International Poster Journal of Dentistry and Oral Medicine, 03/2011

Objectives: Comparison of the treatment outcomes after regenerative periodontal surgery using either an enamel matrix derivative (Emdogain®) or a synthetic bone graft (Ostim®) in wide intrabony defects. Method: Twenty-four patients with chronic periodontitis were recruited at a German university dental clinic. All patients showed intrabony defects of at least 4 mm depth and 2 mm width. Using a microsurgical technique a modified papilla preservation flap was prepared. After debridement, patients were randomly assigned to Emdogain group (test) or Ostim group (control). Assessments at baseline and after 6 months included bone sounding, attachment level, probing pocket depth, bleeding on probing, and recession. Early wound healing, adverse effects and patients perceptions were also recorded. Results: Both treatment modalities led to significant clinical improvements. Change in bone fill 6 months after surgery was 1.5mm (±1.3) in the test group and 1.5mm (±1.7) in the control group, respectively. A gain in clinical attachment of 2.1mm (±1.8) in the test group and 1.7mm (±2.1) in the control group was observed. A reduction in probing pocket depth of 3.2mm (±1.4) in the test group and 2.9mm (±1.8) in the control group was recorded. One week after surgery primary closure was maintained in 100% of both the test and control groups. No differences in patients' perceptions were found. Conclusion: In both treatment procedures (Emdogain® and Ostim®) regenerative periodontal surgery in deep 1- or 2-wall intrabony defects resulted in significant clinical improvement after 6 months compared to baseline. Further investigation is needed to identify factors influencing individual responses. Keywords: regenerative periodontal surgery, chronic periodontitis, intrabony defects, bone fill

Purpose: This study compared the shear bond strength (SBS) and strain energy release rate (G-value (J/m2) or interfacial toughness) testing methodologies for measuring the adhesion between porcelain and commercially pure titanium (CP Ti) with a chromium interlayer. Materials and Methods: Shear specimens consisting of porcelain discs (6 mm in diameter x 4 mm thickness) fired onto CP Ti plates grade II (10 mm x 10 mm x 1 mm). Strain energy release rate (G) specimens consisting of rectangular specimens of CP Ti plates grade II (8 mm x 30 mm x 1.5 mm) veneered by porcelain with the same dimensions as the CP Ti plates. The specimens in each test were divided into seven groups according to the electroplating treatment; Gr 1 (control without electroplating, n = 10); Gr 2 (5% w/v chromium nitrate solution for 30 minutes, n = 10); Gr 3 (5% w/v chromium nitrate solution for 60 minutes, n = 10); Gr 4 (5% w/v chromium nitrate solution for 120 minutes, n = 10); Gr 5 (10% w/v chromium nitrate solution for 30 minutes, n = 10); and Gr 6 (10% w/v chromium nitrate solution for 60 minutes, n = 10) and Gr 7 (10% w/v chromium nitrate solution for 120 minutes, n = 10). Each group was further equally divided into two subgroups according to the type of porcelain used. Two titanium-porcelains (Vita Titankeramik and Triceram) were applied to each subgroup (n = 5). The specimens were tested in shear and four point flexure in a universal testing machine. Failure types were examined by SEM. Data were analyzed using ANOVA and a Tukey\'s multiple comparison test. Results: The values obtained from the shear test were more scattered and poorly correlated. More reliable and reproducible results were obtained with the strain energy release rate test. SEM images showed that the chromium interlayer enhanced the adhesion between porcelain and titanium. Conclusion: Adhesion between porcelain and CP Ti can be improved by use of chromium interlayer prior to porcelain firing. Strain energy release rate is a more preferable test for quantifying adhesion than shear bond strength tests. Keywords: Adhesion, Shear bond strength, Strain energy release rate, Porcelain, Titanium, Chromium, Electroplating, Metal-ceramic

The identification of unknown dead bodies depends on scientific and on non-scientific methods. Scientific methods include molecular-genetic examination (DNA), fingerprints and dental documents. Scientific methods are only successful when ante- mortem material exsist to be compared with post-mortem evidence. Ante-mortem produced and stored DNA-profils are relative seldom and therefore useless for routine ckeck-up. Keywords: identification, forensic odontology, archives of armed forces

Retrospective follow-up of CAD/CAM Abutments Stock Abutments are a common therapeutic method in implant dentistry. The geometric form is round like the implant. Teeth have a natural geometry which is individual for every patient. The Atlantis® Abutments (Astra Tech GmbH, Elz) are individual Abutments, CAD-designed and CAM- fabricated. The VAD® (Virtual-Abutment-Design) reduces the nature tooth geometry to an individual Abutment. This leeds to an emergence profile which supports the gingiva like the lost tooth. It is possible to produce the Abutments in Zirconia, Titanium and in Titanium gold hue. Keywords: CAD/CAM abutments, emergence profile, individual abutments

A theoretical model was developed for the correlation between the applied amount of light and the depth of cure of composite resin. The hardening depths of different composite resins were determined by means of ISO 4049. The depth of cure increases nonlinear with rising dose of light and decreases with rising time of radiation. With duplication of exposure time a constant growth of depth of cure can be measured. The depth of cure can be described by the equation d = A+B (ln(D×k) / ln2), with A representing the depth of cure achieved with 10 J/cm² dose of light and B representing the increase of depth of cure in mm with duplication the dose of light. Clinical relevance: several thin layers require a shorter exposure time than one thick layer. We propose that the manufacturers publish the for their composite applicable constants A and B and calibrate the scales of the light curing units in J/cm². Keywords: composite, depth of cure, dose of light, layering technique

Removable implant-supported prosthesis should combine easy handling and hygiene, suitable fixation and aesthetic rehabilitation. Especially for elder and manually handicapped patients removable dentures are state of the art. There are different options of anchorage to attach removable overdentures to implants. Telescopic systems are established in conventional prosthetics for a long time. Alternatively to bars or balls telescopic retainers have advantages in implant dentistry concerning retention, maintenance, hygienic aspects, and in divergent implant angulations. Furthermore telescopic retainers enable an uncomplicated integration of implants and natural abutment teeth to support a removable prosthesis. The use of all ceramic abutments offers various advantages like good biocompatibility to peri-implant tissues and low plaque accumulation. Furthermore aesthetic outcome of ceramic abutments is often more attractive to many patients. Conventional telescopic abutments consist of two pieces from metal and ceramic often luted with a resulting gap. Contemporary computer-aided design/computer-assisted manufacturing-technologies allow milling of one-piece abutments from ZrO2 which can be torqued directly to the implant. The aim of this report was to present the application of all-ceramic CAD/CAM milled zirconia one-piece implant telescopic abutments in complex clinical situations. Furthermore options for the integration of natural abutment teeth were demonstrated. In one edentulous maxilla six implants were inserted on bone level. Another patient received four implants in the edentulous maxilla and one implant in the mandible in addition to three natural abutment teeth. Both patients were treated with telescopic anchored prosthesis. All telescopic one-piece implant abutments and the telescopic copings were milled in zirconia by a special CAD/CAM system. To achieve passive fit highly precise electroplated gold meso-structures were luted intraoral with a cobalt-chromium-molybdenum framework. One year follow-ups showed good clinical results. The presented clinical cases demonstrated the application of an alternative type of telescopic abutment from zirconia. The introduced one-piece and gap free telescopic abutment offers advantages compared to conventional two-piece implant abutments. Controlled clinical studies have to prove the success of this restorative option. Keywords: ceramic, zirconia, telescopic abutments, implant therapy outcomes, prosthetic aspects, Straumann CAD/CAM

With increasing popularity and the demand for the use of dental implants use of specialized technique for the preoperative planning of oral implant placement: cone beam computed tomography (CBCT) has been encouraged. This poster highlights the significance of CBCT (i-CAT®) in the planning of endosseous dental implants in a case with history of trauma. A case of anterior maxillary and mandibular trauma for which implants were decided upon as an esthetic replacement option is presented. Keywords: 3-D imaging, cone-beam computed tomography, dental implants, radiography, tomography, x-ray computed/instrumentation

The aim of this study was to investigate the potential for microbial contamination in the dental laboratory during dentures' processing. A total of 14 patients from the Department of Removable Prosthodontics of the Faculty of Dental Medicine in Bucharest participated in this study. 20 microbial samples were collected and 50 bacterial strains have been isolated. The species were aerobic bacterias and fungi. They were generally part of the normal oral flora and could cause different pathologies especially in immunocompromised patients. In conclusion, dentures tend to accumulate plaque and they become a reservoir for numerous microbial species, some of which may be responsible for a wide range of infections. A faulty manipulation in the dental office and in the laboratory of the removable dentures presents a risk of cross-contamination. Keywords: denture, cross-contamination, bacterial colonization

Collagen-based biomaterials are increasingly appreciated by specialists in dentistry. Although they enjoy remarkable attention, they are still under research and/or clinical trial. The purpose of the drug delivery systems (DDS) is the controlled release of drugs on the affected tissue. Several interdisciplinary fields as polymer science, pharmacy, chemistry, molecular biology and dentistry are involved in the development of such complex biomaterials. The aim of this paper is obtaining of DDS which has collagen (natural biomaterial with haemostatic properties) in form of gel or spongious (matrix) and as support and lidocainne (local anesthetics used to stop sending pain signals) as drug. Both gels and matrices were obtained from type I collagen with concentrations of 1.0, 1.2 and 1.4% and 0.1% lidocaine. These were characterized by FT-IR and water absorption. In vitro lidocaine release from collagen supports were performed by a sandwich device adapted to USP apparatus simulating physiological conditions. Clinical trial reveals in vivo a shorter coagulation, bleeding, healing time, and an decrease of postextraction pain. Keywords: collagen, gel, matrice, lidocaine

Case Report: Mesiodens in monozygotic male twins: Diagnosis and surgical therapy. Introduction: The incidence of supernumerary teeth reported in the literature is 0.15 - 3.9% and it is five times more common in permanent dentition teeth. Mesiodens is defined as a tooth additional to the normal dentition, commonly seen in the maxillary arch, centrally located between the roots of the upper incisors. The overall incidence is 0.15% - 1.9%, with the ratio men to women being 2:1. The aim of this case report is the presentation of diagnostic and surgical treatment of mesiodens, including etiological factors in monozygotic twins. Clinic: We report on two 10-year-old monozygotic male twins. Evaluation of the DVT in the upper jaw showed a rudimentary, inverted conical mesiodens centrally located between the root apices of teeth 11 and 21, cranially limited by a thin cortical lamina to the nasal floor. Radiographic imaging of the single maxillary anterior region of his twin brother also revealed a mesiodens in the same region. The DVT showed a varied location of the rudimentary, slightly enlarged, inverted and conical mesiodens in the same region, in mirror-symmetrical position relative to the median sagittal plane. Surgical removal of the mesiodens in both twins was performed under local anesthesia, using intrasulcular vestibular incision and minimally invasive osteotomy. Discussion: The occurrence of mesiodentes in twins is rare, only few case reports depicted in the literature can elucidate the etiology and a presumed genetic component. The absolute incidence of monozygotic twins is 3.5 - 4 per thousand pregnancies and is independent of maternal age or race and is similar in all populations. Regarding the etiologic background, a zygote that divides prior to lateral differentiation will produce identical monozygotic twins. The division of the blastocyst at a later stage can lead to increased levels of asymmetry. The different relationship of twins to each other within the membranes of the placenta has an impact on the respective axial asymmetries. The mirror image of unilateral mesiodentes occurring in twins has been described. An autosomal dominant disorder with incomplete penetrance genes may play a role in the increased incidence among first-degree relatives. Even small differences of epigenetic influences on tooth development may be responsible for differences in the expression in monozygotic twins. So far, several theories have been put forward for the formation of mesiodentes. These include the theories of atavism, the dichotomy / schizodontia, hyperactivity of the dental lamina, family history, asymptomatic autosomal dominant holoprosencephaly and environmental factors such as radiation, and the influence of exogenous epidermal growth factor and vitamin A. Supernumerary teeth may occur in isolation or in combination with syndrome disorders. Complications related to mesiodentes are eruption in the nasal cavity, retention and abnormal root development of permanent front teeth, crowding and development of diastema, as well as the emergence of follicular cyst or keratocystic odontogenic tumour, which may lead to root resorption and rotation of the adjacent teeth. Early diagnosis and treatment is required to avoid complications. Conclusion: In monozygotic twins with a positive family history of supernumerary tooth germs, a radiological examination of the twin sibling may reveal a similar condition. A DVT is helpful for three-dimensional diagnostics and surgical planning. DVT is an excellent tool for the surgical removal of the mesiodentes in terms of protecting adjacent structures and for deciding whether surgery should be performed before or after the commencement of the completed root development of permanent incisors. Keywords: mesiodens, monozygotic twins, digital volume tomography, surgical removal

The interleukin-4 receptor (IL-4R) can bind both, IL-4 and IL-13. Then T-cells were stimulated to differentiate to Th2-cells which promote B-cell proliferation and antibody production. The 1902 A/G polymorphism of the gene encoded for the α chain of the interleukin-4 receptor (IL-4RA) was found associated with enhanced IL-4 receptor activity. Therefore, the aim of this study was to evaluate putative associations of this polymorphism to generalized aggressive or chronic periodontitis and five periodontopathogens. Methods: 120 patients with severe generalized periodontitis (attachment loss >6mm in >35% of the teeth, chronic periodontitis: n=53, mean age=48.9±9.8 years; aggressive periodontitis: n=67, mean age=41±9.9 years) in comparison to periodontitis free controls (n=81, mean age=46.9±10.7 years). Interleukin-4RA polymorphism was analyzed by PCR-SSP (CTS-Kit, Heidelberg). Distributions of single alleles and genotypes were calculated by Chi²-Test with Yates correction or Fisher's exact test. Subgingival bacteria were analyzed molecular biologically using micro-Ident® test (HainLifescience, Nehren). Adjusted odds ratios were determined by logistic regression with respect to established cofactors for periodontitis such as age, gender, smoking status, and plaque index. Results: The mutant allele IL-4RA 1902 G (28.3% vs. 17%, p=0.041) and the mutant genotypes GA+GG (50.9% vs. 29.6%, p=0.021) occurred more frequently in patients with chronic periodontitis. The latter association could be confirmed by logistic regression analysis (OR=2.1, 95%CI 1.2-4.0, p=0.016). In the total study cohort the genotypes GA+GG were positive associated to the presence of T. forsythia (88.9% vs. 76.75%, p=0.045). This result remained significant after logistic regression (OR=1.5 95%CI 1.2-1.9, p= 0.001). Conclusions: The IL-4RA 1902 AG polymorphism is a putative risk indicator for generalized chronic periodontitis and the subgingival occurrence of T. fosythia. Keywords: IL-4 receptor alpha, polymorphism, chronic periodontitis, aggressive periodontitis

Background: The receptor of advanced glycation end products (RAGE) is mediating inflammatory processes e.g. involved in the occurrence of severe periodontitis via activation of transcription factor NF-B. Its expression is influenced by the c.-374T>A-SNP, located in the promoter region of this gene. The aim of this study was to evaluate links between this SNP and the occurrence of aggressive periodontitis. Patients and Methods: 81 patients with generalized aggressive periodontitis (mean age: 40.4+9.8y, 63% females) and 85 periodontitisfree controls (mean age: 46.7+10.8y, 54.1% females) were included in the study. The c.-374T>A-SNP was determined by RFLP using Tsp509I restriction endonuclease. Clinical parameters including smoking status, plaque and bleeding indexes, pocket depth and attachment loss were assessed. Subgingival bacterial colonization was evaluated molecularbiologically using the micro-Ident®test (Hain Diagnostik, Nehren). Results: Investigating genotype and allele frequencies of the c.-374T>a SNP, it could be shown that carrier of the AT+TT genotypes (pcorr.=0.003, OR=14.4, 95%CI: 1.84-113.2) as well as T-allele carriers (pcorr.=0.026, OR=1.8, 95%CI: 1.1-2.8) are at higher risk for aggressive periodontitis. In binary logistic regression analysis, the T-allel (OR=1.8, 95%CI: 1.07-2.97, p=0.026) could be proven as an independent risk factor for aggressive periodontitis considering age, gender, smoking, and clinical attachment loss as confounding factors. No genotype or allele dependent associations with clinical markers of periodontitis including the subgingival occurrence of periodontopathogens could be proven for this SNP. Conclusions: The results emphasize the role of the T-allele of RAGE-SNP c.-374T>A as a putative risk indicator for aggressive periodontitis in this German cohort irrespective of further periodontal risk factors. This finding could be possibly based on an impaired immune response due to the decreased promoter activity associated with the T-allele. Keywords: periodontitis, polymorhisms, RAGE-gene

Autogenous bone is considered to be the current gold standard for bone augmentation; however, only limited amounts of autogenous bone can be harvested at the implantation site. Furthermore this procedure may lead to morbidity problems. As an alternative, a commercially available synthetic bone graft substitute comprising porous biphasic calcium phosphate, in the form of granules, has been on the market since 2004. In this study we report long-term implant survival rate. Keywords: implant survival, bone augmentation, biphasic calcium phosphate

Adipose tissue (AT) and bone marrow (BM) are well known sources to recover multipotent mesenchymal stromal cells for tissue engineering and regeneration of bone. Therefore human adipose tissue (AT) and bone marrow (BM) were obtained from 4 patients, mesenchymal stromal cells (SC) were isolated and analysed (FACS, n=14). Both, ATSC and BMSC show the same marker-profile expression, characteristic for multipotent mesenchymal cells. Osteogenic differentiation was possible for both cell-lines in 2D and 3D-cell culture systems (RT-PCR analyses), while the effect was stronger in BMSC. Keywords: osteogenic differentiation, ATSC, BMSC

Ultrasonography has been a useful diagnostic tool in dentistry since its inception in 1960s. It is a process that uses the reflection of high-frequency (3 to 10MHz) sound waves to make an image of structures deep within the body. Ultrasound is produced by the vibration of a synthetic crystal that possesses piezoelectric properties. Ultrasound is generated when a rapidly alternating electrical potential causes the crystal to vibrate. When the burst meets an acoustic boundary part of the energy is reflected, this echo is detected by the transducer. By means of the reversed piezoelectric effect the reflected sound waves are transformed by the crystals in the transducer into an electrical signal. The amplitude of the electrical signal is proportional to the acoustic properties of the tissue interface. In the scan converter the amplified signal is converted into a digital signal enabling it to be easily processed and stored.The types of ultrasonography include A-mode ultrasonography, B-mode ultrasonography, Gray-scale ultrasonography, M-mode ultrasonography, Doppler ultrasonography, real time and endoscopic ultrasonography. Technological progress in sonography has made this noninvasive procedure with multiple operating modes the initial imaging technique of choice for the salivary glands and head & neck cancer. Owing to the superficial location of these glands, high-frequency ultrasound transducers provide markedly better spatial resolution than other imaging modalities. Ultrasound can also effectively guide and improve the safety of aspiration biopsy of inflammatory and tumoral lesions. Color doppler allows assessment of salivary gland function and accurate analysis of tumor vascularity. The vascular pattern and displacement of vascularity of the lymph nodes are also assessed using ultrasonography.Metastatic and lymphomatous nodes tend to have sharp borders, whereas reactive and normal nodes usually show unsharp borders. Also, serial change in size of malignant nodes is useful in monitoring patient's response to treatment. Normal, reactive, lymphomatous and tuberculous nodes are predominantly hypoechoic when compared with the adjacent muscles. In cellulitis, well defined hypoechoic septa between fat and connective tissue is seen[characteristic cobblestone appearance] In abscess, anechoic to hyperechoic areas due to sediment, septa or gas may be seen. Ultrasonography is used in the assessment of Temporomandibular joint. Head of the condyle and the articular eminence, is generally hypoechoic ,the margin of the bone is hyperechoic. The joint capsule, retrodiscal tissue,lateral pterygoid and masseter muscles,are isoechoic and appear grey.More recently it has been useful in the diagnosis of fracture of teeth, measurement of enamel thickness and periodontal pocket depth and distraction osteogenesis. Thus ultrasonography is a non-ionizing, non-invasive and relatively inexpensive imaging modality which can be used effectively in maxillofacial imaging. Keywords: ultrasonography