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1.
Article in English | MEDLINE | ID: mdl-35060963

ABSTRACT

The present study aimed to evaluate the osseoconduction ability of an airborne particle-abraded and etched (SAE) titanium alloy surface when placed in humans with poor bone quality. Four patients scheduled to receive an implant-supported full-arch prosthesis received two additional reduced-diameter implants to be harvested after 6 months of submerged healing. Undecalcified vestibulopalatal/vestibulolingual histologic sections were prepared after the micro-computerized tomography (µCT) examination. Six implant sides from four biopsied implants displayed a type IV bone environment and were included in the present study. Bone-to-implant contact (BIC) was first measured on each implant side. The estimated initial BIC (E-iBIC) was evaluated by superimposing the implant profile 0.25 mm away from its actual position. The µCT provided information about the local and adjacent bony architecture. The mean BIC was 62.5% ± 10.6%, while the mean E-iBIC was 33.1% ± 4.4%. The E-iBIC/BIC ratio was 1.81 ± 0.38. The 3D µCT sections showed the thin bone trabeculae covering the implant surface; although they seemed to be separated from the rest of the bony scaffold, they were much more interconnected than what appeared to be on the 2D histologic preparations. This limited number of human histologic samples document, for the first time, that the SAE titanium alloy implant surface is apparently osseoconductive when placed in poor human bone quality. The average BIC was 1.81 times higher than the E-iBIC. This high osseoconductivity may explain the predictable clinical behavior of implants with this type of SAE textured surface in type IV bone.


Subject(s)
Dental Implants , Titanium , Acid Etching, Dental , Alloys , Dental Prosthesis Design , Humans , Mandible , Osseointegration , Surface Properties , X-Ray Microtomography
2.
Int J Implant Dent ; 6(1): 2, 2020 Jan 15.
Article in English | MEDLINE | ID: mdl-31938897

ABSTRACT

PURPOSE: The aim of the present paper is to evaluate a simplified implant site preparation technique to preserve bone bulk and enhance osseointegration using a new conical self-tapping implant in cancellous bone. MATERIALS AND METHODS: Ten Expander® 3.8 × 10 mm implants (NoDrill®, Milano, Italy) were inserted in the right side (test group) of sheep's iliac crest using only the pilot drill 1.8 mm in diameter. Ten 3.8 × 10 mm Dynamix® implants (Cortex, Shlomi, Israel) were inserted in the right side (control group) of the same animals following the drilling protocol provided by the manufacturer. Histological, histomorphometric, and biomechanical analyses were performed after 2 months. RESULTS: Implants that belonged to the test group showed a %BIC of 70.91 ± 7.95 while the control group implants had a %BIC value of 49.33 ± 10.73. The %BV was 41.83 ± 6.30 in the test group and 29.61 ± 5.05 in the control group. These differences were statistically significant. A phenomenon of osseocorticalization, characterized by more bone volume percentage around implant area than in the neighboring areas, caused by implant threads geometry, was evident in the test group. CONCLUSION: This surgical protocol allows to insert an innovative fixture geometry in low-density bone using only a pilot drill. This technique demonstrated many clinical and histological advantages with respect to standard implant drilling procedures and classical implant geometry.

3.
Int J Oral Maxillofac Implants ; 35(1): 25-38, 2020.
Article in English | MEDLINE | ID: mdl-31923287

ABSTRACT

PURPOSE: To examine the effect of controlled progressive orthodontic loading on bone around implants subjected to overloading forces. MATERIALS AND METHODS: Bilateral edentulous alveolar ridges were created in the posterior maxilla of five beagle dogs and left to heal for an 8-week period, after which 40 implants were placed. In the overloading group (OL), 16 implants were inserted and left to osseointegrate for 16 weeks; impressions were made, and metal crowns were mounted on with supraocclusal contacts with the antagonist teeth. Implants were exposed to dynamic overloading for 16 weeks. In the progressive loading + overloading group (PL+OL), 16 implants were left to osseointegrate for 8 weeks, and custom abutment cores were fabricated and coupled by pairs with Ni-Ti orthodontic springs. Ascending static forces of 100g, 200g, and 300g were each applied for a 3-week period, for a total 9-week progressive loading period. Thereafter, metal crowns with supraocclusal contacts were adapted, and a 16-week overloading protocol for implants was followed as for the overloading group. In the unloaded control group (UL), eight implants were inserted and left uncovered and unloaded for 32 weeks, that is, until the end of the experimental period, at which point all 40 implants were removed with the surrounding bone. Histologic, histomorphometric, and statistical analysis followed. RESULTS: Higher bone-to-implant contact percentage was reported for the OL group (P = .006) and PL+OL group (P < .001) compared with the UL group. Between the OL and PL+OL groups, the addition of progressive loading did not increase the bone-to-implant contact percentage (P = .225). Bone density 1 mm and 2 mm distant to the threads did not differ significantly between the three groups. Significantly lower crestal bone resorption was detected around OL group implants (P = .006) and PL+OL group implants (P = .004) compared with the UL group implants. The implant success rate was 87.5% for the UL group, 67.5% for the OL group, and 87.5% for the PL+OL group. CONCLUSION: The application of controlled progressive orthodontic loading on osseointegrated implants preceding overloading forces did not increase bone-to-implant contact. When applied, overloading significantly increased bone-to-implant contact compared with the unloaded implants. A significantly higher implant success rate was reported in the PL+OL group compared with the OL group.


Subject(s)
Alveolar Bone Loss , Dental Implants , Animals , Dental Implantation, Endosseous , Dogs , Implants, Experimental , Mandible , Maxilla , Osseointegration
4.
Article in English | MEDLINE | ID: mdl-29451931

ABSTRACT

This report presents six consecutive cases of peri-implantitis associated with residual methacrylate cement. The cases responded to cement removal and disinfection procedures. Six patients, each presenting one methacrylate cement-retained implant restoration and showing peri-implant inflammation and bone loss, were treated. All the cases were negative for bleeding on probing after 6 weeks, and this was maintained at 1 year of follow-up from nonsurgical therapy and crown refixation with alternative and resorbable cement. The treatment effectively solved the inflammation and led to complete restoration ad integrum, as evaluated clinically and radiographically, after 1 year.


Subject(s)
Alveolar Bone Loss/therapy , Dental Cements/adverse effects , Dental Implants/adverse effects , Peri-Implantitis/therapy , Adult , Alveolar Bone Loss/diagnostic imaging , Crowns , Dental Implant-Abutment Design , Dental Prosthesis, Implant-Supported , Dental Restoration Failure , Follow-Up Studies , Humans , Inflammation , Methacrylates/adverse effects , Middle Aged , Peri-Implantitis/chemically induced , Peri-Implantitis/diagnostic imaging , Periodontal Index , Retrospective Studies
5.
Int J Oral Maxillofac Implants ; 33(4): 824-830, 2018.
Article in English | MEDLINE | ID: mdl-30024998

ABSTRACT

PURPOSE: Primary implant stability represents the first step for successful osseointegration. The knowledge of the correlation between host bone density, insertion torque, and implant macrogeometry seems to be fundamental to achieve sufficient primary implant bone fixation in each clinical situation. The purpose of this study was to measure, in vitro, the impact of dental implant macrogeometry and insertion torque values on primary stability in relation to different bone densities, representing both the human mandible and maxilla. MATERIALS AND METHODS: One hundred twenty 3.8 ± 11-mm commercial dental implants were used. Forty implants had small threads with a machined neck, 40 implants had small threads with a microthreaded neck, and the last 40 implants had large threads with a reverse neck design. Fresh bovine ribs, representing a medium-dense bone density (D2-D3), and fresh ovine iliac crest, representing a soft bone density (D4), were used. Insertion torque and micromobility under lateral force data were recorded for each implant. RESULTS: In the medium-dense bone type, the reverse neck implant design showed less primary implant stability than the conventional straight implant neck. In soft bone, both implants with the large thread design and microthreaded neck implants showed better implant stability than the implant with a small thread design with a straight machined neck. Implants with large and self-cutting threads showed significantly (P < .05) lower micromobility values than other implants in postextractive sites in low-density bone. CONCLUSION: Implant geometries and bone density are the main factors involved in the degree of primary implant stability. Large-thread implant designs are highly desirable in cases of poor bone quality. Each implant geometry generates an insertion torque value, which is correlated to the stability of that specific implant in a specific bone quality, but the insertion torque is not an objective value to compare primary stability between different implant types.


Subject(s)
Bone Density/physiology , Dental Implantation, Endosseous , Dental Prosthesis Retention , Animals , Cattle , Dental Implants , Dental Prosthesis Design , Humans , Mandible/surgery , Maxilla/surgery , Mechanical Phenomena , Osseointegration/physiology , Sheep , Surface Properties , Torque
6.
Implant Dent ; 27(3): 271-275, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29652756

ABSTRACT

PURPOSE: The aim of the present radiological study was to analyze the alveolar bone morphology of the lower molars in physiological conditions. The main goal is to describe the bone anatomy of a hypothetically postextractive site in lower molar area. MATERIALS AND METHODS: Computed tomography scans of 100 patients were examined. Axial, paraxial, and Panorex sections were analyzed using a dedicated software. Precise reference points were encoded to make the bone measurements clear and repeatable. RESULTS: The total number of dental sites examined was 235. The mean available bone height was 13.32 ± 3.23 mm in first molars and 11.76 ± 2.82 mm in second molars. The inter-radicular septum was present in 86% out of cases in first molar sites and in 52% in second molar sites. The lingual cortex mean width, at the most coronal point, measured 1.41 ± 0.52 mm in first molar alveoli and 1.67 ± 0.66 mm in second molar alveoli. CONCLUSIONS: Proper clinical conditions, for scheduling a postextraction immediate implant placement surgery, involve the presence of 4 bone walls showing and sufficient height and width. The accurate knowledge of alveolus bone morphology of mandibular molars, prior extraction, could be an important guide to avoid potential failures due to nonideal anatomical features to fixture stabilization.


Subject(s)
Alveolar Process/anatomy & histology , Alveolar Process/diagnostic imaging , Mandible/anatomy & histology , Mandible/diagnostic imaging , Molar/anatomy & histology , Molar/diagnostic imaging , Tomography, X-Ray Computed , Adult , Anatomic Landmarks , Female , Humans , Immediate Dental Implant Loading , Male , Radiographic Image Interpretation, Computer-Assisted , Radiography, Panoramic , Software , Tooth Extraction
7.
Implant Dent ; 27(2): 171-176, 2018 04.
Article in English | MEDLINE | ID: mdl-29557796

ABSTRACT

PURPOSE: The aim of the present study was to analyze the alveolar bone morphology of the upper first and second molars. This analysis aims to evaluate the morphology of a hypothetical postextractive site in the upper molar area to diagnose the possibility of immediate postextraction implant placement. MATERIALS AND METHODS: Cone-beam CT scans of 100 patients were examined. The measurements were made using a dedicated 3D software. Reference points were identified to allow clear and repeatable measurements. RESULTS: The mean available height was 7.43 ± 3.40 mm for the upper first molars and 7.07 ± 3.09 mm for the upper second molars. The interradicular septum was present in first molars in 74% of cases and 44% of cases in upper second molars. CONCLUSIONS: In most cases, the alveolar sites of the upper first and second molars do not present ideal conditions for immediate implant insertion in a correct position. The primary stabilization of a standard-sized dental implant is often difficult because of the minimum apical bone available. In particular, the interradicular septum, which often represents the ideal fixture position, is rarely adequately represented. Preoperative cone-beam scan and the knowledge of anatomical measurements from the present analysis are fundamental before planning immediate postextractive implants in the upper molar area.

8.
Article in English | MEDLINE | ID: mdl-28817135

ABSTRACT

The purpose of this study was to compare microcomputed tomography (microCT) and histologic analysis outcomes of a periodontal regeneration of a human defect treated with a polylactic- and polyglycolic-acid copolymer. At 11 months following the grafting procedure, the root with the surrounding periodontal tissues was removed and analyzed using microCT and histologic techniques. The results suggest that microCT three-dimensional analysis may be used in synergy with two-dimensional histologic sections to provide additional information for studying the regeneration outcomes normally reported by histologic biopsies in humans. Additional data is needed to validate these findings.


Subject(s)
Guided Tissue Regeneration, Periodontal , Periodontium/pathology , Chronic Periodontitis/surgery , Female , Guided Tissue Regeneration, Periodontal/methods , Humans , Middle Aged , Periodontium/diagnostic imaging , Radiography, Dental , Treatment Outcome , X-Ray Microtomography
9.
Implant Dent ; 26(3): 429-437, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28492424

ABSTRACT

PURPOSE: The aim was to compare the osseointegration degree and secondary implant stability between implants with different surface treatments. MATERIALS AND METHODS: A novel electrochemical treatment was applied to modify the sandblasted and acid-etched surface (SLA) to obtain the new hydrophilic Feeling (FEL) surface presenting a highly soluble and homogenous film made of calcium and phosphorus nanocrystals. Twenty 3.8 × 10-mm dynamix implants (Cortex) were inserted in sheep iliac crests. Sheep were killed after 2 months. Bone-to-implant contact percentage (%BIC) and biomechanical parameters, such as implant stability quotient (ISQ) and value of actual micromotion (VAM), were evaluated for each implants. RESULTS: No implant failures were observed. Implants of test group showed %BIC value 30% higher in respect with control group (P = 0.001). No statistical differences were detected between the 2 groups in VAM and ISQ values. CONCLUSION: Both surface treatments were highly osteoconductive because they were able to significantly increase the bone density onto implant surface in respect with that in which they were inserted (D4 bone density). The hydrophilic FEL surface demonstrated an increase of about 216% in BIC in respect with host bone density and an additional 30% more in respect with SLA surface. Faster osseointegration process is desirable in case of early implant loading protocol.


Subject(s)
Dental Implants , Ilium/surgery , Osseointegration/physiology , Titanium/chemistry , Acid Etching, Dental , Animals , Biomechanical Phenomena , Bone Density/physiology , Bone Regeneration/physiology , Bone-Implant Interface/physiology , Electrochemistry , Female , Hydrophobic and Hydrophilic Interactions , Implants, Experimental , Microscopy, Electron, Scanning , Sheep, Domestic , Spectrometry, X-Ray Emission , Surface Properties
10.
Implant Dent ; 26(1): 121-128, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28060023

ABSTRACT

OBJECTIVE: The present prospective study aimed to more precisely identify the time points of bone changes around hybrid titanium implants up to 30 months of follow-up. MATERIALS AND METHODS: Twelve hybrid T3 implants (Biomet 3i) were placed in 9 healthy patients with the 2-stage surgical approach. Standardized digital Rx were taken at implant insertion (T0); healing-abutment connection after 3.1 ± 0.2 weeks (TX); loading stage after 7.5 ± 0.6 weeks (T1); after 12 months (T2); and after 30 months (T3) of functional loading. The marginal bone loss was digitally measured. RESULTS: The mean marginal bone loss was 0.76 ± 0.37 mm after 30 months. More than 60% (0.42 ± 0.29 mm) of the bone loss took place at healing-abutment connection (TX-T1). No statistically significant bone loss was found between T1-T2 and T2-T3, after 12 and 30 months, respectively. Approximately 40% of bone loss (0.34 mm) was noted between T1 and T3 (P < 0.05), which corresponds to the loading period. CONCLUSIONS: The implant-oral environment connection represents a critical step point in crestal bone loss. The amount of marginal bone loss, measured after 30 months of loading (T1-T3), was much less than that reported in the literature, showing that correct loading has a minor impact on the periimplant bone remodeling as compared to surgical implant reopening.


Subject(s)
Bone Remodeling , Bone-Implant Interface/pathology , Dental Implants , Adult , Alveolar Bone Loss/diagnostic imaging , Alveolar Bone Loss/surgery , Bone-Implant Interface/diagnostic imaging , Dental Implant-Abutment Design/methods , Female , Humans , Male , Middle Aged , Osseointegration , Prospective Studies , Radiography, Dental , Time Factors , Titanium
11.
Implant Dent ; 25(5): 575-80, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27548108

ABSTRACT

PURPOSE: The aim of the present histological and biomechanical analysis was to compare, in vivo, the strength and quality of osseointegration between a laser-treated implant surface and a standard machined surface. MATERIAL AND METHODS: Customized titanium implants, having 2 different surfaces, were used. Implants were longitudinally split in the 2 surfaces: one side was laser treated and the opposite one had a machined surface. Eight implants were inserted in the iliac crest of 2 sheep: 4 with a split laser and machined surfaces, 2 with a completely laser-treated surface, and 2 with fully machined surfaces. The animals were killed 8 weeks after the placement of implants. The histomorphometric and biomechanical parameters calculated for each surface were the bone-implant contact (%BIC) and the reverse torque value (RTV) RESULTS:: The RTV of the laser-treated implants were about 3-fold higher than that of the machined implants. The histomorphometric results showed a significant difference of %BIC around 30% between the laser surfaces compared to the machined ones. CONCLUSIONS: The present study showed that laser surface treatment induces better osteointegration than machined surface. The laser-treated surface seems to be able to increase the osseointegration amount in respect to the machined implants.


Subject(s)
Bone-Implant Interface/physiology , Prostheses and Implants , Animals , Bone-Implant Interface/pathology , Ilium/pathology , Ilium/surgery , Lasers , Osseointegration/physiology , Sheep , Titanium
12.
Dent Mater J ; 35(5): 748-755, 2016 Oct 01.
Article in English | MEDLINE | ID: mdl-27546858

ABSTRACT

This study aims to investigate the mechanical properties, composition and surface preparation for adhesive bonding of the recently introduced zirconia-reinforced lithium silicate (ZLS) glass-ceramic. One single block of ZLS was used to prepare the specimens (n=14). The fracture toughness (Ft) and the Vickers hardness (HV) were measured on specimens partially crystallized (PCs) (n=4) and fully crystallized (FCs) at 840°C for 8 min (n=4). The surface treatment was done using hydrofluoric-acid gel (HF) at different concentrations and times of action on FCs specimens (n=4). SEM-EDX was used to test elemental composition and crystalline phases (n=2). The new ZLS glass-ceramic showed significantly higher values of HV and Ft for FCs, PCs showed a brittle behavior. The surface etching should be made using HF at 4.9% for 20 s.


Subject(s)
Dental Porcelain , Lithium , Acid Etching, Dental , Ceramics , Dental Bonding , Dental Stress Analysis , Hydrofluoric Acid , Materials Testing , Silicates , Stress, Mechanical , Surface Properties
13.
Implant Dent ; 25(4): 532-40, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27129002

ABSTRACT

OBJECTIVES: The aim was to analyze the data about the effects on marginal bone resorption and implant failure rates between implants inserted with high or low insertion torque values. MATERIALS AND METHODS: A systematic literature search until July 2015 was conducted. Data were summarized qualitatively in descriptive tables and quantitatively by performing random effects meta-analyses of effect sizes (ESs) for bone resorption and bone-to-implant contact (BIC) and relative risks (RRs) for implant failures. Risk of bias assessments were performed using the Cochrane tool for human studies and the SYRCLE's tool for animal studies. RESULTS: Four studies in humans and 6 quasirandomized animal studies were included. A total of 591 implants were evaluated qualitatively: 348 installed with high insertion torque (>25 Ncm, up to 176 Ncm) and 243 implants inserted with low torque values (<30-35 Ncm). No significant differences were detected for bone resorption (ES, 0.13; 95% confidence interval [CI], -0.12 to 0.38 in human studies; ES predictive interval from 35.03 to 34.50 in animal studies), implant failure (RR, 0.39; 95% CI, 0.01-20.77 in human studies; RR, 2.05; 95% CI, 0.19-21.71 in animal studies), or BIC (ES predictive interval from -3.84 to 5.13 in animal studies). CONCLUSION: The current review indicated that there is no significant difference in marginal bone resorption and implant failure rate between implants inserted with high or low insertion torque values.


Subject(s)
Bone Resorption , Dental Implantation, Endosseous/adverse effects , Dental Implants/adverse effects , Dental Restoration Failure , Animals , Dental Implantation, Endosseous/methods , Humans , Torque
14.
Clin Oral Implants Res ; 27(11): 1423-1430, 2016 Nov.
Article in English | MEDLINE | ID: mdl-26727557

ABSTRACT

OBJECTIVES: The osseointegration process replaces the surgically damaged bone with newly formed bone in contact to the implant surface. This involves some loss of primary stability, which will continue until new bone is formed providing a new stability, known as "secondary stability." A direct measurement of secondary implant stability appears fundamental to determine the period and modalities for implant loading. The aim of this study was to validate the measurement of the implant micromotion to test secondary implant stability. MATERIALS AND METHODS: Twenty-four 3.8 × 11.5 mm implants (Dynamix, Cortex, Shlomi, Israel) were inserted in sheep iliac crests. The animals were sacrificed after 2 months, and the freshly retrieved bone blocks were immediately fixed on a customized device to calculate the value of actual micromotion (VAM) according to a previously described technique. Implant stability quotient (ISQ) values, reverse torque value (RTV), %bone-to-implant contact (%BIC), bone volume percentage (%BV) and crestal bone loss (CBL) were also calculated for each implant. Statistical correlations between VAM and the other parameters were calculated. RESULTS: Data correlation analysis between the examined parameters showed that VAM significantly correlates (P < 0.05) to RTV, %BIC, ISQ and CBL. CONCLUSIONS: As VAM showed to be statistical correlated to the other parameters of osseointegration, it may be used to clinically check the amount of implant osseointegration, secondary stability and CBL. Future studies are needed to confirm these results moreover. An instrument to measure VAM in the oral cavity still needs to be developed.


Subject(s)
Dental Implantation, Endosseous/methods , Dental Implants , Dental Restoration Failure , Ilium/surgery , Osseointegration/physiology , Animals , Biomechanical Phenomena , Dental Stress Analysis , Female , Humans , Implants, Experimental , Osteotomy , Sheep , Sheep, Domestic , Surface Properties , Torque
15.
Implant Dent ; 25(1): 24-31, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26584202

ABSTRACT

PURPOSE: The aim of this study was to evaluate a new surgical technique for implant site preparation that could allow to enhance bone density, ridge width, and implant secondary stability. MATERIALS AND METHODS: The edges of the iliac crests of 2 sheep were exposed and ten 3.8 × 10-mm Dynamix implants (Cortex) were inserted in the left sides using the conventional drilling method (control group). Ten 5 × 10-mm Dynamix implants (Cortex) were inserted in the right sides (test group) using the osseodensification procedure (Versah). After 2 months of healing, the sheep were killed, and biomechanical and histological examinations were performed. RESULTS: No implant failures were observed after 2 months of healing. A significant increase of ridge width and bone volume percentage (%BV) (approximately 30% higher) was detected in the test group. Significantly better removal torque values and micromotion under lateral forces (value of actual micromotion) were recorded for the test group in respect with the control group. CONCLUSION: Osseodensification technique used in the present in vivo study was demonstrated to be able to increase the %BV around dental implants inserted in low-density bone in respect to conventional implant drilling techniques, which may play a role in enhancing implant stability and reduce micromotion.


Subject(s)
Bone Regeneration , Dental Implantation, Endosseous/methods , Animals , Bone Density , Dental Stress Analysis , Female , Sheep
16.
Clin Oral Implants Res ; 27(7): 910-7, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26202378

ABSTRACT

OBJECTIVE: To evaluate histologically and histomorphometrically, the peri-implant bone reaction around implants subjected to controlled progressive orthodontic loading. MATERIALS AND METHODS: In three beagle dogs, bilateral edentulous flat alveolar ridges were created in the maxillary area posterior to the canines. After 8 weeks of healing, 24 implants (Biomet 3i) were inserted in the edentulous sites. Two experimental groups were created. Progressive loading group: Twelve implants were left to heal for 8 weeks uncovered, and abutments were adapted and connected by pairs with Ni-Ti orthodontic springs. A gradual static force of 100, 200 and 300 g was applied for a 3-week period each. Thus, a total progressive loading period of 9 weeks was exercised. Unloaded control group: Twelve implants were left to heal undisturbed. At the end of the experimental period, all implants of both groups were removed with the surrounding bone. Histologic and histomorphometric analyses were performed, and the following parameters were measured: bone-to-implant contact, bone density 1 and 2 mm distant to the implant threads and crestal bone resorption. Median regression models are used for statistical analysis. RESULTS: Implants of the progressive loading group exhibited significantly higher percentage of bone-to-implant contact compared to the unloaded control implants (P = 0.018). Bone density 1 and 2 mm distant to the threads was found to be the same between the two groups (P = 0.734 and P = 0.961, respectively). Crestal bone resorption did not differ between loaded and unloaded implants (P = 0.813). CONCLUSION: The application of progressive loading by controlled orthodontic force on osseointegrated implants provoked significant increase in the percentage of bone-to-implant contact of the low-density bone of the dog maxilla.


Subject(s)
Bone-Implant Interface/pathology , Dental Implants , Dental Stress Analysis , Animals , Dogs , Maxilla , Osseointegration
17.
Implant Dent ; 24(4): 384-91, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25939083

ABSTRACT

PURPOSE: This study evaluated the effect of 2 different thread designs on secondary stability (micromotion) and osseointegration rate in dense and cancellous bones. MATERIALS AND METHODS: Forty large threaded and 40 small threaded implants (Cortex) were placed in low- (iliac crest) and high-density (mandible) bone of sheep. Two months later, micromobility tests and histological analysis were performed to measure secondary stability, osseointegration (bone-to-implant contact percentage [%BIC]), and bone density (bone volume percentage [%BV]). The value of actual micromotion of implant is introduced as a new parameter to evaluate secondary stability. RESULTS: Large threaded implants showed significantly higher %BIC and %BV than small threaded implants in low-density bone and statistically higher secondary stability in cancellous and cortical bones. CONCLUSIONS: Implants in dense bone reach higher secondary stability than those in cancellous bone, despite the lower %BIC. Implant geometry and bone density play a key role in secondary stability. Large thread design improves bone anchorage mechanically and histologically as compared with small threaded implants.


Subject(s)
Bone Density/physiology , Dental Implantation, Endosseous , Dental Implants , Dental Prosthesis Design , Dental Stress Analysis , Osseointegration/physiology , Surface Properties , Animals , Female , Mandible/surgery , Sheep
18.
J Oral Maxillofac Surg ; 73(5): 861-88, 2015 May.
Article in English | MEDLINE | ID: mdl-25795180

ABSTRACT

In the posterior maxillary sextants, the residual dimensions of the edentulous ridge can considerably limit the insertion of implants with the desired length and diameter. A minimally invasive procedure for transcrestal sinus floor elevation (tSFE), namely the Smart Lift technique, which is based on a standardized sequence of specifically designed drills and osteotomes, was introduced in 2008 and subsequently validated in a series of recent studies. The present technical note describes the use of the technique by a staged approach, called incremental tSFE (i-tSFE), in the augmentation of severely resorbed edentulous ridges. The i-tSFE consists of 2 staged tSFE procedures performed with a transcrestal access, the second of which is performed concomitantly with implant placement. In the present case series, 3 patients with severe bone atrophy (residual bone height, 2 to 3 mm) in the edentulous posterior maxilla were treated with i-tSFE. At the second surgical stage of i-tSFE, implants at least 8 mm long were placed at all sites, and the success of the implant-supported restoration was monitored to 6 months (1 patient) or 3 years (2 patients). Histologic findings from an augmented site showed the presence of newly formed bone, bone marrow spaces with numerous vascular canals, and residual graft particles occupying approximately 50%, 15%, and 35% of the total area, respectively. The results of the study showed that i-tSFE can be performed successfully with the Smart Lift technique to rehabilitate atrophic maxillary posterior sextants.


Subject(s)
Dental Implantation, Endosseous/methods , Maxilla/pathology , Minimally Invasive Surgical Procedures , Female , Humans , Male , Middle Aged , Surgical Instruments
19.
Implant Dent ; 24(1): 96-100, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25621555

ABSTRACT

OBJECTIVES: To make an in vivo evaluation of the effects of 2 different bone temperatures, on the development of implant osseointegration, in low-density bone. MATERIALS AND METHODS: Fifteen implant osteotomic sites were prepared in the iliac crests of sheep. Before the implant insertion, 5 sites were heated to 50°C for 1 minute, 5 sites to 60°C for 1 minute, and 5 sites were not overheated. Fifteen titanium dental implants (Cortex, Israel) were inserted. After a healing period of 2 months, the histomorphometric parameters calculated for each implant were the Bone-Implant Contact percentage (%BIC) and the infrabony pocket depth. Unpaired t test was applied to find statistical differences between groups. RESULTS: No implants failed. Statistical significant differences in %BIC and periimplant bone loss were found between the 60°C group and control group. No significant differences were found between the 50°C group and control group, although bone suffering signs were present. CONCLUSION: An osteotomic site overheating up to 60°C for 1 minute in low-density bone, before implant insertion, did not lead to implant failure, but it induced significant crestal bone loss during healing and lower %BIC.


Subject(s)
Dental Implantation, Endosseous , Dental Implants , Osseointegration , Animals , Bone-Implant Interface/pathology , Dental Implantation, Endosseous/methods , Female , Hot Temperature , Sheep , Temperature , Titanium
20.
Implant Dent ; 23(5): 516-21, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25238268

ABSTRACT

OBJECTIVES: To evaluate, in vivo, the effects of bone temperatures increased up to 60°C introduced before implant insertion on titanium implant osseointegration. MATERIALS AND METHODS: Twenty-four acid etched and sandblasted implants (Cortex Dental Implants) were inserted in the inferior edge of sheep mandibles. Osteotomic sites were randomly divided into 3 groups before inserting the implant. In test 1 group and in test 2 group, implant sites were overheated, respectively, up to 50°C for 1 minute and 60°C for 1 minute, with an electronic controlled probe of 3 mm in diameter and 10 mm in length. Osteotomic sites in control group were not overheated. Implants were inserted according to standard procedures. After 2 months healing, % bone implant contact (%BIC) and infrabony pockets' depth were measured. Unpaired t test was applied to find statistical differences between groups. RESULTS: No implant failure occurred. No statistical significant difference in %BIC was found among groups. Histological analysis showed that mean infrabony pockets were statistically deeper in 60°C group than in other groups. CONCLUSIONS: Bone temperature up to 60°C for 1 minute does not seem to significantly impair titanium dental implant osseointegration. Bone damage signs evident in the 60°C group suggest that careful drilling procedure with sufficient irrigation is necessary to avoid periimplant infrabony pockets' formation. More in vivo evaluations are needed to identify what is the value of bone temperature increase for irreversible inhibition of implant osseointegration.


Subject(s)
Dental Implants , Hot Temperature , Osseointegration , Animals , Female , Sheep
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