Accuracy of dental implant placement via dynamic navigation or the freehand method: A split-mouth randomized controlled clinical trial.

OBJECTIVES: The aim of this split-mouth randomized controlled clinical trial was to compare the deviations of planned and placed implants placed by the assistance of a micron tracker-based dynamic navigation device or freehand methods. MATERIAL AND METHODS: A thermoplastic fiducial marker was adapted on the anterior teeth, and cone-beam computerized tomography was used for imaging. A minimum of one implant was planned for each side of the posterior maxilla, and the dynamic navigation device or freehand method was randomly used for surgical insertion. Deviations were measured by matching the planning data with a final CBCT image. Linear deviations (mm) between the planned and placed implants were the primary outcome. The results were analysed by generalized linear mixed models (p < .05). (NCT03471208). RESULTS: A total of 92 implants were placed to 32 volunteers, and 86 implants were included in the final analysis. For the linear deviations, mean of differences (Δ) was 0.72mm (Standard deviation (SD): 0.26); (95% Confidence interval (CI): 0.39-1.02) in the shoulder of the implants (p < .001) and 0.69mm (SD: 0.36); (95% CI: 0.19-1.19) in the tip of the implants (p < .001). For the angular deviations, Δ was 5.33° (SD: 1.63); (95% CI: 7.17-3.48); (p < .001). CONCLUSIONS: The navigation technique can be used to transfer virtual implant planning to the patient's jaw with increased accuracy.

Thermal oxidation and hydrofluoric acid treatment on the sandblasted implant surface: A histologic histomorphometric and biomechanical study.

OBJECTIVES: This study aimed to analyze and compare the topographical, chemical, and osseointegration characteristics of a sandblasted acid-etched surface (SLA group), a sandblasted thermally oxidized surface (SO group), and a surface chemically modified by hydrofluoric (HF) acid (SOF group). MATERIALS AND METHODS: Following the preparation and characterization of the relevant surfaces, 90 implants (30 for each group) were placed on the pelvic bone of six sheep. Resonance frequency analysis (RFA), insertion (ITV), removal torque value (RTV), and histomorphometric analyses (BIC%) were performed after three and 8 weeks of healing. The results were analyzed by nonparametric tests (p < 0.05). RESULTS: The roughness value (Ra) in the SOF group was significantly lower than the SLA and the SO group (p = 0.136, p < 0.001, respectively). This resulted in a substantially inferior ITV 14.83 N/cm (SD: 4.04) than those achieved in the SLA and SO groups (19.50 (SD: 6.07) and 20.17 N/cm (SD: 8.95), respectively; p = 0.001). A statistically significant change in the RFA from the baseline (47.36 ISQ, SD: 6.93) to the 3rd week (62.56 ISQ, SD: 5.29) was observed in the SOF group only (p = 0.008). The highest postplacement RFA and RTV values were measured from the SLA group (61.11 ISQ, SD: 7.51 and 78.22 N/cm, SD: 28.73). The early-term (3rd week) BIC% was highest in the SO group (39.93%, SD: 16.14). After 8 weeks, the differences in BIC% values were statistically not significant. CONCLUSIONS: Adjunct HF acid application on the thermally oxidized surface did not provide an additional benefit compared to the sandblasted and acid-etched surface (SLA group).

Combined effect of parathyroid hormone and strontium ranelate on bone healing in ovariectomized rats.

OBJECTIVE: Parathyroid hormone (PTH) enhances bone healing. Strontium ranelate (SR) is an antiresorptive agent that increases bone formation. Reports about combined effects of PTH and SR on local bone regeneration in osteoporotic subjects are limited. We aimed at investigating the efficacy of PTH and SR for promoting new bone formation in critical-sized defects of ovariectomized rats. MATERIALS AND METHODS: Parathyroid hormone- and/or SR-containing poloxamer implant tablets with/without chitosan microparticles were delivered locally to calvarial defects of 90 Wistar rats. Biopsies were analyzed histologically and histomorphometrically at 4 and 8 weeks of healing. RESULTS: Histomorphometry revealed that PTH alone promoted new bone formation at 4 weeks but the efficiency declined in 8 weeks. There was no positive effect of SR alone on bone formation at 4 or 8 weeks. Calvarial defects treated with PTH+SR combinations showed statistically significant greater new bone formation than either treatment alone at both time intervals. Tissue responses were modest and supported the good biocompatibility of the biomaterials used. CONCLUSION: Parathyroid hormone and SR combinations can be effective for calvarial bone regeneration of ovariectomized rats. PTH plus SR may have potential use as bone graft material in orthopedic and dental surgery to enhance bone healing and osseointegration.

The protective effects of different treatments on rat salivary glands after radiotherapy.

This study was aimed to evaluate the efficacy of treatment modalities for minimizing salivary gland damage caused by radiotherapy. Forty rats were divided into five groups. Group 1 had no irradiation or any treatment. Group 2 underwent only 15 Gy single dose radiotherapy. N-acetylcysteine, dexamethasone, hyperbaric oxygen treatment were given, respectively to the group 3, 4 and 5 for 5 days. 15 Gy single dose radiotherapy was applied to the group 3, 4 and 5 on the second day. Pyknosis, lysis, and vacuolization were examined in ductal cells and pyknosis, lysis, vacuolization, inflammation and collective duct damage in acinar cells. Dexamethasone and hyperbaric oxygen did not prove to have a positive effect on acinar and ductal cell. N-acetylcysteine-applied group had statistically significantly lower amount of damage. We determined that the decrease of ductal and acinar cell damage in parotid glands of N-acetylcysteine-applied rats was more distinct and statistically.

Evaluation of the autogenous bone block transfer for dental implant placement: Symphysal or ramus harvesting?

BACKGROUND: The absence of sufficient bone volume is the most relevant problem in implant dentistry. Grafting from exogenous sources may provide a limited gain but exhibits poor performance in large bone defects. Autogenous bone block transfer (ABBT) from the mandibular symphysis and ramus has been used with varying rates of success. The aim of this study was to compare the efficacy of symphysal and ramus ABBT for the restoration of lost horizontal alveolar bone volume in the anterior maxilla. Implants placed in the augmented areas were also evaluated. METHODS: The maxillary alveolar bone deficits of 32 patients were treated by similar-sized autogenous bone blocks (7 × 7 × 4 mm) harvested from the symphysis or ramus area. After 4 to 5 months of healing, implants were inserted. At the end of the osseointegration period, the implants were restored by fixed prostheses. Baseline bone thickness was determined by Cone beam computed tomography and was compared to post-op and one-year post-loading bone thickness values where the implants were inserted. Any complications or consequences were noted. The success and survival of the 45 implants were evaluated. The results were analyzed using the Student t-test and Fisher's exact test (p < 0.05). RESULTS: Post-op complications were frequent in both groups. Baseline bone thickness values were similar at the beginning of the study (p = 0.71) and exhibited a significant increase after the ABBT surgery (6.29 (SD 0.86) and 6.01 (SD 0.92) mm in the symphysis and ramus groups, respectively). The amount of bone thickness gain was 4.34 mm (SD: 0.92) and 4.36 mm (SD: 1.01) in the symphysis and ramus groups, respectively. After one year, the mean surface resorption was 0.6 mm (SD: 0.78) and 0.80 mm (SD: 0.56) for the symphysis and ramus groups, respectively (p = 0.089). The success and survival rates of the implants were 94.11 and 96.42 %, respectively. No graft failures were observed. CONCLUSIONS: Both symphysal and ramus ABBT procedures were successful for the restoration of a horizontal bone defect in the anterior maxilla. Ramus harvesting may be advisable due to fewer complications. Implants placed in the grafted regions exhibited a high success and survival rate within the one-year follow-up period.

Effects of complete dentures on respiratory performance: spirometric evaluation.

OBJECTIVES: There is a lack of data regarding whether edentulous subjects should remove dentures during spirometric measurements or not. The purpose of this study is to determine influences of complete dentures on spirometric parameters in edentulous subjects. MATERIALS AND METHODS: A total of 46 complete denture wearers were included in this study. Respiratory functions of the subjects were evaluated by spirometric tests that were performed in four different oral conditions: without dentures (WOD), with dentures, lower denture only and upper denture only. Forced vital capacity (FVC), peak expiratory flow, forced expiratory volume in 1 s and forced expiratory flow between 25% and 75% were evaluated. The data were analyzed with Friedman, Wilcoxon and paired-samples t tests (α = 0.05). RESULTS: Significant differences were found between spirometric parameters in different oral conditions (p < 0.05). In all spirometric parameters, the most important significant differences were found between conditions WOD, FVC and with lower dentures (FVC), and WOD (forced expiratory volume in 1 s) and with upper dentures (forced expiratory volume in 1 s) (p < 0.001). CONCLUSION: It was observed that complete dentures may unfavourably affect spirometric values of edentulous subjects. However, current findings need to be confirmed with advanced respiratory function tests.

Maxillary Sinus Floor Elevation and Simultaneous Implant Installation via Osseodensification Drills: A Retrospective Analysis of Bone Gain in 72 Patients Followed for 6 Months.

Background/Objectives: The aim of this retrospective study was to radiographically evaluate the endo-sinus bone gain (ESBG) following osseodensification procedures using CBCT and compare the results to more conventional sinus lifting techniques. Methods: A total of 72 patients underwent crestal sinus floor elevation procedures and were provided with 102 implants with a sand-blasted and acid-etched surface with microthreads (Medentika® Microcone Implants, Hugelsheim, Germany). Patients were divided into two groups; the osseodensification group (OD; n = 36) and the osseodensified augmentation group (ODA; n = 36). Results: The mean residual bone height (RBH) was 5.71 (1.77) and 4.30 (0.94) mm in the OD and ODA groups, respectively. An ESBG of 3.45 (1.18) and 5.74 (1.31) mm was observed in the OD and ODA groups, respectively, and as compared to the baseline RBH, the ESBG was statistically significant in both groups after 6 months (p < 0.001). Conclusions: Within the limits of this retrospective study, crestal sinus lifting with the osseodensification technique seems to be a fast, effective, and safe method. Longer follow-up studies with full intrasinus bone topography and structure analyses are needed to prove the success rate of endo-sinus bone gain.

Computer-assisted flapless implant placement reduces the incidence of surgery-related bacteremia.

OBJECTIVE: Bacteremia--the access of bacterium to the bloodstream--may yield life-threatening complications. The aim of this study was to compare the incidence, duration, and type of bacterium leading to bacteremia with relation to conventional and computer-assisted flapless implant surgery. MATERIAL AND METHODS: A total of 377 implants were placed in 68 edentulous jaws using the conventional (conventional group) or a computer-assisted stereolithographic (SLA) template-guided surgery technique (flapless group). Bacteremia was monitored from pre- and postoperative blood samples. RESULTS: The duration of the surgical intervention was significantly shorter in the flapless group (p = 0.3510). Baseline samples were sterile. Following the 15th minute after the placement of the last implant, bacteria were present in 62 and 12 % of the patients in the conventional and flapless groups, respectively (p < 0.0001; relative risk: 3.05). The differences in the incidence of the bacteremia detected at the baseline and 15 min after the last implant placement were statistically significant in the conventional group (p = 0.0001). However, no such statistical significance was present in the flapless group. Staphylocccus epidermidis, Bifidobacterium spp., Streptococcus viridans, Corynebacterium spp., and Streptococcus sanguinis were the isolated bacterium. CONCLUSIONS: Irrespective of the utilized technique, bacteremia may occur upon the placement of four to eight implants to an edentulous jaw. The probability of bacteremia for the patients operated with the conventional technique is, however, 3.05 greater than those operated with the flapless technique. CLINICAL RELEVANCE: Flapless implant placement reduces the incidence of surgery-related bacteremia and, therefore, may be beneficial to patients at risk.

Prevalence and predictors of bruxism in two university clinic patient populations with dental implants: A cross-sectional analysis.

OBJECTIVE: To analyze the prevalence, predictors, and prosthetic complications of bruxing patients with dental implants in two tertiary clinics in Istanbul, Turkey. METHODS: Patients with at least one dental implant and with a fixed prosthesis were examined for the evidence of probable bruxism. Factors that could be related to bruxism were analyzed in relation to patient-specific variables. Technical and mechanical complications were investigated. RESULTS: A total of 1688 patients were analyzed. The overall rate of probable bruxism was 19.72%. Besides self-reported bruxism (p < 0.022), antidepressant use (p < 0.002), frequent headaches (p < 0.014), and observation of linea alba (p < 0.028) were the predictors for probable bruxism. Technical and mechanical complications were frequent in the probable bruxers (p < 0.05). CONCLUSION: Overall prevalence of bruxism was 19.72%, and bruxism was associated with general and gender-specific predictors.

Boron- and Boric Acid-Treated Titanium Implant Surfaces in Sheep Tibia: A Histologic, Histomorphometric and Mechanical Study.

The aim of this study was to compare the topographical, chemical and osseointegration characteristics of sandblasting and acid-etching (SLA) surfaces and dental implants treated by boron compounds. Titanium (Ti) disks (n = 20) were modified using boron (B) and boric acid (H3BO3) and then compared with the conventional SLA surface via surface topographic characterizations. Dental implants (3.5 mm in diameter and 8 mm in length) with the experimental surfaces (n = 96) were inserted into the tibias of six sheep, which were left to heal for 3 and 7 weeks. Histologic, histomorphometric (bone−implant contact (BIC%)) and mechanical tests (removal torque value (RTV)) were performed. The boron-coated surface (BC group) was smoother (Rz: 4.51 µm ± 0.13) than the SLA (5.86 µm ± 0.80) and the SLA-B (5.75 µm ± 0.64) groups (p = 0.033). After 3 weeks, the highest mean RTV was found in the SLA group (37 N/cm ± 2.87), and the difference compared with the BC group (30 N/cm ± 2.60) was statistically significant (p = 0.004). After 7 weeks, the mean RTV was >80 N/cm in all groups; the highest was measured in the H3BO3-treated (BS) group (89 N/cm ± 1.53) (p < 0.0001). No statistically significant differences were found in the BIC%s during both healing periods between the groups. H3BO3 seems to be a promising medium for dental implant osseointegration.

Stability, marginal bone loss and survival of standard and modified sand-blasted, acid-etched implants in bilateral edentulous spaces: a prospective 15-month evaluation.

OBJECTIVES: Chemical modification of the already proven sand-blasted and acid-etched (SLA) implant had increased its surface wettability and consequent early-term osseointegration characteristics. The aim of this clinical trial was to compare the stability changes, success, survival, peri-implant parameters and marginal bone loss (MBL) of the early-loaded standard (SLA) and modified sand-blasted, acid-etched (modSLA) implants. MATERIAL AND METHODS: A total of 96 SLA and modSLA implants were placed in a bi-lateral, cross-arch position to the jaws of 22 patients. Resonance frequency analysis (RFA) was used to measure the implant stability in the surgery and following healing after 1, 3 and 6 weeks. At the stage of loading, a panoramic X-ray was obtained and RFA measurement was repeated for all implants. Implants were restored by metal-ceramic crowns and followed for 1 year to determine the success, survival rate, peri-implant parameters and MBL. Results were compared by one- and two-way ANOVA, log-rank test and generalized linear mixed models (P < 0.05). RESULTS: One modSLA implant was lost after 3 weeks following the surgery yielding to a 100 and 97.91% success rate for SLA and modSLA implants, respectively (P = 0.323). At the loading stage, modSLA implants showed significantly lower MBL (0.18 ± 0.05 mm) than SLA implants (0.22 ± 0.06 mm; P = 0.002). In the loading stage, RFA value of the modSLA implants (60.42 ± 6.82) was significantly higher than the both implant types in the surgical stage (55.46 ± 8.29 and 56.68 ± 8.19), and following 1 (56.08 ± 7.01 and 55.60 ± 9.07) and 3 weeks of healing (55.94 ± 5.95 and 55.40 ± 6.50 for SLA and modSLA implants, respectively). CONCLUSIONS: modSLA implants demonstrated a better stability and a reduced MBL at the loading stage. Both SLA and modSLA implants demonstrated a favorable success and survival at the end of 15-month follow-up.

Osseointegration and stability of a modified sand-blasted acid-etched implant: an experimental pilot study in sheep.

OBJECTIVE: The aim of this pilot study was to compare the early-term osseointegration characteristics of standard (SLA) and modified sand-blasted and acid-etched (modSLA) implants in an experimental animal model. MATERIAL AND METHODS: A total of 30 SLA and modSLA implants were placed to the tibiae of three sheep and the insertion torque value (ITV) and resonance frequency analysis (RFA) measurements were performed. RFA measurement was repeated on 3 and 6 weeks healed implants after which the animals were sacrificed for histomorphometric analysis. Bone-to-implant contact was assessed on the non-decalcified sections. Six weeks healed implants were also subjected to the reverse torque test (RTT). Results were analyzed by the Friedman test, Kruskal-Wallis test and Spearman rank correlation test. RESULTS: All implants reached to a strong primary stability with a mean 36.13 ± 2.47 and 35.47 ± 2.85 N/cm ITV. In the surgical stage, RFA values for SLA and modSLA implants were found to be 72.27 ± 3.17 and 71.6 ± 2.87, respectively. After 3 weeks of healing, mean BIC% (80.64 ± 13.89%) and RFA value (76.8 ± 1.14) of modSLA implants were significantly higher (P=0.0002) than that of SLA implants (64.39 ± 21.2 BIC% and 74.2 ± 4.76 RFA). However, no statistically significant difference between SLA and modSLA implants was recorded after 6 weeks of healing. Both implants revealed similar results in the RTT test (115.2 ± 4.14 and 117 ± 4.47 N/cm for SLA and modSLA implants, respectively). No correlation was found between RFA and BIC%. CONCLUSION: Within the limits of this pilot study, it can be concluded that modSLA implants achieve a higher bone contact and stability at earlier time points when compared with SLA implants.

Implant surgery using bone- and mucosa-supported stereolithographic guides in totally edentulous jaws: surgical and post-operative outcomes of computer-aided vs. standard techniques.

OBJECTIVES: The aim of this study was to compare the surgical and post-operative outcomes of a computer-aided implant surgery performed by bone- and mucosa-supported stereolithographic (SLA) guides against the standard technique. MATERIAL AND METHODS: Multiple- and single-type SLA guides from two commercial manufacturers were produced and a total of 341 implants were placed to 52 patients using the standard technique (Control group), bone- (bone-supported guide [BSG] group) and mucosa-supported SLA guides (Flapless group) in 21, 16 and 15 patients, respectively. Surgical duration (min), number of analgesics (tablets) as well as hemorrhage, difficulty in mouth opening (or trismus) and other incidences were recorded. Pain and swelling was assessed using the visual analog scale (VAS). Parametric and non-parametric tests were used for statistical analysis (P<.05). RESULTS: The mean surgery duration (23.53+/-5.48 min) and the number of analgesics consumed (four tablets) in the Flapless group were lower than those in the control (68.71+/-11.4 min and 10 tablets) and BSG groups (60.94+/-13.07 min and 11 tablets, P<0.01). The change in pain scores (VAS) and the number of analgesics consumed in time were statistically significant (P<0.01 and 0.05, respectively) and the Flapless group reported a lower pain score than the BSG (P<0.01) and Control groups (P<0.001). The Flapless group experienced less hemorrhage (chi(2)=4.12, P=0.041 on the day of surgery) and fewer instances of trismus (chi(2)=6.91, P=0.031 the day after surgery). The differences in early-term failures were not statistically significant between the groups (log-rank test: P=0.782). CONCLUSION: The use of mucosa-supported single SLA guides for flapless implant placement may help reduce the surgery duration, pain intensity, related analgesic consumption and most other complications typical in the post-implant surgery period. However, there are particular drawbacks in both guide types and further studies are required to confirm the prosthodontic conformity and long-term success of implants placed using computer-assisted techniques.

Evaluation of 316 narrow diameter implants followed for 5-10 years: a clinical and radiographic retrospective study.

OBJECTIVES: Narrow diameter implants (NDIs; diameter >3.75 mm) are useful in replacement of missing incisor teeth and when the bucco-lingual width of the edentulous crest is insufficient. The present study evaluated the success and survival rates, peri-implant parameters, mechanical and prosthetic post-loading complications of NDIs followed over a 10-year period. MATERIAL AND METHODS: Three hundred and sixteen NDIs were inserted into 139 patients and restored with 120 prostheses. Clinical and radiographic assessment data were collected during recall visits. Implant success (SC), cumulative survival rate (CSR), marginal bone loss (MBL), peri-implant conditions and prosthetic complications were assessed. Cox proportional hazards regression analysis, Kaplan-Meier survival curves with the log-rank test and life table analysis were used to evaluate the outcome of NDIs within comparable subgroups. MBL and peri-implant parameters measured annually were further analyzed. RESULTS: The mean follow-up time was 9.1 years (range: 60-124 months). Twelve implants were lost in the healing phase and two during function. The mean MBL in the maxilla and the mandible was 1.32 +/- 0.13 and 1.28 +/- 0.3 mm, respectively, after 10 years. SC and CSR were 91.4% and 92.3%, respectively, after 124 months. Smoking and posterior localization were associated with an increased risk of failure. Cement loosening (16.8%) was the most common prosthetic complication. No implants were fractured. CONCLUSIONS: NDIs can be used with confidence where a regular diameter implant is not suitable. MBL around NDIs occurred predominantly within 2 years of loading and was minimal thereafter. Further studies are required to clarify the possible risks associated with smoking and posterior placement.

Shade matching performance of normal and color vision-deficient dental professionals with standard daylight and tungsten illuminants.

STATEMENT OF PROBLEM: The lighting conditions of the environment and visual deficiencies such as red-green color vision deficiency affect the clinical shade matching performance of dental professionals. PURPOSE: The purpose of this study was to evaluate the shade matching performance of normal and color vision-deficient dental professionals with standard daylight and tungsten illuminants. MATERIAL AND METHODS: Two sets of porcelain disc replicas of 16 shade guide tabs (VITA Lumin) were manufactured to exact L*a*b* values by using a colorimeter. Then these twin porcelain discs (13 mm x 2.4 mm) were mixed up and placed into a color-matching cabinet that standardized the lighting conditions for the observation tests. Normal and red-green color vision-deficient dental professionals were asked to match the 32 porcelain discs using standard artificial daylight D65 (high color temperature) and tungsten filament lamp light (T) (low color temperature) illuminants. The results were analyzed by repeated-measures ANOVA and paired and independent samples t tests for the differences between dental professionals and differences between the illuminants (alpha=.05). RESULTS: Regarding the sum of the correct shade match scores of all observations with both illuminants, the difference between normal vision and red-green color vision-deficient dental professional groups was not statistically significant (F=4.132; P=.054). However, the correct shade match scores of each group were significantly different for each illuminant (P<.005). The correct shade matching scores of normal color vision dental professionals were significantly higher with D65 illuminant (t=7.004; P<.001). Color matching scores of red-green color vision-deficient dental professionals (approximately 5.7 more pairs than with D65) were significantly higher with T illuminant (t=5.977; P<.001). CONCLUSIONS.: Within the limitations of this study, the shade matching performance of dental professionals was affected by color vision deficiency and the color temperature of the illuminant. The color vision-deficient group was notably unsuccessful with the D65 illuminant in shade matching. In contrast, there was a significant increase in the shade matching performance of the color vision-deficient group with T illuminant. The lower color temperature illuminant dramatically decreased the normal color vision groups' correct shade matching score.

Oxytocin-loaded sustained-release hydrogel graft provides accelerated bone formation: An experimental rat study.

Restoration of the lost bone volume is one of the most deliberate issues in dentistry. Sustained-release microspherical oxytocin hormone in a poloxamer hydrogel scaffold combined with a mixture of ß-tricalcium phosphate and hydroxyapatite (CP) may serve as a suitable bone graft. The aim of this study was to design and test a novel thermosensitive hydrogel graft incorporating oxytocin-loaded poly(d, l-lactide-co-glycolide) (PLGA) sustained-release microspheres and CP. Thermosensitive poloxamer hydrogel containing CP (HCP graft) was prepared as a base and combined with hollow microspheres (HCPM) and oxytocin-loaded microspheres (HCPOM). Eighty Wistar rats were used for testing the grafts and a control group in 8-mm-diameter critical-sized calvarial defects (CSD); (n = 20). Bone healing at the 4th and 8th weeks was evaluated by histological, histomorphometric, and radiological (micro-computed tomography [µCT]) analyses. The results were analyzed by two-way analysis of variance (P < .05). Oxytocin-loaded PLGA microspheres prepared by the solvent displacement method yielded a high encapsulation efficiency of 89.5% and a slow drug release. Incorporation of the microspheres into the hydrogel graft slowed the release rate down and the release completed within 32 days. HCPOM revealed the highest new bone formation (26.45% ± 6.65% and 30.76% ± 4.37% at the 4th and 8th weeks, respectively; P < .0001) while HCPM and HCP groups revealed a bone formation of around 10% (P > .05). µCT findings of HCPOM group showed the highest mean bone mineral density values (42.21 ± 5.14 and 46.94 ± 3.30 g/cm3 for the 4th and 8th weeks, respectively; P < .0027). The proposed oxytocin-loaded sustained-release PLGA microspheres containing thermosensitive hydrogel graft (HCPOM) provide an accelerated bone regeneration in the rat calvaria.

Injectable calcium phosphate cement as a bone-graft material around peri-implant dehiscence defects: a dog study.

PURPOSE: Peri-implant dehiscence defects occur frequently after dental implant placement. Various graft materials and techniques are proposed for treatment. In this study, an injectable calcium phosphate cement (Augmentech, Wetzlar, Germany) applied to a peri-implant defect was investigated. MATERIALS AND METHODS: Standardized buccal dehiscence defects (5.8 x 3.8 mm) were surgically created after implant site preparation in the right proximal tibiae of 5 beagle dogs. Fifteen stepped cylindrical implants (13 x 3.8 mm diameter) were inserted (3 per dog), and Augmentech injectable calcium phosphate cement was injected into the dehiscences. The bone at the distal side of the implant was left intact to serve as a control. Postsurgically, each dog received double staining of 2 fluorescent labels for estimation of bone cell activity at baseline and after 11 weeks of healing. The animals were sacrificed after 12 weeks. Dissected blocks were processed for histologic, histomorphometric, and fluorescence microscopic analysis, ie, percentage of bone-to-implant contact (BIC) and percentage linear bone height (LBH) were measured. Student t and Mann Whitney U tests were used for statistical analysis (P < .05). RESULTS: Healing was uneventful in all dogs. Augmentech injectable calcium phosphate cement showed good space maintenance and osteoconductive properties with no foreign body reaction. BIC was 34.42 (- 19.88) and 37.00 (- 21.33) (P = .375), while LBH was 84.23 (- 19.73) and 96.10 (- 6.66) (P = .125) for test and control sites, respectively. CONCLUSION: Within the limits of the present study, it was concluded that Augmentech injectable calcium phosphate cement may be a suitable material for the treatment of buccal dehiscence defects around dental implants.

Vascular endothelial growth factor and biphasic calcium phosphate in the endosseous healing of femoral defects: An experimental rat study.

BACKGROUND/PURPOSE: The presence of adequate bone volume is a critical factor in rehabilitative dentistry. Despite the use of many promising alloplasts, success in stimulating bone formation has been limited, mostly due to poor local biological response. Growth factors have been introduced to stimulate angiogenesis and new bone formation. This histologic and histomorphometric study aimed to evaluate the effect of vascular endothelial growth factor (VEGF) and a biphasic alloplastic graft material (BA) on the healing of endosseous defects in rats. MATERIALS AND METHODS: Twenty male Wistar rats were used. Two critical-sized bone defects were created in both the right and left femurs of each rat. Each defect was randomly assigned to be treated with VEGF, BA, or VEGF + BA, or to be left empty as a control. Half of the animals were sacrificed after 1 week, and the remaining half were sacrificed after 2 weeks. Inflammation, necrosis, and new bone areas were evaluated by means of histologic and histomorphometric analyses. RESULTS: Compared to the control group, defects treated with VEGF alone or in combination with BA showed higher rates of bone formation (33.10-46.60%) on Day 7. Additionally, VEGF significantly reduced inflammation and necrosis (P < 0.001). However, the differences were no longer discernable on Day 14. CONCLUSION: VEGF makes a significant contribution to angiogenesis and osteogenesis in the early stages of bone defect healing, and its combination with an osteoconductive grafting material (BA) may further enhance new bone formation.

Effects of sinus membrane perforations on the success of dental implants placed in the augmented sinus.

BACKGROUND: Maxillary sinus lifting procedure enables clinicians to place implant-supported prostheses even in cases with very limited vertical bone height of the maxillary sinus. The aim of this study was to evaluate the implant success with regard to effects of the sinus membrane perforations that occurred during sinus lifting surgery. METHODS: The study group consisted of 91 patients (29 females and 54 males) with edentulous posterior maxilla. Implant placement combined with sinus lifting surgery was performed, and 259 implants were inserted. Sinus membrane perforations were detected in 12 sinus sites. After proper treatment of perforations, 26 implants were placed into perforated sinus areas. Baseline panaromic radiographs were taken before the beginning of prosthetic treatment. Panaromic radiographs taken at the last recall were used for evaluation and compared to the baseline panaromic radiographs using image analysis software to reveal the peri-implant resorption rate for the implants placed in perforated and non-perforated sinus area. The modified sulcus bleeding index and plaque index were used for the assessment of soft tissue conditions. RESULTS: Eleven implants were lost during the follow-up period, resulting in an overall survival rate of 95.9%. Two failures occurred in the group with sinus perforations. There was no statistically significant difference regarding peri-implant bone resorption (P = 0.778) and soft tissue conditions for implants placed into perforated-augmented sinus areas and augmented sinus areas. CONCLUSION: Within the limits of this study, perforation of the sinus membrane did not compromise the osseointegration process or the success of dental implants placed in the augmented maxillary sinus.

Bisphosphonate-related osteonecrosis of the jaw and dental implants.

Bisphosphonate (BP) is one of the possible riskfactors in the osteonecrosis of the jaw (ON J). Surgical interventions during or after the course of treatment by using BPs may expose the patient under this risk. Animal studies, human studies, case reports, and systematic reviews are used to show the relationship between the use of bisphosphonates and dental implants. In this review data about bisphosphonaterelated osteonecrosis of the jaw (BRON J): incidence, prevention and treatment modalities for the patients who are scheduled for dental implant treatment plan and who have been already treated by dental implants will be investigated. Various views for the relationship between dental implants and bisphosphonates will be analyzed depending on the multifactors: duration, route of uptake, dosage of the drug and patient's other medications that affect the effects of bisphosphonate. All patients treated with this drug must be informed about the risk of implant loss or possibility of osteonecrosis.