aim of this microcomputed tomographic investigation is to analyze the alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification (ESC). Methods: Under general anesthesia, 10 beagle dogs underwent atraumatic tooth extractions. Animals were randomly divided into three groups, with 16 sites per group: 1) ESC‐1, single tooth extraction; 2) ESC‐2, two contiguous teeth extraction; and 3) ESC‐3, more than two contiguous teeth extractions. Immediate implants were inserted in each socket, and postoperative plaque control measures were undertaken. After euthanasia, the jaw segments were evaluated for bone thickness, marginal bone loss (MBL), and bone‐to‐implant contact (BIC) using microcomputed tomography. Results: The mean buccal bone thickness (P <0.05) and MBL (P <0.05) was compromised in jaws in ESC‐3 compared to those in ESC‐1 and ESC‐2. The BIC was significantly higher among jaws in ESC‐1 compared to those in ESC‐2 and ESC‐3 (P <0.05). There was no significant difference in the buccal bone thickness, MBL, and BIC among the groups in the maxilla and mandible. Lingual bone remodeling did not reveal any significant differences among the groups in either jaw. Conclusion: Buccal bone remodeling is significantly more extensive around immediate implants placed in multiple contiguous tooth extraction sites compared to immediate implants placed in single tooth extraction sites.     

Single-tooth replacement by immediate implant and connective tissue graft: a 1-9-year clinical evaluation

OBJECTIVES: The aim of the present study was to evaluate the long-lasting efficacy of a combined surgical protocol, using immediate implant and subepithelial connective tissue graft for single-tooth replacement. The advantages of this single-center, longitudinal, randomized, blind examiner research were the following: preservation of both keratinized mucosa amount and bone tissue, optimal peri-implant marginal sealing, satisfactory aesthetic results, reduction in treatment time. MATERIALS AND METHODS: In the time period from 1990 to 1998, 116 patients were consecutively admitted for treatment with a total of 116 solid screw ITI-implants supporting single crowns. Ninety-six patients underwent the proposed combined treatment (test group), while 20 received only single immediate implants (control group). The observation time extended from 1 up to 9 years. RESULTS: The 9-year cumulative survival rate was 100% for both test and control groups. Comparative statistical analysis of soft and hard tissue peri-implant parameters demonstrated better results in the test group than in the control during every single 3-year analysis and especially in the last observation interval. The test group also showed very good results in terms of aesthetic parameters, which estimated the keratinized mucosa width, the alignment of crown emergence profile and the patient's satisfaction. CONCLUSION: Single-tooth replacement by immediate solid screw ITI implants in association with connective tissue autograft was demonstrated to be a predictable procedure. Moreover, this treatment can be considered as a sure system to reach an excellent functional and harmonious aesthetic restoration.     

Electronic percussive testing of the stability of an immediately provisionalized implant placed into a fresh extraction socket: a pilot evaluation

It is important to achieve primary stabilization of dental implants that will be immediately loaded. Noninvasive devices that test the stability of immediately provisionalized implants placed into fresh extraction sockets are discussed. A titanium threaded implant was placed into a fresh extraction socket of a patient's nonrestorable mandibular right canine. The implant received an interim restoration immediately following its placement. The stability of the bone-implant complex was evaluated from the day of implant insertion through day 246 using an electronic percussive testing instrument. During the first month the bone-implant complex became progressively less stable reaching a peak measured level of instability at 30 days postimplantation. This was followed by progressive stabilization first measured on day 46 as the implant continued to osseointegrate. These findings suggest that the bone-implant complex became less stable during the first month after implant placement and was followed by a period of progressive stabilization reflecting bone maturation around the implant. A search of the literature found similar results in a study of single-stage implants (not immediately provisionalized) using resonance frequency analysis. The known sequence of wound healing around dental implants is reviewed to explain the findings of this pilot evaluation. Studies that use noninvasive testing devices to assess implant stability at placement and during healing may provide information that can help to optimize implant treatment outcomes.     

Early and immediate loading of titanium implants with fluoride-modified surfaces: results of 5-year prospective study

Objective: Multiple experimental and animal studies have shown that topographic, mechanical and chemical properties of implant surfaces lead to in vivo responses such as increased bone formation, increased bone anchorage and reduced healing time. A fluoride modification of the titanium implant surface also seems to positively influence bone anchorage as compared with unmodified titanium implants. Using implant survival and marginal bone loss as primary outcome parameters, the purpose of the present prospective study was to investigate whether a fluoride modification of the titanium implant surface has positive clinical effects. Materials and methods: The 17 patients included in this study received 49 Astra Tech OsseoSpeed^? implants for various indications in the maxilla and mandible. Implants were either loaded immediately or after a mean healing period of 9.56 weeks. Fifteen patients were followed up clinically including radiographic examination for 5 years. Forty‐two implants were assessed for implant survival, marginal bone loss, surgical and/or prosthetic complications, presence or absence of plaque, signs of inflammation and size of the papilla. Results: Of the original 17 patients, 15 patients were available for the full 60‐month follow‐up. One early implant failure occurred, leading to an implant survival rate of 97%. Radiographic analyses demonstrated stable bone conditions with a mean marginal bone loss of 0.1 mm (SD 0.4 mm, min ?0.7 mm, max 1.7 mm) after 5 years of function. Immediately loaded implants did not show a different mean marginal bone loss as compared with implants that were not loaded immediately. Repeated soft‐tissue examinations revealed healthy conditions in terms of 6.1% plaque and 4.2% of the implants with signs of inflammation at the 5‐year control. Discussion: Implants used in this study had high survival and success rates after 5 years. Marginal bone was well maintained, irrespective of the loading regime. To cite this article:
Mertens C, Steveling HG. Early and immediate loading of titanium implants with fluoride‐modified surfaces: results of 5‐year prospective study.
Clin. Oral Impl. Res. xx , 2011; 000–000.