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ABSTRACT: The original aim of the study was to determine the osteoconductive capacity of deproteinized bovine bone mineral (DBBM) of different particle sizes underneath acrylic hemispheres in vivo. However, the model failed and allowed us to report on the resorption of DBBM.
Acrylic hemispheres were filled with and without a DBBM at a small particle size of 125-250 μm and at the regular particle size of 250-1000 μm. The hemispheres were positioned on the calvaria of eight minipigs. Histological and histomorphometric analysis was performed after 12 weeks.
We found that the acrylic hemispheres were displaced and a dense fibrous capsule sequestered the augmented area. Histology showed severe resorption activity and the presence of multinucleated cells on the surface of DBBM particles in areas adjacent to the fibrous capsule. Histomorphometric analysis revealed that only less than half of the originally augmented area, which was approximately 30 mm(2) , remained after 12 weeks. The amount of residual DBBM (median 0.9 and 3.49 mm(2)) and bone (median 7.22 and 7.51 mm(2)) in the augmented area was similar in the small and the regular particle size group.
The model represents a pathologic situation of excess resorption of DBBM and bone in an augmented area. The underlying cellular mechanisms remain to be uncovered.
Clinical Oral Implants Research 05/2011; 23(1):95-9. · 2.51 Impact Factor
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ABSTRACT: To evaluate the osteoconductive properties and the volume stability of an injectable paste-like inorganic bone matrix (PBM) in porcine calvaria defects.
We created six circumferential defects in the calvaria of 12 adult iberico pigs. The defects were filled with either PBM, Bio-Oss((R)) of different particle size, carrier alone, or left empty. PBM was composed of Bio-Oss((R)) with a particle size ranging from 250 to 500 mum and a hydrogel-carrier of carboxymethylcellulose and collagen. After 6 and 12 weeks of healing, the animals were sacrificed and undecalcified ground sections were prepared and subjected to histologic and histomorphometric analysis. To quantify the osteoconductive properties of PBM, bone volume per tissue volume (BV/TV) in the defect area was determined. To determine the volume stability, bone substitute volume per tissue volume (BSV/TV) was measured.
After 6 weeks, PBM particles in the center of the defect were surrounded by fibrous connective tissue, which was later replaced by bone. BV/TV in the PBM group increased from 29.7+/-12.7% (minimum 12.2%, maximum 43.7%) after 6 weeks to 43.9+/-14.9% (minimum 27.8%, maximum 63.9%) after 12 weeks (Mann-Whitney test; P=0.6). According to the Friedman test, BV/TV in groups containing Bio-Oss((R)) of different particle sizes, the carrier and the empty defects was similar to the results obtained with PBM (6 weeks P=0.8; 12 weeks P=0.22). BSV/TV in the PBM group was stable over time, with 10.1+/-9% (minimum 3.3%, maximum 27.6%) and 16.5+/-12.9% (minimum 1%, maximum 32.7%), after 6 and 12 weeks, respectively (P=0.72). BSV/TV in the PBM group was comparable to the results obtained with the Bio-Oss((R)) particles of different sizes (Friedman test; 6 weeks P=0.0503; 12 weeks P=0.56).
The results of this preclinical study showed that the PBM is osteoconductive and maintains the augmented volume, similar to commercial Bio-Oss((R)). These data suggest that the osteoconductive properties of Bio-Oss((R)) are maintained at the smaller particle size and in the presence of the carrier.
Clinical Oral Implants Research 08/2009; 20(10):1099-104. · 2.51 Impact Factor
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ABSTRACT: Graft consolidation follows a gradient that reflects the properties of bone substitutes at sites of sinus augmentation. Here we present an analytical method to investigate the process of graft consolidation taking the distance from the maxillary host bone into account.
We therefore evaluated histological specimens, 6 and 12 weeks after the sinus of minipigs was augmented with Bio-Oss((R)), a deproteinized bovine bone mineral, and Ostim((R)), an aqueous paste of synthetic nanoparticular hydroxyapatite. A curve was drawn that represents the changes in histomorphometric parameters within a given distance from the maxillary host bone.
Based on this curve, three regions of interest were defined: R1 (0-1 mm) the bridging distance where new bone is laid onto the host bone, R2 (2-3 mm) a region of osteoconduction where new bone exclusively grows on the biomaterial, R3 (4-5 mm) and a region of osteoconduction where bone formation has reached its maximal extension. Qualitative and quantitative analysis of the three regions can reveal differences in graft consolidation, depending on the bone substitutes and the observation period [Bone volume (BV) per tissue volume after 6 weeks: R1: 19+/-8.4% for Bio-Oss((R)) and 42.9+/-13.2% for Ostim((R)) (P=0.03), R2: 3+/-2.4% for Bio-Oss((R)) and 14.7+/-9.5% for Ostim((R)) (P=0.03), R3: 5+/-4.1% for Bio-Oss((R)) and 5.3+/-5.3% for Ostim((R)) (P=0.86). BV per tissue volume after 12 weeks: R1: 38.0+/-13.3% for Bio-Oss((R)) and 53.3+/-6.6 for Ostim((R)) (P=0.04), R2: 14+/-12.2 for Bio-Oss((R)) and 26.4+/-11 for Ostim((R)) (P=0.18), R3: 6.6+/-7 for Bio-Oss((R)) and 10.7+/-5.8 for Ostim((R)) (P=0.32) after 12 weeks].
Based on the graft consolidation gradient, the impact of bone substitutes to modulate the process of bone formation and the kinetic of degradation within a distinct region of the augmented sinus can be investigated.
Clinical Oral Implants Research 07/2009; 20(10):1078-83. · 2.51 Impact Factor
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ABSTRACT: A direct, simultaneous comparison of bone substitutes is hampered by the limited number of samples that can be tested simultaneously. The goal of this study was to establish a preclinical model for guided bone regeneration that offers testing of different bone substitutes in a one-wall defect situation. We show here that up to eight titanium hemispheres can be placed on the calvaria of minipigs. To establish our model, titanium hemispheres were filled with and without Bio-Oss, a deproteinized bovine bone mineral, Ostim, an aqueous paste of synthetic nanoparticular hydroxyapatite, and Osteoinductal, an oily calcium hydroxide suspension, before being positioned on the calvaria. After 6 and 12 weeks, titanium hemispheres were subjected to histological and histomorphometric analysis. We show here that bone filled approximately one-tenth of the area below the hemispheres which were left empty, indicating a critical size model for guided bone regeneration. In accordance with the documented osteoconductive properties of Bio-Oss and Ostim, titanium hemispheres were almost completely filled with bone. Moreover, the expected degradation profile of Bio-Oss and Ostim could be confirmed by histologic and histomorphometric analysis. Under the same conditions, Osteoinductal failed to exert osteoconductive properties, rather a progressive resorption of the host bone was observed. These results demonstrate that the preclinical model presented here is suitable to simultaneously compare bone substitutes with different material properties. Our model based on the titanium hemispheres allows evaluation of graft consolidation under standardized conditions thereby avoiding intra-individual variations.
Biomaterials 09/2008; 29(22):3195-200. · 7.40 Impact Factor
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ABSTRACT: The purpose of this retrospective study was to compare peri-implant bone loss and mucosal conditions around machined-surface (MS) and anodized-surface (AS) interforaminal implants in the mandible at least 30 months after placement. Fifty patients, each treated with four interforaminal screw-type implants consecutively, were included. Thirty-one patients (62%) with a total number of 124 implants (64 MS and 60 AS implants, both Brånemark type MKIII) were available for follow-up. Rotational panoramic radiographs were used for evaluating marginal bone loss. Clinically, marginal plaque index (mPI), bleeding on probing (BOP) and pocket probing depth (PPD) were evaluated. AS implants showed significantly less marginal bone loss than MS implants (-1.17+/-0.13 vs. -1.42+/-0.13 mm; P=0.03). Marginal bone loss around distal implants was less pronounced at AS implants (-1.05+/-0.14 mm) when compared with MS implants (-1.46+/-0.14 mm; P=0.05). Within the smoking group, there was less peri-implant bone loss around AS implants than around MS implants (-1.08+/-0.27 vs. -1.83+/-0.2; P=0.04). No differences between MS and AS implants were found with respect to mPI (57% vs. 67%), BOP (21% vs. 17%) and mean PPD (2.59+/-0.29 vs. 2.56+/-0.28 mm). Overall, both types of implants, in combination with bar-supported overdentures, can produce excellent long-term results in the interforaminal edentulous mandible with less peri-implant bone loss around rough implant surfaces, which had beneficial effects at distal implants and in smokers.
Clinical Oral Implants Research 01/2007; 17(6):651-7. · 2.51 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the clinical relevance of horizontal distraction osteogenesis (DO) with bone micro screws for reconstructing knife-edge alveolar crests before implant placement. Horizontal DO was performed in upper and lower alveolar crests of seven patients with resorption class IV according to Cawood and Howell. After osteotomy and a 1-week latency period, micro bone screws were reset daily for horizontal expansions by 0.5 mm. Dental implants were placed in the distracted area following a consolidation period of 12 weeks. Computer tomography was performed before DO and implant placement. Morphometric analysis showed a mean gain of 34.01 mm(2) (95% confidence interval [CI]: 10.55-57.48) in bone area and of 3.06 mm (95% CI: 1.81-4.31) in horizontal width, i.e. the horizontal dimension of the alveolus was approximately doubled within the first 5 mm of height. All 12 implants placed into the distracted area fulfilled the success criteria of stable osseointegration after 1 year of functional loading according to Albrektsson and colleagues. Despite the limited number of patients treated, data from the clinical study of horizontal DO with bone micro screws suggest that the generation of sufficient hard tissue in previously knife-edge alveolar crests for subsequent implant placement was possible.
Clinical Oral Implants Research 01/2007; 17(6):723-9. · 2.51 Impact Factor
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ABSTRACT: To evaluate the use of intra-oral bone grafts for closing chronic oro-antral fistulas (OAFs), for providing a sound basis for subsequent conventional sinus lifting and for preserving the teeth adjacent to OAFs.
Twenty-one patients with oro-antral fistulas of variable origin were treated with monocortical bone blocks harvested from the retromolar or interforaminal regions of the mandible. The preoperative treatment, the surgical procedure for both hard and soft tissue closure, and the postoperative management are reviewed in detail.
Press-fit closure for repair of the bony sinus floor was sufficient in 17 patients. Four of them needed additional internal fixation. In all 21 patients adequate closure of the fistulas was obtained, although 3 patients (14.3%) developed wound dehiscences at the grafted sites, which healed by secondary intention. Meanwhile, 3 patients underwent successful sinus lifting.
The use of monocortical bone grafts harvested at intra-oral donor sites is a safe and easy technique for repairing defects of the maxilla, especially OAFs in need of secondary closure. It provides a sound basis for subsequent conventional sinus lifting and preserves the teeth adjacent to OAFs.
Journal of Oral and Maxillofacial Surgery 10/2005; 63(9):1288-94. · 1.64 Impact Factor
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ABSTRACT: Barrier membranes have become a standard treatment option in alveolar ridge augmentation prior to implant placement. However, non-resorbable membranes require secondary surgery and resorbable membranes show an unfavorable degradation profile. The purpose of this study was to evaluate the potential of a slowly biodegradable/bioresorbable prototype trilayer membrane (PTLM) for supporting bone regeneration in alveolar ridge augmentation. Clinically relevant cavities were made 3 months after the extraction of the first and second molars in each jaw of six baboons. Each animal was treated with four different regimens: (1) autogenous bone block (ABB) alone, (2) ABB+PTLM, (3) deproteinized bovine bone mineral (DBBM)+PTLM and (4) no treatment. After 9 months, the baboons were sacrificed and block sections of the augmented area were subjected to histologic and histomorphometric analyses. Newly formed bone areas were determined at a distance of 1, 3, 7 and 10 mm from crestal. The data showed a well-preserved ridge profile at the membrane-protected sites, whereas non-protected bone blocks and control sites underwent severe resorption resulting in knife-edge ridge profiles. Significant differences were found between ABB+PTLM and ABB (P=0.0137-0.0232). DBBM+PTLM also produced a larger bone area compared with ABB alone (P=0.0396-0.0439). No significant difference in bone area was detectable between ABB+PTLM and DBBM+PTLM (P>0.05). The present study supports the use of the slowly biodegradable/bioresorbable PTLM with autografts and DBBM for lateral ridge augmentation in this type of bone defects.
Clinical Oral Implants Research 04/2005; 16(2):220-7. · 2.51 Impact Factor
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ABSTRACT: The osteogenic potential of a graft is based on the parallel lines ability of cells to survive transplantation and to respond to local factors that stimulate new bone formation. Here we investigated the potential of cells that had grown out of porcine cortical bone grafts obtained by 3 preparation techniques to respond to mitogenic and osteogenic stimuli.
Bone grafts were harvested from 2 pigs. Cortical bone was taken in cylindrical form and ground in a bone mill or harvested via drilling and aspiration.
Cell outgrowth was observed in all cortical bone cylinders, bone cylinders homogenized by mill, and 5 of 10 explants of bone dust collected upon drilling. After a 2-week culture period, the number of outgrown cells did not significantly differ among the 3 preparations. Bone cells showed increased proliferation in response to platelet-released supernatants as determined by 3 [H]-thymidine incorporation assay. When cultured under conditions that favor the expression of an osteogenic phenotype, the outgrown cells expressed alkaline phosphatase activity and transcripts of the osteoblast-specific marker osteocalcin. Individual cell preparations showed accumulation of mineral salts in their extracellular matrix. Bone cells also increased alkaline phosphatase activity in response to bone morphogenetic protein (BMP)-2, BMP-6, and BMP-7. The mitogenic and osteogenic response was obtained with cells from the mandible as well as from the maxilla, irrespective of the preparation technique.
These data show that cortical bone grafts contain cells that have the ability to proliferate and differentiate into the osteogenic lineage, suggesting that these cells can contribute to bone regeneration following transplantation.
Journal of Oral and Maxillofacial Surgery 03/2005; 63(2):238-43. · 1.64 Impact Factor
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ABSTRACT: A variety of potential complications associated with sinus lift surgery have been reported in the literature. However, potential alterations of voice quality following sinus elevation have so far not been mentioned or evaluated scientifically. For the majority of patients, slight changes of the voice pattern are of no importance. However, for voice professionals, whose voices have become part of their distinctive profession or trademark, minimal changes may have dramatic consequences. This specific group of patients, such as speakers, actors and singers, depend on the particular quality and timbre of their voice for their livelihood. Consequently, the purpose of this study was to assess the effects of sinus lifting on voice quality in the above patient group. In a collaborative interdisciplinary effort, the Departments of Oral Surgery and Otorhinolaryngology, Section of Phoniatrics and Logopedics, thoroughly evaluated a series of voice parameters of four patients undergoing sinus lifting pre- and postoperatively. The parameters analyzed included pitch, dynamic range, sound pressure level, percent jitter, percent shimmer and noise-to-harmonics ratio with special emphasis on formant analysis. No changes were detected in any of the commonly evaluated parameters. These were rated subjectively by patients and their friends or relatives and objectively with instrumental tools under isolated phoniatric lab conditions. In conclusion, sinus lift surgery appears to be a safe, predictable evidence-based method for regenerating the highly atrophic posterior maxilla, which does not jeopardize the individual characteristic voice pattern of high-profile patients critically dependent on their voices for their livelihood.
Clinical Oral Implants Research 01/2004; 14(6):767-74. · 2.51 Impact Factor
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ABSTRACT: A variety of potential complications associated with sinus lift surgery have been reported in the literature. However, potential alterations of voice quality following sinus elevation have so far not been mentioned or evaluated scientifically. For the majority of patients, slight changes of the voice pattern are of no importance. However, for voice professionals, whose voices have become part of their distinctive profession or trademark, minimal changes may have dramatic consequences. This specific group of patients, such as speakers, actors and singers, depend on the particular quality and timbre of their voice for their livelihood. Consequently, the purpose of this study was to assess the effects of sinus lifting on voice quality in the above patient group. In a collaborative interdisciplinary effort, the Departments of Oral Surgery and Otorhinolaryngology, Section of Phoniatrics and Logopedics, thoroughly evaluated a series of voice parameters of four patients undergoing sinus lifting pre- and postoperatively. The parameters analyzed included pitch, dynamic range, sound pressure level, percent jitter, percent shimmer and noise-to-harmonics ratio with special emphasis on formant analysis. No changes were detected in any of the commonly evaluated parameters. These were rated subjectively by patients and their friends or relatives and objectively with instrumental tools under isolated phoniatric lab conditions. In conclusion, sinus lift surgery appears to be a safe, predictable evidence-based method for regenerating the highly atrophic posterior maxilla, which does not jeopardize the individual characteristic voice pattern of high-profile patients critically dependent on their voices for their livelihood.RésuméQuelques complications potentielles associées à la chirurgie d'épaississement du plancher sinusal ont été rapportées dans la littérature. Les altérations potentielles de la qualité de la voix suivant l'épaississement du plancher sinusal n'ont pas encore été mentionnées et évaluées scientifiquement. Pour la majorité des patients, des petites variations dans le timbre de la voix ne sont pas importantes. Cependant, pour les professionnels de la phonation pour lesquels la voix est devenue une partie importante de leur profession, des variations même faibles peuvent entraîner des conséquences dramatiques. Ce groupe spécifique de patients, tels que les orateurs, les acteurs et les chanteurs dépendent essentiellement de la qualité et du timbre particulier de leur voix dans leur vie professionnelle. Par conséquent, le but de cette étude a été d'estimer les effets d'un épaississement du sinus sur la qualité de la voix dans ce groupe de patients. Dans un effort interdisciplinaire collaboratif, les départements de chirurgie buccale et d'otorhino-laringologie, la section de phonétique et de logopédie ont évalué de manière très précise une série de paramètres de la voix avant et après l'opération chez quatre patients ayant subi un épaississement du sinus maxillare. Les paramètres analysés contenaient la hauteur, l'étalement, le niveau de pression du son, le pourcentage de trac, le pourcentage de chatoiements et la proportion bruit-harmonie avec une insistance spéciale sur l'analyse du formant. Aucun changement n'a été détecté dans aucun des paramètres évalués couramment. Ces derniers étaient estimés subjectivement par les patients et par leurs amis ou parents, et objectivement à l'aide des instruments sous des conditions de laboratoire de phonétique isolé. En conclusion, la chirugie d'épaississement du plancher sinusal semble une méthode sûre, avec un pronostic basé sur l'évidence, permettant de regénérer les maxillaires très atrophiés qui n'empêche pas la caractéristique individuelle de la voix chez des patients avec des profils où la voix est essentielle à leur vie active.ZusammenfassungDer Einfluss einer Sinusbodenelevation auf die Stimmqualität, eine Langzeitstudie und Risikoanalyse.In der Literatur werden eine ganze Reihe von möglichen Komplikationen beschrieben, die bei dem chirurgischen Eingriff der Sinusbodenelevation auftreten können. Veränderungen der Stimme, die als Folge einer Sinusbodenelevation vorkommen können, wurden aber bis heute weder beschrieben, noch wissenschaftlich ausgewertet. Für den Grossteil der Patienten haben leichte Veränderungen der Stimme keine Bedeutung. Für Personen aber, deren Stimme bei der Ausübung ihres Berufes wichtig ist, eventuell ein Teil ihres Berufes oder gar Markenzeichen geworden ist, können kleine Veränderungen dramatische Folgen haben. Diese ausgewählte Gruppe von Patienten, wie zum Beispiel Nachrichtensprecher, Schauspieler oder Sänger, sind im täglichen Leben auf die spezifische Art und den Klang ihrer Stimme angewiesen.Daher war das Ziel dieser Studie, Einflüsse einer Sinusbodenelevation auf die Stimmqualität bei den oben erwähnten Patienten zu untersuchen. In einer interdisziplinären Zusammenarbeit untersuchten die Klinik für Oralchirurgie und Otorhinolaryngologie und die Abteilung für Phonetik und Logopädie an 4 Patienten vor und nach der Sinusbodenelevation sehr eingehend verschiedene Parameter der Stimme. Die untersuchten Parameter waren Tonhöhe, Tonvolumen, den durch den Ton erzeugten Luftdruck, Schwingungen, Vibrationen und das Verhältnis zwischen Nebengeräuschen und harmonischem Klang mit speziellem Augenmerk auf formative Analysen.Man erkannte bei keinem der oben untersuchten Parametern eine Veränderung. Sie wurden sowohl subjektiv durch die Patienten und ihre Freunde oder Verwandten, sowie objektiv mit Messinstrumenten unter absolut schallisolierten Laborbedingungen gemessen.Über die Sinusbodenelevation kann man zusammenfassend sagen, dass es sich um eine sichere, voraussagbare und auf wissenschaftlichen Grundlagen basierende Operationsmethode zum Wiederaufbau einer massiv athrophischen Maxilla im Seitenzahnbereich handelt. Sie gefährdet die individuellen Stimmcharakteristika von kritischen und sehr anspruchsvollen Patienten, die in ihrem täglichen Leben auf ihre charakteristische Stimme angwiesen sind, nicht.ResumenSe han descrito en la literatura una variedad de complicaciones asociadas con la cirugía de la elevación del seno. Pero hasta el momento no se han mencionado ni evaluado científicamente alteraciones potenciales de la calidad de voz tras la elevación del seno. Para la mayoría de los pacientes, pequeños cambios en el patrón de voz no tienen importancia. De todos modos, en los profesionales de la voz, cuyas voces se han convertido en parte distintiva de su profesión o marca, pequeños cambios pueden tener consecuencias dramáticas. Este grupo específico de pacientes, tales como locutores, actores y cantantes, dependen de la calidad particular y timbre de su voz para su sustento. Consecuentemente, el propósito de este estudio fue valorar los efectos de la elevación del seno en la calidad de voz en el anterior grupo de pacientes. En un esfuerzo de colaboración interdisciplinaria, los departamentos de Cirugía Oral y Otorrinolaringología, Sección de Foniatría y Logopedia, evaluaron e profundidad una serie de parámetros de voz de 4 pacientes que se someterían a elevación del seno pre y postoperatoriamente. Los parámetros analizados incluyeron tono, rango dinámico, nivel de presión sonoro, porcentaje de reverberación, porcentaje de tremulación y relación ruido a harmónicos con especial énfasis en el análisis formante. No se detectaron cambios en ninguno de los parámetros evaluados comúnmente. Estos se valoraron subjetivamente por los pacientes y sus amigos o parientes y objetivamente por herramientas instrumentales bajo condiciones de laboratorio de aislamiento foniátrico. En definitiva, la cirugía de elevación del seno parece ser un método seguro, predecible basado en la evidencia para regenerar el maxilar posterior altamente atrófico, que no pone en peligro las características del patrón de voz de los pacientes de características especiales dependientes de manera crítica de sus voces para su sustento.
Clinical Oral Implants Research 11/2003; 14(6):767 - 774. · 2.51 Impact Factor
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ABSTRACT: In this retrospective study, marginal peri-implant bone height around machined and sandblasted/acid-etched interforaminal implants in the mandible was evaluated radiologically at least 3 years after functional loading.
Fifty-one patients, each with 4 interforaminal screw-type implants placed between 1994 and 1998, were included in this study. Of these, 36 patients (70.6%) with a total of 144 implants (76 machined Mk II implants and 68 sandblasted/acidetched Frios implants) were available for follow-up studies. Interforaminal marginal bone loss was evaluated by extraoral rotational panoramic radiographs. In addition, predictive factors such as patient age and sex, nicotine use, implant position, implant life, and site of measurement were recorded, as well as bone loss at surgery (ie, baseline bone loss). Analysis of covariance for repeated measurements was used for statistical analysis. Between-group differences were expressed as least square means +/- standard error.
Sandblasted/acid-etched implants showed significantly less marginal bone loss than machine-surfaced implants (2.4 +/- 0.23 mm vs 1.64 +/- 0.27 mm). Implants placed in the anterior of the arch showed significantly more peri-implant bone loss than implants placed in the posterior (P = .0001).
Significantly less long-term peri-implant bone loss was observed for rough implant surfaces compared to machine-surfaced implants. However, it was also demonstrated that both types of implants, in combination with bar-supported overdentures, can produce excellent long-term results in the atrophic edentulous mandible. Mesially placed implants showed more bone resorption than distally positioned implants, independent of surface roughness.
The International journal of oral & maxillofacial implants 19(2):216-21. · 1.78 Impact Factor
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ABSTRACT: In patients with atrophic mandibles, elevation of the floor of the mouth often prevents intraoral rectangular radiography for longitudinal follow-up studies, while extraoral techniques such as panoramic radiographs tend to produce distorted views of the interforaminal region. In this study, intraoral rectangular radiographs and panoramic radiographs were compared for their accuracy in evaluating peri-implant bone loss.
In a recall program, 22 patients with 88 screw-type implants (44 MKII and 44 Frios) were followed. Interforaminal marginal bone loss was evaluated by extraoral orthopantomograms and by intraoral rectangular radiographs. In addition, pocket depth, Periotest readings, and bleeding on probing were recorded. For statistical analysis, the Spearman coefficient of correlation was used. The effects on bone loss and clinical variables were computed with a mixed model and the Bland and Altman method.
Computed as least square means, the mean difference between panoramic radiographs (2.4 +/- 0.2 mm for MKII implants and 1.6 +/- 0.2 mm for Frios implants) and intraoral radiographs (2.6 +/- 0.2 mm and 1.4 +/- 0.2 mm, respectively) was 0.2 mm (range, 0.1 to 0.8 mm).
In this study, the 2 imaging techniques were comparable clinically in terms of the precision with which they could be used to measure marginal bone loss.
For highly atrophic mandibles with unfavorable imaging conditions, rotational panoramic radiographs can be a useful alternative to intraoral small-format radiographs for evaluating peri-implant bone loss.
The International journal of oral & maxillofacial implants 18(6):873-8. · 1.78 Impact Factor
