Implant Stability Quotient Values Research Articles

Peri-İmplant Kemik Defekti Tipinin Yerleştirme Torku ve Rezonans Frekans Analizi Üzerine Etkisi: İn Vitro Çalışma

Objective: The aim of the present study is to investigate the effects of different peri-implant bone defects on primary stability and the correlation between insertion torque (IT) and resonance frequency analysis (RFA) measurements. Material and Methods: Fourty implant beds were prepared in artificial bone blocks using the 3D surgical guide. Implant osteotomies were divided into 5 groups (n=8) according to defect type: i) no peri-implant bone defect (control), ii) a dehiscence defect, iii) a fenestration defect on the middle part, iv) a fenestration defect on the apical part and v) a circumferential defect. Implants were inserted by using a surgical drilling unit with torque control and RFA measurement were done. Results: IT values for the control group were significantly higher than the other groups (p<0.001). The results of IT measurements for dehiscence defect group were significantly greater when compared to fenestration and circular defect groups (p<0.01). Implant stability quotient (ISQ) values for the control group were significantly higher than other groups (p<0.05). In addition, the ISQ values for the dehiscence defect group were significantly lower when compared to fenestration defect groups (p<0.001), and ISQ values for the circular defect group were significantly lower than any other groups (p<0.001). IT values and, ISQ values are moderately correlated (p=0.013, r=0.388). Conclusion: The location of peri-implant bone defect affects RFA measurements more than IT. However, IT seems to be correlated with bone implant contact. Therefore, in the case of peri-implant bone defect, IT measurement may be preferred for evaluation of primary stability.

Are the Insertion Torque Value and Implant Stability Quotient Correlated, and If So, Can Insertion Torque Values Predict Secondary Implant Stability? A Prospective Parallel Cohort Study.

Primary stability is the most important prognostic index for predicting osseointegration. It is generally thought that to achieve high primary stability, it is necessary to insert an implant with a high insertion torque (IT). To date, it has not yet been determined whether IT and implant stability quotient (ISQ) values are correlated. The primary aim of the study was to determine the correlation between IT and ISQ values at the time of implant insertion (T0); at 2 months, the time of healing (T1); and at 6 (T2) and 12 months (T3) after loading. The secondary aims were to determine the influence of different macroscopic implant designs and of a different insertion arch on this correlation; and to assess whether implants inserted with a high IT, that is, > 50 Ncm, had higher levels of implant stability at 2-, 6-, and 12-month follow-ups. STROBE guidelines were followed. Partially or monoedentulous patients were randomly assigned to receive taper thread on straight-body implants with microthreads (group A) or without microthreads (group B). At implant insertion, IT and ISQ values were recorded. At 2-, 6-, and 12-month follow-ups, the ISQ values were recorded. A spring-style torque wrench was used to assess the IT. The Osstell device was used to determine the ISQ values. Descriptive statistics, Pearson correlation, and t test were used. P was set at ≤ .005. Two hundred fifty subjects were assessed; 142 were included. Two hundred sixty-eight implants were inserted (group A, 137 implants; group B, 131 implants). No subject dropped out, and no implant failed. A statistically significant correlation between ISQ and IT was determined at the time of implant insertion (T0; P = .000). The implant morphology and arch did not influence the correlation. An IT > 50 did not determine a higher secondary stability. There is a strong correlation between IT and primary stability, but IT is not correlated with the secondary stability. A different implant macroscopic design and a different arch of insertion did not influence this correlation. Moreover, implants inserted with IT > 50 Ncm do not result in greater secondary stability.

Bone Level Tapered Implants in the Maxillary Esthetic Zone: A 1-Year Prospective Case Series in Healed Sites.

Bone level tapered implants have an advantage in terms of stability and less need for additional bone augmentation procedures in healed sites, which might be advantageous for the esthetic zone. The aim of this study was to assess the clinical, radiographic, and esthetic performance of bone level tapered implants placed in healed sites in the maxillary esthetic region during a 1-year evaluation period. Thirty participants (15 male, 15 female) with a single-tooth diastema that had healed without an alveolar ridge preservation procedure received a bone level tapered implant. Buccal bone augmentation procedures were performed at implant placement if the labial bone wall thickness was < 2 mm. A provisional crown was connected after a healing phase of 3 months. A definitive crown was placed 3 months after the provisional restoration. Implant stability, peri-implant soft and hard tissue health, esthetics, and patient-reported outcomes were recorded. All the placed implants demonstrated good stability. A labial bone augmentation technique was needed in 23 of the 30 cases. The median implant stability quotient value was 73 (68;76) at implant placement and had increased to 79 (76;81) when the definitive restoration was inserted (P < .005). All patients were present at the 1-year evaluation, and none had lost an implant. The mean loss of marginal bone was 0.07 ± 0.10 mm. The midbuccal mucosa-level recession was 0.14 ± 0.40 mm. There was an overall gain in papilla height: +0.05 ± 0.60 mm mesially and +0.06 ± 0.53 mm distally. Median values of the pink esthetic score and white esthetic score were 6 (4;7 interquartile range) and 8 (7;8.3 interquartile range), respectively. The participants' mean overall satisfaction was 90.1 ± 6.5 on a visual analog scale. No complications occurred. It can be concluded from a 1-year followup that treatment with the bone level tapered implant system resulted in good implant stability, healthy peri-implant soft and hard tissues, satisfying esthetics, and good patient-reported outcomes.

Investigation of Implant Stability Quotient Values of Dental Implants Placed in Vascularized Bone Grafts

Investigation of Implant Stability Quotient Values of Dental Implants Placed in Vascularized Bone Grafts

Implant Stability Following Osseointegration of Dental Implants in Bone Sites Reconstructed with Novel Porous Titanium Scaffold

Porous titanium (porous Ti) possesses excellent mechanical strength and three-dimensional structure. Therefore, it enables bone formation due to its good osteoconduction abilities. Osseointegration can be achieved at the implant site after bone reconstruction with porous Ti. This study aimed to assess implant stability following osseointegration at sites reconstructed with porous Ti. Hollow-shaped porous Ti were placed in the tibiae of six New Zealand white rabbits. Ti dental implants were placed 4 weeks later. Implant placed at the parent bone sites, without porous Ti, served as the controls. Histological and histomorphometric assessments of the porous Ti and control sites were performed 4 weeks later. There was no significant difference in the insertion torque between the porous Ti and control groups. The primary and secondary implant stability quotient value was higher in the porous Ti group than that in the control group. Histologically, bone reconstruction was achieved with porous Ti through osteoconduction into the original bone region and bone marrow region, as osseointegration of implants was achieved even in the bone marrow region. The bone-implant contact ratio was similar in both the groups; however, the bone-implant contact was mainly in the cortical region in the control group. In the present study, the reconstructed bone site with porous Ti showed favorable osseointegration ability when the dental implant was placed. Porous Ti is expected to be a suitable material for bone material before implant placement.

The Effect of Bone Density Measured by Cone Beam Computed Tomography and Implant Dimensions on the Stability of Dental Implants.

The aim of this study was to evaluate the effect of bone density value in Hounsfield unit derived from cone beam computed tomography (CBCT), and implant dimensions in relation to implant stability parameters namely the resonance frequency analysis and the insertion torque (IT) value. It included 24 patients who received 42 dental implants (DI). The bone density of the planned implant site was preoperatively measured using cone beam computed tomography. The implant stability was measured using Osstell implant stability quotient (ISQ). The ISQ values were recorded immediately postoperatively and after 16 weeks. The IT value was categorized as 35 N/cm or > 35 N/cm. The mean (standard deviation) primary stability was 79.58 (5.27) ISQ, which was significantly higher than the secondary stability 74.31 (6.34) ISQ ( P < 0.0001). There was a significant moderate positive correlation of bone density with primary stability ( r = 0.4, P = 0.0099) and no correlation with secondary stability ( r = 0.003, P = 0.9867). The bone density of DI with 35 N/cm IT was significantly lower than with > 35 N/cm IT ( P = 0.0390). Better stability was recorded with wider implants. Whereas the length of the DI showed a nonsignificant correlation with primary and secondary stability ( P = 0.7633 and 0.4670, respectively). The DI dimensions showed a nonsignificant correlation with the IT. Cone beam computed tomography may be considered as a reliable method to assess bone density and predict the implant stability. The diameter of DI affected the implant stability favorably, whereas DI length showed no effect.

Influence of Cortical Layer and Surgical Techniques on the Primary Implant Stability in Low-density Bone:An In Vitro Study

This study aimed at evaluating the influence of cortical layer and surgical techniques on the primary stability of implants in low-density bone. Two solid rigid polyurethane blocks with a density equivalent to 0.32 g/cm3 simulating cancellous bone were used. A short fiber-filled epoxy resin sheet of 2 mm was layered to one block to simulate cortico cancellous bone. A total of 40 implants were used in this study (n = 40). Twenty implants each (n = 20) were inserted in cancellous (Group 1) and cortico-cancellous bone (Group 2), of which 10 implants each (n = 10) were placed using undersized preparation technique with surgical drills-A and osteotomes-B, in both the groups. Insertion torque (IT) and implant stability quotient (ISQ) for each implant placed were assessed to determine the primary stability of each implant using a digital torque meter and resonance frequency analyzer, respectively. The values were statistically analyzed using an independent t-test (p < 0.05). Pearson's correlation analysis was performed to correlate between IT and ISQ. Technique B resulted in significantly higher IT and ISQ values in Group 1 (27.69 ± 1.2 N cm; 52.5 ± 1.05 ISQ) and Group 2 (38.8 ± 0.87 N cm; 70.1 ± 1.04 ISQ) compared to those with technique A (22.40 ± 1.62 N cm; 41.75 ± 1.20 ISQ and 33.24 ± 0.67 N cm; 63.72 ± 1.33 ISQ), respectively. Group 2 exhibited significantly higher IT and ISQ values as compared to Group 1 irrespective of the surgical technique employed (p < 0.05). The presence of the cortical layer significantly influenced the primary stability and preparing low-density bone with an undersized preparation technique using osteotomes that significantly increased the IT and ISQ. Undersizing the preparation site considerably will help achieve a significant increase in primary stability in the poor quality bone as in the posterior maxilla, thereby contributing to the success of the implant.

The Effect of Recipient Jaw and Implant Dimensions on Pre- and Post- Loading Dental Implant Stability: A Prospective Clinical Study

Background: Implant stability is a mandatory factor for dental implant (DI) osseointegration and long-term success. The aim of this study was to evaluate the effect of implant length, diameter, and recipient jaw on the pre- and post-functional loading stability. Materials and methods: This study included 17 healthy patients with an age range of 24-61 years. Twenty-two DI were inserted into healed extraction sockets to replace missing tooth/ teeth in premolar and molar regions in upper and lower jaws. Implant stability was measured for each implant and was recorded as implant stability quotient (ISQ) immediately (ISQ0), and at 8 (ISQ8) and 12 (ISQ12) weeks postoperatively, as well as post-functional loading (ISQPFL). The pattern of implant stability changes throughout the study period and its correlation with the recipient jaw and the DI dimensions were evaluated. Results: There was a significant difference in ISQ values throughout the study. DI stability in the maxilla was significantly higher than that in mandible for the ISQ0, with no significant effect for the rest time points. The effect of implant diameter was significant with DI of 4.1mm diameter being more stable. While for the length, there was no significant difference regarding its effect on ISQ values through-out the study period. Conclusions: DI inserted in the maxilla demonstrated better primary stability with no effect of recipient jaw on secondary stability and after functional loading, also DI with wider diameter had better stability throughout the study whereas DI length showed no significant effect on stability

Short-Term Evaluation of Prosthetic Rehabilitation of Thin Wiry Ridge by Ridge Splitting and Simultaneous Implants Placement: Non-randomized Control Trial.

Objective This article evaluates the success of prosthetic rehabilitation of thin wiry ridge and implants placed simultaneously in splitted ridge both clinically and radiographically. Materials and Methods Twenty-one participants were enrolled of which 13 patients (8 females and 5 males) were suffering from maxillary ridge atrophy and 8 patients (5 females and 3 males) had mandibular ridge atrophy; a total of 42 implants were performed using the ridge expansion technique. The expansion was performed using the conventional disk technique, piezoelectric corticotomy, and self-threading expanders. Implants were placed and loaded with fixed partial denture after 4 months for the mandible and 6 months for the maxilla. Implant stability quotient (ISQ) was measured at T0 (implant placement) and TL (loading). Crestal bone levels were measured at different times: T0, TL, and T12 (12 months). Evaluation of prosthetic and surgical complications was carried out. Data were analyzed and compared using analysis of variance and paired t -tests at a significance level of 5%. Results All implants met the criteria for success. All implants showed a higher mean bone loss from T0 to TL (1.259 ± 0.3020) than from TL to T12 (0.505 ± 0.163) with a statistically significant difference ( p < 0.0001). ISQ values sharply increased at the time of loading (72.52 ± 2.734) than at implant insertion (44.5 ± 4.062) with a significant difference ( p < 0.0001). Minor prosthetic and surgical complications were reported. Conclusion The results from this study support the efficacy of prosthetic rehabilitation of thin wiry ridge using split ridge technique and the success of implants placed simultaneously in splitted ridge.

Effect of the Acid-Etching on Grit-Blasted Dental Implants to Improve Osseointegration: Histomorphometric Analysis of the Bone-Implant Contact in the Rabbit Tibia Model

Previous studies have shown that the most reliable way to evaluate the success of an implant is by bone-to-implant contact (BIC). Recent techniques allow modifications to the implant surface that improve mechanical and biological characteristics, and also upgrade osseointegration. Objective: The aim was to evaluate the osseointegration in rabbit tibia of two different titanium dental implant surfaces: shot-blasted with Al2O3 (SB) and the same treatment with an acid-etching by immersion for 15 s in HCl/H2SO4 (SB + AE). Material and methods: Roughness parameters (Ra, Rt, and Rz) were determined by white light interferometer microscopy. Surface wettability was evaluated with a contact angle video-based system using water, di-iodomethane, and formamide. Surface free energy was determined by means of Owens and Wendt equations. Scanning electron microscopy equipped with X-ray microanalysis was used to study the morphology and determine the chemical composition of the surfaces. Twenty-four grade 4 titanium dental implants (Essential Klockner®) were implanted in the rabbit’s tibia, 12 for each surface treatment, using six rabbits. Six weeks later the rabbits were sacrificed and the implants were sent for histologic analysis. Resonance frequency analysis (RFA) was recorded both at the time of surgery and the end of the research with each device (Osstell Mentor and Osstell ISQ). Results: The roughness measurements between the two treatments did not show statistically significant differences. However, the effect of the acid etching made the surface slightly more hydrophilic (decreasing contact angle from 74.7 for SB to 64.3 for SB + AE) and it presented a higher surface energy. The bone-to-implant contact ratio (BIC %) showed a similar tendency, with 55.18 ± 15.67 and 59.9 ± 13.15 for SB and SB + AE implants, respectively. After 6 weeks of healing, the SB + AE showed an implant stability quotient (ISQ) value of 76 ± 4.47 and the shot-blasted one an ISQ value of 75.83 ± 8.44 (no statistically significant difference). Implants with different surface properties had distinctive forms of behavior regarding osseointegration. Furthermore, the Osstell system was an invasive and reliable method to measure implant stability. Conclusion: Both surfaces of implants studied showed high osseointegration. The SB and SB + AE implants used in our study had similar behavior both in terms of BIC values and RFA. The RFA systems in Osstell Mentor and Osstell ISQ confirmed nearly perfect reproducibility and repeatability.

Preliminary Study with the Use of a Titanium Mesh as Space Maker and Implant Primary Stabilization for One-Stage Sinus Lift in Cases with Less Than 1.5 mm Residual Bone.

(1) Background: In the lateral area of the maxilla, the alveolar bone can lose significant volume due to maxillary sinus pneumatization following teeth extractions. This preliminary study evaluated the effectiveness of a novel technique for one-stage sinus lifting and simultaneous implant placement in cases with less than 1.5 mm residual alveolar bone. The subsequent survival rate at 1-year post-occlusal loading was assessed. (2) Methods: 15 patients were selected, the main inclusion criteria were the partially edentulous area in the posterior maxilla with alveolar bone height of less than 1.5 mm below the sinus. All of the patients underwent one-stage sinus lifting, along with simultaneous implant placement using a “butterfly” anchorage device to optimize the primary stability and xenograft bone as graft material. At 6 to 9 months after surgery, the anchorage device was removed and implants were loaded. Panoramic x-ray images were used to assess the new bone formation, while the biological stability was measured using resonance frequency analysis. (3) Results: 15 implants were inserted. The mean implant stability quotient (ISQ) value was 71.3 (SD = ±2.51) and the mean healing period was 7.3 (SD = ±1.23) months. The mean bone height after the healing period was 14.4 (SD = ±2.05). A statistically significant correlation was found between the healing period and the ISQ value (Spearman rho = 0.684, sig. = 0.005). No statistically significant correlation was found between the ISQ value and the new regenerated bone height (Person r = 0.389, sig. = 0.152). Smoking was identified as a risk factor involved in postoperative complications. (4) Conclusions: The results of the present preliminary study demonstrated that the proposed “butterfly” technique was effective when performing one-stage sinus lifting and simultaneous implant placement in cases with less than 1.5 mm of residual alveolar bone. The survival rate was 100% at 1-year post occlusal loading.

Secondary stability achieved in dental implants with a calcium-coated sandblasted, large-grit, acid-etched (SLA) surface and a chemically modified SLA surface placed without mechanical engagement: A preclinical study.

To assess the osseointegration of calcium-coated (CS) and chemically modified, sandblasted, large-grit, acid-etched (MS) dental implants with a lack of primary mechanical stability. Eighteen implants in CS and MS groups each were loosely placed in the mandible of six mongrel dogs and allowed to heal for 2, 4 and 8weeks. Implant stability quotient (ISQ) and implant stability test (IST) values recorded periodically and bone-to-implant contact (BIC) and the number of Haversian canals per 1mm2 measured histologically were statistically analysed (p<.05). All CS and MS implants placed survived. Compared with immediately after installation, ISQ and IST values in both groups increased significantly to over 76 at 2weeks (p<.0083) and remained stable thereafter. BIC was significantly greater at 8weeks (61.3±13.6% in CS group; 57.6±5.9% in MS group) compared to 2 and 4weeks in both groups (p<.017). There were no significant intergroup differences in ISQ, IST or BIC at different time points. Significantly more Haversian canals were observed in group CS (6.2±1.0/mm2 ) compared with group MS at 4weeks (3.7±1.8 /mm2 ; p<.05), while intergroup difference was not significant at 8weeks. Both CS and MS implants inserted without primary stability obtained osseointegration within 2weeks, and lamellar bone adjacent to the implants was first observed at 8weeks. The formation of primary osteons was more active at 4weeks in group CS than in group MS.

Longitudinal Study of Dental Implants in HIV-Positive Patients.

This study compared the clinical outcome of dental implants and their implant-supported restorations over a 3-year period involving patients both positive and negative for the human immunodeficiency virus. Twenty patients testing positive for the human immunodeficiency virus were recruited for this study. Twenty-one negative control patients were also selected, for a total of forty one patients. Diagnostic impressions were collected and cone beam computed tomography images were obtained. Implant size and positioning were planned using cone beam computed tomography software. Two stage or single surgery was performed as determined by the surgeon (periodontist). After a 6-month healing period, definitive impressions were fabricated using polyvinyl siloxane impression material. Implant stability quotient values were obtained at the time of surgery and placement of the restoration. Screw-retained custom titanium abutments were designed, milled, and placed with 25 N·cm torque using a calibrated torque controller. Porcelain fused-to-metal complete coverage restorations were then cemented with elastomeric resin implant cement. Implants and restorations were assessed at 6-month intervals over a period of 3 years for stability, peri-implant health, and patient satisfaction. Over the 3-year period, 25 of 42 implants placed in the negative control group were assessed, and 17 of 27 implants placed in the positive control group were evaluated. The overall patient retention rate was 77%. At the 3-year follow up, restorations examined were fully functional and causing no pain. Overall implant retention within the positive group was 96%. Implant retention within the negative control group was 100%. No differences were noted between groups for bone loss based on statistical tests. Within the limitations of this clinical investigation, the presence of human immunodeficiency virus per se was not a contraindication to dental treatment with implant-supported restorations.

Comparative Assessment of the Primary Stability of Straumann BLX Implant Design Using an In Vitro Sinus Lift-Simultaneous Implant Insertion Model.

Straumann BLX is a novel implant system that has been proclaimed to provide an ideal primary stability in all types of bone. In the current study, the primary stability of the Straumann BLX implant systems with Straumann tapered effect (TE) implants have been comparatively assessed in bovine ribs by using a simultaneous sinus elevation and implant insertion model. In the study group, BLX (4.0 × 12 mm), TE (4.1 × 12 mm), BLX (4.5 × 12 mm), and TE (4.8 × 12 mm) were placed in each bony window, which resembles the sinus maxillaris. As a control, BLX and TE implants with the same sizes were inserted into the proximal diaphysis of the bovine ribs. A total of 40 implant insertions were performed. Stability was measured with resonance frequency analysis. In the study group, 4.8-mm TE implants showed significantly higher values compared with 4.5-mm BLX implants (P = .116). However, 4.0-mm BLX implants in the control group showed higher stability compared with 4.0-mm-diameter TE (P = .014). The primary stability of the BLX implants in the control group was significantly higher compared with the experimental group in both widths (P= .018 for BLX 4.0 mm and P = .002 for BLX 4.5 mm, respectively). The use of the TE design with a wide diameter in simultaneous implant placement with sinus lift could present higher implant stability quotient values and might be a more appropriate option for implant recipient sites with poor bone volume and quality. However, the advantage of BLX design in standard implant insertion protocols could be of value.

An experimental study on the effects of the cortical thickness and bone density on initial mechanical anchorage of different Straumann\xae implant designs

BackgroundThe aim of the current study was to comparatively assess the primary stability of different Straumann® implant designs (BLX, Straumann Tapered Effect, Bone Level Tapered, and Standard Plus) via resonance frequency analysis by using an implant insertion model in freshly slaughtered bovine ribs with and without cortical bone. Tapered Effect (4.1 × 10 mm), Bone Level Tapered (4.1 × 10 mm), Standard Plus (4.1 × 10 mm), and BLX (4.0 × 10 mm) implants were inserted into the distal epiphysis on the longitudinal axis of the freshly slaughtered bovine ribs. As a control, implants with the same sizes were inserted into the proximal diaphysis. The stability of the implants was examined with resonance frequency analysis.ResultsBLX and Tapered Effect implants showed higher implant stability quotient values in both study and control groups. All implant systems showed a significant decrease of mechanical anchorage in the study group. BLX and Bone Level Tapered designs had a significantly lower loss of mechanical anchorage in the lack of cortical bone.ConclusionBoth Tapered Effect and BLX designs could ensure sufficient initial stability; however, BLX implants could be an appropriate option in the lack of cortical bone and poor bone quality at the implant recipient site.Clinical relevanceBLX is a novel implant system, which could be especially beneficial in the presence of spongious bone type at posterior maxillae.

Analysis of implant stability changes in immediate loading using a laser displacement sensor in vivo and comparison of its sensitivity with that of resonance frequency analysis

The aim of this study was to analyze the stability changes in immediately loaded implants by using an in vivo quantitative measurement of micromotion under functional dynamic loading and to verify the sensitivity of Resonance Frequency Analysis (RFA) as compared to that of actual micromotion. The micromotions of immediately loaded implants placed in the tibia of 11 rabbits were monitored using a laser displacement sensor. Functional dynamic loading forces were applied 5days a week for 6weeks. The implant stability quotient (ISQ) was monitored using RFA. The micromotion of the almost-loaded implants increased to peak values the day after loading was started and subsequently reached a plateau gradually. The ISQ changes in the loaded implants closely correlated with the alterations of the actual micromotion (r=-0.98, p<.01). Although the ISQ value itself correlated with the measured micromotion at the time of initial fixation (r=0.73, p<.05), it did not correlate with the micromotion of the implant that acquired integration. No close correlation was observed between the ISQ and the histomorphometrical data. The immediately loaded implants showed the lowest stability immediately after the start of loading, which gradually increased thereafter. RFA is considered a useful method for examining stability changes and initial stability; however, it cannot determine the absolute magnitude of the stability after integration.

Evaluation of Implant Stability Following Sinus Augmentation Utilizing Bovine Bone Mixed with Platelet-Rich Fibrin

Background: Lateral sinus augmentation and simultaneous insertion of dental implants is a highlypredictable procedure and associated with high rate of implants success.Aims: To evaluate implant stability changes following maxillary sinus augmentation utilizing deproteinizedbovine bone alone or mixed with platelet-rich fibrin.Materials and Methods: A total of 34 lateral sinus augmentation procedures were performed and 50 dentalimplants simultaneously installed. The lateral sinus augmentation cases were allocated randomly into 3groups: Group A comprised 13 procedures and 21 dental implants utilizing solely deproteinized bovine bone.Group B involved 10 cases and 16 dental implants using deproteinized bovine bone mixed with leukocyteand platelet-rich fibrin. Group C included 11 operations and 13 dental implants employing deproteinizedbovine bone mixed with advanced platelet-rich fibrin. Resonance frequency analysis test was performedimmediately after implant installation and 24 weeks postoperatively for the measurement of the implantstability.Results: Implant stability quotient values increased significantly for all study groups 24 weeks after dentalimplants installation (P= 0.001). The implant stability quotient at T1 (day of implant installation) was 56.93±12.01 for group A, 58.34 ±12.82 for group B, and 61.35 ±8.47 for group C. The implant stability quotientat T2 (24 weeks after implant insertion) was 69.17 ±5.10, 69.43 ±5.32, and 68.50 ±7.44, respectively.Conclusion: The addition of leukocyte and platelet-rich fibrin or advanced platelet-rich fibrin to the bovinebone for sinus floor augmentation did not increased the implant stability quotient value in comparison to thebovine bone alone.

Influence of implant geometry and osteotomy design on early bone healing: A pre‐clinical in vivo study

To analyze the early stages of osseointegration around implants with different geometry following installation in sites using different osteotomy protocols. Two types of implants were installed using regular or modified (reduced diameter) osteotomy protocols in mandibular premolar/molar regions following tooth extraction in six dogs. Three implant site categories were created: Reference (A implant and regular osteotomy), Test-1 (B implant and regular osteotomy), and Test-2 (B implant and modified osteotomy). Implant installation procedures were repeated after 4 and 6weeks. The insertion torque (ITQ) was measured during implant installation and resonance frequency analysis providing implant stability quotient (ISQ) values was performed following implant installation and once every week during the course of the study. Biopsies were obtained immediately after the 3rd installation procedure and prepared for histological analysis. The modified osteotomy protocol created a higher insertion torque (ITQ). The analysis also revealed a correlation between insertion torque at implant installation and radiographic bone loss after 6weeks of healing. The decline in ISQ values during healing was more pronounced at Test-2 than other sites. While the degree of bone-to-implant contact (BIC%) in the marginal area was similar in test and reference sites at 6weeks of healing, Test-2 implants presented with a significantly higher BIC% in the mid and apical areas than Test-1 implants. It is suggested that placement of implants in undersized osteotomy sites will result in an increased remodeling of the cortical bone during the early healing process.

Dental implants’ stability dependence on rotational speed and feed-rate of drilling: In-vivo and ex-vivo investigations

This study aimed to explore the effects of drilling rotational speed and feed-rate on the stability of dental implants through in-vivo and ex-vivo experiments. To this end, a total of 16 identical dental implants were inserted in the mandible of four dogs. The osteotomies were made with two drilling rotational speeds, i.e., 800 and 1500 rpm, and two different feed-rates, i.e., 1 and 2 mm/s. Implant stability quotients (ISQs) were recorded immediately after inserting implants and then each week for four subsequent weeks. Then, all animals were euthanized, and a bone sample containing the implants was extracted from each hemi-mandible for the pull-out test. A two-way ANOVA was performed for ISQs, and pull-out strengths (PoS), and the significance level was set to <0.05. The effect of rotational speed and feed-rate, used in this study, on the primary stability quotients was not significant (P > 0.05). Increasing the rotational speed from 800 to 1500 rpm significantly increased both ISQ and PoS values at the end of the 4th week after the implantation (P = 0.022 and P = 0.001, respectively). Moreover, by decreasing the feed-rate from 2 to 1 mm/s, a significant increase in PoSs of the dental implants was observed four weeks after the implantation (P = 0.019). Results of this study showed that either by increasing drilling rotational speed, here from 800 to 1500 rpm, or by reducing feed-rate, here from 2 to 1 mm/s, the secondary stability would be reinforced. Further investigations are needed to see if and how the conclusions made in this study can be generalized.

The effect of triangular cross-section neck design on crestal bone stability in the anterior mandible: A randomized, controlled, split-mouth clinical trial.

This randomized controlled trial aimed to compare crestal bone loss (CBL) and buccal bone thickness (BBT) around triangular cross-section neck (TN) to round neck (RN) implants retaining mandibular overdentures one year after loading, using cone beam computed tomography (CBCT). Twenty edentulous patients receiving 40 implants with similar diameters were randomly assigned to the RN and TN groups. Clinical buccal bone thickness (CBBT) around the implants was measured with a caliper at baseline. A resonance frequency analyzer was used to measure the implant stability quotient (ISQ) at the baseline and two months after insertion. Pocket probing depths (PPD), plaque index (PI), and gingival index (GI) were also recorded at postoperative months 2, 6, and 12. CBCT was used to evaluate proximal CBL and BBT at three levels (0, -2, and -4mm) one year after loading. No implant loss was observed during the follow-up period. No significant differences in CBBT, ISQ values, and scores for PPD, PI, and GI between the two groups were observed at any time (p>.05). BBT was also comparable one year after loading (p>.05). The mean±SD proximal CBL one year after loading was 0.58±0.36mm for TN and 0.91±0.59mm for RN (p<.01). This study found better crestal bone preservation in the implants with the novel neck design than conventional neck design in the anterior mandible after a follow-up of one year. However, it may not be clinically noticeable.