[Show abstract][Hide abstract] ABSTRACT: Prosthodontically driven biomechanical considerations are essential for longterm successful outcomes in dental implant therapy. Correct protocols seek to preclude potential consequences associated with functional and parafunctional occlusal overload such as screw loosening, component fracture, compromised marginal bone maintenance, and the integrity of the induced osseointegration response. Other concerns also need to be addressed, more especially when other implants are selected, for example: bridge insertion torque (BIT) in cases of immediate loading, cantilever length-anteroposterior spread ratio (CL-AP), overall crown-to-implant ratio (oCIR), total bone-to-implant surface area (tBICA), and the status of the opposing dentition. In spite of promising clinical results, evidence-based clinical protocols demand that such biomechanical limits still need to be determined.
The International journal of prosthodontics 07/2015; 28(4):412-414. · 1.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bone grafting of the maxillary sinus is attempted to compensate for sinus pneumatization and permit reliable insertion of endosseous dental implants for prosthetic rehabilitation. The aim of the present clinical investigation was to study bone regeneration four months after transcrestal sinus floor elevation via the Gel-Pressure Technique (GPT) and application of pasteous nano-crystalline hydroxyapatite bone substitute. A total of 25 patients with deficient alveolar ridges in the posterior maxilla (mean residual bone height: 4.7 ± 1.8 mm) were subjected to 32 flapless transcrestal sinus floor augmentations and simultaneous insertion of 40 implants. Sinus membrane elevation height averaged 11.2 ± 2.7 mm and minimal vertical graft resorption of 0.1 mm was observed after four months. Radiographic bone density averaged 460 Hounsfield units in regions adjacent to the native jawbone (1 to 7 mm distance), while reduction of bone density by −7.2%, −11.3%, −14.8%, −19.6% and −22.7% was recorded in more apical regions of 8, 9, 10, 11, and ≥12 mm distance to the original sinus floor, respectively. The results suggest that graft remodeling is completed up to a distance of 7 mm within a healing period of four months after sinus augmentation using nano-crystalline hydroxyapatite bone substitute material.
[Show abstract][Hide abstract] ABSTRACT: Hintergrund Das angeborene Ausbleiben der Zahnentwicklung zählt zu den häufigsten Anomalien. Der Leidensdruck der Betroffen wird neben ästhetischen Problemen durch oft schwere Einschränkungen im alltäglichen und psychosozialen Leben verstärkt. Die Therapie ist meist sehr zeitaufwendig, kostspielig und häufig mit mehreren chirurgischen Eingriffen kombiniert. Therapie Primär richtet sich die Therapieentscheidung nach der Anzahl der Zahnaplasien und dem Patientenalter. Es gibt verschiedene Therapieansätze, dabei ist das skeletale Wachstum ein stark limitierender Faktor bei der Sanierung mithilfe enossaler Implantate. Die Behandlung ist oft komplex, daher ist ein multidisziplinäres Wissen von essenzieller Bedeutung. Die Planung der Therapie muss bei jedem Patienten individuell erfolgen. Die Betreuung in Spezialambulanzen, die auf langjährige Erfahrung in der Behandlung von Zahnaplasien zurückgreifen können, wird deshalb dringend empfohlen.
[Show abstract][Hide abstract] ABSTRACT: Aim: The aim of the present study was to demonstrate the effectiveness of socket grafting followed by guided implant placement in the esthetic zone of the maxilla in terms of esthetic outcome and preservation of periimplant papillae.
Material and Methods: In a total of 25 patients the buccal bony lamella was not intact after extraction of anterior maxillary teeth (13–23) and thus they did not qualify for immediate implant placement. Socket augmentation surgery using a collagen sponge (Bio-Oss Collagen®, Geistlich, Wolhusen, Switzerland) was performed and flapless implants were placed after 4 months of healing using virtual treatment planning (Nobel-Guide™, Nobel Biocare, Gothenborg, Sweden). Marginal bone resorption and implant esthetics were assessed using the Pink Esthetic Score 1 year after crown delivery.
Results: Satisfactory implant esthetics (Pink Esthetic Score of 10 or higher) could be achieved in the majority of patients (71% compared to 56% after bone augmentation procedures involving mucoperiosteal flaps). Papillae could be preserved to their full extent in 77% of cases – compared to only 13% after conventional two-stage surgery.
Conclusion: The present study proves that the concept of flapless augmentation at the time of tooth extraction (socket grafting) followed by flapless implant placement by the use of virtual treatment planning software and stereolithographic templates carries the potential to significantly increase the esthetic outcome of single-tooth implants by 15% and decrease loss of periimplant papillae by 64%.
[Show abstract][Hide abstract] ABSTRACT: Background
Flapless implant placement using surgical templates may guarantee predictable and esthetic results provided that preplanned implant positions are transfered precisely into surgical reality.PurposeThe study aims to investigate the effect of three-dimensional accuracy in guided implant surgery on the esthetic outcome of single-tooth implants in the anterior maxilla.Materials and Methods
Single-tooth implants for delayed replacement of upper incisors were inserted in 27 patients using stereolithographic templates. Superimposition of postoperative cone beam computed tomography (CBCT) scans allowed assessment of positional inaccuracy at the implant shoulder and apex, as well as angular deviation. Objective evaluation of implant esthetics was performed after a mean follow-up of 2.3 years using the Pink Esthetic Score (PES).ResultsMean deviation between planned and actual implant position was 0.84 mm at the implant shoulder and significantly correlated to average PES of 12 (p = .031). Inaccuracy toward the buccal side was most frequent (70%). Deviations ≥ 0.8 mm resulted in significantly worse implant esthetics (median PES: 9.5, interquartile range [IQR]: 8–11) compared with more accurate implant positions (median PES: 13, IQR: 12–13, p = .039).Conclusion
Positional inaccuracy is low in guided implant surgery, but may however significantly compromise implant esthetics in the anterior maxilla.
Clinical Implant Dentistry and Related Research 11/2014; DOI:10.1111/cid.12264 · 2.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: AimThis study aimed to evaluate the healing of peri-implant defects grafted with microparticles (MPs).Material and Methods
Six domestic pigs received nine standardized defects at the calvaria, and an implant was inserted in the middle of each defect. The space between the implant and lateral bone portion was filled with MP pellets (n = 18) or MP supernatant (n = 18) or left unfilled (n = 18). After 14 and 28 days, three animals were sacrificed and specimens removed for further processing. Samples were microradiographically and histologically analysed. In addition, we immunohistochemically stained for anti-vWF as a marker of angiogenesis.ResultsIn the case of bone regeneration and vessel formation, the null hypothesis can be partially rejected. After 14 and 28 days, no significant difference was observed within groups regarding de novo bone formation, bone density and osseointegration. However, superior vessel formation was found at both time points.Conclusion
Microparticles represent a promising treatment option to accelerate peri-implant vessel formation. Further studies are needed to investigate the regenerative properties of MPs more precisely.
[Show abstract][Hide abstract] ABSTRACT: PurposeRehabilitation of the incomplete dentition by means of osseointegrated dental implants represents a highly predictable and widespread therapy; however, little is known about potential risk factors that may impair long-term implant success.MethodsFrom 2004 to 2012, a total of 13,147 implants were placed in 4,316 patients at the Academy for Oral Implantology in Vienna. The survival rates after 8 years of follow-up were computed using the Kaplan-Meier method, and the impact of patient- and implant-related risk factors was assessed.ResultsOverall implant survival was 97% and was not associated with implant length (P=0.930), implant diameter (P=0.704), jaw location (P=0.545), implant position (P=0.450), local bone quality (P=0.398), previous bone augmentation surgery (P=0.617), or patient-related factors including osteoporosis (P=0.661), age (P=0.575), or diabetes mellitus (P=0.928). However, smoking increased the risk of implant failure by 3 folds (P<0.001) and a positive history of periodontal disease doubled the failure risk (P=0.001).ConclusionsSumming up the long-term results of well over 10,000 implants at the Academy for Oral Implantology in Vienna it can be concluded that there is only a limited number of patients that do not qualify for implant therapy and may thus not benefit from improved quality of life associated with fixed implant-retained prostheses.Graphical Abstract
Journal of periodontal & implant science 06/2014; 44(3):102-8. DOI:10.5051/jpis.2014.44.3.102
[Show abstract][Hide abstract] ABSTRACT: Immediate implant placement has established itself over the last 10 years as a feasible treatment concept. This method supplies in strict application of inclusion criteria, predictable aesthetic results. The recent literature indicates a survival rate of 96-97%, which differs only slightly with 98% of the survival rate of late implantation. The case-report presents the therapy of a patient with multiple trauma in the frontal region, which was rehabilitated by immediate implantation and provisional restoration within a few hours. Due to the good prognosis for success, immediate implantation allows a fast and predictable solution of restoring function and aesthetics in the aesthetic area even in the case of trauma.
Informationen aus Orthodontie & Kieferorthopädie 06/2014; 46(2):117-121. DOI:10.1055/s-0034-1376955
[Show abstract][Hide abstract] ABSTRACT: To clinically and radiographically evaluate dental implant treatment in adolescents with extensive oligodontia.
Patients with more than nine permanent teeth congenitally missing and implant treatment before the age of 16 years were included. Clinical follow-ups involved bleeding on probing, plaque index and peri-implant probing value. The peri-implant bone level was analysed on panoramic radiographs at time of implant treatment and at follow-up. Characteristics of the dental implants and patients were retrieved.
This study involved 18 patients (nine males, nine females) having 71 dental implants. The lower left premolar was predominantly missing. The mean age at the time of dental implant treatment was 12.5 (±2.6) years. The bleeding on probing value was determined negative on 44%. The mean pocket depth was 3.6 (±1.1) mm. The peri-implant bone level correlated significantly negative with the age at time of implant placement (r = -0.346, P = 0.004). The region of implant habits had no influence on peri-implant bone level. Dental implant treatment in adolescents resulted in a survival rate of 89% (63/71) and a mean loading time of 11.0 (±4.1) years. The implant crowns to be renewed resulted in 54% (9 of 18 patients, 38 of 71 crowns) after a period of 7.8 ± 4.5 years.
Dental implant treatment in maturing adolescents with extensive oligodontia before is supported by the data of the present study. Providing that other treatment options are considered, the areas of skeletal growth are respected and the patients are well informed. To enhance quality of life of growing children with oligodontia clinicians are asked to evaluate their long-term outcome on dental implant treatment in adolescents.
[Show abstract][Hide abstract] ABSTRACT: Background: It has been an axiom in implant dentistry that longer and wider implants guarantee lower failure rates, although a linear relationship between implant dimensions and success has never been proven. Recently the application of short (<10 mm) and narrow-diameter implants (<3.75 mm) has increased significantly. However, it is still not known what minimal implant surface is needed to maintain osseointegration.
Aim/Hypothesis: The aim of the present study was to determine the exact amount of square-millimeters implant surface that is available for bone contact in implants of various length and diameter and apply these data on a retrospective sample set of patients carrying full-arch bridges.
Material and methods: Four hundred patients received full-arch bridges at the Academy for Oral Implantology Vienna between 2004 and 2013 on implants of 8 to 15 mm length and 3.5 to 5 mm diameter (NobelReplace, Nobel Biocare, Gothenburg, Sweden). Surfaces of all different types of implants were measured using a 5.0 megapixel laser-scanner. Total bone-to-implant contact area (tBICA) along with other factors was correlated to biological and technical success rates.
Results: There was a tendency for lower implant success and a higher frequency of technical complications (screw loosening, abutment or cast fracture, and repair of ceramics) in full-arch bridges showing low total bone-to-implant contact area (tBICA), however, multivariate analysis considering the influence of biomechanical factors did not reveal a defined threshold for minimal overall implant surface.
Conclusion and clinical implications: Total bone-to-implant contact area (tBICA) should exceed minimal thresholds, however, interactive effects with other influencing variables, such as anterior-posterior spread, cantilever length, and bridge insertion torque (in cases of immediate loading) need to be considered.
[Show abstract][Hide abstract] ABSTRACT: Purpose: To evaluate patient satisfaction, oral health-related quality of life, and patients' preferences towards minimally invasive treatment options for graftless rehabilitation of complete edentulism by means of dental implants. Material and methods: A MEDLINE search of literature in the English language up to the year 2013 was performed to summarise current evidence from the patient's perspective. The final selection included 37 studies reporting on minimally invasive implant treatment of 648 edentulous maxillae and 791 edentulous mandibles in 1328 patients, via a total of 5766 implants. Results: Patient satisfaction averaged 91% with flapless implant placement (range: 77 to 100%), 89% with short implants, 87% with narrow-diameter implants (range: 80 to 93%), 90% with a reduced number of implants (range: 77 to 100%), 94% with tilted implant placement (range: 58 to 100%), and 83% with zygomatic fixtures (range: 50 to 97%). Indirect comparison yielded patient preference towards tilted implant placement compared to a reduced number of implants (P = 0.036), as well as to zygomatic implants (P = 0.001). Conclusions: While little evidence on patients' preferences towards minimally invasive treatment alternatives vs. bone augmentation surgery could be identified from within-study comparison, it may be concluded that patient satisfaction with graftless solutions for implant rehabilitation of completely edentulous jaws is generally high. Comparative effectiveness research is needed to substantiate their positive appeal to potential implant patients and possible reduction of the indication span for invasive bone graft surgery. Conflict-of-interest notification: The authors declare that they have no conflict of interest.
[Show abstract][Hide abstract] ABSTRACT: Complete edentulism is a common problem in many countries and can be a serious disability. It concerns about one-fifth of the adult world population, in some countries reaching 50% at the age of 50. The decline in the prevalence of edentulism is offset by the increase of the elderly population. This leads to an increasing demand for implant-based treatments by the potential population of the 150 million who are completely edentulous.
The members of the consensus conference agreed that, when surgery is considered as a treatment option for edentulism, it should be seen as elective surgery.
European Journal of Oral Implantology 01/2014; 7(Suppl 2):235-238. · 2.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Zirconia is the material of choice for implant abutments in the anterior region of the maxilla due to its favorable biomechanical properties, biocompatability and color. Individual abutments carry the advantages of optimum soft tissue support and can be fabricated within 1 week after implant placement and loaded with temporary implant crowns that are replaced after 3–6 months of healing.
Aim/Hypothesis: The aim of the study was to determine treatment outcomes after early insertion of final individual zirconia abutments within 1 week after immediate implant placement in the esthetic zone of the maxilla.
Material and methods: The first 100 patients at the Academy for Oral Implantology (Vienna, Austria) that received 'Copy-Abutments', i.e. final individual zirconia abutments (NobelProcera, Nobel Biocare, Gothenborg, Sweden) within a week after immediate implant placement in the esthetic zone of the maxilla were evaluated in terms of implant success rate, marginal bone remodeling, patient satisfaction, and esthetic outcome using the Pink Esthetic Score.
Results: Treatment satisfaction was high (over 90% in general) and all complications occurred prior to final crown delivery, i.e. no Copy-Abutment had to be redone. Marginal bone levels were stable over the follow-up period up to 8 years. Satisfactory implant esthetics could be achieved in the majority of patients (Pink Esthetic Scores higher than 10).
Conclusion and clinical implications: Individual abutments made from zirconia within a week after immediate implant placement in the anterior maxilla can help to maintain the gingival profile and peri-implant papillae due to optimized soft tissue support in the early healing phase.
[Show abstract][Hide abstract] ABSTRACT: Background: Implant esthetics in the anterior maxilla are influenced by a number of variables including appropriate 3D implant positioning. Virtual treatment planning software and stereolithographic templates may not only permit flapless surgery, thus
preventing loss of interdental papilla and buccal soft-tissue recession, moreover, it may help to precisely achieve desired implant positions.
Aim/Hypothesis: The aim of the present study was to evaluate the association of three-dimensional accuracy of guided implant placement in the anterior maxilla and esthetic outcome assessed using the Pink Esthetic Score.
Material and methods: In 27 patients presenting with missing incisors in the esthetic zone of the upper jaw (12–22) delayed implant placement was performed using virtual treatment planning software (NobelClinician, Nobel Biocare, Gothenborg, Sweden) and stereolithographic mucosa-borne drilling templates (NobelGuide, Nobel Biocare, Gothenborg, Sweden). Deviations of actual implant positions were determined on postoperative cone-beam CT scans and Pink Esthetic Scores were assessed at the 3-year follow up.
Results: Implant esthetics were highly satisfactory (mean Pink Esthetic Score: 10.6 ± �2.2) and significantly correlated to mean accuracy of implant placement (1.2 �± 0.7 mm) at the implant shoulder. Deviations larger than 0.8 mm resulted in significantly compromised esthetic outcomes (mean Pink Esthetic Score: 9.7) compared to patients, in which more accurate transfer of planned implant positions into surgical reality could be achieved (mean Pink Esthetic Score: 12.1).
Conclusion and clinical implications: The present results demonstrate that accuracy of implant placement shows a significant impact on the esthetic results of single-tooth implants in the esthetic zone of the maxilla. Guided implant surgery – although subject to some amount of variability – may help to achieve optimum implant positions to guarantee long-term esthetic results.
[Show abstract][Hide abstract] ABSTRACT: Background: Immediate loading of full-arch bridges for rehabilitation of the edentulous maxilla or patients with failing maxillary dentition carries various advantages. No removable dentures have to be fabricated and worn for a healing period of up to 6 months. However, results in literature are still controversial regarding long-term implant success and marginal bone remodel-ing following immediate loading protocols.
Aim/Hypothesis: The aim of the study was to compare long-term survival and marginal bone loss of immediate implants in the edentulous maxilla subjected to either immediate or delayed loading protocols.
Material and methods: Two hundred and forty patients with failing maxillary dentition were rehabilitated at the Academy for Oral Implantology in the years 2004–2013, of which 981 implants were subjected to immediate loading and 235 implants to delayed loading. Kaplan-Meier survival estimates were computed and marginal bone loss was evaluated in a stratified random sample of 20 patients per group.
Results: Thirty-one of 1216 implants failed (2.5%) and no difference in implant survival rates between loading protocols could be seen. Marginal bone loss did not differ significantly between the immediate loading and delayed loading group (1.3 mm vs. 1.0 mm, P = 0.190).
Conclusion and clinical implications: Immediate loading of interantral implants in the edentulous maxilla yields favorable results compared to delayed loading and should be considered to allow for a fast and pleasant transition from tooth-retained to implant-retained rehabilitation of the edentulous maxilla.
[Show abstract][Hide abstract] ABSTRACT: Background: Buccal bone is frequently missing after tooth extraction in the esthetic zone of the maxilla due to chronic inflammation or trauma. Invasive bone grafting procedures may be used to increase bone volume prior to implant placement, however, it is often not possible to preserve soft tissue conditions and interdental papillae due to flap elevation and two-stage surgery. Thus, an all-flapless concept was developed.
Aim/Hypothesis: The aim of the present study was to demonstrate the effectiveness of socket grafting followed by guided implant placement in the esthetic zone of the maxilla in terms of esthetic outcome and preservation of peri-implant papillae.
Material and methods: In a total of 25 patients the buccal bony lamella was not intact after extraction of anterior maxillary teeth (13–23) and thus they did not qualify for immediate implant placement. Socket augmentation surgery using a collagen sponge (Bio-Oss Collagen, Geistlich, Wolhusen, Switzerland) was performed and flapless implants were placed after 4 months of healing using virtual treatment planning (NobelGuide, Nobel Biocare, Gothenburg, Sweden). Marginal bone resorption and implant esthetics were assessed 1 year after crown delivery.
Results: Satisfactory implant esthetics could be achieved in 71% of patients (compared to 56% after bone augmentation procedures involving mucoperiosteal flap). Papillae could be preserved to their full extent in 77% of cases (compared to 13% after conventional two-stage surgery).
Conclusion and clinical implications: The present study proves that the concept of flapless augmentation at the time of tooth extraction (socket grafting) followed by flapless implant placement by the use of virtual treatment planning software and stereolithographic templates carries the potential to increase the esthetic outcome of single-tooth implants by 15% and decrease loss of peri-implant papillae by 64%.
[Show abstract][Hide abstract] ABSTRACT: Dental implant fracture is a rare biomechanical complication, however, one of the most serious and frustating ones as it is generally associated with implant and prosthesis failure as well as the surgical hazards of explantation and reimplantation. To gain insights into implant fracture rates and the impact of patient-, surgery-, and prosthetic-related factors, systematic review and meta-analysis of the English literature were performed. Electronic and hand searches yielded 69 relevant publications reporting on 827 fractures out of 44521 implants investigated. The overall incidence of implant fractures was 1.6%. Mean patient age at the time of implant fracture was 54 ± 11 years, and 70% occurred in males. The vast majority (85%) occurred in posterior regions of the mouth (premolar or molar positions). No tendency of increased fracture rates could be noted for short implant lengths or narrow implant diameters. Implant fractures occurred after 4.1 ± 3.5 years of loading, on average, in most cases (88%) supporting fixed restorations; however, only 56% were preceded by screw loosening. Although further investigations are needed to fully explore the characteristics and causes of this rare complication, it can be concluded that no more than 2.8% of implants fracture is within a mean loading period of 8.3 years.
[Show abstract][Hide abstract] ABSTRACT: Adhesion of osteogenic cells on titanium surfaces is a prerequisite for osseointegration. Alkali treatment can increase the hydrophilicity of titanium implant surfaces, thereby supporting the adhesion of blood components. However, it is unclear if alkali treatment also supports the adhesion of cells with a fibroblastic morphology to titanium.
Here, we have used a titanium alloy (Ti-6AL-4V) processed by alkali treatment to demonstrate the impact of hydrophilicity on the adhesion of primary human gingival fibroblast and bone cells. Also included were the osteosarcoma and fibroblastoma cell lines, MG63 and L929, respectively. Cell adhesion was determined by scanning electron microscopy. We also measured viability, proliferation, and protein synthesis of the adherent cells.
Alkali treatment increased the adhesion of gingival fibroblasts, bone cells, and the two cell lines when seeded onto the titanium alloy surface for 1 h. At 3 h, no significant changes in cell adhesion were observed. Cells grown for 1 day on the titanium alloy surfaces processed by alkali treatment behave similarly to untreated controls with regard to viability, proliferation, and protein synthesis.
Based on these preliminary In vitro findings, we conclude that alkali treatment can support the early adhesion of cells with fibroblastic characteristics to a titanium alloy surface.
Clinical Oral Implants Research 12/2013; DOI:10.1111/clr.12294 · 3.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Die bei Weitem häufigste Ursache einer odontogenen Sinusitis maxillaris sind Mund-Antrum-Verbindungen nach Zahnentfernungen, die zu aufsteigenden Infektionen der Kieferhöhle führen. Weitere häufige Ursachen sind die periapikale rarefizierende Ostitis, Fremdkörper dentogenen Ursprungs, weit fortgeschrittene parodontale Abbauprozesse, odontogene Zysten sowie zunehmend auch Implantate, die oft nach augmentativen Eingriffen im Bereich der Kieferhöhle gesetzt wurden.