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Blagova B, Krastev D, Krastev N, Malinova L. Tissue changes and tissue reactivity following osteotomy by a conventional rotary device, an ultrasonic unit, and an Er: YAG laser - A comparative study in humans. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2024; 125:101750. [PMID: 38142938 DOI: 10.1016/j.jormas.2023.101750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/11/2023] [Accepted: 12/21/2023] [Indexed: 12/26/2023]
Abstract
INTRODUCTION Innovative technologies from other fields of science are constantly being introduced in medicine. Research works on animals strongly confirm the belief in better results following ultrasound and laser surgery. The main conclusions are based on observations from different animal species, whose biological characteristics differ from those of humans. This requires scientific experiments to be performed and confirmed in humans. MATERIAL & METHODS Human mandible specimens harvested in vivo by a conventional low-speed rotary device, an ultrasonic unit, or an Er: YAG laser were studied and analyzed to compare their effects on bone morphology and tissue response following surgery. RESULTS The cutting surface of eighty biopsies was studied, as well the facial edema, pain levels, and jaw dysfunction were followed up in the same eighty patients from whom the slices were obtained. In the piezosurgery and drill groups, the borders exhibited irregular edges full of bone fragments and debris. Thermal alterations within the superficial surface in all bone samples were generally minimal. In all specimens, intact osteocytes were detectable away from the area of direct action of the bone-cutting device. It was established, that the reactive facial edema, pain levels, and jaw disfunction were with milder values following in vivo osteotomy by an ultrasonic unit and Er: YAG laser compared to the conventional drilling. Moreover, the recovery of the patients in these two groups was more pronounced. The observed tissue changes proved to affect the follow-up tissue reactions in the postoperative period (p ≤ 0.05). DISCUSSION Based on the established effects on human bone by its in vivo cutting, it can be concluded that laser and ultrasonic bone surgery was a superior alternative osteotomy method in humans to conventional drilling.
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Affiliation(s)
- Bistra Blagova
- Department of Anatomy, Histology, and Embryology, Medical University of Sofia, 2 Zdrave Str., Sofia 1431, Bulgaria.
| | - Dimo Krastev
- Medical College "Jordanka Filaretova", Medical University of Sofia, Bulgaria; Faculty of Public Health, Health Care and Sport, South-West University "Neofit Rilski", Blagoevgrad, Bulgaria
| | - Nikolay Krastev
- Department of Anatomy, Histology, and Embryology, Medical University of Sofia, 2 Zdrave Str., Sofia 1431, Bulgaria
| | - Lina Malinova
- Department of Anatomy, Histology, and Embryology, Medical University of Sofia, 2 Zdrave Str., Sofia 1431, Bulgaria
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Chen L, Tong Z, Luo H, Qu Y, Gu X, Si M. Titanium particles in peri-implantitis: distribution, pathogenesis and prospects. Int J Oral Sci 2023; 15:49. [PMID: 37996420 PMCID: PMC10667540 DOI: 10.1038/s41368-023-00256-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/25/2023] [Accepted: 10/30/2023] [Indexed: 11/25/2023] Open
Abstract
Peri-implantitis is one of the most important biological complications in the field of oral implantology. Identifying the causative factors of peri-implant inflammation and osteolysis is crucial for the disease's prevention and treatment. The underlying risk factors and detailed pathogenesis of peri-implantitis remain to be elucidated. Titanium-based implants as the most widely used implant inevitably release titanium particles into the surrounding tissue. Notably, the concentration of titanium particles increases significantly at peri-implantitis sites, suggesting titanium particles as a potential risk factor for the condition. Previous studies have indicated that titanium particles can induce peripheral osteolysis and foster the development of aseptic osteoarthritis in orthopedic joint replacement. However, it remains unconfirmed whether this phenomenon also triggers inflammation and bone resorption in peri-implant tissues. This review summarizes the distribution of titanium particles around the implant, the potential roles in peri-implantitis and the prevalent prevention strategies, which expects to provide new directions for the study of the pathogenesis and treatment of peri-implantitis.
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Affiliation(s)
- Long Chen
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, China
- Department of Stomatology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zian Tong
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, China
| | - Hongke Luo
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, China
| | - Yuan Qu
- Zhejiang University-University of Edinburgh Institute, International Campus, Zhejiang University, Haining, China
| | - Xinhua Gu
- Department of Stomatology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Misi Si
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, China.
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Gulati K, Chopra D, Kocak-Oztug NA, Verron E. Fit and forget: The future of dental implant therapy via nanotechnology. Adv Drug Deliv Rev 2023; 199:114900. [PMID: 37263543 DOI: 10.1016/j.addr.2023.114900] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/11/2023] [Accepted: 05/21/2023] [Indexed: 06/03/2023]
Abstract
Unlike orthopedic implants, dental implants require the orchestration of both osseointegration at the bone-implant interface and soft-tissue integration at the transmucosal region in a complex oral micro-environment with ubiquitous pathogenic bacteria. This represents a very challenging environment for early acceptance and long-term survival of dental implants, especially in compromised patient conditions, including aged, smoking and diabetic patients. Enabling advanced local therapy from the surface of titanium-based dental implants via novel nano-engineering strategies is emerging. This includes anodized nano-engineered implants eluting growth factors, antibiotics, therapeutic nanoparticles and biopolymers to achieve maximum localized therapeutic action. An important criterion is balancing bioactivity enhancement and therapy (like bactericidal efficacy) without causing cytotoxicity. Critical research gaps still need to be addressed to enable the clinical translation of these therapeutic dental implants. This review informs the latest developments, challenges and future directions in this domain to enable the successful fabrication of clinically-translatable therapeutic dental implants that would allow for long-term success, even in compromised patient conditions.
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Affiliation(s)
- Karan Gulati
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia.
| | - Divya Chopra
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia
| | - Necla Asli Kocak-Oztug
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia; Istanbul University, Faculty of Dentistry, Department of Periodontology, 34116 Istanbul, Turkey
| | - Elise Verron
- Nantes Université, CNRS, CEISAM, UMR 6230, 44000 Nantes, France
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Enhanced Corrosion Resistance and Local Therapy from Nano-Engineered Titanium Dental Implants. Pharmaceutics 2023; 15:pharmaceutics15020315. [PMID: 36839638 PMCID: PMC9963924 DOI: 10.3390/pharmaceutics15020315] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/12/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
Titanium is the ideal material for fabricating dental implants with favorable biocompatibility and biomechanics. However, the chemical corrosions arising from interaction with the surrounding tissues and fluids in oral cavity can challenge the integrity of Ti implants and leach Ti ions/nanoparticles, thereby causing cytotoxicity. Various nanoscale surface modifications have been performed to augment the chemical and electrochemical stability of Ti-based dental implants, and this review discusses and details these advances. For instance, depositing nanowires/nanoparticles via alkali-heat treatment and plasma spraying results in the fabrication of a nanostructured layer to reduce chemical corrosion. Further, refining the grain size to nanoscale could enhance Ti implants' mechanical and chemical stability by alleviating the internal strain and establishing a uniform TiO2 layer. More recently, electrochemical anodization (EA) has emerged as a promising method to fabricate controlled TiO2 nanostructures on Ti dental implants. These anodized implants enhance Ti implants' corrosion resistance and bioactivity. A particular focus of this review is to highlight critical advances in anodized Ti implants with nanotubes/nanopores for local drug delivery of potent therapeutics to augment osseo- and soft-tissue integration. This review aims to improve the understanding of novel nano-engineered Ti dental implant modifications, focusing on anodized nanostructures to fabricate the next generation of therapeutic and corrosion-resistant dental implants. The review explores the latest developments, clinical translation challenges, and future directions to assist in developing the next generation of dental implants that will survive long-term in the complex corrosive oral microenvironment.
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Kotsakis GA, Romanos GE. Biological mechanisms underlying complications related to implant site preparation. Periodontol 2000 2022; 88:52-63. [PMID: 35103318 DOI: 10.1111/prd.12410] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Implant site preparation is a critical stage of implant surgery that may underpin various complications related to implant surgery. This review discusses the latest available scientific information on risk factors related to implant site preparation. The role of the drilling process in relation to the density of the available alveolar bone, the effects of insertion torque on peri-implant osseous healing, and implant-related variables such as macrodesign and implant-abutment connection are all factors that can influence implant success. Novel information that links osteotomy characteristics (including methods to improve implant initial stability, the impact of drilling speed, and increase of the implant insertion torque modifying the bone-implant interface) with the appropriate instrumentation techniques will be discussed, as well as interactions at the bone-biomaterial interface that may lead to biologic complications mediated by implant dissolution products.
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Affiliation(s)
| | - Georgios E Romanos
- Department of Periodontology, School of Dental Medicine, Stony Brook, New York, USA.,Department of Oral Surgery and Implant Dentistry, Dental School, Johann Wolfgang Goethe University, Frankfurt, Germany
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El Hassanin A, Quaremba G, Sammartino P, Adamo D, Miniello A, Marenzi G. Effect of Implant Surface Roughness and Macro- and Micro-Structural Composition on Wear and Metal Particles Released. MATERIALS 2021; 14:ma14226800. [PMID: 34832201 PMCID: PMC8620958 DOI: 10.3390/ma14226800] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/04/2021] [Indexed: 02/06/2023]
Abstract
Background: Considerations about implant surface wear and metal particles released during implant placement have been reported. However, little is known about implant surface macro- and microstructural components, which can influence these events. The aim of this research was to investigate accurately the surface morphology and chemical composition of commercially available dental implants, by means of multivariate and multidimensional statistical analysis, in order to predict their effect on wear onset and particle release during implant placement. Methods: The implant surface characterization (roughness, texture) was carried out through Confocal Microscopy and SEM-EDS analysis; the quantitative surface quality variables (amplitude and hybrid roughness parameters) were statistically analyzed through post hoc Bonferroni’s test for pair comparisons. Results: The parameters used by discriminant analysis evidenced several differences in terms of implant surface roughness between the examined fixtures. In relation to the observed surface quality, some of the investigated implants showed the presence of residuals due to the industrial surface treatments. Conclusions: Many structural components of the dental implant surface can influence the wear onset and particles released during the implant placement.
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Affiliation(s)
- Andrea El Hassanin
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples “Federico II”, P.le Tecchio 80, 80125 Naples, Italy;
| | - Giuseppe Quaremba
- Department of Industrial Engineering, University of Naples “Federico II”, Via Claudio 21, 80125 Naples, Italy;
| | - Pasquale Sammartino
- School of Specialization in Oral Surgery, University of Campania “L. Vanvitelli”, Via L. De Crecchio 6, 80100 Naples, Italy;
| | - Daniela Adamo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples “Federico II”, Via Pansini 5, 80131 Naples, Italy;
| | - Alessandra Miniello
- School of Specialization in Oral Surgery, University of Naples “Federico II”, Via Pansini 5, 80131 Naples, Italy;
| | - Gaetano Marenzi
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples “Federico II”, Via Pansini 5, 80131 Naples, Italy;
- Correspondence: ; Tel.: +39-817462118
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Rashad A, Schwan S, Nasirpour A, Schmitz I, Hanken H, Friedrich RE, Gosau M. Bone Micromorphology and Material Attrition After Sonic, Ultrasonic and Conventional Osteotomies. In Vivo 2021; 35:1499-1506. [PMID: 33910827 DOI: 10.21873/invivo.12402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/17/2021] [Accepted: 03/31/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM Osteotomy as the first step in surgery, provides access to the field and its application could influence the outcome. Nowadays, the conventional burr reduction is being challenged by newer sonic and ultrasonic methods. We investigated the bone structural integrity and metal attrition residues both in bone and the irrigation fluid. MATERIALS AND METHODS Bovine ribs were cut using three methods. Bone cuts were studied using Environmental Scanning Electron Microscopy (ESEM) for tissue discrepancies and Scanning Electron Microscopy/Energy Dispersion X-Ray Microanalysis (SEM/EDX) for organic and inorganic debris. RESULTS Better preservation of bone architecture was seen in piezo and sono surgery while metal attrition was not conclusive (p>0.05). Unlike in bone analyses, both bur and ultrasonic osteotomies showed statistically significant higher median inorganic detection per analysis (p=0.021 and p=0.037, respectively). CONCLUSION Sono and piezo surgery proved to be less invasive while attrition properties were the same.
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Affiliation(s)
- Ashkan Rashad
- Department of Oral, Maxillofacial and Facial Plastic Surgery, RWTH Aachen University Hospital, Aachen, Germany.,Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Schwan
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany
| | - Alireza Nasirpour
- Department of Oral and Maxillofacial Surgery, Tehran University of Medical Sciences, Tehran, Iran
| | - Inge Schmitz
- Department of Pathology, Ruhr University Bochum, Bochum, Germany
| | - Henning Hanken
- Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Reinhard E Friedrich
- Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany;
| | - Martin Gosau
- Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Wedge-Shaped Implants for Minimally Invasive Treatment of Narrow Ridges: A Multicenter Prospective Cohort Study. J Clin Med 2020; 9:jcm9103301. [PMID: 33066588 PMCID: PMC7602171 DOI: 10.3390/jcm9103301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 11/17/2022] Open
Abstract
The present study aims to investigate clinical and patient-centered outcomes after the implant-supported rehabilitation of narrow ridges using a novel wedge-shaped implant. Forty-four patients were treated with the insertion of 59 tissue-level wedge implants (1.8 mm bucco-lingual width) in horizontally atrophic ridges (mean bone width 3.8 ± 0.4 mm). The main outcome measures were: implant stability quotient (ISQ), marginal bone loss (MBL) and patient morbidity. Fifty-eight implants were functioning satisfactorily after one year of loading (98.3% survival rate). ISQ values measured in the mesio-distal direction resulted significantly higher than those in the bucco-lingual direction at all time points (p < 0.001). Both mesio-distal and bucco-lingual ISQ values at 6-month follow-up resulted significantly higher than at 4-month follow-up (p < 0.001 for both). Mean MBL was 0.38 ± 0.48 mm at prosthesis delivery (6 months after implant insertion) and 0.60 ± 0.52 mm after one year of functional loading. The majority of patients reported slight discomfort related to the surgical procedure. Postoperative pain score was classified as mild pain on the day of surgery and the first postoperative day and no pain over the following five days. Within the limitations of the present study, the device investigated showed low morbidity and positive short-term clinical results in narrow ridges treatment.
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Barrak FN, Li S, Muntane AM, Jones JR. Particle release from implantoplasty of dental implants and impact on cells. Int J Implant Dent 2020; 6:50. [PMID: 32918144 PMCID: PMC7486360 DOI: 10.1186/s40729-020-00247-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/29/2020] [Indexed: 01/01/2023] Open
Abstract
Background With increasing numbers of dental implants placed annually, complications such as peri-implantitis and the subsequent periprosthetic osteolysis are becoming a major concern. Implantoplasty, a commonly used treatment of peri-implantitis, aims to remove plaque from exposed implants and reduce future microbial adhesion and colonisation by mechanically modifying the implant surface topography, delaying re-infection/colonisation of the site. This in vitro study aims to investigate the release of particles from dental implants and their effects on human gingival fibroblasts (HGFs), following an in vitro mock implantoplasty procedure with a diamond burr. Materials and methods Commercially available implants made from grade 4 (commercially pure, CP) titanium (G4) and grade 5 Ti-6Al-4 V titanium (G5) alloy implants were investigated. Implant particle compositions were quantified by inductively coupled plasma optical emission spectrometer (ICP-OES) following acid digestion. HGFs were cultured in presence of implant particles, and viability was determined using a metabolic activity assay. Results Microparticles and nanoparticles were released from both G4 and G5 implants following the mock implantoplasty procedure. A small amount of vanadium ions were released from G5 particles following immersion in both simulated body fluid and cell culture medium, resulting in significantly reduced viability of HGFs after 10 days of culture. Conclusion There is a need for careful evaluation of the materials used in dental implants and the potential risks of the individual constituents of any alloy. The potential cytotoxicity of G5 titanium alloy particles should be considered when choosing a device for dental implants. Additionally, regardless of implant material, the implantoplasty procedure can release nanometre-sized particles, the full systemic effect of which is not fully understood. As such, authors do not recommend implantoplasty for the treatment of peri-implantitis.
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Affiliation(s)
- Fadi N Barrak
- Department of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Siwei Li
- Department of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Albert M Muntane
- School of Dentistry, University of Central Lancashire, Preston, PR1 2HE, UK
| | - Julian R Jones
- Department of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
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Minimal Invasive Piezoelectric Osteotomy in Neurosurgery: Technic, Applications, and Clinical Outcomes of a Retrospective Case Series. Vet Sci 2020; 7:vetsci7020068. [PMID: 32456065 PMCID: PMC7357104 DOI: 10.3390/vetsci7020068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/16/2022] Open
Abstract
Objective: To report the physical and technical principles, clinical applications, and outcomes of the minimal invasive piezoelectric osteotomy in a consecutive veterinary neurosurgical series. METHODS A series of 292 dogs and 32 cats underwent an osteotomy because a neurosurgical pathology performed with a Mectron Piezosurgery® bone scalpel (Mectron Medical Technology, Genoa, Italy) was retrospectively reviewed. Efficacy, precision, safety, and blood loss were evaluated intraoperatively by two different surgeons, on a case-by-case basis. Postoperative Rx and CT scans were used to assess the selectivity and precision of the osteotomy. A histological study on bony specimens at the osteotomized surface was carried out to evaluate the effects of piezoelectric cutting on the osteocytes and osteoblasts. All the patients underwent a six-months follow-up. A series of illustrative cases was reported. RESULTS All the osteotomies were clear-cut and precise. A complete sparing of soft and nervous tissues and vasculature was observed. The operative field was blood- and heat-free in all cases. A range of inserts, largely different in shape and length, were allowed to treat deep and difficult-to-reach sites. Two mechanical complications occurred. Average blood loss in dogs' group was 52, 47, and 56 mL for traumatic, degenerative, and neoplastic lesions, respectively, whereas it was 25 mL for traumatized cats. A fast recovery of functions was observed in most of the treated cases, early on, at the first sixth-month evaluation. Histology on bone flaps showed the presence of live osteocytes and osteoblasts at the osteotomized surface in 92% of cases. CONCLUSIONS Piezosurgery is based on the physical principle of the indirect piezo effect. Piezoelectric osteotomy is selective, effective, and safe in bone cutting during neurosurgical veterinary procedures. It can be considered a minimal invasive technique, as it is able to spare the neighboring soft tissues and neurovascular structures.
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Naghshbandi J. The influence of local and systemic factors upon dental implant osseointegration: A critical review. SAUDI JOURNAL OF ORAL SCIENCES 2020. [DOI: 10.4103/sjos.sjoralsci_79_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Marenzi G, Impero F, Scherillo F, Sammartino JC, Squillace A, Spagnuolo G. Effect of Different Surface Treatments on Titanium Dental Implant Micro-Morphology. MATERIALS 2019; 12:ma12050733. [PMID: 30836588 PMCID: PMC6427554 DOI: 10.3390/ma12050733] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 12/13/2022]
Abstract
Background: Titanium dental implants are today widely used with osseointegration mainly dependently on the implant surface properties. Different processing routes lead to different surface characteristics resulting, of course, in different in situ behaviors of the implants. Materials: The effect of different treatments, whether mechanical or chemical, on the surface morphology of titanium implants were investigated. To this aim, various experimental methods, including roughness analysis as well scanning electron microscope (SEM) observations, were applied. Results: The results showed that, in contrast to the mechanical treatments, the chemical ones gave rise to a more irregular surface. SEM observations suggested that where commercial pure titanium was used, the chemical treatments provided implant surfaces without contaminations. In contrast, sandblasted implants could cause potential risks of surface contamination because of the presence of blasting particles remnants. Conclusions: The examined implant surfaces showed different roughness levels in relation to the superficial treatment applied. The acid-etched surfaces were characterized by the presence of deeper valleys and higher peaks than the sandblasted surfaces. For this reason, acid-etched surfaces can be more easily damaged by the stress produced by the peri-implant bone during surgical implant placement.
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Affiliation(s)
- Gaetano Marenzi
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples "Federico II", Via Pansini 5, 80131 Naples, Italy.
| | - Filomena Impero
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples "Federico II", P.le Tecchio 80, 80125 Napoli, Italy.
| | - Fabio Scherillo
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples "Federico II", P.le Tecchio 80, 80125 Napoli, Italy.
| | - Josè Camilla Sammartino
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Via Ferrata 1, 27100 Pavia, Italy.
| | - Antonino Squillace
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples "Federico II", P.le Tecchio 80, 80125 Napoli, Italy.
| | - Gianrico Spagnuolo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples "Federico II", Via Pansini 5, 80131 Naples, Italy.
- Institute of Dentistry, I. M. Sechenov First Moscow State Medical University, 119146 Moscow, Russia.
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Noetzel N, Fienitz T, Kreppel M, Zirk M, Safi AF, Rothamel D. Osteotomy speed, heat development, and bone structure influence by various piezoelectric systems-an in vitro study. Clin Oral Investig 2019; 23:4029-4041. [PMID: 30826919 DOI: 10.1007/s00784-019-02838-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/06/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVES The aim of this in vitro study was to evaluate osteotomy speed, heat development, and bone structure influence from osteotomies performed by various piezoelectric devices and insert tips. These devices and tips were compared among each other with regard to conventional rotatory and oscillating systems with special focus on the insert tip design and thickness. MATERIAL AND METHODS The osteotomies were conducted on porcine ribs utilizing 12 different insert tips (straight and angulated) and three conventional systems. After time and temperature measurements, histological analysis was carried out. Light microscopy was used to evaluate the roughness of the osteotomic surface and to search for indications of thermal bone necrosis. A special software analyzing tool was employed to determine cutting width (mm) and debris (%). RESULTS All piezoelectric tips created smooth cuts. Cutting widths in general were wider than the actual insert tip size with a tendency for narrow straight insert tips producing relatively wide osteotomies, whereas narrow angulated inserts produced relatively small osteotomies. None of the samples demonstrated distinct indication of necrosis. Overall, there was only a small amount of debris in all osteotomy gaps. Conventional rotatory saws were faster and created less heat compared to all tested piezoelectric systems. Straight tips proved faster osteotomy speed than angulated tips. Thin insert tips indicated to have a positive correlation to osteotomy time and performed faster than conventional microsaw. The average temperature rise was lower when using conventional systems, but critical exceeding temperatures were only observed in short-time exceptional cases. In general, temperature rise was less when using angulated inserts. CONCLUSION All tested tips are appropriate for bone surgery. Only small differences were found among the piezoelectric insert tips. Although conventional rotatory systems in general performed faster osteotomies, special designed and thin piezoelectric insert tips seem to have a positive influence on osteotomy speed. Ultimately, none of the tested devices or inserts combined all best features of speed, heat development, bone structure influence, and safety. CLINICAL RELEVANCE Narrow and straight piezoelectric insert tips demonstrated reduced osteotomy times. Nevertheless, a combination of conventional and piezoelectric systems in clinical practice might be the best way to work time-efficient, patient-oriented, and safe. The choice of instrument should be based on clinical experience of the user and should be evaluated individually depending on the case.
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Affiliation(s)
- Nicolas Noetzel
- Department for Oral and Cranio-Maxillo and Facial Plastic Surgery, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.
| | - Tim Fienitz
- Department for Oral and Maxillofacial Plastic Surgery, University of Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany
| | - Matthias Kreppel
- Department for Oral and Cranio-Maxillo and Facial Plastic Surgery, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Matthias Zirk
- Department for Oral and Cranio-Maxillo and Facial Plastic Surgery, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Ali- Farid Safi
- Department for Oral and Cranio-Maxillo and Facial Plastic Surgery, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Daniel Rothamel
- Department for Oral and Maxillofacial Plastic Surgery, University of Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany
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Monje A, Insua A, Wang HL. Understanding Peri-Implantitis as a Plaque-Associated and Site-Specific Entity: On the Local Predisposing Factors. J Clin Med 2019; 8:E279. [PMID: 30823574 PMCID: PMC6406659 DOI: 10.3390/jcm8020279] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 12/22/2022] Open
Abstract
The prevalence of implant biological complications has grown enormously over the last decade, in concordance with the impact of biofilm and its byproducts upon disease development. Deleterious habits and systemic conditions have been regarded as risk factors for peri-implantitis. However, little is known about the influence of local confounders upon the onset and progression of the disease. The present narrative review therefore describes the emerging local predisposing factors that place dental implants/patients at risk of developing peri-implantitis. A review is also made of the triggering factors capable of inducing peri-implantitis and of the accelerating factors capable of interfering with the progression of the disease.
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Affiliation(s)
- Alberto Monje
- Department of Periodontology, Universitat Internacional de Catalunya, 08195 Barcelona, Spain.
- Division of Periodontics, CICOM Periodoncia, 06011 Badajoz, Badajoz, Spain Santiago de Compostela, Spain.
| | - Angel Insua
- Division of Periodontics, CICOM Periodoncia, 06011 Badajoz, Badajoz, Spain Santiago de Compostela, Spain.
| | - Hom-Lay Wang
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI 48109, USA.
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Delgado-Ruiz R, Romanos G. Potential Causes of Titanium Particle and Ion Release in Implant Dentistry: A Systematic Review. Int J Mol Sci 2018; 19:E3585. [PMID: 30428596 PMCID: PMC6274707 DOI: 10.3390/ijms19113585] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 11/09/2018] [Accepted: 11/11/2018] [Indexed: 01/03/2023] Open
Abstract
Implant surface characteristics, as well as physical and mechanical properties, are responsible for the positive interaction between the dental implant, the bone and the surrounding soft tissues. Unfortunately, the dental implant surface does not remain unaltered and changes over time during the life of the implant. If changes occur at the implant surface, mucositis and peri-implantitis processes could be initiated; implant osseointegration might be disrupted and bone resorption phenomena (osteolysis) may lead to implant loss. This systematic review compiled the information related to the potential sources of titanium particle and ions in implant dentistry. Research questions were structured in the Population, Intervention, Comparison, Outcome (PICO) framework. PICO questionnaires were developed and an exhaustive search was performed for all the relevant studies published between 1980 and 2018 involving titanium particles and ions related to implant dentistry procedures. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for the selection and inclusion of the manuscripts in this review. Titanium particle and ions are released during the implant bed preparation, during the implant insertion and during the implant decontamination. In addition, the implant surfaces and restorations are exposed to the saliva, bacteria and chemicals that can potentially dissolve the titanium oxide layer and, therefore, corrosion cycles can be initiated. Mechanical factors, the micro-gap and fluorides can also influence the proportion of metal particles and ions released from implants and restorations.
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Affiliation(s)
- Rafael Delgado-Ruiz
- Department of Prosthodontics and Digital Technology, School of Dental Medicine, Stony Brook University, New York, NY 11794, USA.
| | - Georgios Romanos
- Department of Periodontics, School of Dental Medicine, Stony Brook University, New York, NY 11794, USA.
- Department of Oral Surgery and Implant Dentistry, Dental School, Johann Wolfgang Goethe University, 60323 Frankfurt, Germany.
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16
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Atieh MA, Alsabeeha NHM, Tawse-Smith A, Duncan WJ. Piezoelectric versus conventional implant site preparation: A systematic review and meta-analysis. Clin Implant Dent Relat Res 2018; 20:261-270. [PMID: 29148161 DOI: 10.1111/cid.12555] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 10/08/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND The use of a piezoelectric device (PED) for implant site preparation (ISP) has been introduced to overcome the limitations of using conventional drills (CDs). With little and inconsistent information in the literature regarding their efficiency for preparing implant osteotomies, the objective of this systematic review was to compare the use of CDs to PEDs for ISP with regard to implant stability values, marginal bone level changes, operating time, and dental implant failure rate. METHODS The systematic review was prepared according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The literature was searched for studies that assessed the use of CDs and PEDs for ISP. The Cochrane Collaboration risk of bias tool was used to evaluate the selected studies and meta-analyses were performed using statistical software. RESULTS A total of 755 citations were identified. Of these, 4 studies with 178 implant osteotomies in 80 participants were included. The pooled estimates for the implant stability showed significant differences between the 2 surgical techniques in favor of PEDs at baseline, 8 and 12 weeks. A statistically significant difference in the operating time was also shown between the 2 techniques with more time required using PED. The differences in marginal bone level changes or implant failure rate were not statistically significant. CONCLUSIONS With the limitations of this review in mind, PEDs appear to be a viable alternative to traditional drilling techniques for ISP. With the exception of prolonged operating time associated with the use of PEDs, both techniques were comparable in terms of the marginal bone level changes and the risk of implant failure. The favorable influence of the implant stability pattern related to the use of PEDs on the predictability of immediate and early loading protocols need to be confirmed in future studies.
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Affiliation(s)
- Momen A Atieh
- Department of Oral Sciences, Faculty of Dentistry, Oral Implantology Research Group, Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
| | - Nabeel H M Alsabeeha
- Prosthetic Section, Ras Al-Khaimah Dental Center, Ministry of Health, Ras Al-Khaimah, United Arab Emirates
| | - Andrew Tawse-Smith
- Department of Oral Sciences, Faculty of Dentistry, Oral Implantology Research Group, Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
| | - Warwick J Duncan
- Department of Oral Sciences, Faculty of Dentistry, Oral Implantology Research Group, Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
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Troedhan A, Mahmoud ZT, Wainwright M, Khamis MM. Cutting bone with drills, burs, lasers and piezotomes: A comprehensive systematic review and recommendations for the clinician. ACTA ACUST UNITED AC 2017. [DOI: 10.17352/2455-4634.000028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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18
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Micromorphometric analysis of bone blocks harvested with eight different ultrasonic and sonic devices for osseous surgery. J Craniomaxillofac Surg 2016; 44:1143-51. [DOI: 10.1016/j.jcms.2016.04.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/16/2016] [Accepted: 04/14/2016] [Indexed: 12/15/2022] Open
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Rashad A, Sadr-Eshkevari P, Heiland M, Smeets R, Hanken H, Gröbe A, Assaf AT, Köhnke RH, Mehryar P, Riecke B, Wikner J. Intraosseous heat generation during sonic, ultrasonic and conventional osteotomy. J Craniomaxillofac Surg 2015; 43:1072-7. [PMID: 26116310 DOI: 10.1016/j.jcms.2015.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 05/23/2015] [Accepted: 05/26/2015] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES To assess heat generation in osteotomies during application of sonic and ultrasonic saws compared to conventional bur. METHODS Two glass-fiber isolated nickel-chromium thermocouples, connected to a recording device, were inserted into fresh bovine rib bone blocks and kept in 20 ± 0.5 °C water at determined depths of 1.5 mm (cortical layer) and 7 mm (cancellous layer) and 1.0 mm away from the planned osteotomy site. Handpieces, angulated 24-32°, were mounted in a vertical drill stand, and standardized weights were attached to their tops to exert loads of 5, 8, 15 and 20 N. Irrigation volumes of 20, 50 and 80 ml/min were used for each load. Ten repetitions were conducted using new tips each time for each test condition. The Mann-Whitney-U test was used for statistical analysis (p < 0.05). RESULTS Both ultrasonic and sonic osteotomies were associated with significantly lower heat generation than conventional osteotomy (p < 0.01). Sonic osteotomy showed non-significantly lower heat generation than ultrasonic osteotomy. Generated heat never exceeded the critical limit of 47 °C in any system. Variation of load had no effect on heat generation in both bone layers for all tested systems. An increased irrigation volume resulted in lower temperatures in both cortical and cancellous bone layers during all tested osteotomies. CONCLUSION Although none of the systems under the conditions of the present study resulted in critical heat generation, the application of ultrasonic and sonic osteotomy systems was associated with lower heat generation compared to the conventional saw osteotomy. Copious irrigation seems to play a critical role in preventing heat generation in the osteotomy site.
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Affiliation(s)
- Ashkan Rashad
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
| | - Pooyan Sadr-Eshkevari
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, Germany
| | - Max Heiland
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Ralf Smeets
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Henning Hanken
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Alexander Gröbe
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Alexandre T Assaf
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Robert H Köhnke
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Pouyan Mehryar
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, Germany
| | - Björn Riecke
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Johannes Wikner
- Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Max Heiland; MD, DMD, PhD), University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
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Spinato S, Rebaudi A, Bernardello F, Bertoldi C, Zaffe D. Piezosurgical treatment of crestal bone: quantitative comparison of post-extractive socket outcomes with those of traditional treatment. Clin Oral Implants Res 2015; 27:361-6. [PMID: 25639687 DOI: 10.1111/clr.12555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The study aimed to quantitatively compare, for the first time, the clinical outcomes of crestal bone volume resorption in sockets undergoing traditional extraction technique (TET) or piezosurgical extraction technique (PET), also considering the influence of buccal plate thickness. MATERIAL AND METHODS In this prospective study, 19 sockets were randomly treated with TET, and 18 sockets were randomly treated with PET. Furthermore, patients were split into subgroup A, with buccal bone plate thickness (BPT) ≤1 mm, and subgroup B, with BPT>1 mm. Buccal (BCH) and palatal (PCH) cortex height, bucco-palatal ridge (BPR) width were monitored at tooth extraction and after the 4-month post-extractive period of natural healing. RESULTS After 4 months, BCH, PCH and BPR width decreased more in the TET than in the PET group, but only the BPR decrease was statistically significant (P = 0.034) after ANOVA test. In both TET and PET groups, all B subgroup patients showed a lower decrease than A subgroup patients for both BCH, PCH and BPR, statistically significant for PCH (P = 0.019) and BPR (P < 0.001) of TET group, and BPR (P = 0.002) of PET group, after ANOVA. Both A and B subgroups of PET showed a statistically significant lower decrease than the corresponding subgroups of TET, comparing A (P = 0.005) and B (P = 0.037) subgroups for BPR, after ANOVA. CONCLUSIONS With both thin and thick buccal plates, the piezosurgical extraction technique of teeth significantly decreases the horizontal resorption of the hard tissue ridge, but not the vertical resorption. Moreover, buccal plate thickness seems to be a key factor in post-extractive bone resorption: the thinner the buccal plate the greater the horizontal crestal bone loss.
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Affiliation(s)
- Sergio Spinato
- Unit of Periodontology and Implantology, Department of Biomedical and Neuromotor Sciences, School of Dentistry, University of Bologna, Bologna, Italy
| | - Alberto Rebaudi
- Department of Integrated Diagnostic and Surgical Sciences, School of Dentistry, University of Genova, Genova, Italy
| | | | - Carlo Bertoldi
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
| | - Davide Zaffe
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
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Rashad A, Sadr-Eshkevari P, Heiland M, Smeets R, Prochnow N, Hoffmann E, Maurer P. Practitioner experience with sonic osteotomy compared to bur and ultrasonic saw: a pilot in vitro study. Int J Oral Maxillofac Surg 2014; 44:203-8. [PMID: 25277806 DOI: 10.1016/j.ijom.2014.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Revised: 05/07/2014] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
Abstract
The aim of the present study was to compare subjective experiences using bur, ultrasonic, and sonic osteotomy systems. Ten novice (N) and 10 expert (E) practitioners performed osteotomies on bovine ribs with each system. They scored ease of handling and sense of accuracy on visual analogue scales. The duration of the osteotomy procedure and the amount of noise were recorded objectively. Learning experience was evaluated in a second run. The Mann-Whitney U-test, Wilcoxon signed rank tests, and Spearman's rank correlation coefficient were used for the statistical analyses. The sonic system was significantly slower, with the worst noise impact (92.9dB; standard deviation (SD) 7.1). However, both user groups improved significantly in the second run (N 7.9, E 7.6). There were no significant differences in handling. The sense of accuracy was evaluated to be significantly best for the sonic system (N 8.4, E 8.4), compared to the ultrasonic system (N 7.1, E 7.1; both P=0.043) and bur system (N 5.5, P=0.002; E 6.0, P=0.006). The practitioners had a promising experience with the application of the ultrasonic system and particularly with the sonic system.
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Affiliation(s)
- A Rashad
- Department of Oral and Maxillofacial Surgery, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
| | - P Sadr-Eshkevari
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University, Bochum, Germany
| | - M Heiland
- Department of Oral and Maxillofacial Surgery, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - R Smeets
- Department of Oral and Maxillofacial Surgery, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - N Prochnow
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University, Bochum, Germany
| | - E Hoffmann
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University, Bochum, Germany
| | - P Maurer
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University, Bochum, Germany
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