Immediate and Early Loading of Chemically Modified Implants in Posterior Jaws: 3‐Year Results from a Prospective Randomized Multicenter Study

Background: There is a lack of well‐designed prospective, randomized clinical trials evaluating the efficacy of immediate and early loading of implants placed in the partially edentulous posterior maxilla or mandible. Purpose: The aim of this study was to evaluate crestal bone level changes over 3 years following immediate or early loading of Straumann implants with a chemically modified surface (SLActive®, Institut Straumann AG, Basel, Switzerland) placed in the posterior maxilla and mandible. Materials and Methods: Subjects received temporary restorations immediately or 28 to 34 days after surgery, with permanent restorations placed at 20 to 23 weeks. Bone level changes were measured by comparison of standardized radiographs taken on the day of implant placement and 5, 12, 24, and 36 months thereafter. Results: Two hundred thirty‐nine of two hundred sixty‐six patients (89.9%) completed the trial. Implant survival rates were 97.4% and 96.7% in the immediate and early loading groups, respectively (p = not significant). Over 36 months, the mean bone level change for immediately loaded implants was 0.88 ± 0.81 mm versus 0.57 ± 0.83 mm for the early‐loaded group (p < .001). After adjusting for a slight difference in initial placement depth, the time of loading had no significant influence on bone level change. Conclusions: Changes in crestal bone level occurred mostly during the first 5 months postloading. After this bone remodeling period, crestal bone level was stable up to 36 months. Implants with a chemically modified surface are safe and predictable for immediate and early loading in the posterior maxilla and mandible.     

Immediate Occlusal Loading of NanoTite™ Tapered Implants: A Prospective 1‐Year Clinical and Radiographic Study

Background: During the last decade, high success rates have been reported for implants placed with immediate loading procedures, especially when bone quality and quantity provide good implant stability. In many of these studies, straight‐walled implants with moderately rough surfaces were employed. Tapered implants are becoming increasingly more popular due to standardized drilling protocols and reports of high initial primary stability. Purpose: The aim of the present prospective, single center clinical study was to evaluate surface topographical analysis and the clinical and radiographic outcomes of the NanoTite? (BIOMET 3i, Palm Beach Gardens, FL, USA) Tapered Implant when used for immediate loading of fixed prostheses and single‐tooth restorations. Materials and Methods: Forty‐two patients who needed implant treatment and met admission criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 30 Ncm prior to final seating and an implant stability quotient above 55. A total of 139 NanoTite Tapered implants (112 maxillary and 27 mandibular) were placed by one investigator, and the majority of these implants (n = 77/55%) were placed in posterior regions, and in soft bone (n = 90/65%). A total of 57 prosthetic constructions were evaluated consisting of 20 single‐tooth restorations, 30 fixed partial dentures, and 7 complete, fixed maxillary restorations. Radiographs were taken at baseline and at 12 months of follow‐up. Results: Of the 139 study implants, one implant failure was declared. The overall cumulative survival rate at 1 year is 99.4%. Mean marginal bone resorption is 1.01 mm (SD 0.85) during the first year of function. Conclusion: Although limited to the short follow‐up, immediate loading of NanoTite Tapered implants seems to be a viable option in implant rehabilitation, when insertion torque of at least 30 Ncm is achieved. Further studies are needed to authenticate the finding of this study.     

A 1‐Year Controlled Clinical Trial of Immediate Implants Placed in Fresh Extraction Sockets: Stability Measurements and Crestal Bone Level Changes

Purpose: The aim of this study was to measure stability and crestal bone level changes of implants placed in fresh extraction sockets in elderly patients. Methods: Thirty‐five patients who were in need of tooth extractions were recruited for this study. They received a total of 65 implants in both jaws to support fixed or removable prostheses. The teeth were carefully extracted, the implants set directly in the root socket, and resonance frequency analysis (RFA) measurements were simultaneously performed (Time 1 = T1). After a healing time of 6 to 10 weeks the measurements were repeated (Time 2 = T2). Orthograd periapical radiographs were taken when the new prostheses were fabricated and after 1 year of loaded period. The distance between the first visible bone implant contact (BIC) and the implant‐shoulder was measured and crestal bone loss was calculated (ΔBIC). Mean RFA and BIC were compared for various subgroups (p < .05). By means of a fixed effects model, the impact of the parameters gender, jaw, and prosthetic indication on RFA measurements was analyzed (p < .016). Results: The mean implant stability quotient (ISQ) values were 64.4 ± 6.7 at T1 and 64.0 ± at 8.6 T2, with a trend to higher values for male patients. The mixed model showed that only the jaw had a statistically significant impact on ISQ values, with higher values for the mandible. Mean crestal bone loss was small with 0.49 ± 0.81 mm, ranging form 0.1 to 2.4 mm. Twenty percent of the implant sites lost more than 1‐mm crestal bone. No differences were found in subgroups. Conclusions: Good primary and secondary stability of the implants was reached in both jaws. Crestal bone loss was small but may not be fully predictable for a single site. This treatment modality can be applied successfully in elderly patients and can be suggested for various prosthetic indications in both jaws.     

Marginal Bone‐Level Alterations at Implants Installed in Block versus Particulate Onlay Bone Grafts Mixed with Platelet‐Rich Plasma in Atrophic Maxilla. A Prospective 5‐Year Follow‐Up Study of 15 Patients

Background: Extensive atrophy of the alveolar process may require a bone‐grafting procedure prior to implant treatment. Autogenous bone grafts from the iliac crest, used as onlay block and particulate bone, have been used together with sinus‐lift procedure in order to rehabilitate patients with extremely resorbed maxillae. However, there are to our knowledge no 5‐year follow‐up studies evaluating the extent of bone‐level change in patients treated with respectively block and particulate autogenous bone grafts. Purpose: The purpose of this prospective clinical study was to conduct a 5‐year follow‐up analysis with focus on bone‐level alteration in block versus particulate onlay bone grafts. Material and Methods: Fifteen out of originally 19 patients who were treated with iliac bone grafts and oral implants in the maxilla have been followed through the first 5 postoperative years. In a first study conducted on 19 patients, the role of platelet‐rich plasma in conjunction with autogenous bone was evaluated. In this 5‐year follow‐up study, the marginal bone alterations have been documented at base line, 1 year and 5 years of loading to the nearest 0,1 mm at mesial and distal surfaces of the implants. Two implants were installed on each side of the midline in either block or particulate bone grafts giving test and control sides in each patient. Additionally, two implants on each side were installed in residual bone/grafted sinus floor. Result: Marginal bone alteration in the anterior maxilla appeared larger at the side augmented by block bone at baseline, and after 1 and 5 years of loading, but the change was not statistically significant. Moreover, there was a significantly higher degree of marginal alteration during the first year of loading, compared with the examinations after 5 years. Conclusion: The present follow‐up study showed that there is no significant difference in the extension of resorption between block‐ and particulate autogenous bone grafts over a 5‐year period. Most of the resorption occurred during the first year in function.     

A Prospective 1‐Year Clinical and Radiographic Study of Implants Placed after Maxillary Sinus Floor Augmentation with Synthetic Biphasic Calcium Phosphate or Deproteinized Bovine Bone

Background: The technique of using bone grafts or different biomaterials for augmentation of the maxillary sinus prior to implant placement is well accepted by clinicians. However, clinical documentation of some bone substitutes is still lacking. Purpose: This prospective study was designed to evaluate the success rate of implants placed after maxillary sinus augmentation with a novel synthetic biphasic calcium phosphate (BCP) or deproteinized bovine bone (DBB), the latter acting as control. Material and Methods: Nine edentulous patients and two partially edentulous patients with a mean age of 67 years with a bilateral need for sinus augmentation, <5 mm residual bone in the floor of the sinus and a crestal width ≥4 mm, were included in the study. After bilateral elevation of the Schneiderian membrane, all patients were randomized for augmentation with synthetic BCP in one side and DBB in the contralateral side. After 8 months of graft healing, 62 implants with an SLActive surface were placed. Implant survival, graft resorption, plaque index, bleeding on probing, sulcus bleeding index, probing pocket depth, and implant success rate were evaluated after 1 year of functional loading. Results: After a mean of 118 days, all patients received their fixed prosthetic constructions. One implant was lost in each biomaterial, giving an overall survival rate of 96.8%. Success rates for implants placed in BCP and DBB were 91.7 and 95.7%, respectively. No significant difference in marginal bone loss was found around implants placed in BCP, DBB, or residual bone, respectively. The mean graft resorption was 0.43 mm (BCP) and 0.29 mm (DBB). Conclusion: In this limited study, implant success rate was not dependent on the biomaterial used for maxillary sinus augmentation. Similar results were found after 1 year of functional loading for implants placed after sinus augmentation using BCP or DBB.     

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

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.     

Bone‐to‐Implant Contact Around Immediately Loaded Direct Laser Metal‐Forming Transitional Implants in Human Posterior Maxilla

Objective: Direct laser metal forming (DLMF) is a procedure in which a high‐power laser beam is directed onto a metal powder bed and programmed to fuse particles according to a computer‐aided design file, generating a thin metal layer. This histologic study evaluated the bone‐to‐implant contact (BIC%) around immediately loaded DLMF transitional implants retrieved after 2 months from posterior human maxillae. Methods: Twelve totally edentulous individuals (mean age, 66.14 ± 2.11 years) received DLMF transitional implants divided in twelve immediately loaded (IL) and twelve unloaded (UI) implants. These transitional implants were placed between conventional implants to support the interim complete maxillary denture during the healing period. After 8 weeks, the transitional implants and the surrounding tissue were removed and prepared for histomorphometric analysis. Results: Mature woven preexisting bone lined by newly formed bone in early stages of maturation were found around all retrieved implants. Histometric evaluation indicated that the mean BIC% was 45.20 ± 7.68% and 34.10 ± 7.85% for IL and UI, respectively (P <0.05). Conclusion: The present data obtained in humans showed that, although both IL and UI presented good BIC%, IL DLMF implants had a higher BIC% in the posterior maxilla.     

Marginal Bone Level Changes and Prosthetic Maintenance of Mandibular Overdentures Supported by 2 Implants: A 5‐Year Randomized Clinical Trial

Background: Documentation of early loading of mandibular overdentures supported by different implant systems is scarce. Purpose: This study aimed to compare the biologic and prosthetic outcome of mandibular overdentures supported by unsplinted early‐loaded one‐ and two‐stage oral implants after 5 years of function. Materials and Methods: Twenty‐eight consecutive patients were screened following an inclusion and exclusion criteria, and randomly allocated to treatment groups. Ball‐retained mandibular overdentures were fabricated on two unsplinted Straumann® (Institut Straumann AG, Basel, Switzerland) and Brånemark® (Nobel Biocare AB, Göteborg, Sweden) dental implants and subjected to an early‐loading protocol. During the 5‐year period, prosthetic complications were recorded. At 5‐years of function, plaque, peri‐implant inflammation, bleeding, and calculus index scores were recorded, and standard periapical radiographs were obtained from each implant for measurement of marginal bone loss. Results: All implants survived during the observation period. The peri‐implant inflammation, bleeding, and calculus index scores around Straumann and Brånemark implants were similar (p > .05). The marginal bone loss around Brånemark implants (1.21 ± 0.1) was higher than Straumann implants (0.73 ± 0.06) at 5 years of function (p = .002). Kaplan–Meier tests revealed that 1‐ and 5‐year survival of overdentures on Straumann and Brånemark implants were similar (p = .85). Wear of the ball abutment in the Brånemark group was higher than in the Straumann group (p < .05). Complications regarding the retainer and the need for occlusal adjustments were higher in the Straumann group (p < .05). Chi‐square test revealed that the frequency of retightening of the retainer was higher in the Straumann group than in the Brånemark group (p < .05). Conclusions: Mandibular overdentures supported by unsplinted early‐loaded Straumann and Brånemark implants lead to similar peri‐implant soft tissue and prosthetic outcomes, although higher marginal bone loss could be observed around Brånemark implants after 5 years.     

One‐Year Outcomes of Neoss Bimodal Implants. A Prospective Clinical,Radiographic, and RFA Study

Background: The Neoss implant system has been available since 2004. Few studies documenting the clinical performance of this implant are available. Purpose: To study the stability and clinical/radiographic outcomes of Neoss implants 1 year of loading when using a two‐stage protocol. Materials and Methods: Ninety (90) consecutive patients scheduled for implant treatment using a two‐stage procedure were enrolled in a prospective follow‐up study. A total of 218 implants (Neoss System, Bimodal surface, Neoss Ltd, Harrogate, UK) in diameters of 3.5, 4.0, and 4.5 mm and in lengths from 7 to 15 mm were placed to support 29 single tooth replacements, 53 partial bridges, 5 full bridges, and 10 overdentures in both jaws. Abutment connection was made after a healing period of 3–4 months. The patients were followed during 1 year of loading with clinical, radiographic, and resonance frequency analysis (Osstell Mentor?, Osstell AB, Gothenburg, Sweden) examinations. Prostheses were removed at the annual check‐up for individual testing of implant stability. Results: Three implant failures were experienced, giving a survival rate of 98.6% after 1 year. A mean bone loss of 0.6 mm (SD 0.8) was observed after 1 year. There was a significant inverse correlation between implant diameter and marginal bone loss (p < .003). The mean implant stability quotient levels were 73.7 (SD 7.6), 74.4 (SD 6.4), and 76.7 (SD 5.2) at placement, abutment connection, and first annual check‐up, respectively. The stability had increased significantly from placement to 1 year (p < .001) and from abutment to 1 year (p < .0001). Implant stability was higher in the mandible than in the maxilla at all time points. There was a significant correlation between bone quality and stability at placement (p < .0001) and abutment connection (p < .001) but not after 1 year. Conclusions: The use of Neoss implants for prosthetic rehabilitation of consecutive edentate patients with different needs resulted in predictable clinical and radiographic outcomes after 1 year of loading. Implant stability measurements revealed a favorable bone tissue reaction to the implants.     

Immediate Occlusal Loading of NanoTite™ PREVAIL® Implants: A Prospective 1-Year Clinical and Radiographic Study

Background: Recently, a new implant surface texture, featuring application of nanometer‐scale calcium phosphate has been shown to enhance early bone fixation and formation in preclinical studies and in human histomorphometric studies, which may be beneficial in immediate loading situations. Aim: The purpose of the present prospective clinical study was to, during 1 year, clinically and radiographically evaluate a nanometer scale surface modified implant placed for immediate loading of fixed prostheses in both maxillary and mandibular regions. Materials and Methods: Thirty‐five out of 38 patients who needed implant treatment and met inclusion criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 25 Ncm prior to final seating and an implant stability quotient above 55. A total of 102 NanoTite? PREVAIL® (NTP) implants (BIOMET 3i, Palm Beach Gardens, FL, USA) (66 maxillary and 36 mandibular) were placed by one investigator, and the majority of these were placed in posterior regions (65%) and in soft bone (69%). A total of 44 prosthetic constructions were evaluated consisting of 14 single‐tooth restorations, 26 fixed partial dentures, and four complete fixed restorations. All provisional constructions were delivered within 1 hour, and the final constructions placed after 4 months. Implants were monitored for clinical and radiographic outcomes at follow‐up examinations scheduled for 3, 6, and 12 months. Results: Of the 102 study implants, one implant failed. The simple cumulative survival rate value at 1 year was 99.2%. The average marginal bone resorption was 0.37 mm (SD 0.39) during the first year in function. According to the success criteria of Albrektsson and Zarb, success grade 1 was found with 93% of the implants. Conclusion: Although limited to the short follow‐up, immediate loading of NanoTite Prevail implants seems to be a viable option in implant rehabilitation, at least when a good initial fixation is achieved.     

A 10‐Year Prospective Study of Single Tooth Implants Placed in the Anterior Maxilla

Purpose: The aim of the study was to evaluate the biological and technical outcomes of early and delayed placed single tooth implants after 10 years of follow‐up. Materials and Methods: Twenty consecutive patients who needed a single tooth replacement in the anterior maxilla were included in this study. Ten implants were placed with an early placement protocol, that is, 4 weeks after tooth extraction, whereas the other 10 implants were placed with a conventional delayed placement protocol, for example, 12 weeks after tooth extraction. At the baseline and at the annual re‐examinations, pain from implant regions, mobility, plaque, mucositis, and marginal bone levels were recorded. Biological and technical complications were registered. The patients evaluated the functional and aesthetic outcomes subjectively on a visual analogue scale after 3 and 10 years. Results: All implants were still in situ after 10 years. The cumulative implant survival rate was 100%. Two implant‐supported crowns were remade because of ceramic fractures. The 10‐year crown survival rate was 90%. No significant differences in implant survival rates were found between the early and delayed protocols, regarding plaque retention, mucositis, or marginal bone levels. After 10 years, the mean marginal bone loss at both sides of the implants was less than 1.0 mm in the two groups. During the 10‐year interval, 1 patient lost more than 1.5 mm of marginal bone, 3 patients lost between 1.0 mm and 1.4 mm of bone, and 16 patients lost less than 1.0 mm of bone as an average of the mesial and distal bone loss. Conclusions: This 10‐year prospective clinical trial demonstrated a 100% implant survival and a 90% crown survival. The average marginal bone level change was less than 1 mm, and there was no difference between early and delayed implant placement. Patient satisfaction with the implant‐supported single crowns reduced with time.     

Marginal Bone Loss in Implants Placed in the Maxillary Sinus Grafted With Anorganic Bovine Bone: A Prospective Clinical and Radiographic Study

Background: Sinus elevation is a reliable and often‐used technique. Success of implants placed in such situations, even with bone substitutes alone, prompted the authors of this study to strive for bone loss close to zero and research variables that cause higher or lower rates of resorption. The objective of this study is to evaluate survival rates and marginal bone loss (MBL) around implants placed in sites treated with maxillary sinus augmentation using anorganic bovine bone (ABB), and identify surgical and prosthetic prognostic variables. Methods: Fifty‐five implants were placed in 30 grafted maxillary sinuses in 24 patients. Periapical radiographs were evaluated immediately after implant placement (baseline), 6 months, and at the most recent follow‐up. MBL was calculated from the difference between initial and final measurements, taking into account a distortion rate for each radiograph compared with original implant measurements. Results: Survival rate was 98.2%, with only one implant lost (100% survival rate after loading) over a mean follow‐up time of 2.0 ± 0.9 years. MBL ranged from 0 to 2.85 mm: 75.9% of mesial sites and 83.4% of distal sites showed <1 mm of MBL, whereas 35.2% of mesial sites and 37% of distal sites exhibited no bone loss. MBL was significantly (P <0.05) greater in open‐flap compared with flapless surgery. Conclusions: Within the limitations of the present study, it was concluded that maxillary sinus elevation with 100% ABB gives predictable results, and that flapless surgery results in less MBL compared with traditional open‐flap surgery.