Healing of Alveolar Sockets Treated with Concentrated Growth Factors: A Split-Mouth Study.

Background: tooth extraction is a common procedure in oral surgery. The socket healing process involves hard and soft tissues and is characterized by intense remodeling, which may determine consistent dimension changes. Several autologous platelet concentrates (APCs) proved to be effective for enhancing alveolar socket healing after tooth extraction, accelerating socket closure and countering alveolar bone resorption. Concentrated growth factors (CGFs) are one of the most recently developed APCs, and their effect on the socket healing process still needs to be confirmed. Aim: The aim of the present split-mouth study was to evaluate the effectiveness of CGFs in enhancing the healing process in the postextraction alveolar socket and reducing postoperative pain. Methods: One hundred and fifty-four extractions were performed. One of the extraction sockets of each patient was treated with CGFs (test site), and the other socket was unfilled (control site). The main outcomes were: healing index, alveolar dimensions at the crestal level, socket closure, and pain perception. Descriptive statistics of the results were analyzed. Follow-up data were compared to baseline using paired tests. Results: The healing index on day 7 was significantly better (p < 0.001) in the test group (5.01 ± 1.30) as compared to the control group (6.65 ± 1.41). The mean visual analog scale for pain (VAS) was significantly higher for the control group when compared to the CGF group in the first 5 days postextraction. There was a trend toward greater socket closure in the CGF group, indicating faster healing, as compared to the control group at 7, 14, and 21 days. Conclusions: CGFs can represent a useful adjunctive tool, considering their mechanical and biological properties, for improving alveolar socket healing and reducing postoperative patient discomfort.

Dental Implants with a Calcium Ions-Modified Surface and Platelet Concentrates for the Rehabilitation of Medically Compromised Patients: A Retrospective Study with 5-Year Follow-Up.

BACKGROUND: Platelet concentrates are biological, autologous products obtained from the patient's whole blood, consisting of a supraphysiological concentration of platelets and growth factors, that have proved beneficial in different applications in the medical and dental fields. They are used in several medical and dental applications to enhance tissue healing. Previous evidence shows that platelet concentrates may be beneficial in patients with compromised systemic conditions, in which the healing process is impaired. AIM: To evaluate the 5-year clinical outcome of implant treatment using acid-etched implants with calcium ions-modified surface in association with plasma rich in growth factors, in patients with systemic diseases of a different nature. METHODS: Charts of 99 medically compromised patients, who had received a total of 224 dental implants from January 2013 to June 2013, were retrospectively evaluated. Patients were divided into four groups, according to their condition: diabetes (n = 39 patients), osteoporosis (n = 36), lupus erythematosus systemic (n = 5), rheumatoid arthritis (n = 19). The main outcomes were implant survival, marginal bone level (MBL) change and complications throughout follow-up. RESULTS: Mean follow-up was 63.06 ± 1.90 months (range 60.1 to 66.4 months). In total, eight implants failed in 6 diabetic patients and 4 in 3 patients with rheumatoid arthritis. Overall 5-year implant survival was 94.6%. In total, 30 complications occurred in 24 patients, mostly transient, and no severe adverse event occurred. Overall MBL change was 0.45 ± 0.12 mm, with no significant differences among groups. CONCLUSIONS: In the present sample of medically compromised patients, rehabilitation with calcium ions-modified surface implants associated with plasma rich in growth factors proved to be a safe and effective treatment. The satisfactory results achieved after 5-year follow-up are comparable to those historically reported for healthy patients.

In Vitro Simulation of Dental Implant Bridges Removal: Influence of Luting Agent and Abutments Geometry on Retrievability.

Implant fixed dental prostheses are widely used for the treatment of edentulism, often preferred over the screw-retained ones. However, one of the main features of an implant-supported prosthesis is retrievability, which could be necessary in the case of implant complications. In this study, the retrievability of implant-fixed dental prostheses was investigated considering two of the main factors dental practitioners have to deal with: the abutments geometry and the luting agent. Impulsive forces were applied to dental bridge models to simulate crowns' retrievability in clinical conditions. The number of impulses and the impulsive force delivered during each test were recorded and used as retrievability indexes. One-hundred-and-five tests were conducted on 21 combinations of bridges and luting agents, and a Kruskal-Wallis test was performed on the results. The abutment geometry significantly influenced the number of impulses needed for retrieval (p < 0.05), and a cement-dependent trend was observed as well. On the other hand, the forces measured during tests showed no clear correlation with bridge retrievability. The best retrievability was obtained with long, slightly tapered abutments and a temporary luting agent.

In Vitro Impact Testing to Simulate Implant-Supported Prosthesis Retrievability in Clinical Practice: Influence of Cement and Abutment Geometry.

Cement-retained implant-supported prosthetics are gaining popularity compared to the alternative screw-retained type, a rise that serves to highlight the importance of retrievability. The aim of the present investigation is to determine the influence of luting agent, abutment height and taper angle on the retrievability of abutment-coping cementations. Abutments with different heights and tapers were screwed onto an implant and their cobalt-chrome copings were cemented on the abutments using three different luting agents. The removals were performed by means of Coronaflex®. The number of impulses and the forces were recorded and analyzed with a Kruskal-Wallis test. Harvard cement needed the highest number of impulses for retrieval, followed by Telio CS and Temp Bond. However, abutment height and taper showed a greater influence on the cap's retrievability (p < 0.05). Long and tapered abutments provided the highest percentage of good retrievability. The influence of the luting agent and the abutment geometry on the cap's retrieval performed by Coronaflex® reflects data from literature about the influence of the same factor on the maximum force reached during uniaxial tensile tests. The impulse force was slightly affected by the same factors.

Immediate Loading of Mandibular Overdentures Retained by Two Mini-Implants: A Case Series Preliminary Report.

PURPOSE: This preliminary case series report sought to evaluate the efficacy of an immediate loading protocol for mandibular overdentures retained by two mini-implants with the outcome measures patient satisfaction, masticatory cycles, and masticatory efficiency at 1 year. MATERIALS AND METHODS: A convenience sample of 11 patients was recruited, and the clinical protocol consisted of immediately loading two mini-implants (10 mm long and 2.4 mm or 2.9 mm in diameter) via a mandibular overdenture connection with Locator attachments. Each patient completed a satisfaction questionnaire and underwent masticatory cycle recordings and masticatory efficiency tests. Implant-related evaluations were carried out by assessing probing depth (PD), Plaque Index (PI), bleeding on probing (BOP), mobility, and pain. All tests and evaluations were carried out six times: before implant surgery (T0), just before implant surgery with patient under anesthesia (T1), following implant insertion with patient still under anesthesia (T2), and at 3 months (T3), 6 months (T6), and 1 year (T12) after implant insertion. RESULTS: Implant survival rate was 95%, and statistically significant increases (P < .05) in masticatory cycle patterns, masticatory efficiency, comfort, stability, and phonetics were also recorded. CONCLUSION: The employed treatment protocol suggests promise as a viable treatment option that in the short term provides improved prosthesis stability, comfort, and function while decreasing surgical invasiveness. Long-term follow-up outcomes in larger patient sample studies will be required to confirm and validate the merits of this preliminary report.

Method to improve passive fit of frameworks on implant-supported prostheses: An in vitro study.

STATEMENT OF PROBLEM: The passivity of the superstructure to the abutments of implant-supported prostheses is necessary for implant-prosthesis success. Improvements are needed in the methods of verifying passivity. PURPOSE: The purpose of this in vitro study was to evaluate an inexpensive, easy to make, and user-friendly device to verify the position of the implant abutment replicas of the definitive cast and to avoid framework misfit before fabrication. MATERIAL AND METHODS: Eighty stone devices were constructed on a metal base for the in vitro tests. The horizontal, vertical, and angled positions of the implant replicas were created to simulate misfits. The devices were fitted on the abutment replicas, and their ability to identify misfits was evaluated. A statistical analysis was not indicated, because the probability of fracture of the stone devices was 0 or 1. Two mathematical models were built using computer-aided design software (SolidWorks Premium; Dassault Systèmes SolidWorks Corp), and the finite element method was used (Ansys; ANSYS Inc) to simulate the structural behavior of 2 implant configurations (4 and 6 implants). RESULTS: Horizontal misfits of 150 µm, vertical misfits of 50 µm, and angled misfits of 1 degree were detected during the in vitro tests. Different loads and bone quality in the mathematical models did not change stress in the prosthesis configurations on 4 or 6 implants in a relevant way. CONCLUSIONS: The fabricated device was easily able to detect the misfits in accordance with the defined parameters.

In vitro standardization of two different removal devices in cemented implant prosthesis.

OBJECTIVES: The purpose of this study was to describe the force generated by two different removal devices used to retrieve cemented crowns on implant abutments. The influence of six different operators was evaluated. MATERIAL AND METHODS: Three replicated Coronaflex(®) (Kaltenbach & Voigt GmbH, KaVo Dental GmbH) and reverse hammer setups were tested. The experimental setup has employed a screw bearing a diametral hole through which a loop holder passed. The screw was attached to a force transducer (Brüel & Kjaer, type 8201), and the loop holder arm was kept perpendicular to the transducer axis. The results were statistically evaluated with ANOVA. RESULTS: The operator has resulted to play significant influence with reference to reverse hammer (coefficient of variation 43.3%) rather than with Coronaflex(®) (9.8%). Evaluating every single operator, more variation can still be found by considering each reverse hammer (37.5%) rather than each Coronaflex(®) (8.8%). CONCLUSION: Coronaflex(®) device was found to systematically reach a more repeatable and higher peak amplitude of forces compared with reverse hammer, both by experienced and inexperienced operators.

An alumina toughened zirconia composite for dental implant application: in vivo animal results.

Ceramic materials are widely used for biomedical applications because of their remarkable biological and mechanical properties. Composites made of alumina and zirconia are particularly interesting owing to their higher toughness with respect to the monolithic materials. On this basis, the present study is focused on the in vivo behavior of alumina toughened zirconia (ATZ) dental implants treated with a hydrothermal process. A minipig model was implemented to assess the bone healing through histology and mRNA expression at different time points (8, 14, 28, and 56 days). The novel ATZ implant was compared to a titanium clinical standard. The implants were analyzed in terms of microstructure and surface roughness before in vivo tests. The most interesting result deals with a statistically significant higher digital histology index for ATZ implants with respect to titanium standard at 56 days, which is an unprecedented finding, to the authors' knowledge. Even if further investigations are needed before proposing the clinical use in humans, the tested material proved to be a promising candidate among the possible ceramic dental implants.

A method to improve passive fit of frameworks on implant-supported prostheses: an in vivo study.

PURPOSE: A die stone jig was evaluated as to its ability to clinically verify the position of the abutment replicas on the master cast. MATERIALS AND METHODS: A clinical evaluation was made on 58 edentulous arches necessitating rehabilitation with fixed partial dentures. Any broken jigs detected were replaced with a new set of jigs and clinically retested. Data were statistically confirmed. RESULTS: Fifty-five percent of the 58 jigs broke, with a 95% confidence interval (CI) of 42.5 to 67.3; after replacement, there were no breakages (95% CI: 0 to 6.2). CONCLUSIONS: The jig detected misfits in clinical trials, according to the parameters defined in the literature.

Cytokines and growth factors involved in the osseointegration of oral titanium implants positioned using piezoelectric bone surgery versus a drill technique: a pilot study in minipigs.

BACKGROUND: Most dental implants are positioned using a drilling surgery technique. However, dentistry recently experienced the implementation of piezoelectric surgery. This technique was introduced to overcome some of the limitations involving rotating instruments in bone surgery. This study used biomolecular and histologic analyses to compare the osseointegration of porous implants positioned using traditional drills versus the piezoelectric bone surgery technique. METHODS: Porous titanium implants were inserted into minipig tibias. Histomorphology and levels of bone morphogenetic protein (BMP)-4, transforming growth factor (TGF)-beta2, tumor necrosis factor-alpha, and interleukin-1beta and -10 were evaluated in the peri-implant osseous samples. RESULTS: Histomorphological analyses demonstrated that more inflammatory cells were present in samples from drilled sites. Also, neo-osteogenesis was consistently more active in bone samples from the implant sites that were prepared using piezoelectric bone surgery. Moreover, bone around the implants treated with the piezoelectric bone surgery technique showed an earlier increase in BMP-4 and TGF-beta2 proteins as well as a reduction in proinflammatory cytokines. CONCLUSION: Piezoelectric bone surgery appears to be more efficient in the first phases of bone healing; it induced an earlier increase in BMPs, controlled the inflammatory process better, and stimulated bone remodeling as early as 56 days post-treatment.

Biological factors involved in the osseointegration of oral titanium implants with different surfaces: a pilot study in minipigs.

BACKGROUND: The stability of titanium implants is determined by the rigid load-bearing connections that are formed by the bone, a process that involves a complex network of cells, pro- and anti-inflammatory mediators, and growth factors. The osseointegration processes at the interfaces of machined and porous implants were studied using molecular and histological techniques. METHODS: Two machined and two porous titanium implants were inserted into the tibiae of four minipigs. The animals were sacrificed at 15, 30, 60, and 90 days post-implantation. The levels of bone morphogenetic protein (BMP)-4, transforming growth factor (TGF)-beta1, and tumor necrosis factor (TNF)-alpha were quantified in the peri-implant osseous samples. The levels of interleukin (IL)-1beta, IL-6, IL-10, and TNF-alpha in the serum were also assessed. RESULTS: Histomorphological analysis showed evidence of bone ossification around the porous implant at 60 days. Surrounding the machined implants, highly sclerotic fibrous pads started the healing response at 90 days, and the levels of TGF-beta1 and BMP-4 began to increase at 60 days, at which time bone ossification around the porous implants was already evident. TNF-alpha was not present in the bone next to the implants. The serum levels of cytokines IL-1beta, IL-6, and IL-10 were not increased. The serum level of TNF-alpha increased during the healing process. CONCLUSIONS: We observed that the levels of BMP-4 and TGF-beta1, which play essential roles in the osteogenesis process, increased earlier around the porous implants than around the machined implants. Similarly, the ossification process was initiated earlier at the surfaces of the porous implants than at the surfaces of the machined implants.

Retention of luting agents on implant abutments of different height and taper.

OBJECTIVE: The purpose of this study was to evaluate the retention of four cements used to lute metal restorations onto computer designed and manufactured titanium implant abutments of different heights and convergence angles. MATERIAL AND METHODS: Test specimens consisted of metal coping cemented on Procera titanium abutments of 5, 7, and 9 mm of height, and of 0 degrees , 4 degrees , and 8 degrees of convergence angle. The cements used were zinc-phosphate, zinc oxide-eugenole, polyurethane resin with and without vaseline. The samples were tested in a universal testing machine. The mean uniaxial load at point of separation was determined. The results were statistically evaluated with ANOVA. RESULTS: The luting agent, the height, and the taper influence the retention of metal casting on customized CAD-CAM implant abutments. CONCLUSION: The most retentive cement was zinc-phosphate, followed by polyurethane, polyurethane plus vaseline, and zinc oxide-eugenol.