ABSTRACT
PURPOSE: The primary objective of this prospective cohort study was to evaluate primary and secondary implant stability values of implants placed into healed free fibula-reconstructed mandibles. The secondary objective was to investigate whether a correlation existed between primary implant stability and the quantity of cortical bone-implant contact and of cortical fibular bone in contact with the implants. MATERIALS AND METHODS: The study participants are patients enrolled in a registered trial (No. CTRI/2012/07/002764). Patients with healed segmental mandibular reconstruction by means of free fibula flaps were chosen to undergo implant-supported dental rehabilitation. Preoperatively, computed tomography (CT) scans were used to measure the quality (density) of bone in Hounsfield units (HU). Implant stability quotients (ISQ) were obtained at the time of implant placement (primary), as well as 6 months later (secondary). The amount of cortical bone-to-implant contact (CBIC) was measured from postoperative panoramic radiographs using image analysis software (Image J). A paired t test was used to compare the mean primary and secondary ISQ values. Pearson correlation was used to determine the relationship between primary ISQ and CBIC. Statistical significance was set at the 5% level (P < .05). RESULTS: Of 54 patients (156 implants) who were enrolled, 35 (104 implants) were assessed. The reasons for exclusion were as follows: 11 patients (34 implants) had inadequate preoperative CT documentation, 7 patients (16 implants) had unreadable panoramic radiographs, and 1 patient (2 implants) had partial necrosis of the flap. The mean primary and secondary ISQ values were 78.1 (SD = 4.3) and 77.8 (SD = 4.6), respectively (P = .348). The mean density of cortical fibula bone was 1,344 HU (SD = 93.6). The mean CBIC was 3.7 mm (SD = 1.4). The study results showed a positive correlation between CBIC and implant stability (r = 0.274, P = .005). CONCLUSION: This study showed no differences in primary and secondary ISQ values of implants placed into the fibula. Implant stability quotients correlated positively with CBIC.
ABSTRACT
BACKGROUND: Implant treatment is today a common and most widely accepted prosthetic therapy worldwide. The quality and quantity of the bone available at the anticipated implant site is of prime importance. Accurate measurement of alveolar bone and adjacent anatomic structures are of paramount importance in implant insertion. Proper pre-surgical assessment requires precise radiographic visualization of anatomic structures and pathologic conditions. However, the concern for radiation exposure has also grown. MATERIALS AND METHODS: A total of 15 partially or completely edentulous human cadaveric mandibles were used which were further subdivided into three further groups for cone-beam computed tomography (CBCT), orthopantomography (OPG), and direct measurements (DM). Mandibles were prepared for each sample and subjected to radiographs according to the respective techniques, and radiographic measurements were done using the appropriate software. The cadaveric mandibles were then sectioned, and the actual measurements were done using a digital vernier caliper. RESULTS: Analysis of variance test revealed that there was no significant difference among the three different measurements techniques. CONCLUSION: A sizable portion of the CBCT measurements with respect to width showed slight overestimation when compared to DMs. There were no statistically significant differences found between CBCT, OPG, and DM when height was taken into consideration.
ABSTRACT
BACKGROUND: Debonding is one of the frequent causes of failure experienced in fiber-reinforced composite posts, and establish along post space-dentin adhesive interface. The purpose of this study was to assess push-out bond strength of a fiber-reinforced post system using four different resin cements. MATERIALS AND METHODS: In this in-vitro study 40 mandibular premolars were decoronated, and roots were treated endodontically. Following the post space preparation, the roots were grouped into four groups of 10 specimens each. Fiber-reinforced composite posts were cemented with four resin cement systems: (a) Multilink Speed, (b) Rely X Unicem, (c) Calibra, and (d) Permaflo DC. Three sections of each root, with a thickness of 3 mm, were prepared. The push-out test was with a universal testing machine at a crosshead speed of 1 mm/min, and bond strength values were evaluated. The data were analyzed with using multivariate analysis of variance (MANOVA) and post-hoc Scheffe test. RESULT: The mean push-out bond strength was highest for Rely X Unicem (18.0 ± 1.81), followed by Multilink Speed (13.1 ± 0.75) and Permaflo DC (12.8 ± 0.95). The lowest mean push-out bond strength was seen with Calibra (11.8 ± 0.69). There were statistically significant differences seen in the push-out bond strength of resin cement in different root canal regions using MANOVA and post-hoc Scheffe test. CONCLUSION: Mean push-out bond strength was highest for Rely X Unicem, followed by Multilink Speed and Permaflo DC. Lowest mean push-out bond strength was seen with respect to Calibra.
