Roland Glauser

Five-year results of implants with an oxidized surface placed predominantly in soft quality bone and subjected to immediate occlusal loading

STATEMENT OF PROBLEM Numerous studies have demonstrated the feasibility and predictability of immediate implant loading or immediate implant restoration. However, most of these studies report primarily short-term outcomes. PURPOSE The purpose of this prospective clinical study was to document the 5-year outcome of immediate occlusally loaded implants with an oxidized, microtextured surface placed to support fixed prostheses in various regions of the jaws. MATERIAL AND METHODS Thirty-eight patients received a total of 51 implant-supported fixed prostheses, 29 mandibular and 22 maxillary, the day of implant insertion. Thirty were fixed partial dentures (FPDs), 20 replaced single teeth, and 1 was a fixed mandibular complete denture. The restorations were supported by 102 slightly tapered, screw-type implants, the majority of which were placed in posterior regions (88%) and primarily in soft bone quality (76%). Patients with ongoing signs of parafunctional habits were not included. All implants were placed using conventional flap procedures. Treatment with local regenerative procedures in connection with implant placement was accepted within the study design. Resonance frequency implant stability measurements and marginal periimplant soft tissue evaluations were conducted. Radiographic examinations were performed at the time of prosthesis insertion, at 1-and 6-month follow-ups, and annually at the 1- through 5-year follow-up visits. This report presents the results after 5 years of loading, summarized with descriptive statistics. RESULTS Three maxillary implants were removed, although stable, in 1 patient at the 8-week follow-up due to postoperative infection in the adjacent guided bone regeneration (GBR) area. No additional implants were lost. This resulted in a cumulative implant success rate of 97.1% after 5 years of prosthetic loading. The mean marginal bone remodeling (SD) after 5 years of function was 1.54 (0.99) mm. At the 5-year examination, absence of marginal plaque and absence of bleeding on probing was reported for 75% and 74% of the sites, respectively, and remained generally unchanged from the 1-month follow-up. CONCLUSIONS The 5-year follow-up data indicate that an immediate loading protocol using a slightly tapered implant design with an oxidized, microtextured surface is a successful treatment alternative in regions exhibiting soft bone quality.

The defense architecture of the human periimplant mucosa: A histological study

STATEMENT OF PROBLEM The primary function of the periodontal tissues, besides attaching the tooth to the jaw, is gingival protection; that is, to provide a seal against the contaminated environment of the oral cavity. Detailed data regarding protection of the periimplant mucosa in patients with transmucosal implants are lacking. PURPOSE The purpose of this histological study was to demonstrate the structural and ultrastructural features of the interface between transmucosal titanium implants with oxidized, machined, and acid-etched surfaces and surrounding tissues by combined light and electron microscopy. MATERIAL AND METHODS Five patients received 12 experimental titanium, 1-piece mini-implants with an oxidized, acid-etched, or machined surface distal to conventional implants. Following transmucosal healing of 8 weeks and at the abutment connection of the regular implants, the mini-implants were removed with a layer of surrounding hard and soft tissue. The specimens were fixed and processed for light, transmission electron, and scanning electron microscopy. RESULTS For all 3 types of surfaces, substantial structural analogies were demonstrated between gingiva and periimplant mucosa in humans, both shown to provide protection for the underlying soft tissues and alveolar bone. Depending on the implant surface texture, substantial differences were noted in the manner the implants interface with connective tissue. CONCLUSIONS The mechanisms of protection in the periimplant mucosa correspond to those in the gingiva surrounding a tooth. The surface texture of implants may affect the orientation of collagen fibers of the connective tissue at the implant surface.

Immediate vs. early loading of dental implants: 3-year results of a randomized controlled clinical trial

OBJECTIVES The aim of the present study was to test whether or not immediately loaded implants exhibit the same survival rates as early loaded implants. MATERIAL AND METHODS Eleven patients with bilateral free end mandibles were randomly assigned to treatment either with immediately (test) or early loaded implants (control). Test implants received provisionals in occlusion on the day of surgery, control implants 6 weeks later. Parameters assessed included implant stability quotient (ISQ), plaque, prosthesis stability and radiographs at baseline (implant insertion), 1 and 3 years. The statistical analysis was performed by means of Students paired t-test and Wilcoxons signed-rank test. The level of significance was set at P<0.05. RESULTS After a mean observation period of 39.8 months (36.7-53.1), three test implants were lost in two patients resulting in a survival rate of 85% compared with 100% for control implants. At baseline, the mean marginal bone level was significantly higher at test implants (mean=0.36 mm, SD +/-0.5) compared with control implants (1.08+/-0.37 mm). For both test and control implants, the bone level significantly decreased from baseline to 3 years (test: 1.51+/-0.79 mm; control: 0.89+/-0.94 mm). The bone loss until 3 years was not significantly different between test and control group. There was no significant difference for ISQ both at test and control implants between baseline (test: 63.59+/-4.62 mm, control: 65.35+/-7.43 mm) and 3 years (test: 66.47+/-7.47 mm, control 68.80+/-8.75 mm). CONCLUSIONS Immediate loading was associated with a lower implant survival rate. Although the test implants were placed with increased sink depth compared with the control implants, the marginal bone levels were not different between test and control at 3 years.

Implants with an Oxidized Surface Placed Predominately in Soft Bone Quality and Subjected to Immediate Occlusal Loading: Results from a 7-Year Clinical Follow-Up: Implants with an Oxidized Surface Placed Predominately in Soft Bone Quality and Subjected to Immediate Occlusal Loading

PURPOSE The purpose of this clinical follow-up was to document the 7-year outcome of immediately loaded implants exhibiting an oxidized surface. MATERIAL AND METHODS Thirty-eight patients received a total of 51 implant-supported fixed prostheses. The restorations were supported by 102 implants, the majority of which were placed in posterior regions (88%) and primarily in soft bone quality (76%). Radiographic examinations were performed at prosthesis insertion, at 1- and 6-month follow-ups, and annually at the 1- through 5-year follow-up visits. Marginal peri-implant soft tissue evaluations were conducted at all these follow-ups. This report presents the results after at least 7 years of loading. RESULTS After 7 years of prosthetic loading, the cumulative implant survival rate was 97.1% and the mean marginal bone remodeling was -1.51 mm (SD 1.00, n = 73) with significantly more initial remodeling at sites having received marginal guided bone regeneration procedures. A low rate of biological and technical complications was detected after 7 years of function. The quantification of intrasulcular plaque sampling showed no significant difference between teeth and implants. CONCLUSION The 7-year follow-up data indicate that the introduced immediate loading protocol is a successful treatment alternative also including regions exhibiting soft bone conditions.