Effect of drilling technique on the early integration of plateau root form endosteal implants: an experimental study in dogs

Short and Extra Short Dental Implants in Osseous Microvascular Free Flaps: A Retrospective Case Series

There is limited information regarding implant and prosthetic survival after osseous microvascular free flap (OMFF). This case series aims to describe the placement of short and extra short implants in osseous microvascular free flaps to support prostheses, and present an up to 40-month retrospective follow-up. Short and extra short dental implants were placed in six fibula free flaps (FFF) and in two microvascular deep circumflex iliac artery (DCIA) flaps. In total, 27 short and extra short dental implants have been placed into two different types of free flaps. Kaplan-Meyer (K-M) survival analyses were performed to evaluate the survival and success outcomes of implants and prostheses. Out of the eight patients reconstructed with free flap, five were rehabilitated with prostheses, one patient has a temporary prosthesis, and two patients are in the process of prosthetic rehabilitation. Twenty-seven implants were followed up for up to 40 months, and K-M analyses showed 100% implant survival probability (95% confidence interval: 100%), while the implant success probability was 91.0% (95% confidence interval: 68.6-97.7%). Short and extra short dental implants placed in OMFF presented high survival and success rates in a retrospective case series after up to 40 months.

Employing Indirect Adenosine 2A Receptors (A2AR) to Enhance Osseointegration of Titanium Devices: A Pre-Clinical Study

The present study aimed to evaluate the effect of dipyridamole, an indirect adenosine 2A receptors (A_2AR), on the osseointegration of titanium implants in a large, translational pre-clinical model. Sixty tapered, acid-etched titanium implants, treated with four different coatings ((i) Type I Bovine Collagen (control), (ii) 10 μM dipyridamole (DIPY), (iii) 100 μM DIPY, and (iv) 1000 μM DIPY), were inserted in the vertebral bodies of 15 female sheep (weight ~65 kg). Qualitative and quantitative analysis were performed after 3, 6, and 12 weeks in vivo to assess histological features, and percentages of bone-to-implant contact (%BIC) and bone area fraction occupancy (%BAFO). Data was analyzed using a general linear mixed model analysis with time in vivo and coating as fixed factors. Histomorphometric analysis after 3 weeks in vivo revealed higher BIC for DIPY coated implant groups (10 μM (30.42% ± 10.62), 100 μM (36.41% ± 10.62), and 1000 μM (32.46% ± 10.62)) in comparison to the control group (17.99% ± 5.82). Further, significantly higher BAFO was observed for implants augmented with 1000 μM of DIPY (43.84% ± 9.97) compared to the control group (31.89% ± 5.46). At 6 and 12 weeks, no significant differences were observed among groups. Histological analysis evidenced similar osseointegration features and an intramembranous-type healing pattern for all groups. Qualitative observation corroborated the increased presence of woven bone formation in intimate contact with the surface of the implant and within the threads at 3 weeks with increased concentrations of DIPY. Coating the implant surface with dipyridamole yielded a favorable effect with regard to BIC and BAFO at 3 weeks in vivo. These findings suggest a positive effect of DIPY on the early stages of osseointegration.

Osseointegration in relation to drilling speed in the preparation of dental implants sites: A systematic review

STATEMENT OF PROBLEM

The drilling speed used for preparing dental implants may affect bone-implant contact (BIC), implant stability quotient (ISQ), and bone area fraction occupancy (BAFO). Different rotational speeds and the presence or absence of irrigation during site preparation have been investigated, but an established protocol for achieving the best osseointegration results is lacking.

PURPOSE

The purpose of this systematic review was to investigate the influence of drill rotational speed on bone drilling for dental implant placement and its relationship with osseointegration.

MATERIAL AND METHODS

This review included the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and was registered in the international prospective register of systematic reviews (PROSPERO) database. Electronic searches were performed in the MEDLINE (PubMed), Scopus, Science Direct, and Embase databases. The risk of bias was analyzed by using the systematic review center for laboratory animal experimentation (SYRCLE).

RESULTS

A total of 1282 articles were found, and after removing duplicates and applying the eligibility criteria to in vivo articles on animals that addressed drilling speed and its relationship to osseointegration, 8 articles were selected for analysis. Of these, 5 articles showed no statistical differences, and 3 others showed significantly better osseointegration results by analyzing the parameters of BIC, BAFO, ISQs, and pull-out forces (PoFs). In all selected articles, high-speed drilling was performed with irrigation.

CONCLUSIONS

Although drilling speed seems to affect bone perforation, no definitive protocol was found in the literature consulted. The results vary depending on the combination of different factors, including bone type, irrigation, and drilling speed.

Evaluation of Change in Radiographic Fractal Dimension around Dental Implants Placed with Low-Speed Drilling and Standard Drilling Protocols

Osseointegration is a process that depends on a multitude of factors, including the type of drilling, whether biological or conventional. Objective: Establish box-counting dimension values for radiological images in patients with implants placed with both drilling methods. Material and method: The sample included 129 implants corresponding to 50 patients. A double-blind study of data collection was carried out with the subsequent analysis of the fractal dimension as a comparative value of the state of the trabecular architecture. Results: We found no significant differences (p ≥ 0.05) between the two study groups comparing both drilling techniques. The values for the conventional drilling technique are 0.24 ± 0.07 and for biological drilling: 0.19 ± 0.11 with a p-value of 0.767. Conclusions: The drilling technique does not influence the success of the procedure and the osseointegration process.

An Osteotomy Tool That Preserves Bone Viability: Evaluation in Preclinical and Clinical Settings

The main objectives of this work were to assess the efficiency, ease-of-use, and general performance of a novel osseoshaping tool based on first-user clinical experiences and to compare these observations with preclinical data generated in rodents using a miniaturized version of the instrument. All patients selected for the surgery presented challenging clinical conditions in terms of the quality and/or quantity of the available bone. The presented data were collected during the implant placement of 15 implants in 7 patients, and included implant recipient site (bone quality and quantity) and ridge evaluation, intra-operative handling of the novel instrument, and the evaluation of subsequent implant insertion. The instrument was easy to handle and was applied without any complications during the surgical procedure. Its use obviated the need for multiple drills and enabled adequate insertion torque in all cases. This biologically driven innovation in implant site preparation shows improvements in preserving vital anatomical and cellular structures as well as simplifying the surgical protocol with excellent ease-of-use and handling properties.

Radiographic comparisons of crestal bone levels around implants placed with low-speed drilling and standard drilling protocols: Preliminary results

Background

The present study aimed to investigate the mean crestal bone loss (CBL) by placing implants using two different drilling-protocols, i.e., standard drilling with saline irrigation and low-speed drilling without saline irrigation.

Material and Methods

The patients were enrolled in the present study from a university teaching institute. Patients who fulfilled the inclusion criteria were randomly placed in two study groups: 1) control group: Standard drilling with saline irrigation and 2) test group: low-speed drilling without saline irrigation. The radiographic mean crestal bone loss (CBL) was evaluated at 3 months of follow-up before implant loading. Data analysis was performed using SPSS 20.0 (IBM product, Chicago, USA) and a p-value ≤ 0.05 was considered statistically significant.

Results

Sixteen patients (10 males and 6 females) participated in the study. Thirty Camlog®-screw-line implants were placed (15 implants per study group). After 3 months of follow-up, the means CBL of implants placed with standard drilling and low-speed drilling protocols were 1.01 ± 0.49 mm and 0.74 ± 0.62 mm, respectively. No statistically significant difference could be recorded between two groups (p = 0.206).

Conclusions

Dental implants placed with low-speed drilling without saline irrigation exhibited a similar CBL to implants installed with the standard drilling protocol. However, further randomised clinical trials are recommended to obtain stronger evidence and a better understanding of the effect of the low-speed drilling protocol without saline irrigation on mean CBL and long-term implant survival.

Low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation: a systematic review

PURPOSE

This paper aims to review the evidence comparing low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation.

MATERIALS AND METHODS

A systematic review was carried out based on the PRISMA statement. Four databases and gray literature were searched up to November 2020. In vitro, animal, and clinical studies were included. The variables were temperature change, drilling time, quantity of harvested bone, osteotomy precision, marginal bone loss, implant success rate, osseointegration, and the histomorphologic characteristics and cellularity of the osteotomy and of the harvested bone. Different tools for the assessment of bias were applied for each study design.

RESULTS

A total of 626 articles were identified, of which 13 were included. Both low-speed drilling without irrigation (test group) and conventional drilling (control group) maintained temperatures below the critical temperature of 47 °C. The test group yielded a greater quantity and more beneficial cellular and histomorphologic properties of harvested bone, with a longer drilling time and greater osteotomy precision (p < 0.05). No significant results were obtained regarding drill wear, osseointegration, marginal bone loss, implant success rate, and histomorphology of the dental implant osteotomy (p > 0.05). The results, in particular on the osteotomy precision and quantity of harvested bone chips, should be interpreted with caution because outcomes are based in only one in vitro study.

CONCLUSIONS

Low-speed drilling without irrigation seems to be comparable to conventional drilling in preparing dental implant osteotomies. In some situations, low-speed drilling without irrigation might offer advantages over conventional drilling. The results should be interpreted with caution due to the low percentage of clinical human studies. Accordingly, more clinical studies are needed to improve the scientific evidence on this topic.

CLINICAL RELEVANCE

The low-speed drilling without irrigation is a valid technique for dental implant osteotomy preparation. Its higher quantity and quality of harvested autologous bone might be particularly beneficial in cases of dental implant placement with minor simultaneous bone regeneration.

Effect of Surgical Instrumentation Variables on the Osseointegration of Narrow- and Wide-Diameter Short Implants

PURPOSE

The aim of the present study was to systematically analyze how a multifactorial surgical instrumentation approach affects osseointegration on both narrow-diameter and wide-diameter short implants.

MATERIALS AND METHODS

Twelve skeletally mature female sheep were used in the study along with 144 plateau-root-form healing chamber titanium (Ti-6Al-4V) implants (Bicon LLC, Boston, MA), evenly distributed between narrow (3.5 mm) and wide (6.0 mm) diameters. The presence or the absence of irrigation, different drilling speeds, and 2 time points quantifying bone-implant contact (BIC) and bone area fraction occupancy (BAFO) to evaluate the osteogenic parameters around the implants.

RESULTS

There were no signs of inflammation, infection, or failure of the implants observed at either healing period. The narrow 3.5-mm implant, at 6 weeks, yielded significant differences in terms of BIC at a drilling speed of 50 rotations per minute (RPM), with higher values of the samples using irrigation (30.6 ± 6.1%) compared with those without (19.7 ± 6.1%). No statistical differences were detected for 500 and 1,000 RPM with or without irrigation. The wide 6-mm diameter implant showed differences with respect to drilling speed, 500 and 1,000 RPM, with higher values associated with samples subjected to irrigation. BAFO results, for both diameters, only detected statistical differences between the 2 times (3 vs 6 weeks); no statistical differences were detected when evaluating as a function of time, drilling speed, and irrigation.

CONCLUSIONS

Surgical instrumentation variables (ie, drilling speed [RPM] and irrigation) yielded to be more of an effect for BIC at longer healing time (6 weeks) for the wider implants. Furthermore, deploying narrow or wide plateau-root-form implants, where conditions allow, has shown to be a safe alternative, considering the high BIC and BAFO values observed, independent of irrigation.

Alveolar Ridge Expansion: Comparison of Osseodensification and Conventional Osteotome Techniques

OBJECTIVE

The aim of this in vivo study is to compare the osseointegration of endosteal implants placed in atrophic mandibular alveolar ridges with alveolar ridge expansion surgical protocol via an experimental osseodensification drilling versus conventional osteotome technique.

METHODS

Twelve endosteal implants, 4 mm × 13 mm, were placed in porcine models in horizontally atrophic mandibular ridges subsequent to prior extraction of premolars. Implants were placed with osseodensification drilling technique as the experimental group (n = 6) and osteotome site preparation as the control group (n = 6). After 4 weeks of healing, samples were retrieved and stained with Stevenel's Blue and Van Gieson's Picro Fuschin for histologic evaluation. Quantitative analysis via bone-to-implant contact (BIC%) and bone area fraction occupancy (BAFO%) were obtained as mean values with corresponding 95% confidence interval. A significant omnibus test, post-hoc comparison of the 2 drilling techniques' mean values was accomplished using a pooled estimate of the standard error with P-value set at 0.05.

RESULTS

The mean BIC% value was approximately 62.5% in the osseodensification group, and 31.4% in the regular instrumentation group. Statistical analysis showed a significant effect of the drilling technique (P = 0.018). There was no statistical difference in BAFO as a function of drilling technique (P = 0.198).

CONCLUSION

The combined osseodensification drilling-alveolar ridge expansion technique showed increased evidence of osseointegration and implant primary stability from a histologic and biomechanical standpoint, respectively. Future studies will focus on expanding the sample size as well as the timeline of the study to allow investigation of long-term prognosis of this novel technique.

A Novel Osteotomy Preparation Technique to Preserve Implant Site Viability and Enhance Osteogenesis

The preservation of bone viability at an osteotomy site is a critical variable for subsequent implant osseointegration. Recent biomechanical studies evaluating the consequences of site preparation led us to rethink the design of bone-cutting drills, especially those intended for implant site preparation. We present here a novel drill design that is designed to efficiently cut bone at a very low rotational velocity, obviating the need for irrigation as a coolant. The low-speed cutting produces little heat and, consequently, osteocyte viability is maintained. The lack of irrigation, coupled with the unique design of the cutting flutes, channels into the osteotomy autologous bone chips and osseous coagulum that have inherent osteogenic potential. Collectively, these features result in robust, new bone formation at rates significantly faster than those observed with conventional drilling protocols. These preclinical data have practical implications for the clinical preparation of osteotomies and alveolar bone reconstructive surgeries.

Accuracy of computer-guided implant placement in anterior regions

STATEMENT OF PROBLEM

Implant placement in the anterior regions is often challenging because of limited space and bone volume availability.

PURPOSE

The purpose of this clinical study was to investigate the accuracy of computer-guided surgery with a long drill key to place implants in the anterior regions.

MATERIAL AND METHODS

Computer-guided implant surgery was performed for 32 participants requiring implants in anterior regions. The procedure involved using a 12-mm-long drill key to guide the 2.0-mm-diameter drill. Deviations between the planned and actual implant positions were evaluated by using cone beam computed tomography (CBCT) scans obtained before and after surgery. A t test was used for comparisons between the planned and placed implants and to determine the influence of the arch (maxilla/mandible) and time (immediate/delayed) on accuracy.

RESULTS

A total of 40 implants (20 implants in the maxilla and 20 implants in the mandible) were placed. The mean linear deviation was 0.46 mm (range, 0 to 1.15 mm) for the implant shoulder and 0.67 mm (range, 0.14 to 1.19 mm) for the implant apex. The mean angular deviation was 1.40 degrees (range, 0.30 to 2.57 degrees). The mean depth deviation was 0.15 mm (range, 0.10 to 0.82 mm).

CONCLUSIONS

This clinical study showed that the accuracy of computer-guided implant placement may be enhanced by using a long drill key and may thus enable more accurate implant placement in anterior regions.

Effect of 2 Different Drilling Speeds on the Osseointegration of Implants Placed With Flapless Guided Surgery: A Study in Rabbits

OBJECTIVE

The aim of this study was to evaluate the influence of the drilling speed on bone healing and the osseointegration of implants placed with a guided flapless surgical technique in rabbit tibias.

METHODS

For the evaluation of bone healing, a total of 30 perforations (defects) were made in both tibias of 15 rabbits using 2 different drilling speeds (1500 rpm-control group; 50 rpm-test group). The regeneration of bone tissue in the surgical sites was evaluated at 0, 7, and 14 days. For the evaluation of implant osseointegration, another 15 rabbits underwent drilling in both tibias for implant placement. Thirty implants (3.75 × 10 mm) were placed to evaluate osseointegration at 4, 8, and 12 weeks after surgery.

RESULTS

Both groups showed a progressive healing of the defect, which involved the complete closure of the perforation. The osseointegration occurred in all groups with no statistically significant differences in the assessment of the osseointegration between the groups.

CONCLUSION

In the experimental models used, the drilling speed does not prejudice the pattern of bone healing and osseointegration of implants placed with guided flapless surgery.

The effect of osseodensification drilling for endosteal implants with different surface treatments: A study in sheep

This study investigated the effects of osseodensification drilling on the stability and osseointegration of machine-cut and acid-etched endosteal implants in low-density bone. Twelve sheep received six implants inserted into the ilium, bilaterally (n = 36 acid-etched, and n = 36 as-machined). Individual animals received three implants of each surface, placed via different surgical techniques: (1) subtractive regular-drilling (R): 2.0 mm pilot, 3.2 and 3.8 mm twist drills); (2) osseodensification clockwise-drilling (CW): Densah Bur (Versah, Jackson, MI) 2.0 mm pilot, 2.8, and 3.8 mm multifluted tapered burs; and (3) osseodensification counterclockwise-drilling (CCW) Densah Bur 2.0 mm pilot, 2.8 mm, and 3.8 mm multifluted tapered burs. Insertion torque was higher in the CCW and CW-drilling compared to the R-drilling (p < 0.001). Bone-to-implant contact (BIC) was significantly higher for CW (p = 0.024) and CCW-drilling (p = 0.006) compared to the R-drilling technique. For CCW-osseodensification-drilling, no statistical difference between the acid-etched and machine-cut implants at both time points was observed for BIC and BAFO (bone-area-fraction-occupancy). Resorbed bone and bone forming precursors, preosteoblasts, were observed at 3-weeks. At 12-weeks, new bone formation was observed in all groups extending to the trabecular region. In low-density bone, endosteal implants inserted via osseodensification-drilling presented higher stability and no osseointegration impairments compared to subtractive regular-drilling technique, regardless of evaluation time or implant surface. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 615-623, 2019.

Osteogenic potential of three different autogenous bone particles harvested during implant surgery

OBJECTIVES

The aim was to compare the osteoblast activity and osteogenic potential of autogenous bone particles harvested using three different techniques and determine the most advantageous method of collecting autogenous bone particles.

SUBJECTS AND METHODS

Bone particles were harvested from 20 patients during dental implant surgery using bone scraping, low-speed drilling and bone trap filtering. After the osteoblasts were cultured, cell proliferation, migration, mineralization, transcription of osteogenesis-related genes, secretion of osteogenesis-related proteins and osteoinductive protein content in the bone particle matrix were evaluated.

RESULTS

Osteoblast activity and osteogenic potential were higher in bone samples harvested by scraper or low-speed drilling than in samples harvested by bone trap filter. Although these parameters were slightly lower in the low-speed drilling group than in the scraper group, significant differences were found only in bone Gla protein levels. However, the levels of osteoinductive proteins in the bone particle matrix were significantly higher in the low-speed drilling group than in the scraper group.

CONCLUSIONS

Low-speed drilling is a recommendable and effective technique for collecting autogenous bone particles. In implant operations, low-speed drilling can be considered the first-line option, and if the quantity of harvested bone is insufficient, bone shavings obtained by the scraper may be considered.

Biophysical regulation of osteotomy healing: An animal study

BACKGROUND

Osteotomies have been performed for centuries yet there remains a remarkable lack of consensus on optimal methods for cutting bone. There is universal agreement, however, that preserving cell viability is critical.

PURPOSE

To identify mechanobiological parameters influencing bone formation after osteotomy site preparation.

MATERIALS AND METHODS

A murine maxillary osteotomy model was used to evaluate healing. Computational modeling characterized stress and strain distributions in the osteotomy, as well as the magnitude and distribution of heat generated by drilling. The impact of osteocyte death and bone composition were assessed using molecular and cellular assays.

RESULTS

The phases of osteotomy healing in mice align closely with results in large animals; in addition, molecular analyses extended our understanding of osteoprogenitor cell proliferation, differentiation, and mineralization. Computational analyses provided insights into temperature changes caused by drilling and the mechanobiological state in the healing osteotomies, while concomitant cellular assays correlate drill speed with osteocyte apoptosis and bone resorption. Even when drilling was controlled, trabeculated, spongy (Type III) bone healed faster than densely lamellar (Type I) bone because of the abundance of Wnt responsive osteoprogenitor cells in the former.

CONCLUSIONS

These data provide a mechanobiological framework for evaluating tools and technologies designed to improve osteotomy site preparation.

Osseodensification for enhancement of spinal surgical hardware fixation

Integration between implant and bone is an essential concept for osseous healing requiring hardware placement. A novel approach to hardware implantation, termed osseodensification, is described here as an effective alternative. 12 sheep averaging 65kg had fixation devices installed in their C2, C3, and C4 vertebral bodies; each device measured 4mm diameter×10mm length. The left-sided vertebral body devices were implanted using regular surgical drilling (R) while the right-sided devices were implanted using osseodensification drilling (OD). The C2 and C4 vertebra provided the t=0 in vivo time point, while the C3 vertebra provided the t=3 and t=6 week time points, in vivo. Structural competence of hardware was measured using biomechanical testing of pullout strength, while the quality and degree of new bone formation and remodeling was assessed via histomorphometry. Pullout strength demonstrated osseodensification drilling to provide superior anchoring when compared to the control group collapsed over time with statistical significance (p<0.01). On Wilcoxon rank signed test, C2 and C4 specimens demonstrated significance when comparing device pullout (p=0.031) for both, and C3 pullout tests at 3 and 6 weeks collapsed over time had significance as well (p=0.027). Percent bone-to-implant contact (%BIC) analysis as a function of drilling technique demonstrated an OD group with significantly higher values relative to the R group (p<0.01). Similarly, percent bone-area-fraction-occupancy (BAFO) analysis presented with significantly higher values for the OD group compared to the R group (p=0.024). As a function of time, between 0 and 3 weeks, a decrease in BAFO was observed, a trend that reversed between 3 and 6 weeks, resulting in a BAFO value roughly equivalent to the t=0 percentage, which was attributed to an initial loss of bone fraction due to remodeling, followed by regaining of bone fraction via production of woven bone. Histomorphological data demonstrated autologous bone chips in the OD group with greater frequency relative to the control, which acted as nucleating surfaces promoting new bone formation around the implants, providing superior stability and greater bone density. This alternative approach to a critical component of hardware implantation encourages assessment of current surgical approaches to hardware implantation.

Biomechanical and histologic basis of osseodensification drilling for endosteal implant placement in low density bone. An experimental study in sheep

A bone drilling concept, namely osseodensification, has been introduced for the placement of endosteal implants to increase primary stability through densification of the osteotomy walls. This study investigated the effect of osseodensification on the initial stability and early osseointegration of conical and parallel walled endosteal implants in low density bone. Five male sheep were used. Three implants were inserted in the ilium, bilaterally, totaling 30 implants (n=15 conical, and n=15 parallel). Each animal received 3 implants of each type, inserted into bone sites prepared as follows: (i) regular-drilling (R: 2mm pilot, 3.2mm, and 3.8mm twist drills), (ii) clockwise osseodensification (CW), and (iii) counterclockwise (CCW) osseodensification drilling with Densah Bur (Versah, Jackson, MI, USA): 2.0mm pilot, 2.8mm, and 3.8mm multi-fluted burs. Insertion torque as a function of implant type and drilling technique, revealed higher values for osseodensification relative to R-drilling, regardless of implant macrogeometry. A significantly higher bone-to-implant contact (BIC) for both osseodensification techniques (p<0.05) was observed compared to R-drilling. There was no statistical difference in BIC as a function of implant type (p=0.58), nor in bone-area-fraction occupancy (BAFO) as a function of drilling technique (p=0.22), but there were higher levels of BAFO for parallel than conic implants (p=0.001). Six weeks after surgery, new bone formation along with remodeling sites was observed for all groups. Bone chips in proximity with the implants were seldom observed in the R-drilling group, but commonly observed in the CW, and more frequently under the CCW osseodensification technique. In low-density bone, endosteal implants present higher insertion torque levels when placed in osseodensification drilling sites, with no osseointegration impairment compared to standard subtractive drilling methods.

The effect of low-speed drilling without irrigation on heat generation: an experimental study

OBJECTIVES

In this study we evaluated heat generation during the low-speed drilling procedure without irrigation.

MATERIALS AND METHODS

Ten artificial bone blocks that were similar to human D1 bone were used in this study. The baseline temperature was 37.0℃. We drilled into 5 artificial bone blocks 60 times at the speed of 50 rpm without irrigation. As a control group, we drilled into an additional 5 artificial bone blocks 60 times at the speed of 1,500 rpm with irrigation. The temperature changes during diameter 2 mm drilling were measured using thermocouples.

RESULTS

The mean maximum temperatures during drilling were 40.9℃ in the test group and 39.7℃ in the control group. Even though a statistically significant difference existed between the two groups, the low-speed drilling did not produce overheating.

CONCLUSION

These findings suggest that low-speed drilling without irrigation may not lead to overheating during drilling.

Implant design and its effects on osseointegration over time within cortical and trabecular bone

Healing chambers present at the interface between implant and bone have become a target for improving osseointegration. The objective of the present study was to compare osseointegration of several implant healing chamber configurations at early time points and regions of interest within bone using an in vivo animal femur model. Six implants, each with a different healing chamber configuration, were surgically implanted into each femur of six skeletally mature beagle dogs (n = 12 implants per dog, total n = 72). The implants were harvested at 3 and 5 weeks post-implantation, non-decalcified processed to slides, and underwent histomorphometry with measurement of bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within healing chambers at both cortical and trabecular bone sites. Microscopy demonstrated predominantly woven bone at 3 weeks and initial replacement of woven bone by lamellar bone by 5 weeks. BIC and BAFO were both significantly increased by 5 weeks (p < 0.001), and significantly higher in cortical than trabecular bone (p < 0.001). The trapezoidal healing chamber design demonstrated a higher BIC than other configurations. Overall, a strong temporal and region-specific dependence of implant osseointegration in femurs was noted. Moreover, the findings suggest that a trapezoidal healing chamber configuration may facilitate the best osseointegration. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1091-1097, 2016.

The effect of simplifying dental implant drilling sequence on osseointegration: an experimental study in dogs

Objectives. To test the hypothesis that there would be no differences in osseointegration by reducing the number of drills for site preparation relative to conventional drilling sequence. Methods. Seventy-two implants were bilaterally placed in the tibia of 18 beagle dogs and remained for 1, 3, and 5 weeks. Thirty-six implants were 3.75 mm in diameter and the other 36 were 4.2 mm. Half of the implants of each diameter were placed under a simplified technique (pilot drill + final diameter drill) and the other half were placed under conventional drilling where multiple drills of increasing diameter were utilized. After euthanisation, the bone-implant samples were processed and referred to histological analysis. Bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) were assessed. Statistical analyses were performed by GLM ANOVA at 95% level of significance considering implant diameter, time in vivo, and drilling procedure as independent variables and BIC and BAFO as the dependent variables. Results. Both techniques led to implant integration. No differences in BIC and BAFO were observed between drilling procedures as time elapsed in vivo. Conclusions. The simplified drilling protocol presented comparable osseointegration outcomes to the conventional protocol, which proved the initial hypothesis.

Osseointegration assessment of chairside argon-based nonthermal plasma-treated Ca-P coated dental implants

This study investigated the effect of an Argon-based nonthermal plasma (NTP) surface treatment-operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: Calcium-Phosphate (CaP) and CaP + NTP (CaP-Plasma). Surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and chemistry by X-ray photoelectron spectroscopy (XPS). Six adult beagles dogs received 2 plateau-root form implants (n = 1 each surface) in each radii, providing implants that remained 1 and 3 weeks in vivo. Histometric parameters assessed were bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed by Kruskall-Wallis (95% level of significance) and Dunn's post-hoc test. The XPS analysis showed peaks of Ca, C, O, and P for the CaP and CaP-Plasma surfaces. Both surfaces presented carbon primarily as hydrocarbon (C-C, C-H) with lower levels of oxidized carbon forms. The CaP surface presented atomic percent values of 38, 42, 11, and 7 for C, O, Ca, and P, respectively, and the CaP-Plasma presented increases in O, Ca, and P atomic percent levels at 53, 12, and 13, respectively, in addition to a decrease in C content at 18 atomic percent. At 1 week no difference was found in histometric parameters between groups. At 3 weeks significantly higher BIC and BAFO were observed for CaP-Plasma treated surfaces. Surface elemental chemistry was modified by the Ar-based NTP. Ar-based NTP improved bone formation around plateau-root form implants at 3 weeks compared with CaP treatment alone.

Argon-based atmospheric pressure plasma enhances early bone response to rough titanium surfaces

This study investigated the effect of an Argon-based atmospheric pressure plasma (APP) surface treatment operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: rough titanium surface (Ti) and rough titanium surface + Argon-based APP (Ti-Plasma). Surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and chemistry by X-ray photoelectron spectroscopy (XPS). Six adult beagles dogs received two plateau-root form implants (n = 1 each surface) in each radii, providing implants that remained 1 and 3 weeks in vivo. Histometric parameters assessed were bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed by Kruskall-Wallis (95% level of significance) and Dunn's post-hoc test. The XPS analysis showed peaks of Ti, C, and O for the Ti and Ti- Plasma surfaces. Both surfaces presented carbon primarily as hydrocarbon (C-C, C-H) with lower levels of oxidized carbon forms. The Ti-Plasma presented large increase in the Ti (+11%) and O (+16%) elements for the Ti- Plasma group along with a decrease of 23% in surface-adsorbed C content. At 1 week no difference was found in histometric parameters between groups. At 3 weeks significantly higher BIC (>300%) and mean BAFO (>30%) were observed for Ti-Plasma treated surfaces. From a morphologic standpoint, improved interaction between connective tissue was observed at 1 week, likely leading to more uniform and higher bone formation at 3 weeks for the Ti-Plasma treated implants was observed.