PubMed Health⌕ Search

Biomedical subjects

Adriano Piattelli

Publications and source records attributed to Adriano Piattelli.

At least 19 recordsLinked to original sources
PubMed2007

Influence of implant surface topography on early osseointegration: a histological study in human jaws.

The purpose of this study was to evaluate the influence of the oxidized surface on bone-to-implant contact (BIC%), the bone density in the threaded area (BA%), as well as the bone density outside the threaded area (BD%) in human jaws after 2 months of unloaded healing. Thirteen subjects (mean age 42.61 +/- 6.15 years) received two microimplants (2.5 mm diameter and 6 mm length) each, during conventional mandible or maxilla implant surgery. The microimplants with commercially pure titanium surfaces (machined) and oxidized surfaces served as the control and test surfaces, respectively. After 2 months, the microimplants and the surrounding tissue were removed and prepared for histomorphometric analysis. All microimplants, except two machined and one oxidized microimplant surfaces, were found to be clinically stable after the healing period. Histometric evaluation indicated that the mean BIC% was (21.71 +/- 13.11)% and (39.04 +/- 15.75)% for machined and oxidized microimplant surfaces, respectively. The BD% was higher for the oxidized surface, although there was no difference for maxilla and mandible. The oxidized surface impacted the BA% for the type-IV bone. Data suggest that the oxidized surface presented a higher bone-to-implant contact rate compared with machined surfaces under unloaded conditions, after a healing period of 2 months.

Adult↗
PubMed2007

Wide-diameter implants: analysis of clinical outcome of 304 fixtures.

BACKGROUND: In the last decade, the use of wide-diameter implants (WDIs; diameter >3.75 mm) has increased. Although good clinical outcomes have been reported in recent literature, there are few reports on this topic. Thus, we planned a retrospective study on a large series of WDIs to evaluate the clinical outcome. METHODS: From October of 1996 to December of 2004, 205 patients were operated on, and 304 WDIs were inserted. The mean postloading follow-up was 30 months. Implant diameter and length ranged from 5.0 to 6.5 mm and from 8.0 to 15 mm, respectively. Because only five of 304 implants were lost (i.e., a survival rate of 98.4%) and no statistical differences were detected among the studied variables, no or reduced crestal bone resorption (CBR) was considered an indicator of success to evaluate the effect of several host-, surgery-, and implant-related factors. A general linear model (GLM) was performed to detect variables that were associated statistically with CBR. RESULTS: Only five of 304 WDIs were lost, and no differences were detected among the studied variables. On the contrary, the GLM showed that distal teeth (i.e., premolars and molars), small implant diameter (i.e., 5.0 and 5.5 mm), and short implant length (i.e., <13 mm) correlated with a statistically significant lower CBR. CONCLUSION: The use of WDIs is a viable treatment option, and it may provide benefits in posterior regions for long-term maintenance of various implant-supported prosthetic rehabilitations.

Adolescent↗
PubMed2006

Comparative evaluation of the peri-implant bone tissue mineral density around unloaded titanium dental implants.

OBJECTIVE: The mechanical properties of bone are greatly influenced by the percentages of organic and mineral constituents. Nevertheless, the information about the mineral content on a microscopic scale in peri-implant bone is scarce. The aim of this work was to analyze the bone mineral density of peri-implant bone under different techniques. DESIGN: Five unloaded titanium dental implants with a micro-structured surface (three XiVE plus and two Frialit 2, DENTSPLY-Friadent, Mannheim, Germany) were retrieved from the mandible of five patients after a 6-month period. scanning electron microscopy with backscattered electron signal (BSE), light microscopy (LM) with a double staining technique, fluorescence microscopy and confocal laser microscopy were used for measuring microscopic mineral content variations in peri-implant bone. Histomorphometry and image intensity (grey level) were evaluated using a software package for image analysis. RESULTS: The low mineral density index (LMDI) for LM was of 29.2+/-3.1 (mean+/-S.D.), while the high mineral density index (HMDI) was of 88.2+/-3.6 (mean+/-S.D.). The one-way ANOVA analysis showed a significant difference (P<0.001) among the groups. The pairwise Holm-Sidak test identified the differences among HMDI indexes for both LM and SEM values and also for cross-evaluation of the LMDI and HMDI values. The comparison between LMDI indexes for both SEM and LM did not show any significance. The fluorescence microscopy analysis showed clearly the difference between old (high mineralized) and new (low mineralized) bone tissue near the implant surface. Under confocal laser microscopy the same sections showed the area of bone modelling closest to implant surface. CONCLUSION: In this study it was found that bone around unloaded implants showed a low mineral density index under all the investigation methods used. It was also found that the conventional LM technique with the double staining method was able to intensely stain the bone area with a low mineral content.

Analysis of Variance↗
PubMed2006

Bone microvascular pattern around loaded dental implants in a canine model.

The vascularity of the implant bed is a very important parameter in both bone formation and maintenance after dental implants insertion. The relationship between bone and vessels network organization is still unknown. The aim of this study was to investigate the three-dimensional bone vascular canals of the peri-implant bone after loading. A total of ten implants with sandblasted and acid-etched surface were placed in the mandible of a beagle dog. Three months later, the implants were connected and loaded. The dog was killed after 12 months. The specimens were embedded and processed for scanning electron microscopy (SEM) analysis. After a 1-year loading period, a very intricate vessel network could be seen around the implants. The vessels, with neighbouring soft tissues, were round in shape and showed a lot of anastomoses with a mesh-like appearance. They ran circularly around the dental implant. In the bone, the majority of the vessels appeared to ran parallel to the mandibular canal. After a 1-year loading period, the peri-implant bone vasculature looked like a mesh that surrounded the implants. Nevertheless, the presence of many thick vessels inside the peri-implant crestal bone indicates a high metabolic need and also a different bone organization, as no osteons were noted. The crater-like bone loss around the marginal part of the implant could be related to the microvasculature "strain". A high strain level could continuously activate the osteocyte-vessel syncytium, producing a net bone loss.

Alveolar Bone Loss↗
PubMed2006

Tissue healing under provisional restorations with ovate pontics: a pilot human histological study.

STATEMENT OF PROBLEM: Ovate pontics mimic the natural tooth contour and provide an esthetic result however, few studies have evaluated the histological changes in underlying tissues. PURPOSE: The purpose of this pilot study was to histologically evaluate the healing of gingival tissues in contact with provisional ovate pontics after 2 weeks. MATERIAL AND METHODS: Three patients requiring fixed partial dentures participated in this study. The provisional restorations consisted of a fixed partial denture having 2 ovate pontics: one in acrylic resin (Jet), with an ovate shell made of low-fusing ceramic (Duceram LFC); the other made completely of the same acrylic resin (control). After 2 weeks, biopsies of the gingival tissues beneath the pontics were retrieved for histological examination, and immunohistochemistry for evaluation of the vascular endothelial growth factor (VEGF) was performed. Data were analyzed using descriptive statistics. RESULTS: Clinically, all of the ovate pontic-prepared sites showed partial healing. Histologically, the thickness of the entire mucosa was similar in both specimens; however, in some regions, the epithelium presented ulcerations that were generally deeper and more frequent in control sites than in test sites. Immunohistochemical results showed that tissues beneath LFC pontics seemed to be less inflamed since they demonstrated a lower expression of VEGF (10.7 +/- .8) compared to those beneath acrylic resin ovate pontics (33.9 +/- 2.5). CONCLUSION: This pilot study demonstrated that the placement of provisional LFC ovate pontics may be advantageous for the reparative processes of the underlying tissues.

Acrylic Resins↗
PubMed2006

Chondroid metaplasia in inflamed pulp tissue: a case report.

OBJECTIVE: The aim of the present report is to report an unusual case of chondroid metaplasia of the dental pulp. STUDY DESIGN: A white 45-year-old female patient appeared with signs and symptoms of an irreversible pulpitis on an upper left decayed third molar. After extraction, the tooth was fixed, demineralized, and processed for light microscopy. RESULTS: Pulp tissue was replaced at one of the pulp horns by a colliquative necrosis surrounded by neutrophil leucocytes and congested blood vessels. Serial sections demonstrated a complete opening of the decayed tooth to the oral environment, and an area of chondroid metaplasia of the pulp was evident. Chondroid tissue was surrounded by a dense concentration of chronic inflammation cells. CONCLUSIONS: According to the best knowledge of the authors, this is possibly the first report of an occurrence of chondroid metaplasia in the dental pulp. This metaplasia could be the result of an attempt at tissue repair by the pulp tissue injured by the carious lesion. The pathologic changes in the dental pulp could have activated some of the mechanisms that have been described in other tissues, producing the formation of chondroid tissue. Pulp tissue may adapt to changed environmental stimuli by a deviation from normal cell differentiation.

Cartilage↗
PubMed2006

Collagen fiber orientation near a fractured dental implant after a 5-year loading period: case report.

PURPOSE: Fracture of an implant is one of the possible complications of dental implants. It is a quite rare event but of high clinical relevance. Nevertheless, it represents an important opportunity for evaluating the peri-implant bone-tissue response to implant overloading in human beings. The aim of the present study was a scanning electron microscopy evaluation of a screw-shaped implant retrieved because of fracture and a birefringence analysis of the tissue near the fractured implant. MATERIALS AND METHODS: There was 1 fractured screw-shaped implant retrieved from a patient with a trephine bur, and it was processed for histology. The specimen was analyzed under both scanning electron microscopy and circularly polarized light microscopy. RESULTS: The scanning electron microscopy fractography analysis showed the typical signs of a fatigue-fracture, with large plastic deformations on the implant. The fracture seemed to start from the internal coil of the implant. Under circularly polarized light microscopy investigation, a bone-implant contact percentage of 81.6% +/- 1.5% (mean +/- standard deviation) was found. The amount of the transverse collagen fibers was of 68.3%, and the amount of the longitudinal collagen fibers was of 31.7%. The difference was statistically significant for z = 2.247 (P = 0.025). CONCLUSION: The fracture of the implant was most probably correlated to a fatigue of the material mainly associated to a lesion of the internal coil. The high level of bone-implant contact percentage was correlated to a predominant transverse collagen fiber orientation of the collagen fibers in the peri-implant bone.

Bone Remodeling↗
PubMed2006

Maxillary sinus augmentation with different biomaterials: a comparative histologic and histomorphometric study in man.

OBJECTIVE: Rehabilitation of the edentulous posterior maxilla with dental implants can be difficult because of insufficient bone volume caused by pneumatization of the maxillary sinus and crestal bone resorption. Different biomaterials have been used for sinus augmentation. The aim of the study was to compare different materials in maxillary sinus augmentation in man. METHODS: A total of 94 patients participated in this study. Inclusion criteria were maxillary partial (unilateral or bilateral) edentulism involving the premolar/molar areas, and the presence of 3-5-mm crestal bone between the sinus floor and alveolar ridge. A total of 362 implants were inserted. There were 9 biomaterials used in the sinus augmentation procedures. Each patient underwent 1 biopsy after 6 months. A total of 144 specimens were retrieved. RESULTS: None of the 94 patients had complications. All implants were stable, and x-ray examination showed dense bone around the implants. Mean follow-up was 4 years. There were 7 implants that failed. Histologic resultsshowed that almost all the particles of the different biomaterials (i.e., autologous bone, demineralized freeze-dried bone allograft Biocoral [Inoteb, St. Gonnery, France], Bioglass [US Biomaterials, Alachua, FL], Fisiograft [Ghimas, Bologna, Italy], PepGen P-15 [Dentsply Friadent CeraMed, Lakewood, CO], calcium sulfate, Bio-Oss [Geistlich Pharma AG, Wohlhusen, Switzerland], and hydroxyapatite) were surrounded by bone. Some biomaterials were more resorbable than others. Included are the histomorphometry clarified features of the newly formed bone around the different grafted particles. CONCLUSION: All biomaterials examined resulted in being biocompatible and seemed to improve new bone formation in maxillary sinus lift. No signs of inflammation were present. The data are very encouraging because of the high number of successfully treated patients and the good quality of bone found in the retrieved specimens.

Aged↗
PubMed2006

Histologic evaluation of 3 retrieved immediately loaded implants after a 4-month period.

OBJECTIVE: To perform a histologic and histomorphometric analysis of the peri-implant tissue reactions and bone-titanium interface in 3 immediately loaded (provisional loaded) titanium implants retrieved from a man after a loading period of 4 months. MATERIALS & METHODS: A 35-year-old patient with a maxillary partial edentulism did not want to wear a provisional removable prosthesis during the healing period. It was decided to insert 3 definitive implants and use 3 provisional implants for the transitional period. The provisional implants were loaded the same day with a resin prosthesis in occlusal contact. During the second surgical phase, after 4 months, the provisional prosthesis was removed, and the provisional implants were retrieved with a trephine bur. Before retrieval, all implants appeared to be clinically osseointegrated. The specimens were processed for observation under light microscopy. RESULTS: At low magnification, it was possible to observe that bone trabeculae were present around the implant. Areas of bone remodeling and haversian systems were present near the implant surface. Under polarized-light microscopy, it was possible to observe that in the coronal aspect of the thread, the lamellar bone showed lamellae that tended to run parallel to the implant surface, while in the inferior aspect of the thread, the bone lamellae ran perpendicular to the implant surface. CONCLUSIONS: Histologic data pertaining to these 3 immediately loaded implants, and retrieved after a 4-month loading period, show that immediate loading did not produce untoward effects on peri-implant bone healing.

Adult↗
PubMed2006

Genetic effects of Medpor on osteoblast-like cells.

Porous polyethylene (PP or Medpor) is an alloplastic material used worldwide for craniofacial reconstruction. Although several clinical studies are available, there is a lack as regard the genetic effects. Because PP is always fixed on bone and the mechanism by which PP acts on osteoblasts is unknown, we therefore attempted to address this question by using microarray techniques to identify genes that are differently regulated in osteoblasts exposed to PP. By using DNA microarrays containing 19,200 genes, we identified in osteoblast-like cell lines (i.e. MG-63) cultured on PP several genes where expression was differentially regulated. The differentially expressed genes cover a broad range of functional activities: 1) signal transduction, 2) transcription, 3) translation, 4) cell cycle regulation, 5) vesicular transport, and 6) production of cytoskeletal elements, cell-adhesion molecules and extracellular matrix components. The data reported are, to our knowledge, the first genetic portrait of osteoblast-like cells cultured on PP. They are relevant to better understanding of the molecular mechanism of bone-PP interaction and as a model for comparing other materials used for bone reconstruction.

Bone Substitutes↗
PubMed2006

Soft tissue myxoma: report of an unusual case located on the gingiva.

BACKGROUND: Soft tissue myxoma of the oral cavity is rare. Only three cases of myxoma of gingiva have been reported in the literature. We present a case of soft tissue myxoma arising from the left maxillary adherent gingiva in a 42-year-old male [correction of female] patient. METHODS: Histological examination showed spindle-shaped cells in a myxoid stroma. Immunohistochemical stains with S-100 protein were negative, while those with vimentin were positive. RESULTS: Clinical examination revealed a soft tissue mass, with tense elastic consistency on palpation. The overlying mucosa was normal and healthy. A clinical diagnosis of fibroma was given. Histological examination showed spindle-shaped and stellate cells, arranged in a myxoid fibrous stroma, with collagen fibres distributed uniformly. Scattered islands or strands of inactive odontogenic epithelium were present. On the basis of the histological and immunohistochemical findings, the final diagnosis was soft tissue myxoma. CONCLUSIONS: Further studies are necessary to clarify the origin and histogenesis of this lesion.

Adult↗
PubMed2006

Parallel screw cylinder implants: comparative analysis between immediate loading and two-stage healing of 1,005 dental implants with a 2-year follow up.

BACKGROUND: Recently, several authors have focused on the possibility of an immediate functional loading of dental implants to minimize the delay between surgical and prosthetic phases. PURPOSE: The aim of this study was a reevaluation of the XiVE dental implant (Dentsply-Friadent, Mannheim, Germany) with: (1) a longer follow-up period; (2) a higher number of fixture; and (3) a proper statistical method. MATERIALS AND METHODS: In July 2001 and December 2002, 371 patients (180 males and 191 females; ages ranging from 17 to 83; mean age, 53 years) were consecutively enrolled in this study. In 371 patients, a total of 1,005 XiVE dental implants were distributed as follows: 484 immediately loaded implants (test group) were inserted in 130 patients, whereas 521 unloaded implants were inserted in 241 patients (control group). RESULTS: The implant survival was 98.7 and 99.4% in immediate loading and control group, respectively. Univariate analysis showed no statistically significant difference between the two groups. CONCLUSION: In a previous report, we showed that immediate loading offered a predictable and reliable procedure also for XiVE implants, at least in the short period. In this study, we confirmed the results of the previous study and added information regarding the survival rate and marginal bone level stability with a 2-year follow up.

Adolescent↗
PubMed2006

Immediately loaded titanium implants with a porous anodized surface with at least 36 months of follow-up.

BACKGROUND: Results from some studies clearly suggest that immediate loading can achieve equal success rates as those found in delayed or unloaded implants. There is still a lack of knowledge about the role of surface oxide properties during the peri-implant bone healing processes. PURPOSE: The aim of this study was a clinical follow-up study of immediately loaded implants with a porous anodized surface. MATERIALS AND METHODS: A total of 142 TiUnite (Nobel Biocare, Göteborg, Sweden) implants were inserted from January to September 2001. All implants have been used in fixed restorations. Fifty implants were inserted in completely edentulous mandibles, and 69 implants were inserted in completely edentulous maxillae. All 119 implants were subjected to immediate functional loading (IFL) (immediate restoration with full occlusal contact). The other 23 implants, inserted in 12 patients, underwent immediate nonfunctional loading (INFL) (immediate restoration without occlusal contact) in different anatomical configurations (single tooth, small bridges in the anterior mandible, anterior maxilla, and posterior maxilla). All 142 implants have been followed for at least 3 years. RESULTS: All implants appeared to be osseointegrated from a clinical and radiographic point of view. No failures were observed in the IFL and INFL groups. The implant success was 100%. The mean marginal bone loss was 0.8 and 1.0 mm at 12 and 36 months, respectively. CONCLUSION: Implants with a porous anodized surface appear to work well under an immediate loading state in the long term.

Adult↗
PubMed2006

Syncrystallization: a technique for temporization of immediately loaded implants with metal-reinforced acrylic resin restorations.

BACKGROUND: Rigid temporization has been recognized to have a significant impact on the peri-implant tissue response in immediate implant loading since it reduces the mechanical stress exerted on each implant. PURPOSE: A successful protocol for immediate loading of multiple implants depends on an adequate fixation and immobility of the implants to prevent the risk of micromovements in relation to the surrounding bone. The objective of this article was to evaluate a prosthetic concept for an accelerated rigid splinting of multiple implants for same-day immediate loading with metal-reinforced provisional restorations using a technique of welding temporary implant abutments with a prefabricated titanium bar directly in the oral cavity (syncrystallization). MATERIALS AND METHODS: Between June 2004 and January 2005, immediate loading of threaded implants with a metal- reinforced acrylic resin provisional restoration at stage 1 surgery was evaluated in 40 consecutive patients. A total of 192 implants were placed in selected edentulous or partially edentulous patients using the syncrystallization technique. Once the titanium bar was welded intraorally to the abutments, opaque was applied and the provisional restoration was relined and screw-retained the same day. In addition, a comparison of deformations and stress distributions in implant-supported, metal-reinforced and nonmetal-reinforced resin provisional restorations was analyzed in the edentulous mandible by a three-dimensional finite element model (FEM). RESULTS: All of the 192 rigidly temporized immediately loaded implants osseointegrated. An implant success rate of 100% was achieved over a period of 6 months postplacement. No fracture or luting cement failure of the provisional restoration occurred during the observation time. Compared to mere acrylic superstructures, a significant reduction of deformation and strain within metal-reinforced provisional restorations was detected by FEM analysis. CONCLUSION: The results of this study indicate that the syncrystallization technique allows an expedite and adequate rigid splinting of multiple immediately loaded implants. The advantages of the technique are: (1) reduction of treatment time for immediate temporization at stage 1 surgery; (2) predictable fixation and immobility of implants in the early stages of bone healing; and (3) less time for repairing provisional restorations as a result of no or rare fracture.

Acrylic Resins↗
PubMed2006

Correlation between implant stability quotient and bone-implant contact: a retrospective histological and histomorphometrical study of seven titanium implants retrieved from humans.

BACKGROUND: Primary stability has a relevant role in the long-term success of dental implants. A quantitative method for the measurement of implant stability has been introduced (resonance frequency analysis [RFA]). Information about the significance of RFA measurements and about the relationship between RFA values and their association with implant osseointegration, success, or failure is important from a clinical point of view. PURPOSE: The aim of the present histological and histomorphometric study was to see if a correlation existed between the bone-implant contact (BIC) percentage of retrieved human implants and RFA values. MATERIALS AND METHODS: Seven implants inserted in the posterior mandible, with a sandblasted and acid-etched surface and retrieved after a 6-month period, were evaluated in the present study. These seven implants had been retrieved for different causes. All these implants were submerged and were retrieved with a 5-mm trephine bur and immersed in 10% buffered formalin to be processed for histology. RESULTS: A statistically significant correlation could be detected between implant stability quotient and BIC (p=.016). CONCLUSIONS: Even if the relationship between bone structure and RFA is still not fully understood, in our study, a statistically significant correlation was found between RFA and BIC values. Further studies are needed to evaluate a correlation of RFA and BIC in human implants retrieved after a range of healing periods.

Dental Implantation, Endosseous↗
PubMed2006

Five-year outcome of 111 immediate nonfunctional single restorations.

Immediate loading is a surgical-prosthetic procedure extensively used in implant dentistry. Despite its frequent use, minimal data are available on the long-term clinical success rate of immediate functional loading (IFL) and immediate nonfunctional loading (INFL) of implants. The aim of this study was to evaluate the long-term survival and bone loss of immediate nonfunctional single implant restorations in a group of patients that were monitored for 5 years. One hundred and eleven patients (41.4% men) with a median age of 40 years were included in this study. A total of 111 implants were placed. All implants were placed with a minimum insertion torque of 25 Ncm. A temporary restoration was relined with acrylic resin, trimmed, polished, and cemented or screw-retained 1 to 2 hours later. Occlusal contact was avoided in centric and lateral excursions. After provisional crown delivery, a periapical radiograph was performed by means of a customized Rinn holder device. Data were analyzed by means of Kaplan-Meier and life-table algorithms. Stratification of implant survival was performed for the available variables of interest, and comparisons were analyzed using a log-rank test. Investigated parameters were time of implant placement, bone quality, implant site, implant diameter and length, and type of implant surface enhancement. The parameters for overall success rate were defined by bone resorption <1.5 mm after the first year of loading and <0.2 mm thereafter. During the 5-year follow-up period, a survival rate of 95.5% was observed. All failures occurred within 4 months of implant loading. There were statistically significant differences regarding healed vs post-extraction implant sites (100% and 92.5%, respectively, P = .05) and type of bone (D1 vs D4 yielded 100% and 95.5%, respectively, P <.05). No differences were detected for: (1) site (100% for mandible and 94.63% for maxilla, P =-.319); (2) implant diameter (survival rates of 97.26% for <4.5-mm diameter and 92.11% for >4.5mm diameter, P = .206); (3) implant lengths (survival rates of 96.97% for implants >13 mm and 94.87% for implants <13 mm, P =.624); and (4) type of implant surface enhancement (survival rates of 94.03% for 67 cases of grit-blasted and acid-etched surfaces and a failure rate of 4 out of 5, and 94.12% for 17 cases of hydroxyapatite (HA)-coated surfaces with only 1 failure). The success rate (defined as bone resorption >1.5 mm after the first year of loading and >0.2 mm thereafter) was 97.2%. Immediate nonocclusal loading of single implants is a reliable surgical-prosthetic procedure with a low rate of implant loss and a low quantity of peri-implant bone loss over time.

Adolescent↗
PubMed2006

Preferred collagen fiber orientation human peri-implant bone after a short- and long-term loading period: a case report.

Immediate loading of dental implants offers treatment cost advantages to patients and avoids the functional and psychological problems caused by the wearing of provisional dentures. There is evidence that the amount of transverse collagen fiber orientation in bone is influenced by mechanical stresses and strains. Two osseointegrated dental implants in humans were used in the present study. Two implants inserted in the maxilla were analyzed: 1 short-term implant (implant A) immediately loaded and retrieved after 4 months of loading and 1 long-term implant (implant B) immediately loaded and retrieved after 12 years. We hypothesized that the bone functional strain caused by immediate loading correlated well with the collagen fiber organization occurring after both short- and long-term functional healing. Circularly polarized light (CPL) was used to assess the area fraction extension related to the transverse collagen fiber orientation in the bone matrix. After evaluating a total of 68 digitized images taken at x50 magnification, birefringence measurements were performed all around the implant surfaces by using 2 central sections from each implant. The results showed that the bone-to-implant contact (BIC) percentage for implant A was 67.9% +/- 9.5% (mean +/- SD), whereas the BIC percentage for implant B was 74.6% +/- 11.2% (mean +/- SD). The area fraction extension was 2.7% +/- 1.4 % (mean +/- SD) for implant A, whereas the area fraction extension was 4.7% +/- 1.2% (mean +/- SD) for implant B. The CPL measurements of the birefringence for transverse collagen fibers of implant A vs implant B indicated that the bone fraction area difference was not high. In the bone near both dental implants, no differences were found in the amount of transverse collagen fibers. Immediate loading seemed to determine and maintain the collagen fiber's orientation over a long period.

Adult↗