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Background: During the sexual maturation, gluteal femoral adipose tissue is subjected to numerous modifications, not observable in other regions, in particular in women and less in men. Other authors described this region, but they used imaging techniques having lower resolution, than MRI proposed in this study. High resolution imaging techniques might provide important and more detailed information about the anatomy of gluteal femoral region. Methods: This study has been performed using 7 T‐magnetic resonance imaging and ultrastructural analysis in order to provide accurate description of the subcutaneous adipose tissue and dermis of gluteal femoral region. In this study specimens harvested from cadavers and form living patients have been analyzed. Results: The results showed the presence of three layers: superficial, middle, and deep, characterized by different organization of fat lobules. High resolution imaging showed the adipose papilla that originates from dermis and protrude in subcutaneous adipose tissue. Adipose papilla is characterized by a peculiar morphology with a basement, a neck and a head and these elements represent the functional subunits of adipose papilla. Moreover, ultrastructural study evidenced the relationship between adipocytes and sweat glands, regulated by lipid vesicles. Conclusions: This study provides important information about subcutaneous and dermal fat anatomy of gluteal femoral region, improving the past knowledge, and move toward a better understanding of the cellulite physiopathology. [ABSTRACT FROM AUTHOR]

Background: The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived aesthetics is in high demand among patients. This factor, combined with the increase in the number of non‐invasive facial aesthetic treatments, has led to the need to understand potential risk factors in the application of medical devices to the perioral skin in patients with fixed orthodontic appliances. The aim of this study was to evaluate in vitro heating of the orthodontic bracket following electromagnetic fields and negative pressure (V‐EMF) used as an anti‐aging treatment. Methods: Two different types of titanium alloy wires, one made of "beta‐Titanium" alloy and the other "Ni‐Ti" (DW Lingual Systems GmbH—Bad Essen—Germany) were used. The orthodontic wires and brackets mounted on a resin mouth were covered with porcine muscle tissue, then subjected to anti‐aging therapy with a Bi‐one LifeTouchTherapy medical device (Expo Italia Srl—Florence—Italy) which generates a combination of vacuum and electromagnetic fields (V‐EMF) already adopted for antiaging therapy. During administration of the therapy, the orthodontic brackets and porcine tissue were thermally monitored using a Wavetek Materman TMD90 thermal probe (Willtek Communications GmbH—Germany). In total 20 orthodontic mouths were used, 10 with Beta Titanium wires and 10 with Nickel Titanium wires. Results: A temperature increase of about 1°C was recorded in each group. The outcome of the present research shows that the absolute temperatures measured on orthodontic appliances, which, despite having a slightly different curve, both show an increase in temperature of 1.1°C at the end of the session, thus falling well within the safety range of 2°C as specified by the standard CENELEC EN 45502‐1. Therefore, V‐EMF therapy can be considered safe for the entire dental system and for metal prostheses, which tend to heat up at most as much as biological tissue (+0.9°C/1.1°C vs. 1.1°C/1.1°C). Conclusion: In conclusion, anti‐aging therapy with V‐EMF causes a thermal increase on orthodontic brackets that is not harmful to pulp health. [ABSTRACT FROM AUTHOR]

Background: The implantation of artificial hair is a successful standardized procedure to restore bald areas or scarred alopecic surfaces of the scalp in both sexes. Materials and Methods: Sebometric measurements were taken, pre, 1, 3, and 6 months postimplant in two symmetric frontotemporal areas of the scalp of seven volunteers to be implanted with 50 units of artificial hair. The artificial hair used in this study are Biofibre 4.0 produced by Medicap srl, Italy. Results: The dermaroller assisted procedure was performed only on one side, and the plain random implant contralaterally for comparison. A marked downregulation of the sebum concentration was observed in the dermaroller treated area 1, 3, and 6 months later in respect to the control side. Conclusion: The dermaroller assisted procedure is safe and effective in reducing the foreign body reaction by the sebaceous glands and the vascular axis injured by the implanting needle; a longer standing success of the implanted hair can thus be achieved reducing the burden of inflammatory reaction. [ABSTRACT FROM AUTHOR]

Objectives: To describe the association between endodontic treatment failure and medication‐related osteonecrosis of the jaw (MRONJ) in a cohort of oncologic patients in therapy with antiresorptive and antiangiogenic drugs. Materials and Methods: Patients were selected as affected by MRONJ in absence of the common local risk factors (oral surgical procedures or ill‐fitting dentures) but showing failure of previous endodontic treatment performed at least 6 months before the starting of antiresorptive/antiangiogenic therapies. Jaw lesions were all surgically treated and patients underwent a strict clinical and radiological follow‐up. Results: Among 18 patients, who developed 18 MRONJ, the only detectable local risk factor was the presence of teeth with failed endodontic treatment (more precisely, root canal underfilling in eight cases, root canal overfilling in two cases, root perforation in three cases, root fracture in five cases). All patients completely healed after surgical procedure and no recurrence was observed. Conclusions: Endodontic treatment failure should be considered a local risk factor for MRONJ development in oncologic patients. For such reason, it is mandatory to carefully evaluate them prior than the beginning of antiresorptive and antiangiogenic drugs administration. [ABSTRACT FROM AUTHOR]

Objective: Skin laxity and wrinkling are common signs of the aging process. This physiological condition of the skin is often accompanied by psychological and social concerns, especially for females, entailing considerable expenses for cosmetics and pharmaceuticals to cease or slow down its advancement. The objective of this study was to evaluate the short‐term impact of a new non‐ablative radiofrequency device available in the skin face cosmetic field. Methods: A randomized study was run on 62 healthy subjects with normal‐age related–grade skin laxity, subdivided into two groups. Group 1 received one treatment with Modula RF device (Wavemed, San Cesareo RM, Italy) over the whole face surface. Group 2 received three monthly treatments. Results: Clinical improvements of the exposed areas were detected by measuring skin parameters, such as total water content, elasticity, and sebum levels at baseline and 1 h after the treatment. Data showed significant effects of Med‐RF treatment on skin hydration (p < 0.001), skin elasticity (p < 0.0001), and sebum (p = 0.0009). Moreover, a negative linear correlation was obtained between women's age and hydration. Conclusion: In conclusion, the results of this study suggest that radiofrequency significantly improves the subjective and objective judgment of patients and doctors, supported by the positive results obtained on the skin quality parameters evaluated. These results confirm that Med‐RF technology represents an important tool to achieve face rejuvenation in the field of non‐invasive procedures. [ABSTRACT FROM AUTHOR]

Background: Cellulite is a topographic alteration of the skin with unknown etiology and is characterized by the presence of a dimpled or puckered aspect, as resembling an orange peel and cottage cheese or as having mattress‐like appearance. Aim: The aim of this research was to find the different histological aspect of cellulite in sixty patients. Materials and Methods: A total of 60 women, mean age 48.8 (± 11.08) were included in the study. Among these, 11 women were in menopause (18.33%). All patients after physical examination, aesthetic, and dermatological evaluation were subjected to five cellulite biopsies with a 2.0 mm diameter and 1.5 mm in length in the trochanteric region affected by cellulite. The descriptive statistics were performed for each study predictors demographic age, height, bmi, waist, belly, hip thigh, and knee. Results: The histological analysis of the stained slides showed five different histological features were present in the most of patient. Conclusion: In conclusion, the outcome of this study shows that the histological evidence does not characterize the different states of cellulite, but several different histological aspects were present in the same patient, which effectively eliminates staging and could consider cellulite as a degenerative disease. [ABSTRACT FROM AUTHOR]

Background: In esthetic medicine, different techniques have been used against the aging of the human skin especially in the facial area. Hyaluronic acid is used for improving the quantity of water and extracellular matrix molecule. The aim of this study is a clinical and histological evaluation of the effect of low‐molecular‐weight hyaluronic acid fragments mixed with amino acid (HAAM) on the rejuvenation the face skin treated with intradermal microinjections. Methods: Twenty women with mean age 45 range from 35 to 64 were studied, thereof 8 in menopause and 12 of childbearing age. The patients were treated with the HAAM products by mesotherapy technique; before and after 3 months of the therapeutic procedure, each patient underwent small biopsies with a circular punch biopsy. Results: The clinical results of the present study showed that the administration of the dermal filler containing fragments of hyaluronic acid between 20 and 38 monomers and amino acid via dermis injection technique produces an esthetic improvement in the faces of the treated patients, while the histological evaluation shows an increased fibroblast activity with the production of type III reticular collagen and increased number of vessels and epidermis thickness. Conclusions: The clinical and histological assessment showed that subcutaneous HAAM infiltration has a significant impact on the dermis and clinical aspects of the face. [ABSTRACT FROM AUTHOR]

Background: Nasal telangiectasias are superficial, small vessels in the ala nasi and nasolabial crease with a varying origin. They represent an unaesthetic condition, frustrating patients who frequently request their removal. Microsclerotherapy, electrosurgery, different types of laser therapy, needle‐assisted electrocoagulation, and TRASER therapy have been described for treating this condition. Aims: The aim of this study is to describe a novel technique that removes nasal telengectiasias using voltaic arc dermabrasion (VAD). Patients/Methods: Voltaic arc dermabrasion treatment was used to remove nasal telangiectasia in 23 patients. The post‐treatment condition was monitored by means of photographic records and the evaluation of erythema, pain score, patient and surgeon satisfaction, and skin temperature. The timing points were 1, 4, 6 days and 1 year after treatment. Results: Patients referred a moderate pain during the treatment that ceased at the end of the procedure. Moderate erythema and punctiform fine crusting were present in all patients that lasted until the 6th day after treatment. No other adverse effects were observed. After 1‐year, the mean patient and surgeon satisfaction scores were 2.90 and 3.00 ± 0.3, respectively. A single treatment was effective in 85% of the patients and no recurrences were recorded for one year. The skin temperature increased about 18.2 ± 3.2°C during the treatment but returned to basal values in about 20 seconds in most of the patients. Conclusion: Voltaic arc dermabrasion treatment is a viable, easy to use, and inexpensive tool for successful nasal telangiectasia removal, with minimal post‐treatment discomfort. [ABSTRACT FROM AUTHOR]

Background: In recent literature, different approaches have been proposed to improve the long‐lasting treatment of age‐related alterations on the human face with decreased invasiveness and side effects such as scar tissue. Voltaic arc dermabrasion is a minimally painful procedure that does not create discomfort to the patient and requires no anaesthesia. Aims: The aim of this investigation was to evaluate the voltaic arc technique for the treatment of skin wrinkles in the periauricular area. Methods: A total of 80 patients were treated in this study, 56 females and 24 males. The population was visited at 1 week, 1 month, and 2 months postoperative follow‐ups to evaluate the healing of the treated regions. Results: All subjects showed evidence of tissue contraction related to the skin of the periauricular region with a cosmetic reduction of wrinkles in the treated area. No scars, complications, or pigmentary alterations were reported. At 1 month, all treated areas showed complete healing. Conclusions: The voltaic arc dermabrasion can be considered a useful tool for a noninvasive treatment of wrinkles related to the periauricular skin, with no discomfort for the patient or complications related to the procedure. [ABSTRACT FROM AUTHOR]

Purpose The present study aimed to assess clinical and biological performances of several bone substitute biomaterials ( BSBs). Materials and Methods The evaluation was conducted at 6 months and after several years on 295 patients undergoing sinus augmentation with 13 different BSBs; the data belonging to previously published studies have been analyzed using innovative mathematical models to evaluate the bone regenerative index ( Br) and the structural density index ( Ds). Results After 6 months, compared to the Ds index of native bone, the regenerated bone showed a D3 bone type; while, after several years, the regenerated bone type was D2, with an evident increase in the density of the regenerated bone over time. Moreover, the values of Br were higher for combined biomaterials indicating a fewer amount of residual particles and marrow spaces, while the values of Ds were higher for anorganic bovine bone indicating a greater new bone formation and a lesser amount of marrow spaces. After 20 years, the bone regenerated using hydroxyapatite still had a D4 bone quality. Conclusions After 6 months of healing, the regenerated bone had a composite structure resembling poor D3 bone type, and covered approximately one-third of the space filled by BSBs. None of the evaluated biomaterials seemed to be ideal. [ABSTRACT FROM AUTHOR]

Purpose The purpose of the present preliminary in vitro study on bovine ribs was to validate a new intraoperative site-specific classification of bone Density Index ( IDI), obtained by an innovative computerized implant motor, by correlating these data with the data obtained by the histomorphometrical evaluation of the same samples. Materials and Methods Five segments of bovine ribs were used, and a total of 22 perforations were performed. A computerized implant motor (' Torque Measuring Motor') was used to evaluate the bone density, which was classified into four classes: ID1, ID2, ID3, and ID4. Histomorphometrical analysis of bone density, expressed as percentage of bony trabeculae over the total biopsy area, was also performed. The data of bone density obtained by the implant motor were statistically correlated with the histomorphometrical results. Results A significant positive correlation was found between the bone density measured by the implant motor and the bone density assessed by histomorphometry (r = 0.89, p < .0001). Moreover, a significant positive correlation in D1, D2, and D4, whereas a negative, not significant correlation in D3 was found. Conclusion Within the limitations of this in vitro study, the intraoperative site-specific classification of bone density, obtained with this innovative system, could be helpful for the clinician to tailor the surgical protocol to the different situations in implant dentistry. [ABSTRACT FROM AUTHOR]

Background Differences in implant microtexture are important in conditioning the bone response around dental implants. Purpose The aim of the present study was an evaluation of the bone response in machined ( M), blasted with apatitic calcium phosphate (tricalcium phosphate/hydrossyapatite [ HA] blend) particles (resorbable blast texturing [ RBT]), and coated with HA implants. Methods A total of 48 (16 M, 16 RBT, and 16 HA) threaded screw-shaped implants were inserted into the tibia of 12 rabbits. The specimens were retrieved after 1, 2, 4, and 8 weeks and processed for histology. Results All experimental groups showed an increase of the bone-implant contact percentages through the study period. Higher and highly statistically significant differences were found in the percentages of bone observed in the concavities rather than in the convexities of the implants retrieved after 1, 2, and 4 weeks, while no significant differences were found after 8 weeks. In the different time periods, higher percentages of bone-implant contact were found in the RBT and HA-coated implants both in the concavities and in the convexities, but these differences were not statistically significant. Conclusions The newly formed bone present in the concavity of the threads was not influenced by the implant surface in the first healing period, while after 4 to 8 weeks, the percentage of bone observed in the concavities and convexities was similar. Additional histological studies are necessary to further evaluate the critical role of the concave geometry in bone differentiation and formation around dental implants. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study is to perform a systematic review of the literature on the use of titanium grids for implant surgery before and simultaneously with implant placement and to assess the success rate of the procedure, as well as survival and success rates of implants placed in the regenerated areas. Methods: Medline was used to identify studies in English published from 1996 to 2011. An additional hand search was performed of the relevant journals and of the bibliographies of the papers identified. Articles retrieved by two independent authors were screened using specific inclusion criteria: randomized controlled trials (RCTs), controlled clinical trials, and prospective clinical studies regarding vertical and/or horizontal regeneration of the alveolar ridge using titanium grids, in association or not with biomaterials, before and simultaneously with implant placement. Results: Six articles were selected, including a total of 79 patients, 87 titanium grids, and 141 implants. Twenty-four implants were placed simultaneously with titanium grids, and 117 implants were inserted after a period of 4 to 9 months. Titanium grids in combination with autogenous bone were used in 43 cases, 25 in combination with a mixture of autogenous bone and bone substitutes, 14 in association with bone substitutes, five using only titanium grids. The overall success rate of the regenerative procedures was 98.86%; the overall survival and success rates of implants were 100% and 93.2%, respectively. Conclusions: The main limit of the present systematic review is the scarcity of papers with an adequate and consistent methodology regarding the data collection and analysis and the lack of RCTs and large well-designed long-term trials. Survival and success rates of implants placed in the areas treated with titanium grids were comparable to those of implants placed in native, non-regenerated bone and of implants placed in bone regenerated with resorbable and non-resorbable membranes. [ABSTRACT FROM AUTHOR]

Objectives Various grafts or combination of graft materials have been used in sinus floor augmentations, and human histological reports on their performance are available, although limited in number. Histological analysis of the regenerated tissues will provide useful information regarding the nature and amount of newly formed bone. Aim of the present study was a histological and histomorphometric evaluation, in humans, of specimens retrieved from sinuses augmented with phycogene hydroxyapatite, biphasic calcium phosphate ceramics, calcium carbonate, porcine bone and anorganic bovine bone, after a healing period of 6 months. Materials and methods A total of 15 patients, undergoing 30 sinus augmentation procedures with five different biomaterials, participated in this study. A total of 82 titanium dental implants were inserted in the augmented sinuses after a healing period of 6 months. A total of 60 bone cores, 2 for each augmented sinus, 12 for every biomaterial, were retrieved and all were stored immediately in 10% buffered formalin and processed to obtain thin ground sections. Results In all biomaterials, many grafted particles were lined and, sometimes, bridged by newly formed bone. Some biomaterials particles appeared to be partially resorbed and substituted by newly formed bone. Histomorphometry showed that, in all biomaterials, newly formed bone and residual grafted material particles represented about 30%. Conclusions Longer term histological and histomorphometric studies will be necessary to understand better the resorption times of all these biomaterials. The high interconnecting microporosity allowed, in all the present biomaterials, the ingrowth of newly formed bone and vessels in the pores of the partially resorbed particles. In conclusion, within the limitations of the present study, the data provided support the fact that all these biomaterials can be used, successfully, in sinus augmentation procedures. [ABSTRACT FROM AUTHOR]

Background: Two-piece implants present gaps and cavities between the implant and the abutment, and these hollow spaces can act as a trap for bacteria. The aim of the present in vitro study was to evaluate the migration of two different microbial species from the inside to the outside of the implant-abutment assembly in three different connection types. Methods: A total of 30 implants (10 implants per group) were used. The implants presented a screwed trilobed connection (group 1), a cemented connection (group 2), and an internal conical connection (group 3). The inner parts of five implants, per group, were inoculated with Pseudomonas aeruginosa suspension and the remaining five implants, per group, with Aggregatibacter actinomycetemcomitans. The penetration of bacteria into the surrounding solution was determined by the observation of turbidity of the broth. Results: In group 1, bacterial contamination was found in six of 10 implants. In group 2, no contaminated samples were found. In group 3, bacterial contamination was found in one implant of 10. Statistically significant differences were detected between group ] versus group 3 (P <0.05) and between group 1 versus group 2 (P<0.01), whereas no significant differences were found when comparing group 2 versus group 3 (P>0.05). Conclusion: The present study confirms previous results about the hermeticity of the cement-retained implant-abutment assembly, the very low permeability to bacteria of the conical implant-abutment connection, and the high prevalence of bacterial penetration of screw-retained implant-abutment assemblies. [ABSTRACT FROM AUTHOR]

ABSTRACT Background: A few studies have investigated the influence of drilling on bone healing. Many factors have been reported to influence temperature rise during surgical preparation for implant placement: drill geometry, drilling depth, sharpness of the cutting tool, drilling speed, pressure applied to the drill, use of graduated versus one-step drilling, intermittent versus continuous drilling, and use or not of irrigation. Purpose: The objective of this study was to quantify the temperature changes in cortical bone and at the apical portion of the drills during implant site preparation with a cylindrical implant drill versus a conical implant drill. Materials and Methods: Two implant drill systems were evaluated in vitro using bovine femoral cortical bone. The two implant drill systems evaluated in this study were system A (a cylindrical drill with triple twist drills) (Bone System, Milano, Italy) and system B (a conical drill with quadruple twist drills) (Bone System). Site preparation began, and the temperature of the cortical bone and at the apical portion of the drill was measured by the infrared thermography. Results: The mean temperature produced in the cortical bone during implant preparation was 31.2 ± 0.5°C for the cylindrical drills and 29.1 ± 0.6°C for the conical drill. The mean temperature produced in the apical portion of the drill during implant site preparation was 32.1 ± 0.7°C for the cylindrical drill system and 29.6 ± 0.6°C for the conical drill. Statistically significant differences were found in the temperature measurements in the cortical bone in the two groups ( p < .05). A statistically significant difference was observed for the temperature measurements in the apical portion of the drill in the two groups ( p < .005). Discussion: The model system used in this work was able to evaluate the temperature in the cortical bone and in the apical portion of the drills; the temperature modifications in the apical portion of the drill seemed to be correlated to the drill geometry. The results of the present study showed that drill geometry seems to be an important factor in heat generation during implant site preparation. Conclusion: The drill geometry could explain the increased temperature in the apical portion of the drill. [ABSTRACT FROM AUTHOR]

Background: Rehabilitation of partially or totally edentulous posterior mandible with implant-supported prosthesis has become a common practice in the last few decades, with reliable long-term results. The use of miniscrews and miniplates have been reported to increase the risk of fracture of the osteotomy segments. The purpose of this case series was to use an inlay technique, without the use of miniscrews and miniplates for stabilization of the transported bone fragments. Materials and methods: Nine consecutive patients (six men and three women) aged between 26 and 51 years (mean 44 years) were enrolled in this study. A horizontal osteotomy was performed 2-3 mm above the mandibular canal, and two oblique cuts were made using a piezosurgery device. The final phase of the osteotomy was performed with chisels. The osteotomized segment was then raised in the coronal direction, sparing the lingual periosteum. Two miniblocks of xenograft without miniscrews and miniplates were inserted mesially and distally between the cranial osteotomized segment and the mandibular basal bone. The residual space was filled with particles of cortico-cancellous porcine bone. Four months after surgery, a panoramic X-ray was taken before implant insertion. A bone trephine with an internal diameter of 2 mm was used as the second dental drill to take a bone core biopsy during preparation of the #35 and #37 or #45 and #47 implant sites. Results: The postoperative course was uneventful in seven of the nine patients. No dehiscence of the mucosa was observed at the marginal ridge of the mobilized fragment. Newly formed bone was present near the osteotomized segments, and was observed in the bottom half of the specimens and was identified by its higher affinity toward the staining. Newly formed bone was observed to be in close contact with the particles of biomaterials. No gaps or connective tissue were present at the bone-biomaterial interface. Histomorphometry demonstrated that 44±2.1% of the specimens was composed by newly formed bone, 18±0.8% by marrow spaces, and 33±2.4% by the residual grafted biomaterial. Conclusion: The rigidity of the equine collagenated block allowed to eliminate the use of miniscrews and miniplates and simplified the technique. Moreover, the rigidity of the block allowed maintenance of the space. To cite this article: Scarano A, Carinci F, Assenza B, Piattelli M, Murmura G, Piattelli A. Vertical ridge augmentation of atrophic posterior mandible using an inlay technique with a xenograft without miniscrews and miniplates: case series. Clin. Oral Impl. Res. 22, 2011; 1125-1130 doi: 10.1111/j.1600-0501.2010.02083.x [ABSTRACT FROM AUTHOR]

Bone substitutes, such as allografts, xenografts, and alloplasts, have been proposed in several augmentation procedures. The aim of the present study was a histologic and histomorphometric evaluation of specimens retrieved 4 or 6 months after sinus augmentation using cortical porcine bone augmentation material. A total of 77 specimens, retrieved after 4 and 6 months from augmented sinuses, were used in this study. The specimens were processed to be observed under light microscopy. Histomorphometric measurements were presented as means ± standard deviations. Most of the particles were surrounded by newly formed bone with large osteocyte lacunae. Histomorphometry showed that, after 4 months, the newly formed bone represented 28%, marrow spaces 36%, the residual graft material 37%, while, after 6 months, the newly formed bone represented 31%, marrow spaces 34%, while the residual graft material was 37%. The present results show that cortical porcine bone is a biocompatible, osteoconductive biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that simultaneous elevation of the sinus mucosal lining and placement of dental implants without graft materials can be a predictable procedure. Nevertheless, few prospective, controlled, and randomized studies have evaluated this technique. The aim of this prospective, controlled, and randomized clinical study is to evaluate whether sinus membrane elevation and simultaneous placement of dental implants without autogenous bone graft can create sufficient bone support to allow implant success 6 months post-surgically. Methods: Sinus membrane elevation and simultaneous placement of dental implants were performed bilaterally in 15 patients in a split-mouth design. The sinuses were assigned to two groups: the test group, with simultaneous sinus mucosal lining elevation and placement of dental implants without graft materials; and the control group, with simultaneous sinus mucosal lining elevation and placement of dental implants with intraoral autogenous bone graft. After 6 months of healing, abutments were connected. For each implant, length of implant protrusion into the sinus, resonance frequency analysis, and bone gain were recorded at baseline and 6 months follow-up. Results: Clinical complications were not observed, except for two postoperative fistulas and suppuration in both groups. Only one implant of the test group was lost, reaching a success rate of 96.4% and 100% for the test and control groups, respectively. After healing, radiographic new peri-implant bone was observed in both groups ranging between 8.3 ± 2.6 and 7.9 ± 3.6 mm for the control and test groups, respectively (P>0.05). Resonance frequency analysis values were lower for the control group compared to baseline (P <0.05). However, these values were similar at 6 months (P>0.05). A significant positive correlation was found between the protruded implant length/ bone gain and implant survival/sinusitis (P <0.0001). Conclusion: Implants placed simultaneously to sinus membrane elevation without graft material resulted in bone formation over a period of 6 months. J Periodontol 2011;82:403-412. [ABSTRACT FROM AUTHOR]

Background: Little is known about the mechanisms of bacterial interaction with implant materials in the oral cavity. Other surface characteristics, in addition to surface roughness, seem to be extremely important in relation to plaque formation. Different adhesion affinities of bacteria were reported for different materials. Anatase is a nanoparticle that can be applied to titanium surfaces as a coating. The anatase coating gives special characteristics to the implant surface, including some genetic effects on osteoblasts. In this study, the antibacterial effect of anatase is investigated. The aim of this study is to characterize the percentages of surfaces covered by bacteria on commercially pure (cp) titanium and anatase-coated healing screws. Methods: Ten patients participated in this study. The protocol of the study was approved by the ethics committee of the University of Chieti-Pescara. A total of 20 healing screws (10 test and 10 control screws) were used in the study. The control screws were made of cp titanium, whereas the test screws were coated with anatase. Cleaning procedures and agents for chemical plaque control were not applied to the healing screws for the complete duration of the test period. After 7 days, all healing screws were removed, substituted, and processed under scanning electron microscopy for evaluation of the portions of the surfaces covered by bacteria. Results: The supracrestal screw surfaces covered by bacteria on test specimens were not significantly lower than those of control screws (P = 0.174). The subcrestal screw surfaces and threads covered by bacteria on test specimens were significantly lower than those of control screws, and P values were 0.001 and 0.000, respectively. Conclusion: Results show that anatase could be a suitable material for coating implant abutments, with a low colonization potential. [ABSTRACT FROM AUTHOR]

Background: Novel implant surface treatments with a nanothickness bioactive ceramic deposition onto rough surfaces have been recently introduced. This study aims to evaluate histologically and histomorphometrically (bone-to-implant contact [BIC] and bone area fraction occupancy [BAFO]) the early bone response to plasma-sprayed calcium--phosphate (PSCaP)-coated versus a 300- to 500-nm thickness bioactive ceramic nano-coated plateau root form implants in a rabbit femur model. Methods: A total of 48 plateau root form implants were bilaterally placed in the distal aspect of the femur of 12 white New Zealand rabbits, remaining for 20, 30, and 60 days in vivo (n = 4 animals per time in vivo, n = 2 implants per surface per animal). After sacrifice, the implants in bone were non-decalcified processed to slides of approximately 30 µm thickness, and were morphologically and morphometrically (BIC and BAFO) evaluated. Results: Higher degrees of bone structural organization were temporally observed for the PSCaP surface compared to the nano surface over time. BIC and BAFO was significantly higher (P<0.05) for PSCaP at all implantation times evaluated. Conclusions: Within the limits of this study it is possible to state that bioactive ceramic coatings of both thicknesses were biocompatible and osteoconductive. However, the early bone response was favored by the presence of the thicker PSCaP coating. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate clinically, histologically, and ultrastructurally the integration process of the acellular dermal matrix used to increase the hand of keratinized tissue while achieving gingival inflammation control. Methods: Ten patients exhibiting a mucogingival problem with bands of keratinized tissue ≤ 1 mm and gingival inflammation of the related teeth were included in the study. The surgical procedures were performed to augment the gingival tissue using acellular dermal matrix. Clinical measurements were assessed at baseline and after 3 months. A specimen of the allograft and surrounding tissues was obtained immediately before the surgery and 4 minutes and 1, 2, 3, 4, 6, and 10 weeks after grafting. Results: Clinically, a gain of keratinized tissue of 2.92 ± 0.65 mm was observed after 3 months. Histologically and ultrastructurally, many macrophages were observed phagocytosing preexisting collagen fibers in the first weeks. From week 2 on, fibroblasts synthesizing new collagen, epithelial cells colonizing the graft surface, and revascularization were noticed. After 6 weeks it was difficult to find the acellular dermal matrix preexisting collagen fibers. This process of substitution was completed after 10 weeks, when the reepithelialization of the entire graft throughout a well-structured basement membrane was achieved. Conclusion: The acellular dermal matrix graft seemed to be an easily handled material for use in keratinized tissue augmentation that, in humans, was substituted and completely reepithelialized in 10 weeks according to histologic and ultrastructural results. [ABSTRACT FROM AUTHOR]

Purpose: PerioGlas® (PG) is an alloplastic material that has been used for grafting periodontal osseous defects since the 1990s. In animal models, it has been proven that PG achieves histologically good repairs of surgically created defects. In clinical trials, PG is effective as an adjunct to conventional surgery in the treatment of intrabony defects; however, how PG alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microRNA (miRNA) microarray techniques to investigate the translation process in osteoblasts exposed to PG. Materials and Methods: By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we identified several miRNA whose expression was significantly modified in osteoblast-like cell lines (MG-63) cultured with PG. Results: There were ten up-regulated miRNA (mir-337, mir-377, mir-9, mir-516, mir-515-3p, mir-496, mir-200b, mir-489, mir-25, mir-423) and two down-regulated miRNA (mir-26a, mir-30d). Conclusion: PG acts on miRNAs, which in turn regulate several messengers. Among them there are mRNAs related to bone formation and skeletal and cartilage development. The vast majority of detected genes are down-regulated, and some are homeobox genes like NOG, EN1, and CHRD. Other down-regulated genes are receptors (like GHRHR) and extracellular matrix proteins (like COMP). Although the exact mechanism of PG action on osteoblasts is still incompletely understood, these data demonstrate that PG has not only an osteoconductive effect, but also regulates bone formation. [ABSTRACT FROM AUTHOR]

Background: Immediate loading of dental implants is a successful treatment concept. The importance of healthy peri-implant soft tissues for the long term success of dental implants has been widely recognized. The aim of this study was to evaluate the peri-implant soft tissues around immediately loaded and submerged implants in monkeys. Methods; A total of 48 implants were inserted in six Macaca fascicularis monkeys. For 24 implants (test implants), the prosthetic abutments were inserted immediately, and a custom-made metal superstructure was cemented after 3 days; the other 24 implants were left unloaded (control implants). Block sections of bone segments containing the implants were retrieved 9 months after surgical placement. A histomorphometric measurement of sulcular epithelium (SE), junctional epithelium (JE), and connective tissue (CT) contact percentage of the soft tissues around test and control implants was carried out. Results: In some specimens, the peri-implant epithelium was very similar to a pocket epithelium, whereas in others it was possible to observe a n SE and a long junctional like epithelium with a moderate amount of inflammatory cells. The supracrestal peri-implant CT was dense and organized in collagen fibrous bundles in an annular pattern around the implant. No statistically significant differences were present in the dimensions of SE, JE, and CT in test and control implants (P >0.05). Conclusion: Immediate loading did not produce changes in the dimensions of the peri-implant soft tissues. [ABSTRACT FROM AUTHOR]

Background: MicroRNAs (miRNAs) are a class of small, functional, noncoding RNAs of 19 to 23 nucleotides which induce degradation of specific messenger RNAs (mRNAs), thus controlling the translational process (ie, synthesis of proteins from mRNAs). In addition, mRNAs regulate the promoter of specific miRNAs activating an autoregulatory feedback loop. Purpose: Titanium and zirconium dioxide ceramics (ZDCs) are used to make dental implants. Because the molecular mechanism by which ZDC and Ti act on osteoblasts is incompletely understood, we attempted to get more information by comparing the effect of ZDC and Ti on osteoblast miRNAs. Materials and Methods: By using miRNA microarray technique, we identified in osteoblast-like cell line (MG63) grown on grade 3 Ti and ZDC disks several miRNAs whose expression was modified. We collected mRNAs after 24 hours of cell culturing to better understand molecular events related to early bone healing around inserted implants. An mRNA microarray technique was then performed as a control. Results: There were six up- and four down-regulated miRNAs. Because every miRNA regulates hundreds of genes, we focused only on those related to bone formation. Among them, the most notable are BMP4 and 7, which are both up-regulated in osteoblasts cultured on Ti disks. Conclusion: The detected miRNAs differentially expressed in osteoblast-like cells grown on ZDC versus Ti act on a limited number of miRNAs and bone-related genes. The most notable are BMP4 and 7, which are more expressed in osteoblasts exposed to Ti surface. Consequently, we suggest that Ti surfaces could provide some advantages to immediate load implantology. [ABSTRACT FROM AUTHOR]

Titanium is the gold standard among materials used for prosthetic devices, because of its good mechanical and chemical properties. When exposed to oxygen, titanium becomes an oxide that is biocompatible and able to induce osseointegration. Three allotropic forms of titanium dioxide exist, that is brookite, rutile, and anatase. Anatase can be prepared as a colloidal suspension and then used to coat surfaces. Anatase coating (AC) can potentially have specific biological effects. Here we are testing the effect of AC on osteoblast‐like cells (MG63) by using microarray techniques to identify genes that are differently regulated in osteoblasts exposed to AC. By using DNA microarrays containing 20,000 genes, we identified in osteoblast‐like cell lines (MG‐63) cultured on AC, several genes whose expression was significantly up‐ or downregulated. They cover a broad range of functional activities: signaling transduction, immunity, cell cycle regulation, lysosomes composition and vesicular transport, cell adhesion, cytoskeleton and extracellular matrix components, proliferation, and apoptosis. The data reported constitute, to our knowledge, the first genetic portrait of AC effects. They can be relevant to a better understanding of the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [ABSTRACT FROM AUTHOR]

Background: After implant insertion and loading, crestal bone usually undergoes remodeling and resorption. If the horizontal relationship between the outer edge of the implant and a smaller-diameter component (‘platform switching’) is altered, there seems to be reduced crestal bone loss. Immediate loading allows immediate restoration of esthetics and function, reduces morbidity, and facilitates functional rehabilitation. Materials and methods: Three Morse cone connection implants were inserted in the right posterior mandible in a 29-year-old partially edentulous patient. The platform of the implant was inserted 2 mm below the level of the alveolar crest. After a 1-month loading period, the most distal mandibular implant was retrieved with a trephine bur for psychological reasons. Results: At low-power magnification, it was possible to see that bone was present 2 mm above the level of the implant shoulder. No resorption of the coronal bone was present. No infrabony pockets were present. At the level of the shoulder of the implant, it was possible to observe the presence of dense connective tissue with only a few scattered inflammatory cells. Newly formed bone was found in direct contact with the implant surface. The bone–implant contact percentage was 65.3±4.8%. Conclusions: Abutments smaller than the diameter of the implant body (platform switching) in combination with an absence of micromovement and microgap may protect the peri-implant soft and mineralized tissues, explaining the observed absence of bone resorption. Immediate loading did not interfere with bone formation and did not have adverse effects on osseointegration. [ABSTRACT FROM AUTHOR]

Calcium sulfate (CaS) is a highly biocompatible material and enhances bone formation in vivo. However, how CaS alters osteoblast activity to promote bone formation is incompletely understood. We therefore investigated the translation regulation in osteoblasts exposed to CaS by using microRNA microarray techniques. Transduction, transcription, and translation are the three levels of regulation of cell activity. Recently, a new type of translation regulation has been identified: RNA interference (RNAi). RNAi is a process in which microRNA, (miRNA), that is, noncoding RNAs of 19–23 nucleotides can induce sequence‐specific mRNA degradation and/or translational repression. The human genome encodes a few hundred miRNAs that can post‐transcriptionally repress thousands of genes. The miRNA oligonucleotide microarray provides a novel method of carrying out genome‐wide miRNA profiling in human samples. By using miRNA microarrays containing 329 probes designed from Human miRNA sequences, we identified in osteoblast‐like cells line (MG‐63) cultured with CaS (Surgiplaster, Classimplant, Roma, Italy) several miRNA whose expression is significantly modified. The data reported are, to our knowledge, the first study on translation regulation in osteoblasts exposed to CaS. They could be relevant to a better understanding of the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008 [ABSTRACT FROM AUTHOR]

Background: Little is known about the healing pattern and the osseointegration processes at the interface of implants placed into different grafting materials in man. Anorganic bovine bone (ABB) is a xenogenic material with a high biocompatibility and osteoconductivity. Methods: A 47-year-old patient underwent a monolateral sinus-augmentation procedure using 100% ABB. Two titanium dental implants were inserted at the same time as the grafting procedure. After 6 months, a fixed prosthetic restoration was placed. After a 5-year loading period, the distal implant fractured, and the implant was removed with a 5-mm trephine bur. Results: At low magnification, in the peri-implant bone in the grafted area, many particles of ABB were still present. Bone was always interposed between the ABB particles and the metal surface, and in no case were the graft particles in contact with the implant. No acute or chronic inflammatory cell infiltrate or foreign body reactions were present around the particles or at the bone-implant interface. The tissues around the implant were composed of 40% ± 2.4% bone, 12% ± 2.9% ABB particles, and 50% ± 62% marrow spaces. The percentage of bone-to-implant contact was 48.6% ± 3.7%. Conclusions: A high percentage (~50%) of direct contact between bone and implant, without the interposition of graft material particles, was present ABB had enabled implant integration to take place, which had remained stable for 5 years. [ABSTRACT FROM AUTHOR]

Background: Anorganic bone matrix (ABM) is reported to have osteoconductive properties. No inflammatory or adverse responses have been reported when this material is used in sinus augmentation procedures. ABM is said to be a bioabsorbable biomaterial, but histologic data seem to suggest that the resorption process is slow. Long-term histologic data in humans are lacking. The aim of this case report was to evaluate the bone response to ABM used in maxillary sinus augmentation and retrieved 14 years after surgery. Methods: Titanium dental implants were inserted in two sinuses augmented with ABM. The implants were osseointegrated and functioned well for 14 years. After this period of loading, the connecting screw of one of the implants inserted in the left maxilla broke, and it was necessary to remove the implant. A bone core of the augmented area was harvested separately during the implant removal. Results: A very high quantity of mature, compact bone and a small percentage of residual grafted bio-material were found. About 5% to 7% of the bone was undergoing remodeling. In most cases, residual ABM particles were surrounded by marrow spaces. In other areas, lamellar bone was found in tight contact with the particle surfaces. Histomorphometry showed that the mean amount of mature, compact bone was 71.0% ± 2.28%, the mean amount of ABM was 22.1% ± 3.18%, and the mean amount of marrow spaces was 11.2% ± 5.42%. Conclusions: ABM seemed to resorb very slowly; after 14 years, only a small quantity of residual grafted particles was present. ABM is an effective graft material for sinus augmentation procedures. Vital, mature bone was formed and maintained over a long period with no chronic inflammatory cell infiltrate, foreign body response, or other adverse effects [ABSTRACT FROM AUTHOR]

Background: Controversy over the long-term clinical effectiveness of hydroxyapatite (HA)-coated dental implants still persists, despite numerous clinical studies documenting high survival rates. Concerns about the degradation of the coating over the years have been raised; it has been speculated that resorption of the HA could produce a space between the implant and the bone with a resultant mechanical instability. Methods: Two HA coated implants were retrieved due to a fracture of the abutment screws after a loading period of 14 year's and were treated to obtain thin ground sections for histologic evaluation. Results: At low-power magnification, it was possible to observe that the HA coating was in contact with mature bone. No gaps or connective fibrous tissue was found at the implant-bone interface. No epithelial downgrowth was present. No acute or chronic inflammatory cell infiltrate was present at the implant-bone interface. No foreign body reaction was present in the peri-implant tissues. Some osteocytes were in direct contact with the coating For implant 1, the percentage of bone titanium contact was 25% ± 2.1%, and the percentage of bone HA contact was 35% ± 1 4% The total bone-implant contact was ∼60%. The HA coating appealed to he resorbed in 46% ± 3.2% of the implant perimeter especially in the coronal portions of the implant. For implant 2, the mean percentage of bone-HA contact was 13% + 1.8%, and the mean percentage of bone-titanium contact was 15% ± 2.3%. The total bone implant contact was ∼28%. The HA coating appeared to be resorbed for a mean of 68% ± 4.1 % of the implant perimeter, especially in the coronal portion of the implant. Conclusions: No acute or chronic inflammatory cell infiltrate was present in the peal-implant tissues. No signs of coating infection, fatigue, or failure were observed in two specimens. The HA coating may not be susceptible to degradation or dissolution under long term function. [ABSTRACT FROM AUTHOR]

Background: Placement of dental implants in the posterior maxilla has been associated with higher rates of failure that are due, in part, to the poor bone quality of this region. The purpose of the present study was the histologic and histomorphometric evaluation of the bone around a new implant surface treatment created by a deposition of nanometer sized calcium phosphate particles added to the dual acid-etched surface. Methods: One custom-made 2 x 10-ram site evaluation implant (SEI) with this novel treatment surface (test) and one SEI with the dual acid-etched surface without treatment (control) were placed in the posterior maxilla of 15 patients. All SEIs were retrieved after 2 months and evaluated under confocal laser scanning microscopy (CLSM) and by light microscopy for histomorphometric analysis of the bone implant contact (BIC). Results: Histologic observations in control SCIs showed formation of new bone around the implant surface; however. it was not always in direct contact with the entire perimeter of the threads. The mean BIC was 19% ± 14.2%. Test SEIs showed peri-implant bone tightly contacting the implant surface and better adapted to the threads. Three-dimensional re construction of sections obtained using CLSM showed the intimacy of the contact between bone and test SEI surface through the entire thickness of the specimens. The mean BIC was 32.2% ± 18.5%. Conclusions: After 2 months of healing, comparison of the BIC values showed a statistically significant greater mean BIC for test SEIs than for controls. The clinical implications of these results included shortening of the implant healing period and earlier loading protocols. J Periodontol 2007;78:209-218. [ABSTRACT FROM AUTHOR]

Background: The purpose of the present study was the histologic and ultrastructural evaluation of a biomaterial composed of cortical pig bone in the form of granules. Methods: After maxillary sinus augmentation using this biomaterial, 10 specimens were retrieved after 5 months in 10 patients using this biomaterial. The specimens were processed to be observed under light microscopy (LM) and trans mission electron microscopy (TEM) Histomorphometric measurements were presented by means ± standard deviations. Results: LM showed that most of the particles were surrounded by newly formed bone. In some areas, the osteoid matrix was present; however, mainly compact bone was present at the interface There was no evidence of an acute inflammatory infiltrate. The newly formed bone was 36% ± 2.8% and marrow spaces were 38% ± 1.6%, whereas residual grafted material was 31% ± 1.6%. Under TEM, all phases of bone formation (osteoid matrix, woven, and lamellar bone) were observed in proximity with the biomaterial particles. The bone biomaterial interface showed a close contact between the porcine bone particles and the surrounding bone that had mainly features of mature bone with numerous osteocytes. A lamina limitans was sometimes present at this interface. Conclusions; According to our knowledge, this is the first study presenting data on TEM of a porcine bone-derived biomaterial used in sinus augmentation procedures in humans. Our findings show that this is a biocompatible biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes. [ABSTRACT FROM AUTHOR]

Background: Primary stability has a relevant role in the long-term success of dental implants. A quantitative method for the measurement of implant stability has been introduced (resonance frequency analysis RFA]). Information about the significance of RFA measurements and about the relationship between RFA values and their association with implant osseointegration, success, or failure is important from a clinical point of view. Purpose: The aim of the present histological and histomorphometric study was to see if a correlation existed between the bone-implant contact (BIC) percentage of retrieved human implants and RFA values. Materials and Methods: Seven implants inserted in the posterior mandible, with a sandblasted and acid-etched surface and retrieved after a 6-month period, were evaluated in the present study. These seven implants had been retrieved for different causes. All these implants were submerged and were retrieved with a 5-mm trephine bur and immersed in 10% buffered formalin to be processed for histology. Results: A statistically significant correlation could be detected between implant stability quotient and BIC ( p=.016). Conclusions: Even if the relationship between bone structure and RFA is still not fully understood, in our study, a statistically significant correlation was found between RFA and BIC values. Further studies are needed to evaluate a correlation of RFA and BIC in human implants retrieved after a range of healing periods. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study in humans was to conduct a comparative immunohistochemical evaluation of vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS) expression, inflammatory infiltrate, proliferative activity expression, and microvessel density (MVD) in peri-implant soft tissues of titanium and zirconium oxide healing caps. Methods: Five patients, three men and two women (aged 30 to 66 years; mean: 49 years), participated in this study. All patients received dental implants that were 3.8 mm in diameter and 11 mm in length. All implants were left to heal in a non-submerged (single-stage) mode. Healing caps (3.8 mm in diameter and 3.0 mm in height) were inserted in all implants. Half of the implants were supplied with standard, prefabricated caps of commercially pure titanium, whereas the other half were provided with test zirconium oxide caps. After a 6-month healing period, a gingival biopsy was performed with a circular scalpel (5.5 mm in diameter) around the healing caps of both groups, without unscrewing or removing the healing caps. The dimensions of the gingival biopsies were 1.7 mm (5.5 - 3.8 mm) in thickness and 3 mm in height. Results: Statistically significant differences were found in the microvessel density between titanium and zirconium oxide healing caps and group Il (P ≤0.0001). Statistically significant differences were likewise found in the low and high intensities of NOS1, NOS3, and VEGF (P ≤0.0001). In conclusion, the high intensity of NOS1, NOS3, and VEGF were mostly expressed in the titanium group, whereas the low intensity of NOS1, NOS3, and VEGF were mostly expressed in the zirconium oxide group. Conclusions: In our specimens, the inflammatory infiltrate was mostly present in the titanium specimens. Their extension was much larger than that of the zirconium oxide specimens. Higher values of MVD were observed in the titanium specimens (29.l versus 15.8). In addition, a higher expression of VEGF intensity was observed in the peri-implant tissues of titanium healing caps, whereas predominantly lower expressions of VEGF intensity were noted around the zirconium oxide healing caps. The Ki-67 expression was higher in the titanium specimens. All these data revealed that the tissues a round titanium healing caps underwent a higher rate of inflammation-associated processes, most probably correlated to the higher inflammation processes observed in these tissues. A higher intensity expression of NOS1 and NOS3 was recorded in the tissues a round titanium, whereas, on the contrary, a lower intensity of expression was found in the tissues around zirconium oxide specimens. These latter data indicate that the higher expression of these two mediators could be correlated to the higher amount of bacteria present around the titanium samples. [ABSTRACT FROM AUTHOR]

Background: A subject of controversy in implant dentistry is what is the most appropriate material for sinus augmentation. Little is known about the healing pattern and the osseointegration processes al the interface of implants placed in different grafting materials in man. Bovine porous bone mineral (BPBM) is a xenogenic material similar to human cancellous bone with a high biocompatibility and osteoconductivity. Methods: A 50-year-otd patient presented a posterior left maxilla with an insufficient bone height for implant insertion. In January 1999, a sinus lifting procedure was performed and the left sinus was augmented with BPBM; in November 1999, three implants were inserted, and in July 2000 a fixed prosthetic restoration was positioned. In June 2003 the connecting screw of the middle implant fractured and it was decided to remove the implant using a 5 mm trephine bur. Results: All BPBM particles were surrounded by newly formed bone. No BPBM particle was in direct contact with the implant surface, and between the implant surface and the particles there was newly-formed bone. BPBM seemed to undergo a very slow resorption; the particles constituted 36% ± 3% of the peri-implant tissues. The bone-implant contact percentage was 72% ± 4%. Conclusions: In our specimens, we found an intimate, direct contact between bone and implant without an interposition of the graft, material particles. A very high bone-to-implant contact percentage was present. Our results show that the slow resorption of the graft particles did not jeopardize the osseointegration of the implant. [ABSTRACT FROM AUTHOR]

Background: Crestal bone loss has been shown to occur around dental implants. This crestal bone resorption may determine a more apical position of the gingival margin. A clear trend of increased bone loss with increased interimplant distance has been reported. Purpose: The aim of the present study was to evaluate, in the canine mandible, the crestal bone behavior around dental implants inserted with different interimplant distances. Materials and Methods: Sandblasted and acid-etched implants (Bone System, Milano, Italy) were placed in the mandibles of six beagle dogs. Each dog received 10 implants in the mandible (five in the right side and five in the left side). A total of 60 implants was used in this study. The implants were divided in four groups: group I, with a 2 mm interimplant distance; group II, with a 3 mm interimplant distance; group III, with a 4 mm interimplant distance; and group IV, with a 5 mm interimplant distance. The dogs were killed after 12 months. Results: No statistically significant differences were found in regard to vertical bone loss whereas on the contrary, statistically significant differences were found in regard to lateral bone loss (p = .0001). Statistically significant differences also were found in regard to vertical crestal bone loss (p = .0001). In fact vertical crestal bone loss decreased, from 1.98 mm in group I to 0.23 mm in group IV. Conclusions: The clinical significance of these data lies in the fact that the increased crestal bone loss results in an increase in the distance between the base of the contact points of the neighboring implants and the crest of bone, and this fact could determine whether the papilla is present or absent between two implants. [ABSTRACT FROM AUTHOR]

Background: Little is known about the mechanisms of bacterial interaction with implant materials in the oral cavity. A correlation between plaque accumulation and progressive bone loss around implants has been reported. Bacterial adhesion shows a direct positive correlation with surface roughness. Other surface characteristics also seem to be extremely important with regard to plaque formation. Different adhesion affinities of bacteria have been reported for different materials. The aim of this study was to characterize the percentage of surface covered by bacteria on commercially pure titanium and zirconium oxide disks. Methods: Ten patients participated in this study. A removable acrylic device was adapted to the molar-premolar region, and commercially pure titanium (control) and zirconium oxide (test) disks were glued to the buccal aspect of each device. The surface roughness of titanium and test specimens was similar. After 24 hours, all disks were removed and processed for scanning electron microscopy, for the evaluation of the portion of surface covered by bacteria. Results: In control specimens, the area covered by bacteria was 19.3% ± 2.9; in test specimens, the area was 12.1% ± 1.96. The disk surface covered by bacteria on test specimens was significantly lower than that of control specimens (P= 0.0001). Conclusion: Our results demonstrate that zirconium oxide may be a suitable material for manufacturing implant abutments with a low colonization potential. [ABSTRACT FROM AUTHOR]

In recent years, several investigations have demonstrated, in clinical and histologic studies, the practicality of the use of immediate loading in implant dentistry. Purpose: The aim of the present study was to analyze the periimplant responses to immediately loaded implants retrieved from two patients after a 6-month loading period. Materials and Methods: Three immediately loaded implants (two hydroxyapatite [HA] coated, one with a sandblasted surface) were retrieved from two patients after a 6-month loading period. The implants were treated to obtain thin ground sections. Results: Bone was present at the interface with all three implants. Bone-implant contact percentage was 80.6% ± 4.7. Bone was present also in the thread concavities found at a distance from preexisting bone and in those concavities that were at the interface with the supracrestal tissues or with wide marrow spaces. No gaps or fibrous tissues were present at the interface. No inflammatory infiltrate was present at the interface. The mean of the sulcus depth in all three implants was 0.9 ± 0.1 mm, the length of the junctional epithelium was 0.9 ± 0.05 mm, and the length of connective tissue contact was 1.1 ± 0.05 mm. Conclusions: Our results show that immediate loading of dental implants did not impede the formation of mineralized tissue at the interface, and it can probably be a viable alternative in implant dentistry. KEY WORDS: dental implants, histology, hydroxyapatite, immediate loading [ABSTRACT FROM AUTHOR]

Background: Several investigators have reported high survival rates for early or immediately loaded dental implants. Purpose: The aim of the present study was to analyze histologically the periimplant tissue reactions and the bone-titanium interface of clinically retrieved immediately loaded titanium implants. Materials and Methods: Eleven implants were inserted in the posterior jaw regions of six patients, serving as the most distal abutments of fixed provisional bridges and subjected to immediate occlusal loading. After a 10-month loading period, all 11 implants were retrieved with a trephine. Results: Mature bone was present at the interface of all implants. Some vertical bone loss was observed; this was more pronounced for cylindric implants. The bone-implant contact was approximately 60 to 65% for all implants. Conclusions: The results demonstrate that osseointegration of dental implants can occur during immediate loading. [ABSTRACT FROM AUTHOR]

Background: Titanium nitride (TiN) has been used in many fields as a coating of surgical instruments, with the purpose of creating materials more resistant to wear and corrosion and also reducing adhesion. Purpose: The aim of this study was to evaluate the biocompatibility of TiN-coated dental implants. Materials and Methods: Forty-five rats were used in this study. One hundred eighty 2 mm x 2 mm implants (P.H.I.®, San Vittore Olona, Milano, Italy) were used. The implants were divided into the following three groups: • Group 1 (n = 60): 30 machined and 30 machined coated with TiN • Group 2 (n = 60): 30 sandblasted and 30 sandblasted coated with TiN • Group 3 (n = 60): 30 titanium plasma sprayed, 30 titanium plasma sprayed and coated with TiN Four implants were placed in each rat, two implants coated with TiN on the right tibia and two uncoated implants on the left. The animals were killed after 5, 10, 20, 30, or 60 days. Another 18 implants were used for surface roughness analysis. Results: The present study showed that the healing around the TiN-coated implants was similar to that observed around the uncoated surfaces. Conclusions: TiN coating demonstrated a good biocompatibility, did not have untoward effects on the periimplant bone formation, and did not change the surface roughness values. [ABSTRACT FROM AUTHOR]

Background: Implant failures are rare but do occur. Mechanical factors are certainly important in implant failures; so are biologic, iatrogenic, and functional factors. Mobility is the cardinal sign of implant failure. Three major etiologic factors have been suggested for implant failures: infection, impaired healing, and overload. The aim of the present study was to histologically and histochemically evaluate the fibrous connective tissue found around failed dental implants removed due to mobility. Methods: In a 5-year period, 51 root-form implants were retrieved because of mobility and underwent histological examination. Thin ground sections were obtained from each implant. Results: Almost all implants had been inserted in posterior (premolar-molar) regions of both jaws. In all specimens, there was the presence of a 600 to 1,100 µm thick connective tissue between implants and surrounding bone. In every case, the surrounding bone was compact and highly mineralized, with well-structured Haversian canals and few areas of remodeling. No bacteria were found in the most coronal portion of the implants. A scarce inflammatory cell infiltrate was present in the connective tissue of some specimens. In about 10% of specimens, the epithelium tended to surround the perimeter of the implant. Conclusion: Our histological results are consistent with the hypothesis that late failures of osseointegrated implants can be caused by a combination of poor bone quality, mechanical trauma to bone, and overloading forces. [ABSTRACT FROM AUTHOR]

Background: It has been hypothesized that a certain width of the peri-implant mucosa is required to enable a proper epithelial-connective tissue attachment and, if this soft tissue dimension is not adequate, bone resorption will occur to ensure the establishment of attachment with an appropriate biological width. The reason for the accelerated bone loss around submerged 2-piece implants in the first year after the restoration is not known, but one possibility is that the gap between components plays a role in this process. Recent studies have shown that for all 2-part implants, the bone crest level charges appeared dependent on the location of the microgap. Methods: The aim of the present study was a retrospective histologic evaluation in monkeys of the bone response to implants inserted 1 to 2 mm above the alveolar crest (group 1, 15 implants), at the level of the alveolar crest (group 2, 12 implants), or 1 to 1.5 mm below the alveolar crest (group 3, 13 implants). These implants had been early loaded, immediately loaded, and inserted immediately postextraction. Results: In group 1, a 0.13 ± 0.12 mm bone increase in a coronal direction was seen. In group 2, a 2.1 ± 0.29 mm vertical bone loss was present. In group 3, a mean 3.6 ± 0.46 mm vertical bone loss extending in an apical direction was observed. Statistically significant differences were observed between all 3 groups. Conclusions: Our results confirm data published previously that if the microgap was moved coronally away from the alveolar crest, less bone loss would occur and if the microgap was moved apical to the alveolar crest, greater amounts of bone resorption were present. This remodeling is not dependent on early and immediate loading of the implants or on immediate postextraction insertion. [ABSTRACT FROM AUTHOR]

Background: The purpose of this investigation was to determine the influence of the surface structure of dental implants on epithelial cell spreading and growth in vitro. Cell morphology on machined and sandblasted titanium surfaces was investigated. Methods: A total of 10 machined and 10 sandblasted discs and 10 glass coverslips were used for the present study. Samples were analyzed using scanning electron microscopy (SEM) and the cell spreading area was determined using d video image analysis system. Results: After 24 hours incubation, keratinocytes grown on sandblasted titanium samples displayed numerous, long, and branched or dendritic filopodia closely adapted to the surface roughness. Filopodia varied from 3 to 12 µm in length and 0.1 to 0.3 µm in width. Cells cultured on a machined surface did not present such cytoplasmic extensions and displayed a round morphology. Keratinocytes seeded on glass coverslips were flat and edged by filopodia {maximum length 7 to 8 µm) on the spreading site of the cluster. Though cell morphology is comparable with that observed on sandblasted specimens, cytoplasmic extensions suggestive of strong adhesion and spreading attitude were less pronounced. Conclusion: These results indicate that sandblasted surfaces are the optimal substrata for epithelial cell adhesion and spreading. [ABSTRACT FROM AUTHOR]

Background: Early implantation may preserve the alveolar anatomy, and the placement of a fixture in a fresh extraction socket helps to maintain the bony crest. Although a number of clinical studies exist, no histological reports show the outcome of implantation in fresh extraction sockets without the use of membranes in humans compared to implants placed in mature bone. Methods: Forty-eight healthy patients, receiving at least 4 fixtures in each of 2 symmetrical quadrants, underwent placement of 1 experimental fixture placed in a fresh extraction socket (TI) and 1 contralateral fixture in mature bone (CI). TI were placed after atraumatical tooth extraction, with a surgical site at the apex of the socket and a tight contact between the fixture and the socket's walls, but without the use of filling materials or membranes. The flap was coronally repositioned to obtain primary wound closure. Immediately after surgical intervention, a standardized periapical radiograph was taken. Second-stage surgery was done after 6 months. Six months after the second surgery, a second standardized periapical radiograph was taken and clinical parameters (bleeding and plaque index) recorded. Marginal bone loss (MBL) from the time of implant placement to the time of fixture removal was calculated by comparing periapical radiographs. TI and CI were then removed by a hollow drill to obtain histological specimens. Non-demineralized sections were stained by acid fuchsin and toluidine blue, and by von Kossa to evaluate the degree of bone mineralization. The percentage of direct implant-bone contact (DBC) was calculated by a computerized microscopic digitizer. Results: No significant differences in the clinical and radiographic parameters were observed between the 2 experimental categories. There was no statistically significant difference between TI and CI for DBC either in the maxilla or in the mandible. No connective or fibrous tissues were present around TI or CI. Bone resorption was not present in any of the histological sections. Conclusions: The present study shows that when a screw-type dental implant is placed without the use of barrier membranes or other regenerative materials into a fresh extraction socket with a bone-to-implant gap of 2 mm or less, the clinical outcome and degree of osteointegration does not differ from implants placed in healed, mature bone. [ABSTRACT FROM AUTHOR]

Background: It has been recently observed that in implants with screw-retained abutments, in in vitro as well as in vivo conditions, bacteria can penetrate inside the internal cavity of the implant as a consequence of leakage at the implant-abutment interface An alternative to screw-retained abutments is represented by implants that can receive cemented abutments. In this case, the abutment goes through a transmucosal friction implant extension (collar) and is cemented inside the internal hexagonal portion of the implant. The aim of the present research was to compare fluids and bacteria] penetration in 2 different implant systems, one with cement-retained abutment; (CRA) and the other with screw-retained abutments (SRA). Methods: Twelve CRA dental implants and 12 SRA implants were used in this study. The research was done in 3 steps; scanning electron microscopic (SEM) analysis, fluid penetration analysis, and bacterial penetration analysis. Results: 1) Under SEM it was possible to observe in the SRA implants a mean 2 to 7 µ gap between implant and abutment, while in the CRA implants, the gap was 7 µ. In the latter group, however, the gap was always completely filled by the fixation cement. All the spaces between abutment and implant were filled by the cement. 2) With SRA implants, it was possible to observe the presence of toluidine blue at the level of the fixture-abutment interface and the internal threads; the absorbent paper was stained in all cases. With CRA implants, the absorbent paper inside the hollow portion of the implants was never stained by toluidine blue. No penetration of toluidine blue was observed at the implant-abutment interface and inside the hollow portion of the implants. 3) In all the SRA implant assemblies, bacterial penetration was observed at the implant-abutment interface. No bacteria were detected in the hollow portion of the CRA implants. Conclusion: On the basis of the results obtained in the present study using 2 different implant systems, we conclude that CRA implants offer better results relating to fluid and bacterial permeability compared to SRA implants. [ABSTRACT FROM AUTHOR]

Bone neogenesis was studied in membrane-protected defects in a rabbit calvaria defect model using neutral, negatively, and positively charged titanium-reinforced GTAM membranes. Two standardized circular 8 mm wide and 1 mm deep defects were created in the calvaria of 36 rabbits leaving the inner cortex intact. The defects were subsequently covered with dome-shaped Ti-reinforced GTAM membranes stabilized with a titanium screw allowing the edges of the membranes to be closely approximated to the bone surface. The animals were divided into 6 groups of 6 rabbits each and were sacrificed at 5 days (Group l), 10 days (Group 2), 3 weeks (Group 3), 5 weeks (Group 4), 10 weeks (Group 5), and 20 weeks (Group 6). The distribution of the 72 membranes according to charge yielded 4 positively charged, 4 negatively charged and 4 neutral domes in each group. Histomorphometric analysis showed a more rapid and increased bone neogenesis with the negatively charged domes. A mean total area of 27.95% of newly-formed bone was observed in the negatively charged membrane sites at 10 days while negligible bone formation occurred with the neutral and positively charged domes at the same evaluation interval. Over time, negatively charged membranes supported more new-bone formation than neutral membranes while positively charged membranes showed the least new bone. This work demonstrates that negative electrical stimulation accelerates and maintains bone neogenesis. These results also suggest the potential applications of negatively charged GTAM membranes in clinical settings. [ABSTRACT FROM AUTHOR]

Purpose: PerioGlas (PG) is an alloplastic material that has been used for grafting periodontal osseous defects since the 1990s. In animal models, it has been proven that PG achieves histologically good repairs of surgically created defects. In clinical trials, PG is effective as an adjunct to conventional surgery in the treatment of intrabony defects; however, how PG alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microRNA (miRNA) microarray techniques to investigate the translation process in osteoblasts exposed to PG., Materials and Methods: By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we identified several miRNA whose expression was significantly modified in osteoblast-like cell lines (MG-63) cultured with PG., Results: There were ten up-regulated miRNA (mir-337, mir-377, mir-9, mir-516, mir-515-3p, mir-496, mir-200b, mir-489, mir-25, mir-423) and two down-regulated miRNA (mir-26a, mir-30d)., Conclusion: PG acts on miRNAs, which in turn regulate several messengers. Among them there are mRNAs related to bone formation and skeletal and cartilage development. The vast majority of detected genes are down-regulated, and some are homeobox genes like NOG, EN1, and CHRD. Other down-regulated genes are receptors (like GHRHR) and extracellular matrix proteins (like COMP). Although the exact mechanism of PG action on osteoblasts is still incompletely understood, these data demonstrate that PG has not only an osteoconductive effect, but also regulates bone formation.