The biological properties of OGI surfaces positively act on osteogenic and angiogenic commitment of mesenchymal stem cells

Osteogenesis process displays a fundamental role during dental implant osteointegration. In the present work, we studied the influence of Osteon Growth Induction (OGI) surface properties on the angiogenic and osteogenic behaviors of Mesenchymal Stem cells (MSC). MSC derived from dental pulp and HUVEC (Human Umbilical Vein Endothelial Cells) were grown in on OGI titanium surfaces, and cell proliferation and DNA synthesis were evaluated by MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] test and DNA quantification. Gene expression has been performed in order to evaluate the presence of mRNA related to endothelial and osteogenesis markers. Moreover, morphological and biochemical analyses of osteogenesis commitments has been performed. On OGI surfaces, MSC and HUVEC are able to proliferate. Gene expression profiler confirms that MSC on OGI surfaces are able to express endothelial and osteogenic markers, and that these expression are higher compared the expression on control surfaces. In conclusion On OGI surfaces proliferation, expression and morphological analyses of angiogenesis-associated markers in MSC are promoted. This process induces an increasing on their osteogenesis commitmen

The 'Alternating Osteotome Technique': a surgical approach for combined ridge expansion and sinus floor elevation. A multicentre prospective study with a three-year follow-up

The aim of this multicentre prospective study was to evaluate the efficacy and safety of a surgical approach based on a novel osteotome technique, in order to obtain both alveolar ridge expansion and sinus floor elevation. Partially edentulous patients requiring an implant-prosthetic rehabilitation with a fixed prosthesis in the posterior maxilla were included in this study according to pre-established inclusion and exclusion criteria. All implants were placed after site preparation with the 'Alternating Osteotome Technique', which consists of the use of alternating concave and convex osteotomes. After a 4 to 6-month healing period, all implants were restored with a definitive fixed prosthesis. Clinical and radiographic examinations were scheduled over a 36-month follow-up of functional loading according to a well-established protocol. Statistical analysis was used to detect any significant differences or correlations (P = 0.05). Seventy-six patients were consecutively treated with a total of 120 implants in three different centres. The mean ridge expansion and sinus floor elevation were 1.8 ± 0.3 and 2.5 ± 0.7, respectively. After three years of functioning, the implant success rate was 99.1% since one implant had failed and the mean marginal bone loss was 0.6 ± 0.3 mm. No complications occurred during the intraoperative and postoperative periods. All parameters analysed were stable and steady throughout the three-year follow-up. The 'Alternating Osteotome Technique' enables the dental surgeon to achieve an adequate implant osteotomy with limited ridge expansion and sinus floor elevation, increasing modestly the vertical and horizontal dimensions of the alveolar crest but reducing significantly the risk of surgical complications

Evaluation of the Esthetic Results of 64 Nonfunctional Immediately Loaded Postextraction Implants in the Maxilla: Correlation between Interproximal Alveolar Crest and Soft Tissues at 3 Years of Follow-Up

Purpose: Many authors have emphasized that immediate loading protocols enable better esthetic results to be achieved compared with delayed loading, especially in the case of postextraction implants that are capable of maintaining the original esthetics of soft tissues. The aim of this study was to establish correlations between the interproximal crest, interproximal papilla, and marginal facial gingiva of immediately loaded postextraction implants by evaluating clinical and radiographic data. Materials and Methods: Fifty-eight consecutive patients underwent a tooth extraction and immediate implant placement with 64 postextraction implants, which were immediately loaded using a provisional single crown from June 2005 to December 2006. At 6months after surgery, all implants were restored with a definitive single crown. Clinical and radiographic data were recorded at the time of surgery, at the time of definitive restoration, and after 3years of functioning, in order to evaluate soft tissues esthetics and bone tissue condition. Statistical analysis was used to assess significant correlations between the interproximal crest, interproximal papilla, and marginal facial gingiva (p=0.05). Results: After 3years of functioning, the implant success rate was 100% because no implants had failed. All parameters were stable and steady during the 3-year follow-up. The regression test revealed a statistically significant correlation between interproximal crest levels and interproximal papilla volume (p=0.0134), and also between interproximal crest levels and marginal gingiva levels (p=0.0226). Conclusions: Postextraction immediately loaded implants represent a predictable technique that should be considered the treatment of choice in cases of single anterior tooth restoration and other cases. Esthetic results seem to depend on correct positioning of the implants, considering the correlation between bone tissue and related soft tissues. Maintaining the original condition of both bone and soft tissues around the tooth to be removed is the key to obtaining optimal esthetic outcomes

Peri-implant conditions around sintered porous-surfaced (SPS) implants. A 36-month prospective cohort study

Objectives: The specific aim of this study was to assess sintered porous-surfaced (SPS) implant system from a biological point of view, through a prospective study of the health status and the evolution of the peri-implant tissues over time and analysis of the changes observed in the various peri-implant parameters. Material and Methods: Hundred and fifty-one patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. To accurately monitor the health and biological evolution of peri-implant soft and hard tissues, a number of clinical parameters were adopted, such as the modified Plaque Index (mPI), the modified sulcus Bleeding Index (mBI), Peri-implant Probing Depth (PPD), and Crestal Bone Level (CBL). Clinical and radiographic examinations were scheduled over a 36-month follow-up of functional loading according to a well-established protocol generally applied to determine implant success rates and Peri-implant Bone Loss (PBL). Statistical analysis was used to determine any significant differences or correlations (P = 0.05). Results: A total of 259 SPS implants in 136 patients were followed up for 36 months. According to Buser's success criteria, the overall implant-based success rate was 98.1% and the mean PBL was 0.48 \ub1 0.29 mm. MBI and mPI mean values showed statistically significant differences between baseline and follow-up analyses (P < 0.001). No statistically significant differences in mean PPD values were found between baseline and control analyses (P = 0.060). Conclusion: This prospective cohort study revealed that the biological behavior of SPS implant system was characterized by high tissue stability during the observation period, both as regards soft and hard tissues. In particular, the crestal bone remodeling pattern was very similar to that reported in other studies, confirming that the bone loss around SPS implants, at least at 36 months, seems to be predictable

Influence of crown-implant ratio on implant success rate of ultra-short dental implants: results of a 8- to 10-year retrospective study

Objectives The use of short implants has been suggested in recent years as an option for facilitating prosthetic restoration in resorbed jawbones. The aim of the present study was to determine how implant success rate is affected in the long term when ultra-short implants are rehabilitated with fixed restorations, resulting in a crown to implant (C/I) ratio of more than 3:1. Materials and methods The study was conducted as an analysis on all patients operated from December 2005 to November 2007 with ultra-short dental implants. All implants were sintered porous-surfaced (SPS) with a length of 5 mm and a diameter of 5 mm (5 x 5 mm) and were restored with a single crown or a fixed dental prosthesis (FDP). Data collected included implant positioning site, crestal bone levels (CBL), and clinical and anatomical C/I ratios, and pre-established success criteria were used to evaluate the success rate of the implants. Statistical analysis was used to determine any significant differences or correlations (p = 0.05). Results Forty-one patients completed the follow-up and were eligible for this retrospective study on a total of 50 ultra-short SPS implants. The mean follow-up was 9.5 years (range 8.3 to 10.2 years). Three of the 50 implants failed because they were lost due to peri-implantitis, while all the other 47 met the pre-established success criteria giving an overall implant success rate of 94%. During the follow-up period, the mean peri-implant bone loss (PBL) was 0.41 + 0.36 mm. Conclusions This study shows that ultra-short SPS implants can prove a reliable solution for prosthetic restoration in patients with severe alveolar bone atrophy. In selected patients with a sufficient bone width, ultra-short implants with a resulting C/I ratio of more than 3:1 presented no contraindications

Primary and Secondary Stability of Implants in Postextraction and Healed Sites: A Randomized Controlled Clinical Trial

PURPOSE: This randomized clinical trial aimed to investigate the relationships between insertion torque, implant stability quotient (ISQ), and crestal bone loss (CBL) of implants placed in fresh or 12-week healed extraction sites. MATERIALS AND METHODS: Forty patients were randomly assigned to one of two groups and had one implant placed immediately (test group, n = 20) or 12 weeks after extraction (control group, n = 20) at premolar or molar sites. For all implants, insertion torque and ISQ scores at insertion and loading were recorded. Patients were followed for up to 12 months. RESULTS: Implant success was 100% in both groups. No differences were observed concerning both ISQ at insertion and ISQ at loading. A stronger correlation was detected between ISQ at insertion and insertion torque in the postextractive group (R = 0.83), than in the delayed group (R = 0.39), while ISQ at loading and insertion torque showed no correlation. CBL at 12 months was significantly different between test (0.68 \ub1 0.43 mm) and control (0.40 \ub1 0.26 mm, P = .02) groups. CONCLUSION: Implant placement timing (immediate or delayed) may affect correlation between insertion torque and ISQ at insertion with ISQ at loading. While insertion torque influences ISQ at insertion, it does not affect ISQ at loading because of successful osseointegration. Postextraction and delayed implants seem to have similar ISQ at insertion and at loading, but different CBL after 12 months of follow-up because of postextraction bone remodeling

Double Duplicate Technique for CAD/CAM Full-Arch Immediate Loading: A Technical Description and Case Report

Full-arch fixed implant-supported prostheses have shown high biologic success rates after long-term follow-up, along with technical and prosthetic complications. Adequate planning is necessary for immediate implant occlusal loading in a completely edentulous maxilla or mandible. For totally edentulous patients, the main prosthetic problem is the transfer of diagnostic information to the master cast when an immediate loading approach is used. The aim of this clinical case report is to illustrate a new prosthetic protocol for immediate implant loading in edentulous or potentially edentulous patients. This innovative procedure can successfully guide the clinician step by step in a predictable way from diagnosis to delivery of an immediately loaded implant-supported full-arch rehabilitation

Evaluation of Crestal Bone Loss Around Straight and Tilted Implants in Patients Rehabilitated by Immediate-Loaded Full-Arch All-on-4 or All-on-6: A Prospective Study

The aim of this prospective study was to compare implant success rate and crestal bone loss around tilted and straight implants supporting immediate-loading full-arch rehabilitations. Twenty consecutive patients with edentulous jaws treated between June 2013 and July 2015 who satisfied all inclusion and exclusion criteria were included in the study. All patients were rehabilitated through a full-arch restoration supported by 4 or 6 immediately loaded implants. Clinical and radiographic examinations were scheduled every 12 months to evaluate implant success rates and crestal bone levels. Significant differences in crestal bone levels and success rates between straight and tilted implants were investigated by means of independent statistical analysis; differences were regarded as significant if P < .05. Seventy straight and 50 tilted implants were placed to rehabilitate 14 mandibles and 12 maxillae in 20 patients. After a follow-up of 12 to 36 months, survival rate was 97.1% for straight implants and 96.0% for tilted implants; while success rates were 94.3% and 94.0%, respectively. Success and survival rates were not significantly different (P > .05). Change in crestal bone level was 0.5 +/- 0.4 mm for straight implants and 0.6 +/- 0.4 mm for tilted implants (P > .05). Straight and tilted implants seemed to have similar behavior after immediate loading rehabilitations. After functional loading, straight and tilted implants did not differ significantly in clinical outcome

Marginal healing using Polyetheretherketone as healing abutments: an experimental study in dogs

OBJECTIVE: To evaluate the marginal soft and hard tissue healing at titanium and Polyetheretherketone (PEEK) healing implant abutments over a 4-month period. MATERIAL AND METHODS: In six Labrador dogs, all mandibular premolars and first molars were extracted. After 4 months of healing, flaps were elevated, and two implants were installed at each side of the mandible, one in the premolar and the other in the molar regions. Four different types of healing abutments were positioned on the top of each implant: (i) titanium (Ti); (ii) PEEK material bonded to a base made of titanium (Ti-P), randomly positioned in the premolar region; (iii) PEEK, pristine (P); and (iv) PEEK, roughened (P-R), randomly positioned in the molar region. The flaps were sutured to allow a non-submerged healing, and after 4 months, the animals were sacrificed and ground sections obtained for histological evaluation. RESULTS: A higher resorption of the buccal bone crest was observed at the PEEK bonded to a base made of titanium abutments (1.0 ± 0.3 mm) compared to those made of titanium (0.3 ± 0.4 mm). However, similar dimensions of the peri-implant mucosa and similar locations of the soft tissues in relation to the implant shoulder were observed. No statistically significant differences were seen in the outcomes when the pristine PEEK was compared with the roughened PEEK abutments. The mean apical extension of the junctional epithelium did not exceed the implant shoulder at any of the abutment types used. CONCLUSIONS: The coronal level of the hard and soft tissues allows the conclusion that the use of PEEK as healing abutments may be indicated