Regular Healing Research Articles

Gelatin-based biomaterials and gelatin as an additive for chronic wound repair.

Disturbing or disrupting the regular healing process of a skin wound may result in its progression to a chronic state. Chronic wounds often lead to increased infection because of their long healing time, malnutrition, and insufficient oxygen flow, subsequently affecting wound progression. Gelatin-the main structure of natural collagen-is widely used in biomedical fields because of its low cost, wide availability, biocompatibility, and degradability. However, gelatin may exhibit diverse tailored physical properties and poor antibacterial activity. Research on gelatin-based biomaterials has identified the challenges of improving gelatin's poor antibacterial properties and low mechanical properties. In chronic wounds, gelatin-based biomaterials can promote wound hemostasis, enhance peri-wound antibacterial and anti-inflammatory properties, and promote vascular and epithelial cell regeneration. In this article, we first introduce the natural process of wound healing. Second, we present the role of gelatin-based biomaterials and gelatin as an additive in wound healing. Finally, we present the future implications of gelatin-based biomaterials.

Sustainable whey proteins-nanostructured zinc oxide-based films for the treatment of chronic wounds: New insights from biopharmaceutical studies

Chronic wounds represent silent epidemic affecting a large portion of the world population, especially the elders; in this context, the development of advanced bioactive dressings is imperative to accelerate wound healing process, while contrasting or preventing infections. The aim of the present work was to provide a deep characterization of the functional and biopharmaceutical properties of a sustainable thin and flexible films, composed of whey proteins alone (WPI) and added with nanostructured zinc oxide (WPZ) and intended for the management of chronic wounds. The potential of whey proteins-based films as wound dressings has been confirmed by their wettability, hydration properties, elastic behavior upon hydration, biodegradation propensity and, when added with nanostructured zinc oxide, antibacterial efficacy against both Gram-positive and Gram-negative pathogens, i.e. Staphylococcus aureus and Escherichia coli. In-vitro experiments, performed on normal human dermal fibroblasts, confirmed film cytocompatibility, also revealing the possible role of Zn2+ ions in promoting fibroblast proliferation. Finally, in-vivo studies on rat model confirmed film suitability to act as wound dressing, since able to ensure a regular healing process while providing effective protection from infections. In particular, both films WPI and WPZ are responsible for the formation in the wound bed of a continuous collagen layer similar to that of healthy skin.

Influence on marginal bone levels at implants equipped with blades aiming to control the lateral pressure on the cortical bone. An experimental study in dogs.

To avoid cortical compression, several implant systems have included in the protocol dedicated drills aimed at widening the cortical region of osteotomy. However, the manual execution of this operation does not guarantee the necessary precision. Hence, the present study aimed to determine the optimal size of the recipient site at the level of the alveolar crest in relation to the size of the coronal region of the implant to achieve the best healing result. Blades of different diameters were incorporated into the coronal part of the implant to prepare the cortical region of the mandibular alveolar bone crest in different dimensions in relation to the collar of the implant. The differences in diameter of the blades in relation to the collar of the implant were as follows: one control group, -175μm, and three test groups, 0μm, + 50μm, or + 200μm. The marginal bone loss (MBL) at the buccal aspect was 0.7mm, 0.5mm, 0.2mm, and 0.7mm in the - 175μm, 0.0μm, + 50μm, + 200μm groups, respectively. The differences were statistically significant between group + 50μm and control group - 175μm (p = 0.019), and between + 50μm and + 200μm (p < 0.01) groups. The level of osseointegration at the buccal aspect was more coronally located in the test groups than in the control group, whereas the bone-to-implant contact percentage was higher in the + 50μm and + 200μm groups. However, these differences were not statistically significant. The lowest bone crest resorption and highest levels of osseointegration were observed in the 0.0μm and + 50μm groups. The cortical region where the blades had performed their cutting action showed regular healing with perfect hard and soft tissues sealing in all the groups. Cortical blades gathered bone particles, particularly in the + 200μm group, which were incorporated into the newly formed bone. The results from the present experiment provide support to the use of blades that produce a marginal gap of 50μm after implant insertion.

An unusual case of incomplete healing with intraosseous fibrous scar formation in the surgically enucleated site associated with a Type II dens invaginatus: A 4-year follow-up case report

Dens invaginatus is a developmental deformation with varying anatomical features, caused by the envelopment of the enamel organ and/or the Hertwig’s epithelial root sheath within the tooth before calcification completes, increasing the vulnerability of pulpal and periodontal inflammation, posing challenges to treatment, and adequate healing. Cell rest of Malassez, remnants of enamel organ or root sheet may cause cystic lesion formations, also hinder the normal healing process and form a fibrous scar. Intraosseous fibrous scar is a result of incomplete wound healing after periradicular surgery which mimics an asymptomatic residual cyst clinically and radiographically. We herein report a case of a surgically managed an immature maxillary lateral incisor affected with Type II dens invaginatus associated with incomplete periradicular healing presented as intraosseous fibrous scar with a persistent well-defined radiolucency between the healthy trabecular bone. The regular clinical and radiographic follow-up records the asymptomatic endodontically treated dens invaginatus with an intact lamina dura and regular healing trabecular bone pattern. Its 4 years of post-operative evaluation has been presented. Features of this case, causes of such incomplete healing, diagnosis, treatment line, prognosis, and the dilemma of the clinician are discussed together with its probable implications.

Bone morphogenetic protein 2-induced cellular chemotaxis drives tissue patterning during critical-sized bone defect healing: an in silico study

Critical-sized bone defects are critical healing conditions that, if left untreated, often lead to non-unions. To reduce the risk, critical-sized bone defects are often treated with recombinant human BMP-2. Although enhanced bone tissue formation is observed when BMP-2 is administered locally to the defect, spatial and temporal distribution of callus tissue often differs from that found during regular bone healing or in defects treated differently. How this altered tissue patterning due to BMP-2 treatment is linked to mechano-biological principles at the cellular scale remains largely unknown. In this study, the mechano-biological regulation of BMP-2-treated critical-sized bone defect healing was investigated using a multiphysics multiscale in silico approach. Finite element and agent-based modeling techniques were combined to simulate healing within a critical-sized bone defect (5 mm) in a rat femur. Computer model predictions were compared to in vivo microCT data outcome of bone tissue patterning at 2, 4, and 6 weeks postoperation. In vivo, BMP-2 treatment led to complete healing through periosteal bone bridging already after 2 weeks postoperation. Computer model simulations showed that the BMP-2 specific tissue patterning can be explained by the migration of mesenchymal stromal cells to regions with a specific concentration of BMP-2 (chemotaxis). This study shows how computational modeling can help us to further understand the mechanisms behind treatment effects on compromised healing conditions as well as to optimize future treatment strategies.

The influence of new immediate tissue level abutment on crestal bone stability of subcrestally placed implants: A 1-year randomized controlled clinical trial.

The relation between implant abutment disconnection (AD) and increased crestal bone loss is still debated. To compare bone changes below implant-abutment junction of subcrestally placed implants between: (1) implant level restorations, that underwent four ADs and (2) implants with immediate tissue level abutment with no AD, 1 month (T2) and 1-year (T3) after final restoration delivery. Sixty-four patients received 64 bone level implants with platform-switching and conical connection in edentulous sites of posterior mandible and maxilla. All implants were placed 1.5 mm subcrestally and distributed among: (1) control group, that received a regular healing abutment and (2) test group with immediate tissue level (ITL) abutment, which was torqued to implants during surgery, transforming bone level implant to tissue level type. After 2-3 months of healing and a 1-month temporization, final zirconia-based screw-retained crowns were delivered to both groups. Crestal bone levels were calculated after final crown delivery (T2); after 1-year follow-up (T3) and compared using Mann-Whitney U test (p ≤ .05). Early bone loss of the test and control groups was 0.14 ± 0.27 mm and 0.64 ± 0.64 mm, respectively; the 0.5 mm difference was statistically significant (p = .0001). Late bone loss was 0.06 ± 0.16 mm and 0.21 ± 0.56 mm for the test and control group, respectively; the 0.15 mm difference between the groups was no more statistically significant (p = .22). Both groups displayed bone gain, 0.08 and 0.43 mm, respectively, and the overall crestal bone loss was reduced. Immediate tissue level abutments can significantly reduce early bone loss when measured 1 month after final prosthesis delivery, however, after 1-year follow-up, difference between the groups was no more statistically significant.

A bioactive nano-calcium phosphate paste for in-situ transfection of BMP-7 and VEGF-A in a rabbit critical-size bone defect: results of an in vivo study.

The aim of this study was to prepare an injectable DNA-loaded nano-calcium phosphate paste that is suitable as bioactive bone substitution material. For this we used the well-known potential of calcium phosphate in bone contact and supplemented it with DNA for the in-situ transfection of BMP-7 and VEGF-A in a critical-size bone defect. 24 New Zealand white rabbits were randomly divided into two groups: One group with BMP-7- and VEGF-A-encoding DNA on calcium phosphate nanoparticles and a control group with calcium phosphate nanoparticles only. The bone defect was created at the proximal medial tibia and filled with the DNA-loaded calcium phosphate paste. As control, a bone defect was filled with the calcium phosphate paste without DNA. The proximal tibia was investigated 2, 4 and 12 weeks after the operation. A histomorphological analysis of the dynamic bone parameters was carried out with the Osteomeasure system. The animals treated with the DNA-loaded calcium phosphate showed a statistically significantly increased bone volume per total volume after 4 weeks in comparison to the control group. Additionally, a statistically significant increase of the trabecular number and the number of osteoblasts per tissue area were observed. These results were confirmed by radiological analysis. The DNA-loaded bone paste led to a significantly faster healing of the critical-size bone defect in the rabbit model after 4 weeks. After 12 weeks, all defects had equally healed in both groups. No difference in the quality of the new bone was found. The injectable DNA-loaded calcium phosphate paste led to a faster and more sustained bone healing and induced an accelerated bone formation after 4 weeks. The material was well integrated into the bone defect and new bone was formed on its surface. The calcium phosphate paste without DNA led to a regular healing of the critical-size bone defect, but the healing was slower than the DNA-loaded paste. Thus, the in-situ transfection with BMP-7 and VEGF-A significantly improved the potential of calcium phosphate as pasty bone substitution material.

Intercondylar eminence fracture treated by resorbable magnesium screws osteosynthesis: A case series

IntroductionTibial spine avulsion fractures are mostly a paediatric injury which appropriate treatment is currently debated in literature. The choice between conservative and surgical treatment is based on the radiographic classification of Meyers-McKeever. The most diffused surgical techniques involve either internal fixation devices (screws) or bone tunnels fixation with resorbable sutures. Today, a third option is represented by resorbable magnesium screws which could combine the best features of the two classical systems. Objective of this study is to investigate the efficacy of these new devices in the surgical treatment of tibial spine avulsions. Materials and methodsSince 2014 we have seen seven patients with tibial eminence fracture. Patients underwent clinical and radiological examination (MRI, CT scan) before surgery. Only 3 patients that presented with a grade III or IV lesion were treated surgically with internal fixation with magnesium resorbable screws. In post-operative follow-up, functional recovery was evaluated at 1, 2, 4, 6 and 12 months, clinically and by X-ray. Lysholm and IKDC scores were submitted at 1, 2, 6 and 12 months. MRI was repeated at 6 and 12 months. ResultsAll three surgical patients showed progressive clinical and functional improvement during the follow-up period. The first case showed a quicker overall recovery rate, which might be due to the lower grade of the lesion. Radiographs and MRI evaluation showed regular healing of the injury. The devices appeared completely resorbed at the 6 months follow-up and replaced by newly formed bone at the 12 months follow-up. ConclusionsThe treatment of tibial spine avulsion fractures with arthroscopic reduction and internal fixation (ARIF) technique by magnesium resorbable screws seems to result in an excellent functional recovery without complications related to fixation devices, which were completely resorbed after 6 months and replaced by newly formed bone after 12 months. This new method could be considered as an alternative option to classic techniques by non resorbable fixation devices or bone tunnel fixation. Further studies are needed in order to evaluate the efficacy of these new devices in a wider group of patients.

Clinical study on implant survival and graft resorption rate after maxillary sinus bone grafting

Purpose: The Purpose of this study is to show the total survival rate of implants with maxillary sinus grafting and the effects that reach the survival rate by classifying types of graft materials, implant type, operation method, residual bone height and evaluate graft material resorption rate after sinus grafting Patients and Methods: 61 dental implants placed with sinus bone grafting in 24 patients at Wonkwang University Sanbon Dental Hospital were installed simultaneously or after regular healing. Various bone grafts (autograft, xenograft, allograft, alloplast) and fourth implant type (GSII, Xive, Implantium, Novel biocare) were used. All implants were investigated clinically and radiographically, being with average 20 months follow-up period after installation. Results: 3 fixtures were lost, resulting in 95.1% cumulative survival rate of 61 osseointegrated dental implant. Survival rate according to bone material type, Implant type, operation method, residual bone height, have no statistically significant differencies. The mean preoperative residual alveolar bone height was 4.75 mm, average postoperative height of graft materials 10.8 mm, vertical bone resorption rate was 10% after 2 years. Resorption rate according to operation method was 7% (simultaneous) and 5% (delayed) after 1 year. Conclusion: It can be suggested that maxillary sinus grafting may have predictable result with various bone graft materials and implant type, residual bone height, operation method

Centella asiatica (Centellicum®) facilitates the regular healing of surgical scars in subjects at high risk of keloids.

Formation of scars after surgical incisions requires the proper appositions of elements contributing to the scarring process. The structural rebuilding of damaged tissues is essential in producing a linear scar. The excess of blood, foreign particles, exuberant sutures, necrotic tissue, possible infective agents, as well as the ongoing inflammatory process may produce a non-linear, sometimes painful keloidal scar. Centella asiatica (CA) extracts have been used topically since ancient times for preventing keloids (i.e. after extensive burns) and for other applications including ulcer healing. The aim of this registry study was to evaluate the effect of supplementation with Centellicum® (Horphag Research Ltd.) on the healing of surgical wounds in subjects with previous hypertrophic or keloid scars, and to identify with ultrasound the collagen components of the scar in order to assess the quality (or linearity) of surgical wounds. Subjects with history of hypertrophic scars or keloid following previous surgery were included in this registry. Short term antibiotic prophylaxis was used as per surgical standards with cephalosporins for three days maximum after surgery. Only patients receiving abdominal or knee surgery were included. A total of 129 patients were included: 64 in the control group treated only with standard management, and 65 in the active treatment group where CA supplementation with Centellicum® was used at the dose of two 225 mg capsules/day from the 2nd to 6th week after surgery. A total of 64 scars were analyzed within the control group and 65 in the supplement group. The tolerability to Centellicum® was overall good, and no side effects were reported. Compliance to treatment was optimal, with >98% of the CA capsules correctly used. The ultrasound-assessed scar tissue regularity was on average lower in controls than in supplemented subjects (P<0.05). Scars also appeared to be significantly more homogeneous in CA patients than in controls. Supplementation with Centellicum® is safe and does not interfere with other concomitant treatments. It is well tolerated and compliance to treatment is optimal.

Long-Term Results of Excimer Laser Surface Ablation with Smoothing for High Myopia

Purpose: To evaluate long-term refractive, aberrometric and anatomical results of surface ablation plus corneal PTK-style smoothing for myopia greater than –7.00 D. Methods: One-hundred-and-fourteen eyes of 69 patients (mean age: 37.7 ± 8.3 years) underwent PRK with the NIDEK EC-5000 excimer laser (NIDEK Co. Ltd., Gamagori, Japan) using multiple optical zones ranging in diameter from 4.89 mm to 7.0 mm, and transition zones (TZ) that were at least 3 mm wider than the optical zones (OZ). A cross-cylinder technique was used for treating astigmatism greater than 0.50 D. All eyes underwent a phototherapeutic keratectomy (PTK) smoothing technique using masking fluid. The Student’s t-test was used to determine a statistically significant change after surgery. A p value less than 0.05 was considered statistically significant. Results: Preoperative corrected distance visual acuity (CDVA) was 0.88 ± 0.16 with –9.53 ± 1.18 D cycloplegic spherical equivalent (SE). Preoperative corneal pachymetry was 560.4 ± 30.1 µ. Three years after surgery uncorrected visual acuity (UCVA) was 0.79 ± 0.26, CDVA was 0.92 ± 0.19 with –0.56 ± 0.90 D SE. Mean corneal haze was highest 1 month after surgery (0.58 ± 0.35), then progressively decreased to 0.11 ± 0.32 by 3 months postoperatively. Following year one, refraction and corneal curvature remained stable. There were no cases of keractasia to date. There was no hyperopic induction due to PTK. Two eyes required retreatment due to undercorrection. Total wavefront error did not change significantly, while astigmatism decreased and coma increased (both with p&lt; 0.001). Conclusion: Surface ablation for the treatment of high myopia using PTK smoothing with a masking fluid was safe and effective. Wide optical and transition zones prevented induction of spherical aberration and the incorporation of the smoothing technique created a regular corneal surface with regular healing and trace to no haze after surgery.

Treatment of large irregular rabbit corneal penetrating injury with fibrin glue

Background Suture stitching is currently the standard treatment for corneal penetrating injuries.The shortcomings of suture stitching have led to the exploration of non-sutured surgical methods.Tissue adhesive is a promising non-suture replacement procedure. Objective This study was to observe the effect of fibrin glue on large irregular rabbit corneal penetrating injury. Methods Eighteen pure white healthy rabbits were randomly divided into suture group and adhesive group.A total length of 6-mm non-self-sealing corneal penetrating injury in non-pupillary-area of the right eye formed with a 15° corneal puncture knife was repaired with fibrin glue plus temporary suture and therapeutic corneal contact lens (9 eyes) or with 3 to 5 interrupted 10-0 nylon sutures (9 eyes) with the fellow eyes acted as the internal controls respectively.Operative time was compared between the two groups.Clinic observation was performed with slit lamp microscope.Animals were humanely sacrificed for histologic examination at week 1, 3, and 8 to evaluate wound healing. Results The average operation time was (3.48±0.48) minutes in the adhesive group, which was significantly lower than that in the suture group ([7.77 ± 1.30]minutes) (t=9.28, P<0.01). The postoperative slit lamp microscope observation indicated corneal wounds were quickly and regularly healed in the glued corneas compared with the stitched ones.The histologic examination revealed that glued corneas had regular healing, mild inflammation, and no corneal neovascularization, while sutured corneas showed irregular fibrin arrays, a large number of inflammatory cells and macrophages infiltration around the suture, heavy inflammatory response.Neovascularization was found at week 3 postoperatively. Conclusions Fibrin glue combined with temporary suture and therapeutic corneal contact lens is an effective treatment in sealing large irregular corneal wounds with considerable advantages over traditional sutures, including simplified operative technique, short surgery time, less postoperative irritation, mild inflammation, more regular wound healing, short healing time, and no corneal neovascularization. Key words: Fibrin glue; Suture; Full-thickness corneal penetrating injury; Disease model/animal; Corneal contact lens/therapeutic

Assessment of degradation and biocompatibility of electrodeposited chitosan and chitosan-carbon nanotube tubular implants.

Designing three-dimensional tubular materials made of chitosan is still a challenging task. Availability of such forms is highly desired by tissue engineering, especially peripheral nerve tissue engineering. Aiming at this problem, we use an electrodeposition phenomenon in order to obtain chitosan and chitosan-carbon nanotube hydrogel tubular implants. The in vitro biocompatibility of the fabricated structures is assessed using a mouse hippocampal cell line (mHippoE-18). As both implants do not induce significant cytotoxicity, they are next subjected to in vitro degradation studies in the environment simulating in vivo conditions for specified periods of time: 7, 14, and 28 days. The mass loss of implants indicates their stability at the tested time period; therefore, the materials are subcutaneously implanted in Sprague Dawley rats. The explants are collected after 7, 14, and 28 days. The assessment of composition and changes in tissues surrounding the implanted materials is made in respect to surrounding tissue thickness as well as the number of blood vessels, macrophages, lymphocytes, and neutrophils. No symptoms of acute inflammation are noticed at any point in time. The observed regular healing process allows concluding that both chitosan and chitosan-carbon hydrogel tubular implants are biocompatible with high application potential in tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2701-2711, 2016.

English

Everyday Portland cement can be a critical product used in generation involving concrete floor. Even though manufacturing of OPC involves many disadvantages such as depletion involving garbage just like lime green natural stone plus the clay-based. Every single great deal of bare cement emits identical quantity of CARBON DIOXIDE. One alternative is actually Geopolymer that is an eco-friendly substance and sensible energy gain. The main substance in addition to structural characteristics linked to geopolymer resulting from travel lung burning ash in addition to slag are generally identified intended for the aftermaths linked to organic substance collection for your houses linked to geopolymer composites. Every one of the materials applied had been indicated with regard to real, chemical substance, morphological in addition to mineralogical qualities. The particular placing qualities of the geopolymer composite had been decided. Geopolymer mortar cubes are generally throw employing fly lung burning ash, soil granulated crank air conditioner slag (GGBS) seeing that binders having alkaline alternative The particular accessible codal conventions had been implemented to be able to throw in addition to test out the specimens. The particular movement feature of the mortar was decided within fresh talk about. The particular specimens had been tested with regard to compressive strength at unique ages. The particular growth regarding compressive strength of the prevents was analyzed to have the perfect mix. Based on the results, the feasibility regarding employing geopolymer mortar prohibit being a structural system was figured out. These resources employed for the analysis have been located ideal for generating geopolymer mortar. The results in the analysis expose the maximum toughness formulated within the mortar for your combined 80% GGBS as well as 20% Journey lung burning ash. It was located 33.59 N/mm2 at the age of 1 week for your fluid-to-binder ratio associated with 0.45. This geopolymer mortar builds up toughness at normal circumstances with no regular healing. This compressive toughness in the geopolymer mortar does raise while using the GGBS content material pertaining to different fluid in order to binder percentages

Biocompatibility of Modified Bionanocellulose and Porous Poly(ϵ-caprolactone) Biomaterials

Biocompatibility of modified bionanocellulose (BC) and porous poly(ϵ caprolactone) (PCL) were compared to UHMWPE. For all the materials lack of cytotoxic effect to mouse fibroblasts was observed in vitro. In vivo study, subcutaneous implantations in Wistar rats, lasted for seven, 14, and 30 days. Subsequently the composition of surrounding tissue and explants surface changes was evaluated. No symptoms of acute inflammation were observed. Surrounding tissue thickness, the number of granulocytes, lymphocytes, macrophages, and blood vessels differed in time and revealed regular healing process. It is concluded that investigated PCL and BC are the materials with superior biocompatibility with high application potential.

Das Parallelsägeblatt

For shortening osteotomy, two exactly parallel osteotomies are needed to assure a congruent adaption of the shortened bone after segment resection. This is required for regular bone healing. In addition, it is difficult to shorten a bone to a precise distance using an oblique segment resection. A mobile spacer between two saw blades keeps the distance of the blades exactly parallel during an osteotomy cut. The parallel saw blades from Synthes® are designed for 2, 2.5, 3, 4, and 5 mm shortening distances. Two types of blades are available (e.g., for transverse or oblique osteotomies) to assure precise shortening. Preoperatively, the desired type of osteotomy (transverse or oblique) and the shortening distance has to be determined. Then, the appropriate parallel saw blade is chosen, which is compatible to Synthes® Colibri with an oscillating saw attachment. During the osteotomy cut, the spacer should be kept as close to the bone as possible. Excessive force that may deform the blades should be avoided. Before manipulating the bone ends, it is important to determine that the bone is completely dissected by both saw blades to prevent fracturing of the corticalis with bony spurs. The shortening osteotomy is mainly fixated by plate osteosynthesis. For compression of the bone ends, the screws should be placed eccentrically in the plate holes. For an oblique osteotomy, an additional lag screw should be used.

Experimental blunt chest trauma impairs fracture healing in rats

In poly-traumatic patients a blunt chest trauma is an important trigger of the posttraumatic systemic inflammatory response. There is clinical evidence that fracture healing is delayed in such patients, however, experimental data are lacking. Therefore, we investigated the influence of a thoracic trauma on fracture healing in a rat model. Male Wistar rats received either a blunt chest trauma combined with a femur osteotomy or an isolated osteotomy. A more rigid or a more flexible external fixator was used for fracture stabilization to analyze whether the thoracic trauma influences regular healing and mechanically induced delayed bone healing differently. The blunt chest trauma induced a significant increase of IL-6 serum levels after 6 and 24 h, suggesting the induction of a systemic inflammation, whereas the isolated fracture had no effect. Under a more rigid fixation the thoracic trauma considerably impaired fracture healing after 35 days, reflected by a significantly reduced flexural rigidity (three-point-bending test), as well as a significantly diminished callus volume, moment of inertia, and relative bone surface (µCT analysis). In confirming the clinical evidence, this study reports for the first time that a blunt chest trauma considerably impaired bone healing, possibly via the interaction of the induced systemic inflammation with local inflammatory processes.

Effect of Dehiscences to the Bone Response of Implants With an Acid-Etched Surface: An Experimental Study in Miniature Pigs

Spontaneous early exposure of submerged implants during the healing phase as a factor for early crestal bone loss around the implants is still being controversially discussed. The aim of this study was to examine the potential impact of dehiscences on the osseointegration process of acid-etched dental implants with a shortened healing period in the maxilla. Five animals received a total of 15 titanium implants 8 weeks postextraction. Eight of these implants were placed in the maxilla to osseointegrate within a shortened healing period of 3 months, whereas the remaining implants were inserted in the lower jaw and served as controls with a regular healing time. Polyfluorochrome sequential labeling with xylenol orange, calcein green, and alizarin complexone was performed 2, 5, and 8 weeks after implant placement. After 12 weeks of unloaded and submerged healing, the animals were killed and the implants removed en bloc. After the processing of the undecalcified PMMA-embedded samples, thin ground sections (40-60 µm) were made. The histomorphometric determination of the bone-to-implant contact (BIC) was calculated using light microscopy. The peri-implant bone apposition rate and the direction of bone growth were determined with the fluorescence microscope. For statistical evaluation, the Mann-Whitney U test, Wilcoxon signed ranks test, and Friedman test were chosen. During the healing period, nonartificial dehiscences were observed at 9 implants. The average BIC was 54.19% (14.51%-68.97%). There were significantly lower BIC rates detected for the cervical part of the implants compared with the middle part. An influence of dehiscences on the osseointegration could not be proven. There were no significant differences between the BIC values of the upper and lower jaw. During the observation period from the third to the eighth week after implantation, the average new bone formation rate was 2.32 µm/d (1.76-2.82 µm/d). During this period, the amount of new bone growth decreased insignificantly. Based on the sequence of the polyfluorochrome labeling, an implantopetal (53.03%) as well as an implantofugal bone growth (46.97%) have been observed. It could be assumed that the acid-etched implants offered a prerequisite to osseointegrate under a shortened healing period. The observed dehiscences seemed not to have compromised the rate of osseointegration.

The retrospective study of survival rate of implants with maxillary sinus floor elevation

Purpose: The purpose of this study is to show the total survival rate of implants with maxillary sinus floor elevation and the effects that reach the survival rate by classifying types of graft materials, implant surface, operation method, bone height. Methods: In a total of 131 patients, 251 implants with sinus floor elevation were installed simultaneously or after regular healing. Various bone grafts (autograft, xonograft, allograft, alloplast) and implant surface (MTX-HA implant, chemical etching implant, Titanium oxide surface implant, resorbable blasting media implant, resorbable blast texturing implant, HA-coated implant) were used. All implants were investigated clinically and radiographically, being with 1 to 5 years follow-up period after installation. Results: The survival rate of 251 implants with maxillary sinus floor elevation was 94%. The types of implant, surface, graft material, bone height have no statistically signi-ficant differencies. Conclusions: It can be suggested that maxillary sinus floor elevation may have predictable result with various bone graft materials and implant surface. (J Korean Acad Periodontol 2009;39:293-301)

A cumulative survival rate of implants installed on posterior maxilla augmented using MBCP after 2 years of loading: A retrospective clinical study

Purpose: The purpose of this study was to evaluate 2 years cumulative survival rate of implants on augmented sinus area using MBCP, mixture of MBCP and ICB, and mixture of MBCP and autogenous bone by means of clinical and radiologic methods. Materials and Methods: In a total of 37 patients, 41 maxillary sinuses were augmented and 89 implant fixtures were installed simultaneously or after a regular healing period. The patients were divided in 3 groups: MBCP only, MBCP combined with ICB, MBCP combined with autogenous bone. After delivery of prosthesis, along 2 years of observation period, all implants were evaluated clinically and radiologically. And the results were as follows. Results: The results of this study were as follows. 1. A 2 year cumulative survival rate of implants placed with sinus augmentation procedure using MBCP was 97.75%. 2. Survival rate of implants using MBCP only was 97.62%, MBCP and ICB was 100%, MBCP and autogenous bone was 95%. There was no statistically significant difference between 3 groups. 3. Only 2 of 89 implants were lost before delivery of prosthesis, so it can be regarded as an early failure. And both were successfully restored by wider implants. Conclusion: It can be suggested that MBCP may have predictable result when used as a grafting material of sinus floor augmentation whether combined with other graft(ICB, autogenous bone) or not. And the diameter, length, location of implants did not have a significant effect on 2 year cumulative survival rate. (J Korean Acad Periodontol 2008;38:669-678)