Bilateral diffuse gingival enlargement in a patient with type 1 neurofibromatosis.
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Adult↗
Biomedical subjects
Antonio Scarano
Publications and source records attributed to Antonio Scarano.
Bone-defect healing with calcium-sulfate particles and cement: an experimental study in rabbit.
Calcium sulfate (CaS) has been shown to be a reasonable alternative to autogenous bone graft for treating bone lesions in dentistry. The aim of this work was an histological study of the bone healing of defects treated with calcium sulfate in the form of cement or beads, in animal. Eight New Zealand rabbits, weighing about 2.5 Kg were used in this study. In each rabbit, four 6 mm bone defects were created in the tibial metaphysis. The 2 defects in the right tibia were filled with calcium sulfate as cement, while the 2 defects in the left one were filled with calcium sulfate as beads. Four rabbits were killed after respectively 2 and 4 weeks, with an intravenous injection of Tanax, and the block sections, containing the bone defects, were retrieved. A total of 16 defects filled by cement and a total of 16 defects filled by beads were retrieved. The specimens were processed to obtain thin ground sections with the Precise 1 Automated System. In the first phases of healing it was possible to observe an intense osteoblastic activity, and in some areas osteoid matrix was present. After two weeks the calcium sulfate (both cement and beads) was still present, and biological fluids and cells were present inside the material. Newly formed bone surrounded the calcium sulfate and filled about 10% of the defect. After four weeks the calcium sulfate was almost completely resorbed and substituted by new bone. Approximately 34% of the defects were filled by newly formed bone. BEI and XRM evaluations showed the structural components of the filled defects. In none of the specimens were inflammatory cells present. No significant differences were found using both calcium sulfate as cement and beads, and they both have shown a high biocompatibility, appearing to promote newly bone formation in the rabbit model, and they did not induce any untoward effect on the bone regeneration processes.
Absorptiometry, Photon↗
Interimplant distance and crestal bone resorption: a histologic study in the canine mandible.
BACKGROUND: Crestal bone loss has been shown to occur around dental implants. This crestal bone resorption may determine a more apical position of the gingival margin. A clear trend of increased bone loss with increased interimplant distance has been reported. PURPOSE: The aim of the present study was to evaluate, in the canine mandible, the crestal bone behavior around dental implants inserted with different interimplant distances. MATERIALS AND METHODS: Sandblasted and acid-etched implants (Bone System, Milano, Italy) were placed in the mandibles of six beagle dogs. Each dog received 10 implants in the mandible (five in the right side and five in the left side). A total of 60 implants was used in this study. The implants were divided in four groups: group I, with a 2 mm interimplant distance; group II, with a 3 mm interimplant distance; group III, with a 4 mm interimplant distance; and group IV, with a 5 mm interimplant distance. The dogs were killed after 12 months. RESULTS: No statistically significant differences were found in regard to vertical bone loss whereas on the contrary, statistically significant differences were found in regard to lateral bone loss (p = .0001). Statistically significant differences also were found in regard to vertical crestal bone loss (p = .0001). In fact vertical crestal bone loss decreased, from 1.98 mm in group I to 0.23 mm in group IV. CONCLUSIONS: The clinical significance of these data lies in the fact that the increased crestal bone loss results in an increase in the distance between the base of the contact points of the neighboring implants and the crest of bone, and this fact could determine whether the papilla is present or absent between two implants.
Alveolar Bone Loss↗
Effect of enamel matrix derivative (Emdogain) on bone defects in rabbit tibias.
The aim of this study was to assess the effect of an enamel matrix derivative (Emdogain, Biora, AB, Malmö, Sweden) on bone healing. Ten New Zealand rabbits, weighing about 2.5 kg, were used. One 8-mm bone defect was created in each tibia. The defect on the right leg was filled with Emdogain, whereas the defect on the opposite leg was left unfilled as control. A total of 20 defects were created. Five rabbits each were killed at 4 and 8 weeks with an overdose of Tanax. Block sections containing the defects were retrieved and the specimens processed for light microscopy examination. The slides were stained with acid and basic fuchsin and toluidine blue. Histologically, no differences were noted in both groups at each observation period; in the test group, remnants of the implanted Emdogain were not present at 4 weeks. Newly formed bone was detectable in both groups at all observation times. At 8 weeks, both groups showed mature bone, and in the test group the material implanted was not visible. No inflammatory cells were visible in both groups. In conclusion, our results indicate that Emdogain implanted in bone defects is fully resorbed after 4 to 8 weeks and does not adversely affect bone formation.
Animals↗
Histologic evaluation of an immediately loaded titanium implant retrieved from a human after 6 months in function.
Clinical and histologic studies have demonstrated that immediate loading can be successfully used in implant dentistry. Many factors are thought to be of importance in obtaining mineralized tissues at the interface. This study describes the implant interface of an immediately loaded implant with a conical implant-abutment connection that had been inserted in the posterior mandible for 6 months. Histology showed that mineralized tissue was present at about 74% +/- 6% of the implant interface. No gaps, fibrous tissue, or inflammatory infiltrate were present at the interface. The bone adjacent to the implant was mainly lamellar (90% +/- 4.5%). Tetracycline was used to label trabecular bone, and labeled bone was found in direct contact with the implant surface. The extensive labelling by tetracycline demonstrated a large quantity of newly formed bone at the implant interface. The distance between the 2 lines marked by tetracycline was 85 +/- 5 mm. The results of this study show that immediately loaded dental implants can form mineralized tissues at the bone-implant interface.
Aged↗
Maxillary sinus augmentation with a synthetic cell-binding peptide: histological and histomorphometrical results in humans.
Bone substitutes should be used when sufficient amounts of autologous bone cannot be harvested from intraoral donor sites. P-15 is a highly conserved linear peptide with a 15 amino acid sequence identical to the sequence contained in the residues 766 to 780 of the alpha-chain of type I collagen. PepGen P-15 (Dentsply Friadent, Mannheim, Germany) is a combination of the mineral component of bovine bone (Osteograf/N 300) with P-15. Bio-Oss (Geistlich, Mannheim, Germany) is a deproteinized sterilized bovine bone with 75% to 80% porosity and a crystal size of approximately 10 microm in the form of cortical granules. The purpose of the present histological and histomorphometrical study was to compare maxillary sinus augmentation procedures in humans performed with PepGen P-15 with procedures associated with Bio-Oss and autologous bone. Seven patients participated in this study (3 men and 4 women; ages between 48 and 69 years, mean of 58 years) and were categorized into 3 groups. In group 1, a mixture of 50% autologous bone from an intraoral source and 50% Bio-Oss was used. In group 2, the graft materials used were 50% Bio-Oss and 50% PepGen P-15. In group 3, 50% autologous bone and 50% PepGen P-15 were used. Group 1 histomorphometry showed that the percentage of newly formed bone was 38.7% +/- 3.2%, marrow spaces represented 45.6% +/- 5%, and residual graft particles constituted the remaining 14.4% +/- 2.1%. Group 2 histomorphometry showed that newly formed bone represented 36.7% +/- 3.3%, marrow spaces represented 39.7% +/- 3.4%, and residual graft particles represented 19.6% +/- 2.1%. In group 3, newly formed bone represented 32.2% +/- 3.2%, marrow spaces represented 38% +/- 2.5%, and residual graft particles represented 28.8% +/- 1.1%. Non-statistically significant differences were found in the percentage of newly formed bone in the different groups (P = .360). Statistically significant differences were found in the percentage of residual graft materials among the different groups (group 1 vs groups 2 and 3) (P = .0001). These data demonstrate that the use of bone-replacement materials, without the addition of autologous bone, could be an alternative in sinus augmentation procedures. Such treatment would increase patient satisfaction, decrease surgical complications, and save the clinician substantial operating time.
Aged↗
Bacterial adhesion on commercially pure titanium and zirconium oxide disks: an in vivo human study.
BACKGROUND: Little is known about the mechanisms of bacterial interaction with implant materials in the oral cavity. A correlation between plaque accumulation and progressive bone loss around implants has been reported. Bacterial adhesion shows a direct positive correlation with surface roughness. Other surface characteristics also seem to be extremely important with regard to plaque formation. Different adhesion affinities of bacteria have been reported for different materials. The aim of this study was to characterize the percentage of surface covered by bacteria on commercially pure titanium and zirconium oxide disks. METHODS: Ten patients participated in this study. A removable acrylic device was adapted to the molar-premolar region, and commercially pure titanium (control) and zirconium oxide (test) disks were glued to the buccal aspect of each device. The surface roughness of titanium and test specimens was similar. After 24 hours, all disks were removed and processed for scanning electron microscopy, for the evaluation of the portion of surface covered by bacteria. RESULTS: In control specimens, the area covered by bacteria was 19.3% +/- 2.9; in test specimens, the area was 12.1% +/- 1.96. The disk surface covered by bacteria on test specimens was significantly lower than that of control specimens (P = 0.0001). CONCLUSION: Our results demonstrate that zirconium oxide may be a suitable material for manufacturing implant abutments with a low colonization potential.
Adult↗
Osseointegration in a sinus augmented with bovine porous bone mineral: histological results in an implant retrieved 4 years after insertion. A case report.
BACKGROUND: A subject of controversy in implant dentistry is what is the most appropriate material for sinus augmentation. Little is known about the healing pattern and the osseointegration processes at the interface of implants placed in different grafting materials in man. Bovine porous bone mineral (BPBM) is a xenogenic material similar to human cancellous bone with a high biocompatibility and osteoconductivity. METHODS: A 50-year-old patient presented a posterior left maxilla with an insufficient bone height for implant insertion. In January 1999, a sinus lifting procedure was performed and the left sinus was augmented with BPBM; in November 1999, three implants were inserted, and in July 2000 a fixed prosthetic restoration was positioned. In June 2003 the connecting screw of the middle implant fractured and it was decided to remove the implant using a 5 mm trephine bur. RESULTS: All BPBM particles were surrounded by newly formed bone. No BPBM particle was in direct contact with the implant surface, and between the implant surface and the particles there was newly-formed bone. BPBM seemed to undergo a very slow resorption; the particles constituted 36% +/- 3% of the peri-implant tissues. The bone-implant contact percentage was 72% +/- 4%. CONCLUSIONS: In our specimens, we found an intimate, direct contact between bone and implant without an interposition of the graft material particles. A very high bone-to-implant contact percentage was present. Our results show that the slow resorption of the graft particles did not jeopardize the osseointegration of the implant.
Animals↗
Residual aluminum oxide on the surface of titanium implants has no effect on osseointegration.
The cleanliness of titanium dental implants surfaces is considered to be an important requirement for achieving osseointegration, and it has been hypothesized that the presence of inorganic contaminants could lead to lack of clinical success. Aluminum ions are suspected to impair bone formation by a possible competitive action to calcium. The objective of the present study was to describe the effects of residual aluminum oxide particles on the implant surface on the integration of titanium dental implants as compared to decontaminated implants in a rabbit experimental model. Threaded screw-shaped machined grade 3 c.p. titanium dental implants, produced with high-precision equipment, were used in this study. The implants were sandblasted with 100-120 microm Al2O3 particles at a 5atm pressure for 1min, then 24 implants (control implants) underwent ASTM F 86-68 decontamination process in an ultrasonic bath. The other 24 implants (test implants) were washed in saline solution for 15min. Both test and control implants were air-dried and sterilized at 120 degrees C for 30min. After sterilization the implants were inserted into the tibiae (two test and two control implants in each rabbit). Twelve New Zealand white mature male rabbits were used in this study. The protocol of the study was approved by the Ethical Committee of our University. No complications or deaths occurred in the postoperative period. All animals were euthanized, with an overdose of intravenous pentobarbital, after 4 weeks. A total of 48 implants were retrieved. The images were analyzed for quantitation of percentage of surface covered by inorganic particles, bone-implant contact, multinucleated cells or osteoclasts in contact with the implant surface and multinucleated cells or osteoclasts found 3mm from the implant surface. The differences in the percentages between the two groups have been evaluated with the analysis of variance. The implant surface covered by inorganic particles on test implants was significantly higher than that of control implants (p=0.0000). No statistically significant differences were found in the bone-implant contact percentages of test and control implants (p=0.377). No statistically significant differences were found in the number of multinucleated cells and osteoclasts in contact with the implant surface (p=0.304), and at a distance of 3mm from the implant surface (p=0.362). In conclusion, our histological results do not provide evidence to support the hypothesis that residual aluminum oxide particles on the implant surface could affect the osseointegration of titanium dental implants.
Aluminum Oxide↗
Direct capping with four different materials in humans: histological analysis of odontoblast activity.
Pulp inflammation in restored teeth is mainly due to the presence of bacteria or bacterial products introduced by microleakage around the restoration or to the material toxicity. Recent knowledge has permitted a precise identification of the risks for pulpal irritation associated with adhesive materials and procedures. The purpose of this work was to evaluate the cellular events that occur in direct pulp exposure capped using different materials. Twenty-four vital teeth without caries, scheduled for extraction for orthodontic reasons, were selected. After a control of the hemostasis, each pulp was directly capped with a different material. The samples were randomly divided into four groups of six specimens each: group I: dental-bonding agent (Solist) followed by resin composite (Ecusit); group II: dental adhesive (Prompt) and resin composite (Pertac II); group III: traditional calcium hydroxide (Dycal) plus resin composite (Ecusit); group IV: light-curing calcium hydroxide (Ultrablend Plus) and amalgam (Dentsply). After 15 days the teeth were extracted, immediately fixed in 10% buffered formalin, embedded in resin (7200 Technovit), and prepared for thin ground sections with Precise 1 System. In the specimens of all groups, there were active odontoblasts near the composite resins and no newly formed dentin. Small quantities of inflammatory cells were present. A 1- to 3-microm layer zone of necrosis was present. In conclusion, all materials tested in this study induced similar tissue responses.
Analysis of Variance↗
Crestal bone remodeling in loaded and unloaded implants and the microgap: a histologic study.
PURPOSE: The aim of this study was to histologically evaluate the crestal bone response to loaded and unloaded implants in beagle dogs. MATERIALS AND METHODS: Sand-blasted and acid-etched implants (Bone System, Milano, Italy) were placed in the mandible of six beagle dogs. The two premolars and the first molars had been extracted 3 months previously. Each dog received 12 implants in the mandible, and a total of 72 implants were used in this study. Three months after implantation, second-stage surgeries were performed for placement of abutments or healing screws. Three dogs were killed after 6 months, and three dogs were killed after 12 months. All 72 implants were retrieved. RESULTS: No statistically significant differences were found in the amount of bone loss between test and control implants, both at 6 and 12 months. Statistically significant differences were found, in both groups, between the bone loss observed at 6 months and that found at 12 months. CONCLUSION: Loading does not seem to be a relevant factor in the peri-implant bone resorption observed during the first year of function. Our results support previous findings that bone crest level changes could depend on the location of the microgap.
Acid Etching, Dental↗
Cortical bone regeneration with a synthetic cell-binding peptide: a histologic and histomorphometric pilot study.
PepGen P-15 is a combination natural anorganic bovine-derived hydroxyapatite matrix (ABM) coupled with a synthetic cell-binding peptide (P-15). This material has been reported to enhance bone formation in periodontal osseous defects. The aim of this study was to assess the effect of ABM/P-15 on the healing of cortical bone defects in rabbits. Five New Zealand rabbits were used. Two 8-mm bone defects were created in each tibia. Eight defects were filled with PepGen P-15, 8 defects with PepGen P-15 Flow, and 4 defects were used as a control group. A total of 20 defects were created. All rabbits were killed at 4 weeks. Block sections containing the defects were retrieved and the specimens processed for light microscopy examination. Newly formed bone was present in both test groups, whereas, in the control-group, only a scarce quantity of newly formed bone was present and the cortical defects had not been filled by the regenerated bone. Statistical evaluation showed that there were statistically significant differences between control sites and sites treated with P-15 and P-15 Flow (P = 0.0001), and also between sites treated with P-15 and P-15 Flow (P = 0.0001), respectively. No acute inflammatory infiltrate cells were visible in both of these groups. Both PepGen P-15 and PepGen P-15 Flow enhanced new bone formation in the cortical drilled defects, whereas control defects showed very little newly formed bone.
Animals↗
Histologic analysis of clinically retrieved immediately loaded titanium implants: a report of 11 cases.
BACKGROUND: Several investigators have reported high survival rates for early or immediately loaded dental implants. PURPOSE: The aim of the present study was to analyze histologically the periimplant tissue reactions and the bone-titanium interface of clinically retrieved immediately loaded titanium implants. MATERIALS AND METHODS: Eleven implants were inserted in the posterior jaw regions of six patients, serving as the most distal abutments of fixed provisional bridges and subjected to immediate occlusal loading. After a 10-month loading period, all 11 implants were retrieved with a trephine. RESULTS: Mature bone was present at the interface of all implants. Some vertical bone loss was observed; this was more pronounced for cylindric implants. The bone-implant contact was approximately 60 to 65% for all implants. CONCLUSIONS: The results demonstrate that osseointegration of dental implants can occur during immediate loading.
Adult↗
Bone healing around titanium and titanium nitride-coated dental implants with three surfaces: an experimental study in rats.
BACKGROUND: Titanium nitride (TiN) has been used in many fields as a coating of surgical instruments, with the purpose of creating materials more resistant to wear and corrosion and also reducing adhesion. PURPOSE: The aim of this study was to evaluate the biocompatibility of TiN-coated dental implants. MATERIALS AND METHODS: Forty-five rats were used in this study. One hundred eighty 2 mm x 2 mm implants (P.H.I. San Vittore Olona, Milano, Italy) were used. The implants were divided into the following three groups: Group 1 (n = 60): 30 machined and 30 machined coated with Group 2 (n = 60): 30 sandblasted and 30 sandblasted coated with Group 3 (n = 60): 30 titanium plasma sprayed, 30 titanium plasma sprayed and coated with TiN Four implants were placed in each rat, two implants coated with TiN on the right tibia and two uncoated implants on the left. The animals were killed after 5, 10, 20, 30, or 60 days. Another 18 implants were used for surface roughness analysis. RESULTS: The present study showed that the healing around the TiN-coated implants was similar to that observed around the uncoated surfaces. CONCLUSIONS: TiN coating demonstrated a good biocompatibility, did not have untoward effects on the periimplant bone formation, and did not change the surface roughness values.
Animals↗
Periimplant bone in immediately loaded titanium implants: histologic and histomorphometric evaluation in human. A report of two cases.
BACKGROUND: In recent years, several investigations have demonstrated, in clinical and histologic studies, the practicality of the use of immediate loading in implant dentistry. PURPOSE: The aim of the present study was to analyze the periimplant responses to immediately loaded implants retrieved from two patients after a 6-month loading period. MATERIALS AND METHODS: Three immediately loaded implants (two hydroxyapatite [HA] coated, one with a sandblasted surface) were retrieved from two patients after a 6-month loading period. The implants were treated to obtain thin ground sections. RESULTS: Bone was present at the interface with all three implants. Bone-implant contact percentage was 80.6% +/- 4.7. Bone was present also in the thread concavities found at a distance from preexisting bone and in those concavities that were at the interface with the supracrestal tissues or with wide marrow spaces. No gaps or fibrous tissues were present at the interface. No inflammatory infiltrate was present at the interface. The mean of the sulcus depth in all three implants was 0.9 +/- 0.1 mm, the length of the junctional epithelium was 0.9 +/-0.05 mm, and the length of connective tissue contact was 1.1 +/-0.05 mm. CONCLUSIONS; Our results show that immediate loading of dental implants did not impede the formation of mineralized tissue at the interface, and it can probably be a viable alternative in implant dentistry.
Alveolar Process↗
Osteoclast activity around loaded and unloaded implants: a histological study in the beagle dog.
The mechanisms of bone loss around dental implants are poorly understood. The osteoclast is the most important bone-resorbing cell. Humoral factors seem able to stimulate the differentiation of osteoclasts from mononuclear phagocytes. Bacterial lipopolysaccharides seem to be directly involved in inflammatory bone loss by stimulation of the survival and fusion of preosteoclasts. Excessive load seems to be able to cause bone loss. The aim of this paper was to evaluate the presence and number of osteoclasts in peri-implant bone in control (unloaded) and test (loaded) implants in order to determine if loading per se could be a contributing factor in peri-implant bone resorption. Forty-eight implants were inserted in the mandibles of 4 beagle dogs. After 3 months, a prosthetic superstructure was inserted on 24 implants, whereas in 24 implants only the healing screws were positioned. Twenty-four implants (12 test and 12 control) were retrieved at 6 months, and 24 implants (12 test and 12 control) were retrieved at 12 months. All implants were osseointegrated. The number of osteoclasts found in the crestal bone in the first 3 mm from the implant surface was evaluated. The mean number of osteoclasts were the following: control implants (6 months), 5.66 +/- 0.81; control implants (12 months), 2.55 +/- 1.05; test implants (6 months), 5.25 +/- 1.55; and test implants (12 months), 2.5 +/- 1.0. No statistically significant differences were observed between the control and test implants. According to our data, loading does not seem to have a relevant importance on the osteoclast activation in peri-implant bone.
Alveolar Bone Loss↗
Bone response to zirconia ceramic implants: an experimental study in rabbits.
This study analyzes the bone response to zirconia ceramic implants inserted in New Zealand white mature male rabbits. The implants were inserted into the tibia, and each rabbit received 4 implants. All the animals were euthanatized after 4 weeks. A total of 20 implants were retrieved. Implants and surrounding tissues were immediately fixed in 4% paraformaldehyde and 0.1% glutaraldehyde in 0.15 molar cacodylate buffer at 4 degrees C and pH 7.4 to be processed for histology. The specimens were processed to obtain thin ground sections with the Precise 1 Automated System. The slides were observed in normal transmitted light under a Leitz Laborlux microscope. A great quantity of newly formed bone was observed in close contact with zirconia ceramic surfaces; in some areas, many osteoblasts were present directly on the zirconia. Percentage of bone-implant contact was 68.4% +/- 2.4%. Mature bone, with few marrow spaces, was present. Small actively secreting osteoblasts were present in the most coronal and apical portions of the implant. No inflamed or multinucleated cells were present. This study concluded that these implants are highly biocompatible and osteoconductive.
Animals↗
Bacterial adhesion on titanium nitride-coated and uncoated implants: an in vivo human study.
Titanium nitride (TiN) has been used in many fields as a surgical instrument coating that makes the surgical materials more resistant to wear and corrosion. The aim of the present study was an in vivo evaluation of the bacterial adhesion to TiN-coated (test) and uncoated (control) titanium implants. Six patients aged between 21 and 25 years and in excellent systemic health participated in the study. All of the participants gave their informed consent. The participants were selected on the basis of good periodontal health and no signs of mouth breathing. In each of the 6 participants, a removable acrylic device was adapted to the molar-premolar region of each quadrant of the jaws. One 4 x 13 mm titanium implant was glued to the buccal aspect of each device. The plasma spray covered 11.5 mm of the body of the implant, whereas the neck was machined titanium. Test implants were glued to the right devices and control implants were glued to the left devices. After 24 hours, the implants were removed from each device and processed for scanning electron microscopy for evaluation of the machined portion of the implant covered by bacteria. A total of 24 implants were used in this study, 12 test and 12 control. Surface characterization of the machined portion of the neck of the implant was performed on an additional 10 implants (5 test and 5 control). On test implants the implant surface covered by bacteria was significantly lower compared with that of control implants (P = .0001). The surface roughness was similar in both groups. TiN surfaces showed a significant reduction of the presence of bacteria, and this fact could probably be important in the decrease of the inflammation of the peri-implant soft tissues.
Adult↗