Davide Berardi

Implant micromotion is related to peak insertion torque and bone density

OBJECTIVES Measuring peak insertion torque in relation to different bone densities, the present study seeks to determine whether micromotion at the interface is related to primary stability achieved by increasing insertion torque. MATERIAL AND METHODS A total of 120 Ti-Bone implants were placed in fresh bovine bone samples representing three density categories: hard, normal and soft (HNS). Five groups of peak insertion torque (20, 35, 45, 70 and 100 N/cm) were evaluated in the three bone density categories noted. Customized electronic equipment connected to a PC was used to register the peak and other insertion torque data. A loading device, consisting of a digital force gauge and a digital micrometer, was used to measure the micromovements of the implant during the application of 20, 25 and 30 N lateral forces. The data were analyzed for statistical significance by ANOVA and Spearmans rank correlation coefficient tests. RESULTS A statistically significant difference between implant micromobility placed with different levels of torque and in different bone densities was demonstrated by ANOVA. Spearmans rank correlation coefficient showed a high dependency between the peak insertion torque and the observed micromovement. Particularly, in soft bone, it was not possible to achieve more than 35 N/cm of peak insertion torque. CONCLUSIONS Results showed that increasing the peak insertion torque reduces the level of implant micromotion. In addition, micromotion in soft bone was found to be consistently high, which could lead to the failure of osseointegration. Thus, immediate functional loading of implants in soft bone should be considered with caution.

Primary stability, insertion torque and bone density of cylindric implant ad modum Branemark: is there a relationship? An in vitro study.

OBJECTIVES Protocols of immediate loading have been reported in several studies. It has also been demonstrated that the cause of failure of immediate loaded implants is due to the micromotion on the bone-implant interface induced by immediate loading. There should be a minimum gap between the implant and the peri-implant bone, without micromotions occurring above a definite threshold risk as they induce bone resorption and fibrosis around the implant. Measurement of the torque necessary to insert an implant in the bone is a parameter for measuring initial stability. The higher the implant insertion torque, the higher the initial stability attained. The aim of this study was to evaluate in vitro the correlation between the micromotion of cylindric screw implants ad modum Branemark and the insertion torque in bone of different densities. MATERIAL AND METHODS The test was carried out on 2 × 2 cm samples of fresh bovine bone of three different densities: hard (H), medium (M) and soft (S). One hundred and fifty hexa implants ad modum Branemark were used, 3.75 mm in diameter and 9 mm long. To screw in the implants, a customized manual key was used, controlled digitally to evaluate the peak insertion torques. Ten implants were prepared for each torque (20, 35, 45, 70 and 100 N/cm). The bone sample was then fixed on a loading device, which allowed evaluating the micromotion. On each sample, we applied a 25 N horizontal force. RESULTS The results indicate that the peak insertion torque and the implant micromotion are statistically correlated, and statistically significant differences in H and M bone were found compared with S bone. In S bone, we noted a micromotion significantly higher than the risk threshold, and it was not possible to reach peak insertion torque above 35 N/cm. In H and M bone, the micromotion is below the threshold of all insertion torques. CONCLUSIONS Increasing the peak insertion torque, we can reduce the extent of the micromotion between the implant and the bone when submitted to lateral forces in vitro. In soft bone, the micromotion was always high; hence, immediate loading of implants in low-density bone should be evaluated with care.

N-3 polyunsaturated fatty acid effect in periodontal disease: state of art and possible mechanisms involved.

Anti-inflammatory properties have been widely reported for n-3 polyunsaturated fatty acids (PUFAs) and some studies have been focalized on their possible role in the modulation of gingivitis and alveolar bone resorption in periodontal disease (PD). Increased formation of arachidonic acid-derived inflammatory eicosanoids and augmented oxidative stress are two molecular mechanisms pathogenetically involved in the progression of PD and known to be inhibited by n-3 PUFAs in PD setting. The present review will focus also on other molecular pathways and factors known to be altered in the development of PD and known to be subject to n-3 PUFA modulation in other pathological settings different from PD. Overall, the available findings strongly encourage further experimental studies on animals subject to experimental PD and treated with n-3 PUFAs, long term n-3 PUFA intervention studies on PD patients and molecular studies to identify additional potential molecular routes of n-3 PUFA action in PD.

Evaluation of Neridronate on the Osseointegration Process of Endeous Titanium Implants in Animal Models

Bisphosphonates are compounds that inhibit bone reabsorption mediated by osteoclasts. The use of bisphosphonates in oral implantology is still in the experimental stage. The aim of this study is to evaluate the efficacy of an aminobisphosphonate to increase the ability of the drug to act on the implant and bone surfaces in the development of the osseointegration in sheep. Forty SLA titanium implants were used on sheep iliac crests. Neridronate added to connective gel (test 1) or to physiological solution (test 2) was used in order to increase the bone and implant adhesiveness. Physiological solution (control 1) or connective gel (control 2) alone was given to the control groups. A topical administration of Neridronate was made on the implant surface and in the implant site. Four Bergamasca sheep were used and were sacrificed by intravenous injection of 10 cc Tanax after 8 weeks from implantation. Histologic and histomorphometric analyses were carried out. The results did not show significant differences between the test group and control group. Our data are different from other similar studies obtaining statistically significant differences. These differences could depend on the procedure of application of the drug on the implant. This study demonstrates the poor efficacy of neridronate applied topically to the implant and implant site during surgery. Further studies using different fixation techniques of the drug may be necessary to confirm the present data.

Primary Stability, Insertion Torque, and Bone Density of Conical Implants With Internal Hexagon: Is There a Relationship?

AbstractBetween implants and peri-implant bone, there should be a minimum gap, without micromotions over a threshold, which could cause resorption and fibrosis. The higher the implant insertion torque, the higher will be the initial stability. The aim was to evaluate in vitro the correlation between micromotions and insertion torque of implants in bone of different densities. The test was performed on bovine bone of hard, medium, and soft density: 150 implants were used, 10 for each torque (20, 35, 45, 70, and 100 N/cm). Samples were fixed on a loading device. On each sample, we applied a 25-N horizontal force. Insertion torque and micromotions are statistically correlated. In soft bone with an insertion force of 20 and 35 N/cm, the micromotion resulted significantly over the risk threshold, which was not found with an insertion force of 45 and 70 N/cm and in hard and medium bones with any insertion torque. The increase in insertion torque reduces the amount of micromotions between implant and bone. Therefore, the immediate loading may be considered a valid therapeutic choice, even in low-density bone, as long as at least 45 N/cm of insertion torque is reached.

Potential applications of biphosphonates in dental surgical implants.

Biphosphonates are largely used for their unquestionable properties of inhibiting bone resorption by osteoclast in the treatment of various osteometabolic illnesses such as osteoporosis, multiple myeloma, tumors which metastasize to the bone and malignant hypercalcemia. In this literature review the physico-chemical properties, biologic activities and the mechanisms of action of biphosphonates are described. The use of these drugs is discussed, analyzing the quantity of results which have emerged through in vitro and in vivo experiments on animal models. In this study the efficiency of these drugs is demonstrated in contrasting the osteolitic processes of the alveolar bone, in promoting the neoformation and in bettering the quality of bone implants. However, it is important to draw attention to a worrying correlation which has emerged during the last 3–4 years, between osteonecrosis of the jaw (ONJ) and the systemic administration of aminobiphosphonates. This collateral effect did not emerge following the use of non-aminobiphosphonates. The aim of this revie w is to identify the guidelines for the use of biphosphonates in oral implant surgery.

In vitro evaluation of the efficacy of a new laser surface implant: cellular adhesion and alkaline phosphatase production tests.

Bone tissue reacts in different ways to implant surfaces with different patterns. The aim of this study is to understand which laser generated surface pattern produces the best cell adhesion in vitro, evaluating both the activity of the alkaline phosphatase and the cells adhering to titanium samples. Tests were carried out on titanium samples with sandblasted surfaces with laser-produced holes with diameters of 5, 10, and 20 μm, and on sandblasted titanium cylinders without holes as controls. The samples were inserted into culture medium containing SaOS-2 cells for 3, 7 and 10 days. The results showed that at days 3 and 7 the laser surfaces stimulated a higher production of alkaline phosphatase (ALP) compared to the data from the control group. At day 10 there were no significant differences between the test group and the control group.

Sinus augmentation procedure of the jaw sinus in patients with mucocele.

The sinus augmentation procedure of the jaw sinus (SAP) is a surgical technique which permits the prosthetic rehabilitation of the edentulous saddles by the insertion of dental implants where unfavourable conditions exist for their application. Nevertheless, apart from malignant tumors, benign pathologies exist, such as mucocele or radicular cysts, which can complicate the SAP, causing sinusal disturbances. In this study we describe our experience of SAP in patients with mucocele of the jaw sinus, and describe our surgical technique without the preventive emptying of the mucocele. Based on our experience, the SAP operation can be carried out without complications if the distance between the top of the mucocele with SAP and the osteomeatal complex (OMC) is 22 mm, or for mucocele no larger than 18 mm. In fact, these parameters guarantee that, because of the lifting of the sinusal membrane, the antral drainage (AD) duct does not alter or become obstructed.

Multiple Chemical Sensitivity: Current Concepts

Multiple Chemical Sensitivity (MS) is characterized by a wide range of symptoms when affected patients come into contact with several chemical products. Very little is known of either the diagnosis or the suitable treatment. In this study we report the case of a 38-year-old woman, previously diagnosed as suffering from MCS, who was referred for an oral health evaluation. After removing all the existing restorations and extracting the diseased teeth, a removable partial denture without metal structure was made after testing her hypersensitivity to these materials. The one year follow-up of the patient did not show any remarkable reaction, confirming the reduction of a large number of MCS symptoms and the increase in her quality of life.

Laser-Treated Titanium Implants: An In Vivo Histomorphometric and Biomechanical Analysis.

Purpose:The aim of the present histological and biomechanical analysis was to compare, in vivo, the strength and quality of osseointegration between a laser-treated implant surface and a standard machined surface. Material and Methods:Customized titanium implants, having 2 different surfaces, were used. Implants were longitudinally split in the 2 surfaces: one side was laser treated and the opposite one had a machined surface. Eight implants were inserted in the iliac crest of 2 sheep: 4 with a split laser and machined surfaces, 2 with a completely laser-treated surface, and 2 with fully machined surfaces. The animals were killed 8 weeks after the placement of implants. The histomorphometric and biomechanical parameters calculated for each surface were the bone-implant contact (%BIC) and the reverse torque value (RTV) Results:The RTV of the laser-treated implants were about 3-fold higher than that of the machined implants. The histomorphometric results showed a significant difference of %BIC around 30% between the laser surfaces compared to the machined ones. Conclusions:The present study showed that laser surface treatment induces better osteointegration than machined surface. The laser-treated surface seems to be able to increase the osseointegration amount in respect to the machined implants.