[Show abstract][Hide abstract] ABSTRACT: Background: Rehabilitation of the edentulous mandible using interforaminal implants and fixed full-arch bridges is a common treatment approach, however, little is known about biomechanic determinants.
Aim/Hypothesis: The aim of the present study was to investigate the impact of Bridge Insertion Torque, implant number and surface, anterior-posterior spread and cantilever length on implant treatment success in the edentulous mandible.
Material and methods: In 487 patients a total of 1900 implants were placed at the Academy for Oral Implantology (Vienna, Austria). Implant success was analyzed using Kaplan-Meier estimates [95% confidence interval] with regards to primary stability and biomechanical factors.
Results: The 8-year implant survival rate was 96% [94.5–97.3%] and did not differ between immediate and delayed implant placement (P = 0.810). The mean Bridge Insertion Torque was 45.6 Ncm, however, did not influence implant success. Mean marginal bone resorption was 1.4 ±� 0.9 mm and was not correlated to the number of implants placed or the total bone-to-implant contact surface. Significantly less bone resorption was seen with large AP spread ≥24 mm and short catilever lengths <5 mm.
Conclusions and clinical implications: Satisfactory long-term implant success can be observed following fixed full-arch bridges for rehabilitation of the edentulous mandible, particularly in cases of cantilever-AP spread-ratios <0.25.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: To quantify the reliability of a new drilling system for implant osteotomy characterized by an eccentric sensor that automatically stops the drill upon contact with soft tissue. This safety mechanism aims to minimize surgical trauma to nerves, vessels, and the maxillary sinus mucosa. The benefits of the eccentric sensor position on planar and angulated surfaces were tested in vitro.
MATERIALS AND METHODS: Predicted drill protrusion after auto-stop was validated against experiments on four human cadaver mandibles (30 osteotomies with varying angles). Measurement of the drill's exit holes allowed calculation of the amount of drill protrusion, and postoperative computed tomographic scans of the mandibles were acquired to determine the drill's exit angles.
RESULTS: Mean drill protrusion into human jawbone was 0.46 ± 0.26 mm and differed significantly from expected drill protrusion, which was based on mathematical modeling, of 0.64 ± 0.3 mm. Detection of bone passage on angulated walls was seen up to 71 degrees. A central sensor position, by contrast, may result in significantly greater drill protrusion into soft tissue (mean difference: 0.55 ± 0.49 mm) that increases with the drill's exit angle (r = 0.93).
CONCLUSION: Auto-stop drills may significantly enhance safety for the patient during osteotomy. The benefits of eccentric sensor positioning were particularly apparent when applied on angulated surfaces, whereas drill angulation was not found to influence this safety mechanism.
Full-text · Article · Sep 2015 · The International journal of oral & maxillofacial implants
[Show abstract][Hide abstract] ABSTRACT: Background: Minimally invasive implantology using reduced implant dimensions as well as virtual treatment planning and CAD/CAM stereolithographic templates has gained popularity in recent years.
Aim/Hypothesis: The aim of the present investigation was to analyze prevailing trends in clinical utilization and survival rates of these graftless therapeutic options.
Material and methods: A total of 12.865 dental implants were placed in 5.365 patients at the Academy for Oral Implantology in Vienna between 2005 and 2012, of which 5.5% were short (length ≤10 mm), 19.5% narrow (diameter ≤3.75 mm) and 10.6% template-guided (NobelGuideTM). Application trends were analyzed using linear regression and compared between jaw location and dentition subgroups.
Results: Use of short implants and guided surgery increased significantly in all subgroups. Narrow-diameter implants were most frequent in single-tooth gaps (24.1%), however, upward trends could only be observed in partially and completely edentulous patients. Short implants were predominantly used in the mandible (9.9% vs. 2.5%, P < 0.001) while guided surgery was favoured in the maxilla (14.2% vs. 5.4%, P < 0.001). Narrow and guided implants revealed higher success rates in the maxilla vs. the mandible (97.6% vs. 94.7%, P < 0.001 and 98.5% vs. 90.7%, P = 0.012, respectively).
Conclusions and clinical implications: Short implants (most frequent in partial edentulism) and guided implant surgery (most frequent in complete edentulism) represent uprising and promising surgical approaches to avoid patient morbidity associated with bone graft surgery.
[Show abstract][Hide abstract] ABSTRACT: Background: Individual abutments carry the advantage of optimum soft tissue support, however, can not be fabricated from zirconia on the day of implant placement using traditional analogue techniques.
Aim/Hypothesis: The aim was to utilize the modern digital workflow to produce an individual zirconia abutment at the day of immediate implant placement using guided implant placement and CAD/CAM technology (Guided Esthetics).
Material and methods: Optical intraoral impressions (TRIOS, 3 shape) were taken prior to as well as after extraction of a left central upper incisor of a 52-year old patient and immediate implant placement (Replace CC, Nobel Biocare) using a M-F1410 scan body (Medentika). The final zirconia abutment was produced within 3 h and a provisional crown was applied at the day of surgery. After 4 months the provisional crown was replaced by the final zirconia crown without removal of the abutment.
Results: No change in the preoperative Pink Esthetic Score of 14 was seen. Optimized soft tissue support from the first day of surgery as well as no disruption of the established periimplant mucosal interface due to multiple abutment (dis)connections may have helped to preserve pink esthetics.
Conclusions and clinical implications: The main advantage of inserting the final zirconia abutement at the day of implant placement is the possibility of immediate prosthetic restoration with provisional crowns and no necessity for abutment change before final crown delivery that may compromise gingival health.
[Show abstract][Hide abstract] ABSTRACT: Background: Rehabilitation of the incomplete dentition by means of osseointegrated dental implants represents a highly predictable and widespread therapy.
Aim/Hypothesis: The aim of the present study was to investigate potential risk factors that may impair long-term implant success.
Material and methods: From 2004 to 2014, a total of 17,343 implants were placed in 5671 patients at the Academy for Oral Implantology in Vienna. The survival rates after 10 years of follow-up were computed using the Kaplan-Meier method, and the impact of patient- and implant-related risk factors was assessed.
Results: Overall 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).
Conclusions and clinical implications: Summing up the long-term results 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.
[Show abstract][Hide abstract] ABSTRACT: Background: Bone augmentation of the maxillary sinus cavity is a routine surgical procedure to increase bone volume in the posterior maxilla available for implant placement.
Aim/Hypothesis: The aim of the present study was to compare 10-year success rates of implants placed simultaneously (one-stage) or 4–6 months after (two-stage) lateral access sinus floor augmentation surgery.
Material and methods: A total of 264 patients (98 men, 166 women, mean age: 56.2 ±� 11.6 years) were subjected to lateral sinus floor augmentation at the Academy for Oral Implantology (Vienna, Austria). Of the 512 implants placed into the bone grafts 38.5% were inserted simultaneously (197 implants) and 61.5% in a two-stage procedure after bone healing (315 implants). Kaplan-Meier survival estimates were computed and treatment groups were compared regarding surgical and prosthodontic determinants.
Results: 10-year implant success rates did not differ between one-stage (96.9% [94.5–99.4%]) and two-stage (97.1% [95.2–99.0%]) implant placement (P = 0.903). Simultaneous implant insertion was significantly associated with higher residual bone height (P < 0.001), reduced mesiodistal gap width (P < 0.001) as well as compromised local bone quality (P < 0.001). Simultaneous implants were less frequently subjected to transmucosal healing (27.0% vs. 37.8%, P = 0.013).
Conclusions and clinical implications: Comparable and highly satisfactory implant success rates 10 years after one- or two-stage implant placement can be achieved in the augmented maxillary sinus region.
[Show abstract][Hide abstract] ABSTRACT: Background: The relevance of an adequate primary stability as a factor for osseointegration was described by many. A possible correlation between primary stability and peri-implant bone density measured within the 3D planning software was not evaluated so far.
Aim/Hypothesis: Aim of this study was to evaluate the possibility of predicting the primary stability of dental implants by measuring the bone mineral density (hounsfield units) using preoperative conducted computed tomography. A specific prognosis of the implant stability allows the modification of the implant site in order to achieve an adequate primary stability.
Material and methods: 24 dental implants (Replace select taperedTM, Nobel Biocare) were placed in 8 edentulous maxillae of human cadavers by using surgical templates according to the NobelGuideTM protocol and the insertion torque values were recorded. The final value of these curves was defined as primary stability. This final value was correlated with the bone mineral density (BMD) measured preoperatively, to evaluate the possibility of predicting primary stabilities of dental implants by using preoperative conducted CT.
Results: A significant correlation between BMD and insertion torque values was observed for the axial slices (r = 0.78; P < 0.001) as well as for the reconstruction slices (r = 0.77; P < 0.001) in CT (hounsfield units). The hounsfield unit values were converted to hydroxyapatite and show similar significant correlations (axial slices: r = 0.8, P < 0.001; reconstruction slices: r = 0.76, P < 0.001).
Conclusions and clinical implications: The radiologic measurement of preoperative CT linked to navigated implantation with a surgical template is an appropriate way to estimate the primary stability of the implant previously planned. These data may help the surgeon to select the optimum implant position.
[Show abstract][Hide abstract] ABSTRACT: Background: Failing residual dentition gives rise to patient concerns regarding the surgical and prosthodontic management of immediate implant rehabilitation.
Aim/Hypothesis: The purpose of the present study was to assess subjective patient experience of full-arch immediate implant loading.
Material and methods: Transition from a hopeless dentition in the maxilla (25 patients) or mandible (25 patients) to full-arch rehabilitation at the day of extraction using 4 interantral/-foraminal implants and provisional restoration (immediate All-on-4� concept) was performed to record postoperative pain, swelling and patient-perceived impairment within the first week.
Results: Absence of pain was reported by 40%, 52% and 66% of patients, at the day of surgery, on the first day after and on the second day after, respectively (significant decrease in pain levels from 1.8 to 0.9, P < 0.001) while patient-reported swelling decreased from 1.5 to 1.3 (P = 0.058) on a 10-point scale. Postoperative impairment of everyday life and work (mean score: 1.1) was significantly less pronounced than impairment of food intake (mean score: 2.2, P = 0.004) or speech (mean score: 1.9, P = 0.002). 88% would again undergo the procedure without doubt.
Conclusions and clinical implications: Patient-perceived morbidity following immediate All-on-4� implant rehabilitation is low in general, however, minor masticatory and phonetic impairment should be accounted for.
[Show abstract][Hide abstract] ABSTRACT: Background: Assessment of implant esthetics is gaining importance in treatment evaluation following dental implant therapy along with growing emphasis on patient-related outcome measures.
Aim/Hypothesis: The aim of the present study was to compare rating systems judging peri-implant mucosal conditions, involving the Pink Esthetic Score (PES), Implant Crown Aesthetic Index (ICAI, mucosal part), Implant Aesthetic Score (IAS), Complex Esthetic Index (CEI, soft tissue part) and Pink and White Esthetic Score (PES/WES, mucosa part).
Material and methods: To identify inherent strengths and drawbacks of these scores 20 dentists performed pre- and postoperative esthetic evaluation in patient cases of significant esthetic improvement as well as no treatment effect.
Results: All scores demonstrated positive discriminative capacity (therapeutic increase of 37–57%, P = 0.002) while the PES/WES was the only score lacking negative discriminative capacity. Inter-rater reliability was significant for all scores except from ICAI (PES showing the highest Kendall’s coefficient of 0.78). Item interrelatedness was acceptable (Cronbach’s α ≥ 0.7) for PES, IAS, and CEI. Overall, PES yielded the greatest consistency with the other scores (94%) as well as the greatest rater satisfaction (86%). Ratings regarding papillae demonstrated the highest inter-rater reliability (Fleiss’ κ = 0.55, P < 0.001) followed by contour
(κ = 0.47, P < 0.001), color (κ = 0.43, P < 0.001), texture (κ = 0.39, P < 0.001), alveolar process (κ = 0.31, P < 0.001) and recession ratings (κ = 0.21, P < 0.001).
Conclusions and clinical implications: In conclusion, methodological differences between the rating scores could be substantiated (Friedman χ2 = 60, P < 0.001), however, scientific research may benefit from standardized evaluation to allow for between-study comparison. Likewise, appraisal of scores rating white esthetics (implant crown apprearance) seems recommendable.
[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.
Full-text · Article · Jul 2015 · The International journal of prosthodontics
[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%.
Full-text · Article · Jan 2015 · Journal Of Clinical Periodontology
[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.
Full-text · Article · Nov 2014 · Clinical Implant Dentistry and Related Research
[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.
No preview · Article · Aug 2014 · Journal Of Clinical Periodontology
[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.
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).
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.
Full-text · Article · Jun 2014 · European Journal of Oral Implantology
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Rehabilitation 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.
From 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.
Overall 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).
Summing 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.
Full-text · Article · Jun 2014 · Journal of periodontal & implant science
[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.
Full-text · Article · Jun 2014 · Informationen aus Orthodontie & Kieferorthopädie
[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.
Full-text · Article · Jan 2014 · Clinical Oral Implants Research