Search

This systematic review analyses the difference of the mean marginal bone loss (MBL) 1 year after implantation depending on the fixation of the restoration. 889 publications on controlled clinical trials were identified, and based on inclusion and exclusion criteria, 22 studies were selected. Related to fixed restorations, the lowest MBL was 0.05±0.67 mm and the highest 1.37±0.5 mm. The MBL for removable restorations ranged from 0.13±0.35 mm to 1.03±0.65 mm. Three studies analyzed the MBL around implants of overdentures in the lower jaw. The estimate for this restoration type was 0.476 mm (95% CI: -0.305 to 1.258). 19 randomized controlled studies dealt with restorations which were fixed to the implants. The estimate for the mean MBL was 0.459 mm (95% CI: 0.325-0.593). There was a decrease in 1-year implant survival with an increase of 1 mm MBL (-0.083%; 95% CI: -0.179 to 0.0123; p=0.083) in fixed restorations. The difference in MBL between fixed and removable restorations was 0.363 mm (95% CI: -0.319 to 1.044; p=0.279). This systematic review indicates that implants with fixed and with removable restorations lead to comparable MBL.

When the SARS-CoV-2 pandemic started

Our ability of screening broad communities for clinically asymptomatic diseases critically drives population health. Sensory chewing gums are presented targeting the tongue as 24/7 detector allowing diagnosis by “anyone, anywhere, anytime”. The chewing gum contains peptide sensors consisting of a protease cleavable linker in between a bitter substance and a microparticle. Matrix metalloproteinases in the oral cavity, as upregulated in peri-implant disease, specifically target the protease cleavable linker while chewing the gum, thereby generating bitterness for detection by the tongue. The peptide sensors prove significant success in discriminating saliva collected from patients with peri-implant disease versus clinically asymptomatic volunteers. Superior outcome is demonstrated over commercially available protease-based tests in saliva. “Anyone, anywhere, anytime” diagnostics are within reach for oral inflammation. Expanding this platform technology to other diseases in the future features this diagnostic as a massive screening tool potentially maximizing impact on population health., Early detection of gum inflammation caused by dental implants helps prevent tissue damage. Here, the authors present a peptide sensor that generates a bitter taste when cleaved by proteases present in peri-implant disease, embed it in a chewing gum, and compare the probe to existing sensors using patient saliva.

When the SARS-CoV-2 pandemic started,[1] science came to the immediate attention of the broad public. People and politicians were hanging on every word of medical doctors, virologists, molecular biologists, data scientists and many others in the hope of finding other protective measures than those used for centuries such as basic hygiene, distance, or quarantine. Here, at the Institute of Chemistry and Biotechnology at the Zurich University of Applied Sciences (ZHAW) we were also willing to provide scientific solutions to overcome the pandemic. Together with our partners from industry, we contributed to the development of a Swiss vaccine, are working on filters for active ventilated full protective suits and are developing tests to show the efficacy and safety of an active antiviral textile that allows controlled virus inactivation through an electrochemical reaction by applying a small current.

Background: In numerous animal and human studies, it could be detected that in bone augmentation procedures, material's physicochemical characteristics can influence the cellular inflammatory pattern and therefore the integration in the host tissue. Histological, histomorphometrical, and clinical analyses of the integration of the biomaterial in the surrounding tissue are well established methodologies; however, they do not make a statement on volume and density changes of the augmented biomaterial. Aims: The aim of the present study was to assess the volume and density of a xenogeneic (Bio-Oss®, BO) and a synthetic (NanoBone®, NB) bone substitute material in split-mouth sinus augmentations in former tumor patients to complete histological and histomorphometrical assessment. Methods: Immediately and 6 months after sinus augmentation computed tomography scans were recorded, bone grafts were marked, and the volume was calculated with radiologic RIS-PACS software (General Electric Healthcare, Chalfont St. Giles, Great Britain) to determine the integration and degradation behavior of both biomaterials. Results: Radiographic analysis revealed a volume reduction of the initial augmented bone substitute material (i.e. 100%) to 77.36 (±11.68) % in the BO-group, respectively, 75.82 (±22.28) % in the NB-group six months after augmentation. In both materials, the volume reduction was not significant. Bone density significantly increased in both groups. Conclusion: The presented radiological investigation presents a favorable method to obtain clinically relevant information concerning the integration and degradation behavior of bone substitute materials.

The aim of this study was to analyse the influence of different loading protocols on marginal bone loss (MBL). The outcomes of different implant loading protocols were assessed at 1year after implantation, with focus on MBL; protocols included immediate, immediate non-occlusal, early, and conventional loading. The search strategy resulted in 889 studies. Twenty-two of these studies fulfilled the inclusion criteria. Among the included studies, the lowest MBL was for immediately loaded implants (0.05±0.67mm) and the highest for immediate non-occlusally loaded implants (1.37±0.5mm). The results of the meta-analysis showed an estimated mean MBL of 0.457mm (95% confidence interval (CI) 0.133-0.781) for immediate loading, 0.390mm (95% CI 0.240-0.540) for immediate non-occlusal loading, 0.488mm (95% CI 0.289-0.687) for early loading (2 days to3 months), and 0.852mm (95% CI 0.429-1.275) for conventional loading (3 months) implant protocols. The lowest decrease in 1-year implant survival per millimetre increase in MBL was observed for immediate loading and the highest for conventional loading. Conventional loading showed a significantly higher MBL than the other three loading protocols. This systematic review and meta-analysis indicates that the immediate loading protocol is a reasonable alternative to the conventional loading protocol.

The modification of the implant surface influences implant osseointegration. A physico-chemical means to modify implant surfaces is the creation of hydrophilic surfaces. The aim is an accelerated osseointegration for earlier implant loading and possibly the increase of bone quantity and quality. This review gives an update on the current scientific knowledge on hydrophilic implant surfaces. In vitro, hydrophilic titanium surfaces exhibit different positive effects on hard and soft tissues with significant differences to hydrophobic surfaces. Several cell types and the initial wound healing phase are positively affected. In vivo, an increased osseointegration is detected in the early phase of wound healing. In later stages these significant differences are rarely detectable. Based on clinical trials, early implant loading of hydrophilic surfaces is considered safe and predictable. There is only few data on hydrophilic surfaces in areas of reduced bone quality or quality.Die Veränderung der Implantatoberfläche ist eine Möglichkeit zur Beeinflussung der Osseointegration. Eine Möglichkeit, die physikochemischen Eigenschaften von Implantatoberflächen zu verändern, ist die Hydrophilisierung der Oberfläche. Ziel ist die beschleunigte periimplantäre Knochenbildung zur sicheren Frühbelastung. Im Weiteren ist von Interesse, ob eine qualitative und quantitative Steigerung der Knochenneubildung möglich ist. Dies könnte auch Vorteile im schwachen Knochenlager haben. Eine zunehmende Anzahl an Patienten leidet an chronischen Erkrankungen, erhält eine Strahlentherapie oder systemische medikamentöse Therapien mit Einfluss auf den Knochenstoffwechsel. Auch in diesen Fällen könnten sich Vorteile zeigen. Diese Übersichtsarbeit gibt ein Update zur aktuellen Studienlage zu hydrophilen Implantatoberflächen. In vitro zeigen hydrophile Titanoberflächen positive Eigenschaften auf das Hart- und Weichgewebe mit signifikanten Unterschieden zu hydrophoben Oberflächen. Hierbei werden verschiedene Zelltypen der initialen Heilungsphase positiv beeinflusst. In vivo zeigt sich in der frühen Einheilphase eine beschleunigte Osseointegration, in späteren Phasen sind diese signifikanten Unterschiede nur bedingt feststellbar. Frühbelastungskonzepte mit hydrophilen Oberflächen gelten auf Basis der bestehenden Studien als sicher und voraussagbar. Zur Osseointegration bei verminderter Knochenqualität liegen derzeit nur wenige Daten vor.La modification de la surface des implants est l’une des possibilités d’influencer leur ostéo-intégration. L’hydrophilisation des surfaces implantaires est l’une des modifications possibles de leurs propriétés physico-chimiques. L’objectif est d’accélérer la néoformation osseuse périimplantaire pour sécuriser la mise en charge précoce. Il est intéressant de déterminer s’il est possible d’obtenir une augmentation quantitative et une amélioration qualitative de la néoformation osseuse. Cela pourrait aussi présenter des avantages lorsque le site osseux n’est pas optimal. Un nombre croissant de patients souffrent de maladies chroniques, sont soumis à des radiothérapies ou à des traitements médicamenteux systémiques qui influencent le métabolisme osseux. Dans ces cas on voit également des avantages. Ce travail de revue présente une mise à jour sur les études actuelles relatives aux surfaces implantaires hydrophiles. In vitro, les surfaces hydrophiles en titane présentent des propriétés positives sur les tissus durs et mous, avec des différences significatives par rapport aux surfaces hydrophobes. Différents types de cellules intervenant dans la phase initiale de la guérison sont influencées favorablement. In vivo, une ostéo-intégration accélérée est mise en évidence au cours de la phase de guérison précoce, alors que dans les phases ultérieures, ces différences significatives ne sont que partiellement détectables. Sur la base des études existantes, les concepts de mise en charge précoce sont considérés comme sûrs et prédictibles avec les surfaces implantaires hydrophiles. Lorsque la qualité osseuse est réduite, il existe peu de données sur l’ostéo-intégration.

The purpose of this study was to evaluate the bone formation capability of polyetheretherketone (PEEK) and carbon fiber-reinforced PEEK (CFR-PEEK) implants coated with different titanium and hydroxyapatite plasma-sprayed layers after 2 and 12 weeks.In six sheep 108 implants were placed in the pelvis. Altogether six different surface modifications were tested. After 2 and 12 weeks, n = 3 implants per group were examined histologically and n = 6 implants per group were tested by a pull-out test.Biomechanically (p = 0.001) as well as histologically (p 0.05) surface coating of PEEK/CFR-PEEK led to an increase of osseointegration from 2 to 12 weeks. After 12 weeks, coated implants demonstrated significant (p 0.001) higher pull-out values in comparison to uncoated implants. Overall, the double coating (titanium bond layer and hydroxyapatite top layer) showed the most favorable results after 2 and 12 weeks.Plasma-sprayed titanium and hydroxyapatite coatings on PEEK or CFR-PEEK demonstrated a significant improvement of osseointegration. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1182-1191, 2016.

OBJECTIVE The main objective of this study was to demonstrate that dental implants made from ultrafine-grain titanium (UFG-Ti) can be created that replicate state of the art surfaces of standard coarse-grain titanium (Ti), showing excellent cytocompatibility and osseointegration potential while also providing improved mechanical properties. MATERIAL AND METHODS UFG-Ti was prepared by continuous equal channel angular processing (ECAP), and surfaces were treated by sandblasting and acid etching. Mechanical properties (tensile and fatigue strength), wettability, and roughness parameters were evaluated. Human trabecular bone-derived osteoblast precursor cells (HBCs) were cultured on all samples to examine cytocompatibility and mineralization after 4 and 28 days, respectively. Biomechanical pull-out measurements were performed in a rabbit in vivo model 4 weeks after implantation. RESULTS Both yield and tensile strength as well as fatigue endurance were higher for UFG-Ti compared to Ti by 40%, 45%, and 34%, respectively. Fatigue endurance was slightly reduced following surface treatment. Existing surface treatment protocols could be applied to UFG-Ti and resulted in similar roughness and wettability as for standard Ti. Cell attachment and spreading were comparable on all samples, but mineralization was higher for the surfaces with hydrophilic treatment with no significant difference between UFG-Ti and Ti. Pull-out tests revealed that osseointegration of surface-treated UFG-Ti was found to be similar to that of surface-treated Ti. CONCLUSION It could be demonstrated that existing surface treatments for Ti can be translated to UFG-Ti and, furthermore, that dental implants made from surface-treated UFG-Ti exhibit superior mechanical properties while maintaining cytocompatibility and osseointegration potential.

Aim Until recently, adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs) on osseointegration of dental implants were unknown. Hence, this study investigated the short- and long-term effects of a 7-day regimen of parecoxib and diclofenac sodium on osseointegration of dental implants in calvarial bone. Material and methods Eighteen New Zealand White rabbits were randomly allocated into three groups (each n = 6): Control group with no postoperative pain killers (Group A), diclofenac group (Group B) and parecoxib group (Group C). In each animal, one dental implant was placed into the calvarial bone (total n = 18). Three rabbits from each group were sacrificed in Week 4. The other three rabbits from each group were sacrificed in Week 12 postoperatively. The implant together with the calvarial bone and dura mater was harvested and subjected to micro-computed tomography (micro-CT) and histomorphometric analysis. Results Quantitative analysis of micro-CT data and histomorphometric data neither revealed any statistically significant (P ≤ 0.05) differences between the three different groups related to osseointegration nor between different time points of observation. Conclusion In rabbits, a 7-day regimen of appropriate doses of diclofenac sodium and parecoxib did not adversely affect osseointegration of dental implants and bone healing in calvaria, neither short nor long term (12 weeks).

Objective Implant surface properties have long been identified as an important factor to promote osseointegration. The importance of nanostructures and hydrophilicity has recently been discussed. The aim of this study was to investigate how nanostructures and wettability influence osseointegration and to identify whether the wettability, the nanostructure or both in combination play the key role in improved osseointegration. Materials and Methods Twenty-six adult rabbits each received two Ti grade 4 discs in each tibia. Four different types of surface modifications with different wettability and nanostructures were prepared: hydrophobic without nanostructures (SLA), with nanostructures (SLAnano); hydrophilic with two different nanostructure densities (low density: pmodSLA, high density: SLActive). All four groups were intended to have similar chemistry and microroughness. The surfaces were evaluated with contact angle measurements, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy and interferometry. After 4 and 8 weeks healing time, pull-out tests were performed. Results SLA and SLAnano were hydrophobic, whereas SLActive and pmodSLA were super-hydrophilic. No nanostructures were present on the SLA surface, but the three other surface modifications clearly showed the presence of nanostructures, although more sparsely distributed on pmodSLA. The hydrophobic samples showed higher carbon contamination levels compared with the hydrophilic samples. After 4 weeks healing time, SLActive implants showed the highest pull-out values, with significantly higher pull-out force than SLA and SLAnano. After 8 weeks, the SLActive implants had the highest pull-out force, significantly higher than SLAnano and SLA. Conclusions The strongest bone response was achieved with a combination of wettability and the presence of nanostructures (SLActive).

The use of rabbits for experimental research has a long historical tradition. The aim of this review consists in outlining the use of the rabbit for research in implant dentistry and related tissue regeneration. Rabbits appear as a first-hand choice for fundamental implant design studies because of their size, easy handling, short life span, and economical aspects in purchasing and sustaining. In the following, the various anatomical sites in the rabbit will be summarized to provide an overview of current possibilities and limitations of this model for bone research in oral implantology.

OBJECTIVES: It was the aim of this study to compare the feasibility of complete osteotomy of long bones in sheep using a newly designed variable square pulsed Er:YAG laser and piezoelectric surgery. In addition to uneventful bone healing after laser osteotomy, the goal was to assess the possibility to cut thick bony structures with both techniques in a surgically acceptable time frame of 2-3 minutes. MATERIAL AND METHODS: A tibia midshaft osteotomy was performed in 24 sheep using either an Er:YAG laser (n = 12) or piezoelectric device (n = 12). Laser and piezoelectric groups were divided in two subgroups (n = 6) with sheep sacrificed after 2 and 3 months, respectively. A complete radiological, histological and histomorphometric analysis was performed to compare the course of bone/fracture healing and remodelling. RESULTS: Laser and piezoelectric osteotomies of the sheep tibia up to a depth of 22 mm were possible without any thermal damage. Radiological and histological results after 2 months showed primary gap healing with distinct periosteal callus formation on the transcortex. After 3 months, radiological and histological analysis revealed less callus formation on the transcortex, with almost no visible osteotomy gap and a distinct formation of lamellar bone crossing the original osteotomy gap. CONCLUSION: Er:YAG laser osteotomy can successfully be used in long bones with a depth of up to 22 mm, thus challenging the dogma of adverse effects of laser osteotomy due to thermal or other damages

Objectives: The purpose of this study was to examine in vitro the anti-bacterial efficacy of two different laser systems (CO(2) and diode) applied to Streptococcus sanguinis or Porphyromonas gingivalis cells in suspensions or adhered to zirconia or titanium dental implant materials, with two different surfaces each. Materials and methods: Bacteria were irradiated at two different power settings with either a CO(2) (lambda=10,600 nm) or a diode laser (lambda=810 nm). The lower mode is used clinically (for CO(2) 100 J/cm(2), diode 50 J/cm(2)) and the higher may alter the materials' surface (for CO(2) 1200 J/cm(2), diode 150 J/cm(2)). After irradiation, the number of viable bacteria was determined by culture. Results: Planktonic cells of both species were more resistant to the laser irradiations than bacteria that adhered to surfaces. Adhered P. gingivalis were effectively killed at both wavelengths lambda=10,600 and 810 nm even at the lower settings, independent of the material. S. sanguinis cells that adhered to either zirconia surface were effectively killed by the CO(2) laser at the lower setting of 100 J/cm(2). However, the higher settings of both lasers were needed to reduce S. sanguinis that adhered to titanium surfaces. The CO(2) laser at the lower setting and the diode laser at the higher setting effectively reduced the viability of S. sanguinis or P. gingivalis that adhered to zirconia surfaces. Conclusions: Under irradiation conditions known not to alter zirconia implant surfaces in vitro, both CO(2) laser (100 J/cm(2)) and the diode laser (150 J/cm(2)) effectively reduced the viability of adhered S. sanguinis or P. gingivalis.

The aim of the study was to compare the histological results after complete osteotomies of the sheep tibia using either the prototype carbon dioxide (CO(2)) laser osteotome 'OsteoLAS' (n = 12) or an oscillating saw (n = 12). The laser parameters were as follows: wavelength 10.6 microm; energy of laser pulses 75-85 mJ; pulse duration 80 mus; pulse repetition rate 200 Hz; spot diameter 460 mum (1/e(2) level); radiant exposure 45-51 J/cm(2); peak irradiance 0.56-0.64 MW/cm(2). Both groups were divided into two subgroups (n = 6), and the animals were killed after 4 weeks or 12 weeks, respectively. Light and fluorescence microscopy with semiquantitative analysis and histomorphometry were performed to compare bone healing. Charring-free laser osteotomies were possible up to a depth of 20 mm with the short-pulsed CO(2) laser. The laser, however, required a significantly longer time to perform, and a wedge-shaped gap was present on the cis-cortex. After 4 weeks the osteotomy gaps were almost unchanged in both groups and filled with connective tissue. After 12 weeks the gaps were filled with newly formed bone in both groups. Primary gap healing was predominant in the laser group and longitudinal cortical remodelling in the control group. On a cellular level, no fundamental differences were observed for early and late stages of bone healing. Further research has to be focussed on improving the CO(2) laser ostetome in order to reduce the long duration of the laser osteotomy and the necessity of creating a wedge-shaped cut in thick bones.

Objective Bacterial cultures from nontraumatic brain abscesses (BAs) frequently contain oral bacteria. We assessed bacterial cultures from BAs and oral infective sources for a bacterial match. Study design Bacterial samples from brain abscesses and oral abscesses, and at sites with probing depths ≥3.5 mm were taken from 11 nontraumatic BA patients and analyzed. Results Brain abscess bacterial cultures were obtained in 9 of the 11 cases, which revealed 5 cases of Streptococcus milleri group bacteria and 4 cases of subgingival flora. The bacteriologic results were interpreted taking all medical and bacteriologic findings into account, which made an oral origin of the BAs most likely in 6 of the 11 cases: from an oral abscess and from the subgingival flora in 3 cases each. Conclusions Early collaboration between neurosurgeons, infectious disease specialists, and oral-maxillofacial surgeons will aid the identification and treatment of suspected oral sources of nontraumatic BAs.

Background: The purpose of this retrospective study was to evaluate the surgical performance, clinical usability and outcome of a new variable square pulsed (VSP) Er:YAG laser for bone cutting in oral and maxillofacial surgery. Materials and Methods: In 40 patients an Er:YAG laser with pulse energy of 1,000 mJ, pulse duration of 300 μs and a frequency of 12 Hz was used for different intraoral osteotomies. The spot size was 0.9 mm, and the handpiece was kept at a distance of 10 mm from the bone surface. Additionally, histological analyses of the fresh osteotomy rims of lasered bone were performed. Results: Er:YAG laser osteotomy revealed a remarkable cutting efficiency without any visible, negative, thermal side effects. There was no damage of adjacent soft tissue structures. However, depth control was limited to visual inspection. Histologically, a 5- to 10-μm-wide zone of a characteristic laser fingerprint appeared on the cut edges. However, there was no sign of thermal tissue damage to the underlying bone structures. Conclusions: VSP Er:YAG laser osteotomy is clinically practicable without any signs of charred tissue and wound healing disturbances. However, the lack of depth control and the necessity for careful handling are still technical limitations to be overcome.

Background and Objectives: It was the aim of this pilot study to evaluate the feasibility, benefits and limitations of a variable square pulse (VSP) Er:YAG laser for harvesting intraoral bone grafts from either the chin or ramus region. Materials and Methods: In 12 patients (5 female, 7 male) a VSP Er:YAG laser was used to harvest bone grafts either from the ramus (3) or the symphyseal area (9). For the osteotomies, the Er:YAG laser was applied with a pulse energy of 1,000 mJ, a pulse duration of 300 microseconds, and a frequency of 12 Hz (energy density 157 J/cm2). The spot size was 0.9 mm and the handpiece was kept at a distance of about 10 mm from the bone surface. Results: There was no visible carbonization or osseous debris on the surface of the osteotomy gap. Damage of adjacent soft tissue structures by mechanical or thermal trauma was minimal. Cutting efficiency was excellent and the overall time required for the procedure was not increased. However, due to a free manual positioning of the laser beam in the non-contact mode, it was difficult to get a well defined osteotomy line without irregularities on the surface. Slight deviations of the original angulation of the laser beam led to considerable bone loss which restricted osteotomy of ramus grafts to three cases. Depth control was limited to visual inspection. Conclusion: The bone ablation technique using a (VSP) Er:YAG laser yielded superior clinical results without impairment of wound healing and in comparison to other laser systems, no significant time loss occurred. Yet, the missing depth control and the necessity of carefully handling the laser beam position and its angulation limit the use of a (VSP) Er:YAG laser to regions where a safe and fixed guidance of the laser beam is feasible.

OBJECTIVE: The purpose of this study was to examine for the first time the feasibility of performing complete osteotomy of sheep tibia using a computer-guided CO2-laser osteotome, and to examine bone healing under functional loading. BACKGROUND DATA: Bone cutting without aggravating thermal side effects has been demonstrated with scanning CO2-laser osteotomy. Further research is necessary to develop a clinically usable laser osteotome, which may allow new types of bone surgical procedures. MATERIALS AND METHODS: The scanning parameters for performing tibial osteotomies were determined in preliminary ex vivo trials. Osteotomies were performed in the mid-diaphysis of sheep tibia using either the prototype laser osteotome (osteoLAS, study group; n = 12), or an oscillating saw (control group; n = 12). Both groups were divided into two subgroups each (n = 6), and the two groups were sacrificed after 4 and 12 wk. Radiographs were taken postoperatively and after 4, 8, and 12 wk to compare the course of bone healing. RESULTS: Laser osteotomies of sheep tibia up to a depth of 20 mm were possible without visible thermal damage to the bone. A sequential PC-controlled cut geometry with artificial widening of the osteotomy gap was required for a complete osteotomy. Both clinically and radiologically, the laser and control groups showed undisturbed primary gap healing. Bone healing was similar and undelayed after both laser osteotomy and osteotomy done by mechanical saw. CONCLUSIONS: Osteotomy of multi-layered bones with a scanning CO2-laser demonstrates clinical and radiological healing patterns comparable to those seen with osteotomy done by standard mechanical instruments. It is, however, a technically demanding procedure, and complete laser osteotomies of long bones are only reasonable in bones with a diameter

Objective The objective of this study was to evaluate piezoosteotomy for bone harvesting at the iliac crest in a pilot collective. Study design Thirteen patients underwent anterior iliac crest bone graft harvesting using piezoosteotomy. These patients were compared to an age- and sex-matched retrospective cohort of 13 patients who underwent bone graft harvesting at the anterior iliac crest using conventional chisels and saws in an otherwise identical protocol. Results Harvested bone volumes and operation times were comparable; hospitalization time was briefer and pain levels at the first 2 postoperative days less in the piezoosteotomy group; pain medication requirement was comparable. Spearman’s-rho correlation showed a strong tie between pain medication requirement and harvested bone volume in the piezoosteotomy group and between harvested bone volume and operation time in the conventional surgery collective. Conclusions The correlation between required pain medication and harvested bone volume together with lower pain levels in the piezoosteotomy group indicate pain more exclusively related to local osseous damage than to correlated soft tissue lacerations. Conventional technique shows a correlation between operation time and harvested bone volume indicating a more time-effective procedure, although total operation time was comparable. Piezoosteotomy appears to have potential use in iliac crest bone harvesting.

Surgical reconstruction of bony defects in the oral cavity can often be challenging since thin and fragile bony structures are especially prone to fracture cased by bulky cutting tips or the application of significant pressure by conventional mechanical instruments. The risk of accidental damage to adjacent soft tissue structures, such as nerves, by a dental drill or saw is also extremely high. The use of modulated ultrasound (piezosurgery) makes it possible to overcome such complications as a result of the precise and minimally invasive surgery technique which is limited to mineralized hard tissue.

Background and Objectives Zirconia implants (ZI) are becoming more popular in implant dentistry, as a result of their favorable esthetic outcome. However, little is known about the impact laser application has on this material in the course of peri-implantitis treatment. The objective of this investigation was to analyze the influence of Er:YAG, CO2 and diode laser irradiation on polished ZI. Material and Methods Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic disks were irradiated at different power settings with either an Er:YAG, CO2 or diode laser. The surface of the disks was analyzed by scanning electron microscopy (SEM) and confocal 3D white light microscopy (CWLM). In addition energy-dispersive X-ray (EDX) analysis was performed on all disks. Six specimens were used for each parameter set of each laser. Results SEM analysis demonstrated that, regardless of the power settings, neither the diode laser nor the Er:YAG laser caused any visible surface alterations to ZI. The results of the CWLM were in agreement with the SEM pictures. However, Er:YAG irradiation did penetrate through the disks. At various power settings, the CO2 treatment was characterized by material cracking and melting. The increased roughness values (from CWLM) of the ZI underlined the SEM observations. Conclusion In contrast to diode and Er:YAG laser irradiation, the CO2 laser revealed distinct surface alterations to zirconia at various laser parameters. However, the Er:YAG laser cannot be recommended for the treatment of ailing implants, as the laser beam penetrates the material. In this respect, currently, diode lasers seem to be the only laser systems offering surface preservation and safety in the treatment of peri-implantits with ZI. Laser Surg. Med. 40:223–228, 2008. © 2008 Wiley-Liss, Inc.

With a wavelength of 2.94 mum, the erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser is suitable for cutting vital osseous tissue. To analyze the benefit of laser osteotomy in implant dentistry, a fiber-guided Er:YAG laser was used for harvesting intraoral bone grafts.In 10 consecutive patients (six males and four females), 12 block grafts were obtained from the ramus (nine cases), chin (two cases), and tuberosity (one case) region. For the osteotomies, the laser settings included a pulse energy of 500 mJ, a pulse duration of 250 microseconds, and a pulse frequency of 12 Hz. During osteotomy, the laser fiber tip was kept 1 to 2 mm away from the bone surface.Cut efficiency was satisfactory with almost no constraint on the positioning of the laser tip. Laser osteotomy was precise and allowed the blocks to be prepared with minimal waste of bone. The risk for accidentally injuring adjacent soft tissues was minimal. The postoperative wound-healing process was not impaired, and there were no signs of carbonization; however, the surgical procedures were time consuming.Using the Er:YAG laser with the aforementioned settings, successful laser osteotomy was achieved without any complications. However, because laser osteotomy was time-intensive and offered no depth control, it demonstrated only slight advantages for intraoral bone-grafting procedures. If the ablation process could be accelerated, the Er:YAG laser would be a promising alternative to conventional instruments for this surgical technique.

The aim of this study was to analyse the osseointegrative potential of phosphoserine-tethered dendrons when applied as surface functionalisation molecules on titanium implants in a sheep model after 2 and 8 weeks of implantation. Uncoated and dendron-coated implants were implanted in six sheep. Sandblasted and etched (SE) or porous additive manufactured (AM) implants with and without additional dendron functionalisation (SE-PSD; AM-PSD) were placed in the pelvic bone. Three implants per group were examined histologically and six implants were tested biomechanically. After 2 and 8 weeks the bone-to-implant contact (BIC) total values of SE implants (43.7 ± 12.2; 53.3 ± 9.0 %) and SE-PSD (46.7 ± 4.5; 61.7 ± 4.9 %) as well as AM implants (20.49 ± 5.1; 43.9 ± 9.7 %) and AM-PSD implants (19.7 ± 3.5; 48.3 ± 15.6 %) showed no statistically significant differences. For SE-PSD and AM-PSD a separate analysis of only the cancellous BIC demonstrated a statistically significant difference after 2 and 8 weeks. Biomechanical findings proved the overall increased stability of the porous implants after 8 weeks. Overall, the great effect of implant macro design on osseointegration was further supported by additional phosphoserine-tethered dendrons for SE and AM implants.

OBJECTIVE To evaluate ridge preservation after ridge splitting with simultaneous implant placement and guided bone regeneration (GBR) in a miniature pig model. MATERIAL AND METHODS In miniature pigs, the mandibular premolars and first molars were extracted together with removal of the interdental and buccal bone. Three months later, ridge splitting and expansion of the buccal plate were performed with simultaneous placement of two titanium implants per quadrant. On the test side, access by a mucoperiosteal flap followed by GBR with a biphasic calcium phosphate and a collagen membrane was performed. On the contralateral control side, a mucosal flap (MF), leaving the periosteum attached to the buccal bone, was elevated. After healing periods of 6 and 12 weeks, eight and four animals, respectively, were sacrificed for histological and histometric evaluation. RESULTS In the MF group, all 16 implants were osseointegrated, while in the GBR group, one bone fracture occurred, and six of 16 implants were lost. After 6 weeks, significantly higher bone crest levels were found for the GBR group than for the MF group both buccally and lingually (P

OBJECTIVE To evaluate the role of the periosteum in preserving the buccal bone after ridge splitting and expansion with simultaneous implant placement. MATERIAL AND METHODS In 12 miniature pigs, the mandibular premolars and first molars were removed together with the interdental bone septa and the buccal bone. Three months later, ridge splitting and expansion of the buccal plate was performed with simultaneous placement of two titanium implants per quadrant. Access by a mucosal flap (MF) was prepared on test sides, while a mucoperiosteal flap (MPF) with complete denudation of the buccal bone was increased on control sides. After healing periods of six and 12 weeks, the animals were sacrificed for histologic and histometric evaluation. RESULTS In the MF group, all 16 implants were osseointegrated, while in the MPF group, four of 16 implants were lost. Noticeable differences of bone levels on the implant surface and of the bone crest (BC) were found between the MF and the MPF group. Buccally after 6 weeks, the median distance between the implant shoulder (IS) and the coronal-most bone on the implant (cBIC) was for the MF group -1.42 ± 0.42 mm and for the MPF group -4.80 ± 2.72 mm (P = 0.15). The median distance between the IS and the buccal BC was -1.24 ± 0.51 mm and -2.78 ± 1.98 mm (P = 0.12) for the MF and MPF group, respectively. After 12 weeks, median IS-cBIC was -2.12 ± 0.84 mm for MF and -7.19 mm for MPF, while IS-BC was -2.08 ± 0.79 mm for MF and -5.96 mm for MPF. After 6 weeks, the median buccal bone thickness for MF and MPF was 0.01 and 0 mm (P < 0.001) at IS, 1.48 ± 0.97 mm and 0 ± 0.77 mm (P = 0.07) at 2 mm apical to IS, and 2.12 ± 1.19 mm and 1.72 ± 01.50 mm (P = 0.86) at 4 mm apical to IS, respectively. After 12 weeks, buccal bone thickness in the MF group was 0 mm at IS, 0.21 mm at 2 mm apical to IS, and 2.56 mm at 4 mm apical to IS, whereas complete loss of buccal bone was measured from IS to 4 mm apical to IS for the MPF group. CONCLUSIONS In this ridge expansion model in miniature pigs, buccal bone volume was significantly better preserved when the periosteum remained attached to the bone.

Background The orbit is prone to being affected by an odontogenous infection, owing to its anatomical proximity to the maxillary sinus. A possible reason for an ophthalmic manifestation of a dental abscess is extraction of an acutely inflamed tooth. Case Description The authors describe the treatment of a man who had painful swelling and redness in the area of his right eye after having a maxillary molar extracted a few days previous. A general dentist referred the patient to the clinic after he began to experience a progressive deterioration of vision of his right eye. Emergency surgical intervention prevented impending loss of vision, and subsequent healing was uneventful. Clinical Implications To avoid serious complications, clinicians should not perform a tooth extraction when the patient is in the acute stage of a maxillary sinus infection. Appropriate diagnostic imaging and profound evaluation of the clinical state play major roles in managing the treatment of patients with inflammatory processes that involve the oral and paraoral regions.

The aim of this case series was to clinically demonstrate successful prevention of bone resorption of the buccal wall after alveolar bone splitting by additional stabilization of the lateral bone plate using a biphasic ceramic bone substitute. In three patients alveolar bone splitting was performed with a piezoelectric device. Clinical as well as radiological results after two and five years revealed stable hard and soft tissue conditions with no soft tissue recessions and peri-implant bone loss in three patients. The advantage of this one-stage procedure was the ability to insert dental implants into a very compromised bony site in a simultaneous procedure. Yet the bone splitting stabilisation technique appeared to be a more user-sensitive method.

Objectives The aim of this study was to compare two different surfaces of one uniform macro-implant design in order to focus exclusively on the osseointegration properties after 2, 4 and 8 weeks and to discuss the animal model chosen. Material and methods In six mature sheep, n = 36 implants with a highly crystalline and phosphate-enriched anodized titanium oxide surface (TiU) and n = 36 implants with a hydrophilic, sandblasted, large grit and acid-etched surface (SLA) were placed in the pelvic bone. TiU implants were custom-made to match the SLA implant design. The implant stability and bone-to-implant contact (BIC) were assessed by resonance frequency (ISQ), backscatter scanning electron microscopy (B-SEM), light microscopy (LM), micro-CT and intravital fluorochrome staining. Biomechanical removal torque testing was performed. Results Overall, no statistically significant differences in BIC total (trabecular + cortical) between TiU and SLA were found via LM and B-SEM. BIC values (B-SEM; LM) in both groups revealed a steady rise in trabecular bone attachment to the implant surface after 2, 4 and 8 weeks. In the 2- to 4-week time interval in the TiU group (P = 0.005) as well as in the SLA group (P = 0.01), a statistically significant increase in BIC trabecular could be observed via LM. B-SEM values confirmed the statistically significant increase for TiU (P = 0.001). In both groups, BIC trabecular values after 8 weeks were significantly higher (P ≤ 0.05) than after 2 weeks (B-SEM; LM). Biomechanical data confirmed the histological data. Conclusion The two surfaces proved comparable osseointegration in this sheep model.

This in vitro study examined (a) the anti-bacterial efficacy of a pulsed erbium-doped yttrium aluminum garnet (Er:YAG) laser applied to Streptococcus sanguinis or Porphyromonas gingivalis adhered to either polished or microstructured titanium implant surfaces, (b) the response of osteoblast-like cells and (c) adhesion of oral bacteria to titanium surfaces after laser irradiation. Thereto, (a) bacteria adhered to titanium disks were irradiated with a pulsed Er:YAG laser (λ = 2,940 nm) at two different power settings: a lower mode (12.74 J/cm(2) calculated energy density) and a higher mode (63.69 J/cm(2)). (b) After laser irradiation with both settings of sterile titanium, disks were seeded with 10(4) MG-63 cells/cm(2). Adhesion and proliferation were determined after 1, 4, and 24 h by fluorescence microscopy and scanning electron microscopy. (c) Bacterial adhesion was also studied on irradiated (test) and non-irradiated (control) surfaces. Adhered P. gingivalis were effectively killed, even at the lower laser setting, independent of the material's surface. S. sanguinis cells adhered were effectively killed only at the higher setting of 63.69 J/cm(2). Laser irradiation of titanium surfaces had no significant effects on (b) adhesion or proliferation of osteoblast-like MG-63 cells or (c) adhesion of both oral bacterial species in comparison to untreated surfaces. An effective decontamination of polished and rough titanium implant surfaces with a Er:YAG laser could only be achieved with a fluence of 63.69 J/cm(2). Even though this setting may lead to certain surface alterations, no significant adverse effect on subsequent colonization and proliferation of MG-63 cells or increased bacterial adhesion was found in comparison to untreated control surfaces.

The aim of the present study was to evaluate a new multi-phosphonate surface treatment (SurfLink®) in an unloaded sheep model. Treated implants were compared to control implants in terms of bone to implant contact (BIC), bone formation, and biomechanical stability. The study used two types of implants (rough or machined surface finish) each with either the multi-phosphonate Wet or Dry treatment or no treatment (control) for a total of six groups. Animals were sacrificed after 2, 8, and 52 weeks. No adverse events were observed at any time point. At two weeks, removal torque showed significantly higher values for the multi-phosphonate treated rough surface (+32% and +29%, Dry and Wet, respectively) compared to rough control. At 52 weeks, a significantly higher removal torque was observed for the multi-phosphonate treated machined surfaces (+37% and 23%, Dry and Wet, respectively). The multi-phosphonate treated groups showed a positive tendency for higher BIC with time and increased new-old bone ratio at eight weeks. SEM images revealed greater amounts of organic materials on the multi-phosphonate treated compared to control implants, with the bone fracture (from the torque test) appearing within the bone rather than at the bone to implant interface as it occurred for control implants., Journal of functional biomaterials, 5 (3), ISSN:2079-4983

Purpose: The purpose of this study was to compare bone healing of experimental osteotomies applying either piezosurgery or two different oscillating saw blades in a rabbit model. Methods: The 16 rabbits were randomly assigned into four groups to comply with observation periods of one, two, three and fiveweeks. In all animals, four osteotomy lines were performed on the left and right nasal bone using a conventional saw blade, a novel saw blade and piezosurgery. Results: All three osteotomy techniques revealed an advanced gap healing starting after oneweek. The most pronounced new bone formation took place between two and threeweeks, whereby piezoelectric surgery revealed a tendency to faster bone formation and remodelling. Yet, there were no significant differences between the three modalities. Conclusions: The use of a novel as well as the piezoelectric bone-cutting instrument revealed advanced bone healing with a favourable surgical performance compared to a traditional saw

The aim of the present study was to evaluate deviations between virtually planned and placed implants by the use of skeletally supported stereolithographic templates.Ten consecutive patients were selected for virtual three-dimensional implant planning using the Facilitate(TM) software (Astra Tech AB, Mölndal, Sweden). Computer tomography images were obtained in the pre- and postoperative phase. Four deviation parameters (i.e. global, angular, depth, and lateral deviation) were defined and calculated between the planned and the placed implants, using the coordinates of their respective apical and coronal points.Deviations at the coronal positions appeared to be smaller (95% confidence interval: 0.15-1.0) as compared with apical positions (95% confidence interval: 0.14-1.1). But only the difference with regard to lateral measurements appeared to be statistically significant (p = .03). Except for depth (p = .01), no significant association between mesial or more distal locations could be detected concerning global (p = .07), lateral (p = .87), and angular (p = .56) values in mixed model analyses. Overall, there was a slight tendency for higher values for more distal locations.As slight deviations between planned and placed implants especially may occur even with skeletal-supported templates, the clinician should be aware not to overestimate advocated surgical safety by using static navigation tools.

Bone augmentation is a vital part of surgical interventions of the oral and maxillofacial area including dental implantology. Prior to implant placement, sufficient bone volume is needed to reduce the risk of peri-implantitis. While augmentation using harvested autologous bone is still considered as gold standard, many surgeons prefer bone substitutes to reduce operation time and to avoid donor site morbidity. To assess the osteogenic efficacy of commercially available augmentation materials we analyzed drill cores extracted before implant insertion. In younger patients, distraction osteogenesis is successfully applied to correct craniofacial deformities through targeted bone formation. To study the influence of mesenchymal stem cells on bone regeneration during distraction osteogenesis, human mesenchymal stem cells were injected into the distraction gap of nude rat mandibles immediately after osteotomy. The distraction was performed over eleven days to reach a distraction gap of 6 mm. Both the rat mandibles and the drill cores were scanned using synchrotron radiation-based micro computed tomography. The three-dimensional data were manually registered and compared with corresponding two-dimensional histological sections to assess bone regeneration and its morphology. The analysis of the rat mandibles indicates that bone formation is enhanced by mesenchymal stem cells injected before distraction. The bone substitutes yielded a wide range of bone volume and degree of resorption. The volume fraction of the newly formed bone was determined to 34.4% in the computed tomography dataset for the augmentation material Geistlich Bio-Oss®. The combination of computed tomography and histology allowed a complementary assessment for both bone augmentation and distraction osteogenesis.

Background In the present study, 4 different metallic implant materials, either partly coated or polished, were tested for their osseointegration and biocompatibility in a pelvic implantation model in sheep. Methods Materials to be evaluated were: Cobalt-Chrome (CC), Cobalt-Chrome/Titanium coating (CCTC), Cobalt-Chrome/Zirconium/Titanium coating (CCZTC), Pure Titanium Standard (PTST), Steel, TAN Standard (TANST) and TAN new finish (TANNEW). Surgery was performed on 7 sheep, with 18 implants per sheep, for a total of 63 implants. After 8 weeks, the specimens were harvested and evaluated macroscopically, radiologically, biomechanically (removal torque), histomorphometrically and histologically. Results Cobalt-Chrome screws showed significantly (p = 0.031) lower removal torque values than pure titanium screws and also a tendency towards lower values compared to the other materials, except for steel. Steel screws showed no significant differences, in comparison to cobalt-chrome and TANST, however also a trend towards lower torque values than the remaining materials. The results of the fluorescence sections agreed with those of the biomechanical test. Histomorphometrically, there were no significant differences of bone area between the groups. The BIC (bone-to-implant-contact), used for the assessment of the osseointegration, was significantly lower for cobalt-chrome, compared to steel (p = 0.001). Steel again showed a lower ratio (p = 0.0001) compared to the other materials. Conclusion This study demonstrated that cobalt-chrome and steel show less osseointegration than the other metals and metal-alloys. However, osseointegration of cobalt-chrome was improved by zirconium and/or titanium based coatings (CCTC, TANST, TAN, TANNEW) being similar as pure titanium in their osseointegrative behavior., BMC Musculoskeletal Disorders, 13, ISSN:1471-2474

Dental implants are prone to bacterial colonization which may result in bone destruction and implant loss. Treatments of peri-implant disease aim to reduce bacterial adherence while leaving the implant surface intact for attachment of bone-regenerating host cells. The aims of this study were to investigate the antimicrobial efficacy of gaseous ozone on bacteria adhered to various titanium and zirconia surfaces and to evaluate adhesion of osteoblast-like MG-63 cells to ozone-treated surfaces. Saliva-coated titanium (SLA and polished) and zirconia (acid etched and polished) disks served as substrates for the adherence of Streptococcus sanguinis DSM20068 and Porphyromonas gingivalis ATCC33277. The test specimens were treated with gaseous ozone (140 ppm; 33 mL/s) for 6 and 24 s. Bacteria were resuspended using ultrasonication, serially diluted and cultured. MG-63 cell adhesion was analyzed with reference to cell attachment, morphology, spreading, and proliferation. Surface topography as well as cell morphology of the test specimens were inspected by SEM. The highest bacterial adherence was found on titanium SLA whereas the other surfaces revealed 50–75% less adherent bacteria. P. gingivalis was eliminated by ozone from all surfaces within 24 s to below the detection limit (≥99.94% reduction). S. sanguinis was more resistant and showed the highest reduction on zirconia substrates (>90% reduction). Ozone treatment did not affect the surface structures of the test specimens and did not influence osteoblastic cell adhesion and proliferation negatively. Titanium (polished) and zirconia (acid etched and polished) had a lower colonization potential and may be suitable material for implant abutments. Gaseous ozone showed selective efficacy to reduce adherent bacteria on titanium and zirconia without affecting adhesion and proliferation of osteoblastic cells. This in vitro study may provide a solid basis for clinical studies on gaseous ozone treatment of peri-implantitis and revealed an essential base for sufficient tissue regeneration.

In the presented work, we investigated the potential capabilities of contrast improvement in soft tissue achieved by x-ray phase contrast imaging. The Talbot-Lau interferometer method was implemented by means of x-ray diffraction gratings. Tomographic measurements were performed on prepared samples containing specimens of different kinds of soft animal tissue. The results showed that phase contrast can provide additional and complementary visualization of soft tissue structures that are invisible to conventional, attenuation contrast x-ray imaging. As an example, the results obtained from the tomography of a bovine artery show that whereas the fat and connective tissue present around the artery can be seen with both absorption and phase contrast, the artery itself can only be recognized in the phase contrast image. Moreover, the situation is even more complicated for specimens containing not only soft tissue but also stronger absorbers such as bones or cartilage. Indeed, the strongly absorbing bones also lead to the scattering of the x-ray beam (due to their dense micro-structure), which results in a loss of the phase information. However, this issue relaxes when higher x-ray energies are used. Measurements of specimens (containing bones and soft tissue) were demonstrated with the set-up optimized for a mean x-ray energy of 50keV.

It was the aim of this study to compare the feasibility of complete osteotomy of long bones in sheep using a newly designed variable square pulsed Er:YAG laser and piezoelectric surgery. In addition to uneventful bone healing after laser osteotomy, the goal was to assess the possibility to cut thick bony structures with both techniques in a surgically acceptable time frame of 2-3 minutes.A tibia midshaft osteotomy was performed in 24 sheep using either an Er:YAG laser (n = 12) or piezoelectric device (n = 12). Laser and piezoelectric groups were divided in two subgroups (n = 6) with sheep sacrificed after 2 and 3 months, respectively. A complete radiological, histological and histomorphometric analysis was performed to compare the course of bone/fracture healing and remodelling.Laser and piezoelectric osteotomies of the sheep tibia up to a depth of 22 mm were possible without any thermal damage. Radiological and histological results after 2 months showed primary gap healing with distinct periosteal callus formation on the transcortex. After 3 months, radiological and histological analysis revealed less callus formation on the transcortex, with almost no visible osteotomy gap and a distinct formation of lamellar bone crossing the original osteotomy gap.Er:YAG laser osteotomy can successfully be used in long bones with a depth of up to 22 mm, thus challenging the dogma of adverse effects of laser osteotomy due to thermal or other damages.

Background and Objectives The aim of this study was to examine the influence of implant bed preparation, using either Er:YAG laser ablation, piezoelectric surgery or drill osteotomy, on osseointegration of titanium dental implants after 4, 6, and 8 weeks. Material and Methods A total of 108 implants (Camlog) were placed in the pelvis of 6 sheep (18 implants/sheep). Implant sites were prepared by an Er:YAG laser, a dental drill or a piezoelectric device. For each time period, six implants were used for biomechanical removal torque testing and six implants for a semi-quantitative histological assessment of the bone-to-implant contact (BIC). Results An initially missing implant adjusted site preparation led to slightly higher BIC and torque values in the piezoelectric and laser groups due to a press-fit effect after 4 weeks. Statistical analysis of the average mean BIC after 4, 6, and 8 weeks revealed no significant differences (P > 0.05) between the different osteotomy techniques. Comparison of individual removal torque values showed the highest value for laser osteotomy after 8 weeks (1,698.50 ± 67.52 Nmm), which was significantly higher than the corresponding value for drill osteotomy (P = 0.006). Conclusion Although BIC and removal torque values decreased in the laser and piezoelectric groups at 6 weeks during an active remodeling process, favorable and superior BIC as well as torque values could be demonstrated at 8 weeks. Thus laser and piezoelectric osteotomy seem to be at least comparable to drill osteotomy, concerning early osseointegration and implant stability. Lasers Surg. Med. 42:652–661, 2010. © 2010 Wiley-Liss, Inc.

The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascularization significantly decreased until day 90 after implantation. In this time period, the bone substitute underwent a significant degradation initiated by TRAP-positive and TRAP-negative multinucleated giant cells together with macrophages and lymphocytes. Although no specific tissue reaction could be related to the described silica degradation, the biomaterial was close to being fully degraded without a severe inflammatory response. These characteristics are advantageous for bone regeneration and remodeling processes.

To evaluate the usability of a variable square pulse (VSP) erbium-doped yttrium aluminium garnet (Er:YAG) laser for a lateral access osteotomy to the maxillary sinus in the course of a sinus elevation procedure.In six formalin-fixed human heads and six fresh sheep heads, a VSP Er:YAG laser was used to perform a bilateral maxillary access osteotomy. For the osteotomies, the Er:YAG laser was applied with a pulse energy of 1000 mJ, a pulse duration of 300 mus, and a frequency of 12 Hz. The spot size was 0.9 mm, and the handpiece was kept approximately 10 mm from the bone surface.In all 24 sites investigated, the Er:YAG laser osteotomy was possible without any visible carbonization or thermal damage. The average time required for laser osteotomy for 12 standardized rectangular lateral windows in human cadavers was 39 s. No anatomical structures limited laser osteotomy, yet a critical evaluation of any membrane perforations was not possible because the postmortem fixation method caused partial detachment and fractional destruction. Laser-access osteotomy in six fresh sheep heads (12 sites) revealed major disruptions and perforations (8 mm) of the sinus membrane (100%).Even though VSP Er:YAG laser osteotomy showed convincing results for efficient bone cutting without thermal damage, applied laser parameters do not seem to be practicable for any clinical sinus elevation procedure. Missing depth control resulted in uncontrollable severe damage of the underlying membrane.

This technical note describes a new surgical technique for a palatal approach to the maxillary sinus for a vertical augmentation prior to dental implant placement. In 12 fully or partially edentulous patients (seven women, five men), 16 palatal sinus elevations were performed. After elevation of palatal full-thickness flap a rectangular access window was cut with a piezosurgical device. The raised sinus cavity was augmented with a synthetic nano-structured hydroxyapatite-based graft material. No harm occurred to the greater palatine artery or the sinus membrane. The vestibular and periimplant gingiva were preserved and there was no disharmonious soft tissue distortion or massive scar formation. Swelling and bleeding were minimal. Primary stability was achieved for all but one implant. This technique may be an alternative to other sinus augmentation approaches in cases where enough transversal width of the posterior alveolar crest is available.

A dorsal pedicled buccal musculomucosal flap was developed to reconstruct medium-sized intraoral defects, too large for primary closure if major functional and esthetic impairment is to be avoided. Although free flaps, axial, or perforator flaps are excellent in large defects, they may not provide mucosal sensitivity, motility, volume, and texture to replace lost structures with similar tissue. Twenty-five flaps were performed in 24 patients, 1(bilateral) up to a flap-size of 60 x 35 mm, in average 45 x 34 mm. Reconstructed became the lateral mouth floor, lateral oral vestibule, lateral tongue margin, the oropharynx, hard and soft palate. Partial necrosis occurred in 1 flap, 22 (92%) patients recovered with good objective as subjective speech and swallowing, esthetics, and if necessary prosthetic rehabilitation. The donor site was closed primarily, mimics and mouth opening resolved after less than 3 months. The parotid duct had to be marsupialized in large flap preparations, never provoking stasis or infection. The 2-point sensitivity of the flaps was in average equal to the nonoperated mucosa in intraindividual correlation and the flaps lost in average 10% of their original size; 5 (21%) had weakness inflating their cheeks postoperatively. The results indicate dorsal pedicled buccal musculomucosal flap to be reliable and technically easy for reconstructing lateral intraoral, medium-sized defect that yields sensitivity, merely risking occasional buccal muscle weakness but facilitating the rehabilitation of oral function.

This study presents successful maxillofacial prosthetic rehabilitation using telescopic and crowns on zygoma implants as abutments.Fifteen patients received 36 zygomatic and 24 dental implants and were followed-up for an average of 65 months (range: 13 to 102 months). Machined zygoma implants were positioned classically in the maxillary molar region. In larger defects, premolar and canine implants were also used. Follow-up included implant and prosthetic success parameters as well as the completion of the Oral Health Impact Profile (OHIP14G).Seventy-three percent of patients during the study period did not encounter notable complications after prosthetic rehabilitation. There was an 89% cumulative 8-year zygoma implant survival rate and a 100% survival rate for the dental implants. Three losses occurred due to overloading and persistent infection; each was immediately replaced. Five successfully osseointegrated implants had to be removed in two patients due to recurrences of disease; one patient died. Peri-implant bleeding and plaque index scores decreased. After prosthetic treatment with electroplated gold or galvanotelescopes, all patients who had participated in the follow-up declared function (i.e., retention, speech, and mastication) and esthetics as having improved. Other positive aspects mentioned were good hygiene, comfortable usage, and a decrease in sore spots. OHIP scores were 25 +/- 12 on a scale of 0 (no impairment) to 56 (maximum impairment).Within the limitations of this study (a variable evaluation period), it was observed that zygomatic implants are reliable retention for maxillofacial prostheses. Losses were diagnosed as occuring primarily from chronic infection and overloading. A trapezoid prosthesis design support is recommended with a sufficient number of implants.

Even though it is known that dental injuries may occur in connection with tracheal intubation, the topic has hardly been evaluated in literature so far. Thus, this retrospective study was conducted including the data of 115-151 patients. All patients involved had been exposed to general anesthesia between 1995 and 2005. The resulting tooth injuries were assessed according to the following parameters: age, kind of hospital conducting treatment, intubation difficulties, pre-existing tooth damage, type and localization of tooth, type of tooth damage, and the number of teeth injured. At least 170 teeth were injured in 130 patients, while patients 50 years of age and older were especially affected. In contrast to older patients where in the majority of cases the periodontium (lateral dislocation) was injured, in younger patients dental hard tissue (crown fracture) was more likely to be affected. It was calculated that patients from the cardiothoracic surgery clinic were showing the highest risk of tooth damage. In more than three-fourth of all cases the anterior teeth of the maxilla, especially the maxillary central incisors, were affected. Pre-existing dental pathology like caries, marginal periodontitis and tooth restorations were often distinguishable prior to operation. Mouthguards in connection with tracheal intubation are not generally recommended as preventive device, due to the already limited amount of space available. Instead, pre-existing risk factors should be thoroughly explored before the induction of intubation narcosis.