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PURPOSE Soft tissue interactions with ceramic dental implants have previously been shown to have favorable esthetic outcomes. This study aimed to evaluate the papilla-crown proportion around zirconia implants in a 3-year follow-up study and the correlation between the gingival biotype and changes in papillary height. MATERIALS AND METHODS This was a prospective study of 39 patients with 40 single-gap implants (Straumann PURE Ceramic ZLA Implant). The papilla-crown proportion was assessed after 3 months, 1 year, and 3 years. In addition, correlations between the peri-implant biotypes and changes in papillary heights were evaluated. RESULTS The papilla-crown proportion improved from 35.5% after 3 months to 41.7% after 3 years. The gingival biotype was correlated very weakly to papilla height alterations. Significant papillary fill was observed in the interdental space between 3 months and 3 years (p < 0.001). CONCLUSIONS An ideal papilla-crown proportion of 40% around single implants was observed after 3 years. A thin or thick gingival biotype showed a very weak correlation with soft tissue alterations.

Compared to conventional techniques, Laser surgery procedures provide a number of advantages, but may be associated with an increased risk of iatrogenic damage to important anatomical structures. The type of tissue ablated in the focus spot is unknown. Laser-Induced Breakdown-Spectroscopy (LIBS) has the potential to gain information about the type of material that is being ablated by the laser beam. This may form the basis for tissue selective laser surgery. In the present study, 7 different porcine tissues (cortical and cancellous bone, nerve, mucosa, enamel, dentine and pulp) from 6 animals were analyzed for their qualitative and semiquantitative molecular composition using LIBS. The so gathered data was used to first differentiate between the soft- and hard-tissues using a Calcium-Carbon emission based classifier. The tissues were then further classified using emission-ratio based analysis, principal component analysis (PCA) and linear discriminant analysis (LDA). The relatively higher concentration of Calcium in the hard tissues allows for an accurate first differentiation of soft- and hard tissues (100% sensitivity and specificity). The ratio based statistical differentiation approach yields results in the range from 65% (enamel-dentine pair) to 100% (nerve-pulp, cancellous bone-dentine, cancellous bone-enamel pairs) sensitivity and specificity. Experimental LIBS measuring setup.

Background The purpose of this study was to evaluate risk factors that influence overall survival (OS)/disease-free survival (DFS)/locoregional recurrence-free survival (LRFS), and distant metastases-free survival (DMFS) in patients with high-risk primary salivary gland carcinoma who underwent surgery and postoperative (chemo)radiotherapy with curative intention. Methods We reviewed data of 63 patients with high-risk primary salivary gland carcinoma in a retrospective single-center audit. Results At a median follow-up of 31 months (range, 5–145 months), cumulative OS and DFS were 91.7%, 77.6%, and 62.9%, and 82.1%, 65.6%, and 57.7%, respectively, after 1, 2, and 5 years. LRFS and DMFS were 92%, 86%, and 86%, and 83.4%, 70.4%, and 62.3% after 1, 2, and 5 years, respectively. Of all patient-related, tumor-related, and treatment-related factors, high-grade histology (G3) was the only factor in univariate and multivariate analysis that was predictive for a shorter DMFS (low/intermediate vs high-grade: 100%, 100%, and 89.4% vs 72.9%, 54.3%, and 42.8% after 1, 2, and 5 years, respectively) and a shorter DFS (low/intermediate vs high-grade: 100%, 90%, and 84.4% vs 71.2%, 50.1%, and 39.4% after 1, 2, and 5 years, respectively) and OS (low/intermediate vs high-grade: 100%, 100%, and 86.5% vs 86.5%, 63.2%, and 46.5% after 1, 2, and 5 years, respectively). Conclusion High-grade tumor histology is a highly significant predictor of a shorter DMFS, OS, and DFS in salivary gland carcinoma, irrespective of histological subtype. © 2016 Wiley Periodicals, Inc. Head Neck, 2016

The aim of this study is to evaluate the effects of nanoporous anodic aluminum oxide (alumina) with pore diameters from 15 to 40 nm on osteoblasts (hFOB) and fibroblasts (HFF). After 7 days, a significantly higher proliferation of osteoblasts with a regular cell morphology is visible on the 40 nm samples compared to the 15 nm pore diameter (p = 0.003). Fibroblasts, on the other hand, have a significantly higher proliferation rate on the 15 nm pore diameter samples compared to the 40 nm samples (p = 0.000). The pore diameter of AAO affects fibroblasts and osteoblasts in opposite ways and makes it possible to cope in a perfect way with different requirements of cells on the implant surface.

Background. Prospective speech intelligibility assessments lack objectivity in patients undergoing surgery for oral squamous cell carcinoma (OSCC) of the tongue. Methods. Speech intelligibility was measured based on word recognition by means of an automatic and objective speech recognition system preoperatively, and 14 to 20 days, and 3 months, 6 months, and 12 months postoperatively. The study comprised 25 patients with OSCC of the tongue and a healthy control group (n=40). Results. Patients yielded significant speech impairments compared to the healthy control group both before surgery and after 12 months (p

Objectives Porcine collagen matrices are proclaimed being a sufficient alternative to autologous free gingival grafts (FGG) in terms of augmenting the keratinized mucosa. The collagen matrix Mucograft® (CM) already showed a comparable clinical performance in the early healing phase, similar histological appearance, and even a more natural appearance of augmented regions. Predictability for long-term stability does not yet exist due to missing studies reporting of a follow-up >6 months. Material and methods The study included 48 patients with atrophic edentulous or partially edentulous lower jaw situations that had undergone an implant treatment. In the context of implant exposure, a vestibuloplasty was either performed with two FGGs from the palate (n = 21 patients) or with the CM (n = 27 patients). Surgery time was recorded from the first incision to the last suture. Follow-up examinations were performed at the following time points: 10, 30, 90, and 180 days and 1, 2, 3, 4, and 5 years after surgery. The width of keratinized mucosa was measured at the buccal aspect of each implant, and augmented sites were evaluated in terms of their clinical appearances (texture and color). Results The groups showed similar healing with increased peri-implant keratinized mucosa after surgery (FGG: 13.06 mm ± 2.26 mm and CM: 12.96 mm ± 2.86 mm). The maximum follow-up was 5 years (5 patients per group). After 180 days, the width of keratinized mucosa had decreased to 67.08 ± 13.85% in the FGG group and 58.88 ± 14.62% in the CM group with no statistically significant difference. The total loss of the width of keratinized mucosa after 5 years was significant between the FGG (40.65%) and the CM group (52.89%). The CM group had significantly shorter operation times than the FGG group. Augmented soft tissues had a comparable clinical appearance to adjacent native gingiva in the CM group. FGGs could still be defined after 5 years. Conclusions The FGG and the CM are both suitable for the regeneration of the peri-implant keratinized mucosa with a sufficient long-term stability. With the CM, tissue harvesting procedures are invalid, surgery time can be reduced, and regenerated tissues have a more esthetic appearance.

Objectives The long-term outcome after sinus augmentation with autogenous bone or a bovine xenograft (Bio-Oss®) was assessed in 47 patients. Inclusion criterion was a vertical dimension of the maxilla of 0.05); both treatments are equivalent (confidence interval 90%) for the equivalence interval [−0.1; 0.1]. 43.5% of the cases showed no reduction in the augmentation height 5 years after implant insertion, when augmentation was performed with autogenous bone, while in the Bio-Oss® group, no resorption was found in 50% of the augmented areas. Up to 25% reduction in augmentation height was found in 47.8% in the autogenous and in 45.8% in the Bio-Oss® group. In 8.7% of all cases in the autogenous bone group and in 4.2 % in the Bio-Oss® group, up to 50% of the augmented height was resorbed. Conclusion After a 5 years evaluation period, Bio-Oss® as material for the indication maxillary sinus augmentation shows to be equivalent to autogenous bone grafting.

von Wilmowsky C, Stockmann P, Harsch I, Amann K, Metzler P, Lutz R, Moest T, Neukam FW, Schlegel KA: Diabetes mellitus negatively affects peri-implant bone formation in the diabetic domestic pig. J Clin Periodontol 2011; 38: 771–779. doi: 10.1111/j.1600-051X.2011.01746.x. Abstract Aim: Diabetes mellitus is classified as a relative contraindication for implant treatment, and higher failure rates have been seen in diabetic patients. The aim of the present study was to investigate the effect of diabetes on peri-implant bone formation in an animal model of human bone repair. Materials and Methods: Diabetes was induced by an intra-venous application of streptozotocin (90 mg/kg) in 15 domestic pigs. Implants were placed after significant histopathological changes in the hard and soft tissues were verified. The bone–implant contact (BIC), peri-implant bone mineral density (BMD), and expression of collagen type-I and osteocalcin proteins were qualitatively evaluated 4 and 12 weeks after implantation. Fifteen animals served as healthy controls. Results: Diabetes caused pathological changes in the soft and hard tissues. The BIC and BMD were significantly reduced in the diabetic group after 4 and 12 weeks. Collagen type-I was increased in the diabetic group at both time points, whereas osteocalcin was reduced in the diabetic group. Conclusions: Poorly controlled diabetes negatively affects peri-implant bone formation and bone mineralization. These findings have to be taken into consideration for diabetic patients with an indication for implant therapy.

Introduction: Recently, it has been demonstrated that the nanoscale environment is a critical factor for cellular behaviour. It has been shown that the diameter of TiO2 nanotube layers controls the cellular behaviour of cells involved in the bone-forming process in vitro. Therefore, the aim of the present study was to investigate the effects of the diameter of TiO2 nanotubes on peri-implant bone formation and the expression of bone matrix proteins in vivo. Materials and methods: Ninety experimental implants with a nanotube diameter ranging from 15 up to 100 nm were placed in the frontal skulls of six domestic pigs, whereas untreated implants served as controls. The bone–implant contact (BIC) as well as the expression of bone morphogenetic protein (BMP)-2, collagen type-I and osteocalcin were histomorphometrically and immunohistochemically analysed after 30 days. Results: Evaluating the BIC, a significant higher value, could be found for the 50, 70 and 100 nm groups compared with the controls, whereas a correlation with the BMP-2 expression was present. The BMP-2 expression within the 50, 70 and 100 nm groups was statistically different compared with the control group. Significant difference was found for the osteocalcin expression in the 70 nm group. No statistical difference was found evaluating collagen type-I. SEM evaluation of the specimen surfaces revealed that the nanotube coatings do resist shearing forces evoked by implant insertion. Conclusion: The nanotube diameter can be designed to support cellular functions of osteoblasts and osteoclasts in vivo, including differentiation and protein expression and therefore offer a powerful tool for the controlled formation of peri-implant bone around medical implant devices. To cite this article: von Wilmowsky C, Bauer S, Roedl S, Neukam FW, Schmuki P, Schlegel KA. The diameter of anodic TiO2 nanotubes affects bone formation and correlates with the bone morphogenetic protein-2 expression in vivo. Clin. Oral Impl. Res. 23, 2012; 359–366. doi: 10.1111/j.1600-0501.2010.02139.x

Oral Diseases (2011) 17, 433–442 Objectives: Bone-destructive disease treatments include bisphosphonates and antibodies against receptor activator for nuclear factor κB ligand (aRANKL). Osteonecrosis of the jaw (ONJ) is a side-effect. Aetiopathology models failed to explain their restriction to the jaw. The osteoproliferative transcription factor Msx-1 is expressed constitutively only in mature jaw bone. Msx-1 expression might be impaired in bisphosphonate-related ONJ. This study compared the expression of Msx-1, Bone Morphogenetic Protein (BMP)-2 and RANKL, in ONJ-affected and healthy jaw bone. Material and methods: An automated immunohistochemistry-based alkaline phosphatase-anti-alkaline phosphatase method was used on ONJ-affected and healthy jaw bone samples (n = 20 each): cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed to quantitatively compare Msx-1, BMP-2, RANKL and GAPDH mRNA levels. Results: Labelling indices were significantly lower for Msx-1 (P

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the sixth most common cancer. The local recurrence of OSSC might result from the existence of occult cancer cells around tumour margins. Exfoliative cytology has lately gained great importance as a method for obtaining RNA samples from suspicious oral mucosal lesions in order to carry out molecular diagnosis. In addition, melanoma associated-A antigens (MAGE-A) are expressed in various tumours and their detection is a highly accurate sign that cancer cells are present. OBJECTIVE: The prediction of a recurrence using MAGE-A mRNA expression analysis to follow-up OSCC cases using a newly established molecular diagnostic technique applied to cytological materials. METHODS: RNA was extracted from three recurrent OSCC cases and from 20 healthy volunteers as a control group using a cytobrush. The expression of MAGE-A3, A4, A6, A10 and A12 was investigated in these specimens using quantitative real-time (RT-PCR). RESULTS: There was no expression of MAGE-A in the specimens of normal oral mucosa. However, the expression analysis of five different MAGE-A genes indicated a high potential for malignant change in biopsy-proven recurrent OSCC cases. Except for MAGE-A10, the rest of the genes were expressed in different ratios by the three recurrent cases, which had been determined on histopathology to be OSCC or carcinoma in situ. CONCLUSION: It is suggested that analysis of MAGE-A expression may be used as a risk prediction method in the diagnosis of recurrence after wide excision of OSCC to enhance the accuracy of exfoliative cytology, which has limitations due to false negative and false positive results.

Cellulose-based scaffolds osteoactivated with different sodium silicate coatings (pure and bisphosphonate or strontium enriched respectively) can serve as long-term depots for a slow drug-release. Thus they are a promising and cost-saving alternative to the short-lived drug delivery systems of recombinant bone promoting proteins.

AIMS/BACKGROUND For sinus floor augmentation and simultaneous implant placement, a minimum of 5 mm of residual bone height has been recommended empirically. This study was designed to test this assumption in an experimental animal trial. MATERIAL AND METHODS In eight mini pigs, three premolars and two molars were removed on one side of the maxilla. Three months later, the animals were assigned to four groups of two animals each. A cavity was created at the base of the alveolar process so that the residual bone height was reduced to 2, 4, 6 and 8 mm, respectively. Six implants were installed and an inlay augmentation procedure was carried out using a particulated iliac bone graft. Implants were loaded with fixed provisional restorations after a healing period of 6 months. The animals were sacrificed after 6 months of functional loading. Histologic specimens were prepared and histomorphometric analysis was performed [bone-to-implant contact (BIC) ratio, interthread bone area, peri-implant bone area, crestal bone resorption (CBR)]. RESULTS Two implants were lost during follow-up and fibrous encapsulation was detected in one additional implant. All failures occurred in one animal with a residual alveolar height of 2 mm. On the buccal aspect, BIC turned out to be significantly higher for 6 mm when compared with 2/4 mm (75.8 +/- 26.1 vs. 58 +/- 23.2/53.9 +/- 22.8; P

Because of their excellent physical properties nonresorbable thermoplastic polymers have become more important for the field of reconstructive surgery. Aim of the present study was to investigate the effects of laser sintered polyetheretherketone (PEEK) with incorporated osteoconductive and bioactive bone substitution materials on osteoblasts in vitro. Human osteoblasts (hFOB 1.19) were seeded onto laser sintered PEEK samples containing nano-sized carbon black, b-tricalciumphosphate (b-TCP), and bioactive glass 45S5. Osteoblasts were investigated for cell viability, cell proliferation and cell morphology. A constant proliferation of osteoblasts could be observed on all samples with the highest values for bioactive glass containing samples at day 7 (OD 1.76 6 0.22) and day 14 (OD 3.75 6 0.31) and lowest values for b-TCP containing probes throughout the study compared with the PEEK pure control group. Highest cell viability was observed for Bioglass containing probes (95.5 6 3.32)% whereas osteoblasts seeded on b-TCP containing probes showed reduced viability (84.4 6 4.32)%. Laser sintered PEEK implants seem to be attractive candidates for use as bone substitutes for reconstructive surgery because of their biocompatibility, individual shape, and the possibility of compounding bioinert polymer powder with osteoconductive and bioactive materials which might benefit bone formation in vivo.

The aim of the study was to assess the suitability of different Ti-6Al-4V surfaces produced by the electron beam melting (EBM) process as matrices for attachment, proliferation, and differentiation of human fetal osteoblasts (hFOB 1.19). Human osteoblasts were cultured in vitro on smooth and rough-textured Ti-6Al-4V alloy disks. By means of cell number and vitality and SEM micrographs cell attachment and proliferation were observed. The differentiation rate was examined by using quantitative real-time PCR analysis for the gene expression of alkaline phosphatase (ALP), type I collagen (Coll-I), bone sialoprotein (BSP) and osteocalcin (OC). After 3 days of incubation there was a significant higher vitality (p0.02) and proliferation (p0.02) of hFOB cells on smooth surfaces (R(a) = 0.077 microm) and compact surfaces with adherent partly molten titanium particles on the surface (R(a)/= 24.9 microm). On these samples cells spread over almost the whole surface. On porous surfaces with higher R(a) values, cell proliferation was reduced significantly. Quantitative real-time PCR analysis showed that the expression of osteogenic differentiation markers was not influenced by surface characteristics. Gene expression did not differ more than twofold for the different samples. Compact titanium samples with adherent partly molten titanium particles on the surface (R(a)/= 24.9 microm) fabricated by the EBM process turned out to be best suited for cell proliferation, while highly rough surfaces (R(a)/= 56.9 microm) reduced proliferation of hFOB cells. Surface characteristics of titanium can easily be changed by EBM in order to further improve proliferation.

Background: Melanoma-associated antigens-A (MAGE-A) are expressed in a variety of tumors but not in normal tissues. Thus, their detection is highly specific to cancer cells, which makes them potential targets for the diagnosis, prognosis and also immunotherapy of neoplastic diseases. Methods: To determine the expression pattern and potential role of MAGE-A antigens in oral squamous cell carcinoma (OSCC), expression patterns of MAGE-A1–A6 and A12 were analyzed in 55 OSCC and 20 healthy oral mucosa using high-sensitive reverse transcription-nested polymerase chain reaction (RT-nPCR). Results: The 85.45% of tumor specimens expressed at least one of these genes. A significant correlation between the expression of MAGE-A1–A6 and A12 and malignancy was ascertained (P = 0.0001). On the contrary, none of the normal mucosal specimens expressed one of the MAGE-A subtypes. Antigen expression did not correlate with clinicopathological parameters, such as TNM classification, grading and clinical stage of OSCC. Conclusions: Multiple simultaneous detection of MAGE-A1–A6 and A12 expression has been found to be more specific and sensitive than the detection of single MAGE-A antigen for the diagnostic and prognostic evaluation of OSCC. In addition, monitoring the expression of several MAGE-A subtypes may determine suitable immunotherapeutic targets. Subsequently, coexpressed genes may be warranted for developing polyvalent vaccines.

The following investigation focuses on polyetheretherketone (PEEK) for bone substitutes intended for maxillofacial surgery. Different three-dimensional discs with a diameter of 12 mm and a height of 3 mm were laser sintered. As filler materials nano-sized carbon black and β-tricalciumphosphate powder with an average grain size of 35 μm were used. Human osteoblasts were cultivated on the discs and examined with scanning electron microscopy. Cell vitality and cell growth was investigated. The data shows that PEEK surfaces does not suppress osteoblast proliferation.

It was the aim of the study to assess differences in patient morbidity between transmucosal implant placement and implant installation after elevation of mucoperiosteal flaps. In five of the patients, implants were placed in the maxilla transmucosally using a CAD/CAM surgical template [test group (TG)]. In the remaining five patients, the implants were installed after the elevation of mucoperiosteal flaps [control group (CG)]. Directly after surgery, at days 1 and 7 after surgery the patients rated pain and discomfort on a visual analogue scale (0=minimal pain and discomfort, 100=maximal pain and discomfort). Optical three-dimensional images were assessed preoperatively and at days 1 and 7 after surgery to determine the visible soft tissue swelling of the upper lip and cheeks. Directly postoperatively, the mean pairwise difference between both groups in view of pain and discomfort ratings (control minus test) was 45.6 (SD, 20.7). At days 1 and 7, the mean differences were 51.6 (SD, 21.8) and 19 (SD, 8), respectively. The overall test of the area under curve (AUC) against the null hypothesis 'AUC of pairwise differences of pain score over study time equals null' yielded a significant difference (P=0.01). The mean pairwise difference between both groups in view of soft tissue volume increase was 6.1 (SD, 2) cm(3) at day 1 after surgery and 4.6 (SD, 1.2) cm(3) at day 7. The overall test of the AUC against the null hypothesis 'AUC of pairwise differences of oedema measurements over study time equals null' yielded a significant difference (P=0.002). Within the limitations of this pilot study, it could be shown that transmucosal implant placement reduces patient morbidity significantly compared with an open approach.

Recent studies have explored the use of biodegradable implants that incorporate antibiotics for the treatment of bone infections. In this study, a biodegradable composite containing bovine collagen and teicoplanin (Targobone®) was used for the treatment of mandibular nonunion defects. Patients with mandibular nonunion defects subsequent to osteosynthesis were treated with Targobone® (n = 9) or with autologous bone grafts (n = 12). Clinical and radiological evaluations were performed preoperatively, immediately postoperatively, and 4 and 24 weeks postoperatively. Bone regeneration was defined relative to the original defect area in the panoramic radiograph by using image analysis software. In the Targobone® group, the defect area decreased to 78% (SD ± 21.8%) of the preoperative area within 4 weeks and to 21% (SD ± 9.7%) of the preoperative area within 24 weeks. In the autologous bone graft group, the defect area decreased to 69% (SD ± 32.4%) of the preoperative area within 4 weeks and to 4.7% (SD ± 5.6%) of the preoperative area within 24 weeks. Thus, Targobone® is a promising option for the treatment of bone defects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007

For augmentations before implant placement in areas of minor bone quantity, autogenous bone is considered the reference to all bone substitutes used alternatively. Autogenous bone transplants originate from various donor areas and can be prepared in different ways before augmentation. They may either be used as block grafts or may be milled to granules that can be used solitarily or in combination with a bone substitute. In a prospective study, 61 patients of the Maxillofacial Surgery Department of our University receiving two-stage sinus floor elevation because of insufficient bone supply were randomly selected. At first-stage surgery, the local augmentation procedure, monocortical probes were obtained on the site of bone harvesting. At second-stage surgery, the implant insertion 6 months after the elevation procedure, bone cores were harvested in the areas of implant placement. Donor regions were the following three areas: the posterior (N=28) and anterior pelvic region (N=15) and the chin region (N=18). The implanted bone in all three groups was particulated to granules of 2-3 mm(2) using a bone mill. All biopsies were analyzed by means of microradiography. The anterior pelvic bone grafts showed a mineralized tissue grade of 35.1+/-7.6% before milling and augmentation. The posterior pelvic bone grafts exhibited a mineralization of 30.7+/-9.5% and the chin bone grafts 74.6+/-8.6%. At second-stage surgery after 6 months, the mineralization was 36.1+/-7.59% in the areas where bone grafts from the anterior pelvic crest were used. Probes harvested from sites with posterior pelvic bone augmentations showed a mineralization rate of 34.5+/-6.5%, and sites were chin bone grafts were applied expressed a mineralization of 54+/-8.6% (P=0.003 compared with the pre-operative value). The comparison of the microradiographical results demonstrated significant differences in the mineralization grades depending on the origin of the graft. The origin of the grafts and their remodeling influenced the mineralization rates found at 6 months. How these data may influence the long-term clinical outcome considering implant survival and bone resorption has to be examined in further long-term studies.

Background: Maxillary sinus augmentation is frequently necessary before placement of dental implants in the posterior maxilla. Besides autogenous bone graft, various bone substitutes have been used, with favourable results. Although platelet-rich plasma (PRP) has been used in the field of oral and maxillofacial surgery for years, its beneficial effects on osseous regeneration still remain unclear. The aim of this study was to evaluate the short and long time effects of PRP on single-stage sinus augmentation using autogenous bone or a fluorohydroxyapatite (Algipore®) in a randomized prospective animal study. Methods: After extraction of maxillary premolars of sixteen minipigs, the wounds were allowed to heal for 2 months. Then, sinus augmentations were performed bilaterally using one of the following grafting materials: autogenous bone and Algipore® with or without PRP. Three dental implants (Ankylos®) were installed in each sinus simultaneously. Four animals were euthanized at each period of observation (1, 2, 8 and 12 months). Implant-bearing specimens were sectioned bucco-lingually along the long axis of implants and undecalcified ground specimens were prepared. The bone-implant-contact (BIC) was measured by means of microradiographic examination. For histological evaluation, the specimens were stained with toluidin blue, and the percentage of the newly formed bone and the remaining bone substitute were evaluated. Results: The grafting materials chosen showed increasing levels of BIC and newly formed bone throughout the period of observation in both PRP and non-PRP groups. Adding PRP resulted in lower BIC and newly formed bone compared with autogenous bone grafts or Algipore® alone. However, a statistical significance was not found. The percentages of the remaining bone substitute in both the PRP and non-PRP groups were closely comparable in all observation periods. Conclusions: The application of PRP could not reveal significant beneficial effects on the BIC, the percentage of the newly formed bone and the remaining bone substitute in this study.

Purpose: The histological differences between the defect and contact areas of the implant surface to bone were tested in 35 New Zealand White rabbits in a standardized model. Microwave plasma chemical vapor-coated implant probes were tested in control and uncoated materials. Material and methods: In each femur of 35 rabbits, cylindrical implant rods with a planed side were inserted. Three groups, divided in coated and uncoated material at half, were observed 42, 84 and 168 days. The probes were examined histologically for bone–implant contact in the curved and plane (defect area) sides. Results: Generally the bone–implant contact seems to be nearly constant in time in the curved area of coated and uncoated probes. Here the implant was inserted in the press-fit mode. Diamond-coated probes showed similar bone–implant contact (51.9% (42 days), 62.5% (84 days), 56.1% (168 days)) compared to uncoated material (56.2%, 65.4%, 62.9%). The defect area (plane side) had no bone–implant contact at the time of insertion and showed increasing values on longer observation times with only significant differences in the 42-day group between coated (17.85%, 35.2%, 47.7%) and uncoated materials (35.5%, 40.55%, 51.81%). Conclusion: The evaluation of the curved side of the implant probe showed no great variation of bone–implant contact within the described observation times. This model simulates the usual implant insertion situation. The diamond-coated material becomes osseointegrated at a later time point. The bone–implant contact was only statistically relevant in one group in comparison to uncoated material.

The aim of the present study was to determine the correlation between the primary stability of dental implants placed in edentulous maxillae and mandibles, the bone mineral density and different histomorphometric parameters. After assessing the bone mineral density of the implant sites by computed tomography, 48 stepped cylinder screw implants were installed in four unfixed human maxillae and mandibles of recently deceased people who had bequeathed their bodies to the Anatomic Institute I of the University of Erlangen-Nuremberg for medical–scientific research. Peak insertion torque, Periotest values and resonance frequency analysis were assessed. Subsequently, histologic specimens were prepared, and bone-to-implant contact, the trabecular bone pattern factor (TBPf), the density of trabecular bone (BV/TV) and the height of the cortical passage of the implants were determined. The correlation between the different parameters was calculated statistically. The mean resonance frequency analysis values (maxilla 6130.4±363.2 Hz, mandible 6424.5±236.2 Hz) did not correlate with the Periotest measurements (maxilla 13.1±7.2, mandible –7.9±2.1) and peak insertion torque values (maxilla 23.8±2.2 N cm, mandible 45.0±7.9 N cm) (P=0.280 and 0.193, respectively). Again, no correlations could be found between the resonance frequency analysis, the bone mineral density (maxilla 259.2±124.8 mg/cm3, mandible 349.8±113.3 mg/cm3), BV/TV (maxilla 19.7±8.8%, mandible 34.3±6.0%) and the TBPf (maxilla 2.39±1.46 mm−1, mandible –0.84±3.27 mm−1) (P=0.140 and 0.602, respectively). However, the resonance frequency analysis values did correlate with bone-to-implant contact of the oral aspect of the specimens (maxilla 12.6±6.0%, mandible 35.1±5.1%) and with the height of the crestal cortical bone penetrated by the implants in the oral aspect of the implant sites (maxilla 2.1±0.7 mm, mandible 5.1±3.7 mm) (P=0.024 and 0.002, respectively). The Periotest values showed a correlation with the height of the crestal cortical bone penetrated by the implants in the buccal aspect of the implant sites (maxilla 2.5±1.2 mm, mandible 5.4±1.2 mm) (P=0.015). The resonance frequency analysis revealed more correlations to the histomorphometric parameters than the Periotest measurements. However, it seems that the noninvasive determination of implant stability has to be improved in order to give a more comprehensive prediction of the bone characteristics of the implant site.

Thirty human zygomatic bone specimens (15 females mean age 81.60 +/- 11.38 years, 15 males, mean age 78.47 +/- 6.58 years) were examined by quantitative computed tomography and histomorphometry. The aim of the study was to assess the bone mineral density, the trabecular bone volume and the trabecular bone pattern factor. Moreover, the anterior-posterior and the medio-lateral dimensions and the estimated implant length within the zygomatic bone were determined. For quantitative computed tomography the specimens were scanned together with a bone mimicking anthropomorphic reference phantom. The bone mineral density was calculated for the specimens in the plane of the intended direction of the implant placement. Subsequently, with the sawing and grinding technique, the specimens were prepared in the same plane for histomorphometry. The trabecular bone mineral density was 369.95 +/- 188.80 mg/cm3 for the female and 398.94 +/- 99.11 mg/cm3 for the male specimens (P = 0.23). The male trabecular bone volume showed a value of 27.32 +/- 9.49%, while the female group reached a value of 19.99 +/- 7.60% (P = 0.23). The trabecular bone pattern factor was 1.2 x 10-2 +/- 1.28 mm-1 for the male and 1.02 +/- 0.96 mm-1 for the female specimens (P = 0.045). The study reveals that the zygomatic bone consists of trabecular bone with parameters that are unfavourable for implant placement. However, the success of implants placed in the zygomatic bone is secured by the employment of at least four cortical portions.

The influence of the osteotome technique on the osseointegration of rough-surfaced stepped cylinder implants (Frialit)-2) was compared to conventional preparation of the implant site in an animal model. A total of 104 implants were placed into the distal femoral condyle of 52 New Zealand white rabbits. This region contains sufficient trabecular bone for implant placement. The implant site was prepared either by the osteotome technique or by conventional technique with drills as a control group. During the healing period polychromatic fluorescence labelling was performed with four different fluorescent dyes. After 2, 4 and 8 weeks, the implants were removed with the surrounding bone. The sample preparation was done using the 'sawing and grinding' technique. Ground sections 100 microm thick were used for fluorescence microscopic analysis; 30- microm-thick ground sections were examined histomorphometrically. After 2 weeks the bone-to-implant contact ratio was 55.0 +/- 7.1% for the osteotome technique and 29.2 +/- 4.8% for the control group (P < 0.0005). After 4 weeks, the bone-to-implant contact ratio was still significantly better for the osteotome technique (bone-to-implant contact ratio osteotome technique 71.1 +/- 7.2%, bone-to-implant contact ratio control 59.0 +/- 6.3%, P = 0.003). Eight weeks after implant placement the bone-to-implant contact ratio was still better for the osteotome technique compared to the conventional implant placement. However it was no longer statistically significant. The qualitative fluorescence microscopic examination showed an earlier and stronger signal for the osteotome technique than the control group. With the latter, the zone of mineralization moved slowly towards the implant surface. Implant sites prepared by the osteotome technique showed a pronounced signal in the whole compressed area already by the second day. In conclusion, the osteotome technique increases new bone formation and leads to an enhanced osseointegration of dental implants in trabecular bone. However, more experimental trials have to be carried out on higher mammals that show a metabolic rate of bone that is more comparable to humans.

20 retromolar bone grafts were harvested in outpatients for augmentation of the implant site from January to June 2000 (10 female, 10 male, 40.9 +/- 12.8 years, minimum 17 years, maximum 66 years). The aim of the study was to assess typical complications of this procedure in a prospective manner. For the determination of the superficial sensory function of the inferior alveolar and the lingual nerve, an objective method was used. The bone grafts were harvested for single tooth reconstruction. In 14 cases a ridge augmentation and in 6 cases an endoscopically controlled crestal sinus floor elevation was performed. Preoperatively, the height of bone above the cranial aspect of the inferior alveolar nerve in the retromolar region was assessed radiologically with known markers. The maximum mouth opening was determined. The superficial sensory function of the inferior alveolar and the lingual nerve was assessed with the Pointed-Blunt Test, the Two-Point-Discrimination Test and the objective method of the 'Pain and Thermal Sensitivity' Test (PATH Test). Moreover, the pulp sensitivity of the teeth of the donor site was determined by cold vitality testing. All tests were repeated 1 week postoperatively. Intraoperatively, the width of the retromolar region was measured with a caliper. The patients rated the operative strain on a visual analogue scale. The height of bone above the inferior alveolar nerve in the retromolar region was 11.0 +/- 2.2 mm. The width of the retromolar area was 14.2 +/- 1.9 mm. Postoperatively, the maximal mouth opening changed significantly (40.8 +/- 3.5 mm preoperatively, 38.9 +/- 3.7 mm postoperatively, P = 0.006). However, the reduction was not relevant clinically. A direct injury of the inferior alveolar or lingual nerve did not occur. A sensitivity impairment could not be detected for either of the nerves by the different test methods 1 week postoperatively. The operative strain related to the donor site was significantly less than the strain generated by the implant placement (rating on a visual analogue scale 2.8 +/- 1.0 and 4.1 +/- 2.0, respectively, P = 0.027). Retromolar bone grafts are a viable method for augmentation of the implant site in conjunction with single tooth reconstruction with low strain on the patient and minimal risk of complications.

Background Following preoperative radiotherapy prior to ablative surgery of squamous epithelial carcinomas of the head and neck region, inflammatory changes and the expression of cytokines involved in wound healing could be observed. These processes lead to a delayed healing of free flaps in the graft bed. The aim of the present experimental study was to analyze the expression profiles of transforming growth factor (activated TGFβ1, TGFβ2) and latency-associated peptide (LAP) in the irradiated graft beds and the transition area between grafts and irradiated graft beds. Methods In Wistar rats (male, weight 300–500 g) undergoing preoperative irradiation of the neck region with 30 Gy (30 animals) and non-irradiated rats (42 animals), a free myocutaneous gracilis flap taken from the groin was transplanted to the irradiated region of the neck. The interval between irradiation and transplantation was 4 weeks. In each group on postoperative days 3, 7, 14, and 28, cytoplasmatic expression of activated TGFβ1, LAP, and TGFβ2 was analyzed by immunohistochemistry to determine labeling indices (positive stained cells/total cells). Results The success rate in graft beds irradiated with 30 Gy was 76% and in non-irradiated graft beds was 86% (p = .02). In the graft beds irradiated with 30 Gy, there was an increased expression of activated TGFβ1 (range, 19.0–33.0), LAP (14.0–21.0), and TGFβ2 (3.0–19.5) together with obvious fibrosis. The expression was located in perivascular fibroblasts and endothelial cells. In contrast, a lower expression of activated TGFβ1 (11.0–21.0), LAP (1.0–8.0), and TGFβ2 (0.0–0.9) (p = .006) was observed in non-irradiated graft beds. In the transition area between graft and irradiated graft bed, high expression of activated TGFβ1 (37.0), LAP (19.0), and TGFβ2 (16.7–33.4) was observed on the 3rd postoperative day in contrast to the transition area in non-irradiated graft beds (activated TGFβ1 26.0, LAP 7.0, and TGFβ2 0.l). Conclusion The radiation induced, increased de novo synthesis of LAP, activation of TGFβ1, and increased expression of TGFβ2 may represent at least one mechanism for the increased fibrosis and wound healing disorders seen in irradiated tissues and in the transition area to graft tissue. The expression of TGFβ1, LAP, and TGFβ2 might possess prognostic value with regard to wound healing and fibrosis in previously irradiated graft beds. © 2002 John Wiley & Sons, Inc. Head Neck 24: 33–41, 2002.

In a prospective study, 20 patients who underwent harvesting of chin grafts as outpatients, were followed up for 12 months (3 further patients with incomplete follow-up data were excluded from the study). Preoperatively and 7 days, 1, 3, 6 and 12 months postoperatively, follow-up data were assessed. Evaluation of the superficial sensory function of the inferior alveolar nerve was determined by the Pointed-Blunt Test and the Two-Point-Discrimination Test. Sensory disturbances were objectively assessed by testing thermal sensitivity with the "Pain and Thermal Sensitivity" Test (PATH Test). In addition, evaluation of the pulp sensitivity of teeth 35-45 was carried out by cold vitality testing. One week postoperatively, 8 patients were affected by superficial sensory impairment. 8 nerve territories showed hypoaesthetic reactions and 5 showed hyperaesthetic reactions. After 12 months, two patients still suffered from hypoaesthesia of one side of the chin. There was a statistically significant sensitivity impairment of the chin for all patients comparing the preoperative data of the Two-Point-Discrimination Test (left/right median: 8.17/8.17 mm, interquartile range (IQR) 1.00/2.00 mm) with the first postoperative measurement (left/right median 9.00/8.33 mm, IQR 1.67/2.66 mm). Comparing the latter to the last postoperative measurement there was significant tendency for regeneration of a nerve function (left/right median 8.00/7.84 mm, IQR 0.66/2.00 mm). In the PATH Test all hypoaesthetic areas could be identified by a reduction of thermal sensitivity. After the first postoperative examination 21.6% (n=38/176) of the examined teeth had lost their pulp sensitivity. After 12 postoperative months 11.4% (n=20/176) still did not react sensitively. Many of these were canines (n=8/20). Comparing the preoperative to the first postoperative examination, there was a significant reduction of pulp sensitivity. However, statistically significant recovery until the last postoperative follow-up could not be detected. The assessed data show that patients have to be informed extensively about disturbances of the inferior alveolar nerve function lasting longer than 12 months. Moreover, the loss of pulp sensitivity is a very frequent event which has always to be taken into account. Considering the high rate of complications with harvesting of chin grafts, more prospective trials should be done to find out whether there are other donor sites for autogenous bone which put less strain on patients.

The aim of the present study was to analyse the long-term survival rate of endosteal implants used for restoration of oral function in patients having undergone oncologic surgery. Eighty-three consecutive patients, who had received a total of 409 endosteal implants ad modum Branemark, subsequent to resections of soft tissue and bone during ablation of oral malignancies, were enrolled into the study. A life-table analysis was used to determine the survival rate of the implants placed during a period of 13 years. Log rank tests and Cox regression analysis were employed to identify relevant effects of surgical parameters on implant survival. A total of 38 implant failures were encountered. Most of the losses ( n =19) occurred during the first year of functional loading. Subsequent failures were evenly distributed across the remaining follow-up period. The cumulative overall survival rate of implants was 56.5%. Previous radiation therapy, insertion into grafted bone or original jaw bone and the technique of grafting did not significantly affect the survival rates. In the Cox regression analysis, the timing of implant placement in the group of patients with bone grafts (primary vs secondary placement) was significantly related to the survival rate ( P =0.0197), with a lower survival rate of 36.2% for primary insertion of implants and 67.1% for secondary placement.

The working group was charged with evaluating the available evidence regarding local or systemic conditions, that might influence the outcome of osseointegrated implants. Some of these factors have been suggested to be associated with an increased risk of implant failure. Verification of local or systemic risk factors might be relevant for treatment planning, modification of treatment protocols, and treatment outcome. As local factors, bone density, vertical and horizontal dimension of the alveolar ridge, and the ability to stabilize implants during insertion have been suggested. Systemic considerations affecting implant therapy may include various systemic diseases and their treatments. In periodontitis, systemic as well as local components are involved. Literature scoping led to search criteria, which were used for specific literature searches in PubMed, and, in some instances, additional manual searching was carried out. Depending on the available information and on the heterogeneity of studies, one systematic and three narrative reviews have been prepared to address the issues related to the topic assigned to this group. In addition to reviewing the available evidence, it was the intention to summarize current clinical implications and to make recommendations for further research. A particular concern was that different implant success criteria were used, complicating the comparison and compilation of results and impeding the construction of conclusions and a common consensus. Most studies had a retrospective design, were not well controlled, and showed a lack of consistency in accounting for patient dropout. In addition, implant failure was often the single clinical finding used for determining treatment outcome.

Purpose: The aim of this study was to show prognostic equivalence between implant loading in the maxilla after 12 weeks versus 4 weeks. Materials and Methods: One hundred four patients, from four centers in this open-labeled randomized multicenter prospective controlled clinical trial, were assigned to either 12 weeks or 4 weeks of unloaded healing. Two hundred sixty-nine implants (sand blasted large-grid, acid etched [SLA] surface, ≥4.1 mm diameter; ≥10 mm length) were inserted and evaluated during an individual 5-year follow-up. Primary outcome was implant success after 12 months; prognostic equivalence was characterized by a maximum difference of ±5% in implant failure rates. Results: Implant-wise 1-year failure rates were estimated 3.1% (5/163 implants) in the 4 weeks group versus 3.6% (4/112 implants) in the 12 weeks group (95% confidence interval [CI] for the difference −3.2 –+4.2%); implant-wise evaluation demonstrated statistically significant prognostic equivalence of 4 and 12 weeks loading. Patient-wise 1-year failure rates were estimated 6.7% (n = 4 patients) in the 4 weeks group versus 5.1% (n = 2 patients) in the 12 weeks group (95% CI for the difference −9.6 –+6.5%). All implant failures occurred within the first 3 months of the individual observation period. Prior bone augmentation, underdimensioned drilling, bone quality, implant type, implant length, implant diameter, residual teeth, and fixing of the restoration did not reveal associations with the implant outcome: trial site, posterior jaw region, and splinting were associated with a higher failure rate. Resonance frequency analysis did not serve as a predictor of implant failures at the time of implant insertion. Conclusion: Loading of standard SLA implants in the maxilla 4 weeks versus 12 weeks after insertion resulted in statistically equivalent failure patterns within a 1-year follow-up period; nevertheless, the observed patient-wise failure patterns of the interim analysis requires further understanding of patient-individual aspects of the early loading concept.