Figure 6. Control group. Some implant thread areas were not covered by bone layer (magnification × 25—toluidine blue)
Figure 6. Control group. Some implant thread areas were not covered by bone layer (magnification × 25—toluidine blue)
Figure 5. Control group. Implants belonging to the control group showed some small surface areas not contacted with bone (magnification × 25—toluidine blue)
Figure 5. Control group. Implants belonging to the control group showed some small surface areas not contacted with bone (magnification × 25—toluidine blue)
Figure 4. Control group. No bone condensation was possible with traditional burs and standard implant (magnification × 25—toluidine blue)
Figure 4. Control group. No bone condensation was possible with traditional burs and standard implant (magnification × 25—toluidine blue)
Figure 3. Test group. The present histological photo showed a continuous thin layer of newly formed bone along the neck area of the implant (magnification × 25—toluidine blue)
Figure 3. Test group. The present histological photo showed a continuous thin layer of newly formed bone along the neck area of the implant (magnification × 25—toluidine blue)
Figure 2. Test group. Implants in the test group showed an extremely high percentage of bone directly contacted to implant surface (magnification × 25—toluidine blue)
Figure 2. Test group. Implants in the test group showed an extremely high percentage of bone directly contacted to implant surface (magnification × 25—toluidine blue)
Figure 1. Test group. The implant achieved a high osseointegration degree. The newly formed bone appeared well interconnected with the pre-existing trabeculae. The “corticalization” phenomenon is evident: the bone appears densified around a titanium implant (magnification × 8—toluidine blue)
Figure 1. Test group. The implant achieved a high osseointegration degree. The newly formed b...
BIC%P < 0.05BV%P < 0.05VamP < 0.05Reverse torqueP > 0.05 NsISQP < 0.05Table 3 Statistical comparison (T test) of examined parameters between the test and control groups. The histomorphometric analysis demonstrated significant differences in BIC% and %BV values between the two implant groups
Implant typeBIC%BV%Vam (μm) ± SDReverse torque (N/cm) ± SDISQ value ± SDTest group70.91 ± 7.9541.83 ± 6.3082.6 ± 23.2798.2 ± 16.8163.5 ± 1.30Control group49.33 ± 10.7329.61 ± 5.0560.5 ± 16.5898.8 ± 24.4059.4 ± 1.39Table 2 Mean values of histomorphometric parameters (%BIC and %BV) and biomechanical values (VAM, reverse torque, and ISQ) of each implant group
Basal %BV 26.17 ± 2.35Test groupControl group 41.83 ± 6.30*29.61 ± 5.05Table 1 Basal bone volume percentage (basal %BV) was compared to %BV around implants after 2 months of healing in both groups. %BV in the test group was significantly higher than basal %BV (P < 0.05)
Trisi, P., Falco, A. & Berardini, M. Single-drill implant induces bone corticalization during submerged healing: an in vivo pilot study. Int J Implant Dent 6, 2 (2020). https://doi.org/10.1186/s40729-019-0198-y
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Received: 30 August 2019
Accepted: 04 December 2019
Published: 15 January 2020
DOI: https://doi.org/10.1186/s40729-019-0198-y
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The Ethics Committee for Animal Research of the Veterinary School of the University of Teramo (Teramo, Italy) approved the study protocol with the protocol number 8110.
The Ethics Committee for Animal Research of the Veterinary School of the University of Teramo (Teramo, Italy) approved the study protocol with the protocol number 8110.
The authors declare that they have no competing interests.
Biomaterial Clinical and Histological Research Association, Private Practice, Via Galilei 8, 65122, Pescara, Italy
Paolo Trisi, Antonello Falco & Marco Berardini
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PT contributed to the study design, animal s...
No grants were received for the present study.
The authors wish to thank Cortex® Dental Implants (Shlomi, Israel) and NoDrill® (Milano, Italy) for providing the implants used in the present study.
Gehrke SA, Bettach R, Aramburú Júnior JS, Prados-Frutos JC, Del Fabbro M, Shibli JA. Peri-Implant Bone Behavior after Single Drill versus Multiple Sequence for Osteotomy Drill. Biomed Res Int. 2018;11:2018.
Möhlhenrich SC, Abouridouane M, Heussen N, Hölzle F, Klocke F, Modabber A. Thermal evaluation by infrared measurement of implant site preparation between single and gradual drilling in art...
Summers RB. A new concept in maxillary implant surgery: the osteotome technique. Compendium. 1994;15:152–6.
Büchter A, Kleinheinz J, Wiesmann HP, et al. Biological and biomechanical evaluation of bone remodelling and implant stability after using an osteotome technique. Clin Oral Implants Res. 2005;16:1–8.
Stavropoulos A, Nyengaard JR, Lang NP, et al. Immediate loading of single SLA implant...
Albrektsson T, Brånemark PI, Hansson HA, et al. Osseointegrated titanium implants. Requirements for ensuring a long-lasting, direct bone-to-implant anchorage in man. Acta Orthop Scand. 1981;52(2):155–70.
Molly L. Bone density and primary stability in implant therapy. Clin Oral Implants Res. 2006;2:124–35.
Chong L, Khocht A, Suzuki JB, et al. Effect of implant design on initial stability of ...
All data and materials are available from the corresponding author in Pescara, Italy.
The hypothesis was accepted. Compressing implants with single-drill bone preparation demonstrated many clinical and histological advantages with respect with to standard implant drilling procedures and classical implant shape and design in low-density bone type. It is possible to summarize the advantages of this technique as follows: higher bone to implant contact percentage than the control group...
The comparison between the basal %BV and %BV in the test group revealed that these innovative implants were able to increase in a significant way the peri-implant bone density with respect to starting host bone density. This increased peri-implant bone density extended from about 0.5–0.7 mm beyond the implant perimeter causing an osseocorticalization around the fixture profile.
A recent study [...
Results from the present study clearly show that it is possible to insert an implant using a one-step concept for the surgical preparation of the bone bed in cancellous bone.
Guazzi et al. [24], comparing the clinical outcome of implants inserted in sites prepared with a simplified protocol consisting of one large single drill versus multiple conventional drilling steps, demonstrated less surgica...
No implant failure was observed after 2 months of healing. The clinical examination, done immediately after the bone block retrieval, showed no crestal bone resorption. No bone defects around implants, such as fenestration or dehiscence, were detected. The host bone density expressed in bone volume percentage (basal %BV) was 26.17 ± 2.35. This low value of BV% is common in soft bone, according to...
Specimens were immediately fixed in 10% neutral buffered formalin and processed for histologic analysis. After dehydration, samples were infiltrated with a methyl-methacrylate resin from a starting solution 50% ethanol/resin and subsequently 100% resin, with each step lasting 24 h. After polymerization, the blocks were sectioned and then ground down to about 40 μm. Toluidine blue staining was use...
After implant insertion, cover screws were secured and the surgical wounds were closed by a resorbable periosteal-muscular inner suture, followed by an external cutaneous 2-0 silk suture.
Each animal underwent systemic antibiotic therapy for 5 days with 8 ml long-acting Clamoxil (Pfizer Limited, Sandwich, USA). After surgery, animals received appropriate veterinary care and were allowed free acce...
The Ethics Committee for Animal Research of the Veterinary School of the University of Teramo (Teramo, Italy) approved the study protocol, which followed the guidelines established by the European Union Council Directive of February 2013 (R.D.53/2013).
Two female sheep, 4–5 years old, were included in the study. Clinical examination determined that all animals were in good general health. Exclu...
The aim of the present paper is to evaluate a reduced implant site preparation technique to preserve bone bulk and enhance primary stability using a new conical self-tapping implant in cancellous type IV bone. A histologic, histomorphometric, and biomechanical comparative analysis was conducted in low-density bone of the sheep’s iliac crest. The hypothesis to test is if undersized preparation an...
It is well documented that implant initial bone fixation, known as primary implant stability, represents the pre-requisite to achieve a successful long-term osseointegration [1].
Many studies demonstrated that the implant primary stability is strictly influenced by host bone density [2], fixture geometry [3, 4], and surgical technique used for preparing bone implant bed [5]. Other studies [6, 7] ...
The aim of the present paper is to evaluate a simplified implant site preparation technique to preserve bone bulk and enhance osseointegration using a new conical self-tapping implant in cancellous bone.
Ten Expander® 3.8 × 10 mm implants (NoDrill®, Milano, Italy) were inserted in the right side (test group) of sheep’s iliac crest using only the pilot drill 1.8 mm in diameter. Ten 3.8 × 10 ...
Code
IT(N•cm)
RT(N•cm)
ISQ
12S
13.67 (1.88)
11.68 (1.06)
51.40 (2.95)
06D
20.19 (1.61)
17.45 (1.28)
53.77 (2.73)
06S
22.30 (1.78)
20.25 (2.47)
55.66(1.62)
Implant code
Thread type
Pitch (mm)
Lead (mm)
Lead angle (degree)
Total thread length (mm)
12S
Single-threaded
1.2
1.2
8.1
64
06D
Double-threaded
0.6
1.2
8.1
129
06S
Single-threaded
0.6
0.6
4.65
129
Figure 6. Bone debris at the contact interfaces. a Numbers of debris particles. b Number and size of debris particles. Each dot indicates a debris particle, and dashes indicate median particle sizes. Particle sizes: small, < 1000 μm2; medium, 1000–10000 μm2, and large, ≥ 10,000 μm2. c Particle size distribution
Figure 5. Microscopic analysis of contact interfaces. Microscopic observations of the artificial bone-implant and number of debris particles. The small arrows in the panel indicate voids in the implant-bone interface
Figure 4. Torque kinetics. Immediately after insertion terminated, the implant was removed using the same load and rotation speed. Torque kinetics were measured during implant insertion (top) and removal (bottom)
Figure 3. Comparison between IT and RT. Maximum IT value was measured when insertion was terminated. Immediately after insertion, the implant was removed, and the RT value was measured when removal commenced
Figure 2. Insertion torque (IT), removal torque (RT), and implant stability quotient (ISQ)
Figure 1. Implants. Implant code 12S is similar to a commercially available standard single-threaded implant with equal thread pitch and a 1.2-mm lead. The thread length of implant code 06D is doubled by adding the second thread (light blue). The thread length of implant code 06S is doubled by a 50% reduction in pitch and lead angles. Characteristics of each implant are summarized in Table 1
Fi...
References
Javed F, Ahmed HB, Crespi R, Romanos GE. Role of primary stability for successful osseointegration of dental implants: factors of influence and evaluation. Interv Med Appl Sci. 2013;5:162–7.
Falco A, Berardini M, Trisi P. Correlation between implant geometry, implant surface, insertion torque, and primary stability: in vitro biomechanical analysis. Int J Oral Maxillofac Implan...
Although bone models composed of a combination of cortical and cancellous bone are also available, this study used a single bone model with a homogeneous density to eliminate any effect of cortical bone and evaluate only the effect of design features on torque and ISQ values.
Experimental implant placement using artificial bone models is generally conducted to si...
Clinicians are advised to recognize the risk associated with using a multithreaded implant with a high lead angle, which may compromise primary stability because of greater bone tissue damage despite faster insertion. The question of placement speed warrants further consideration. Indeed, another advantage of double-threaded implants is placement speed. The implantation speed...
Moreover, the IT and RT values of 12S were consistent with those of the standard implant (Straumann) measured in our previous study. Here, the RT value of each implant was lower compared with their respective IT values, consistent with other reports. The IT and RT values of 06S were highest, followed by 06D and 12S. In contrast, the differences between RT and IT values were highest for...
In the artificial bone adjacent to 06D, there were more voids compared with those associated with 06S or 12S, which accounts for the increase in torque. The highest numbers and larger sizes of debris particles were associated with 06D, followed by 0S and 12S, indicating the potential for greater tissue damage. These results likely explain the lower (50%) torque value of 06S compared with tho...
Discussion
We show here that increasing thread length and reducing pitch can increase primary implant stability without changing the size of an implant. Compared with the standard single-threaded implant with a 1.2-mm pitch/lead (12S), torque values and ISQ were significantly increased by doubling the thread length by adding the second thread (06D) or by reducing pitch/lead and lead angle o...
Results
The IT, RT, and ISQ values revealed significant differences among the implants (Table 2).
The IT and RT values of 12S were not significantly different compared with published data (IT, 13.13 ± 1.763 N cm; RT, 12.37 ± 1.746 N cm) (Student t test, df = 9, t = 2.91, p < .017). Compared with 12S, the IT and RT values of 06D and 06S were significantly different (147% and 150%, a...
Methods
Implants
Three types of grade-4 titanium cylindrical nonself-tapping implants (codes 12S, 06D, and 06S) were specially designed and manufactured (Suwa Co., Ltd., Fujiyoshida, Yamanashi, Japan) (Fig. 1 and Table 1). The code 12S single-threaded implant served as a reference. Codes 06D and 06S were designed to double the thread length compared to 12S. Code 06D was a double-threated impla...
Introduction
Secure primary stability is positively associated with successful long-term implant integration to ensure a successful clinical outcome. Initial implant stability is defined as biomechanical stability upon insertion, which is influenced by factors such as bone quantity and quality, geometry of the implant, surgical technique, and insertion torque (IT). New bone develops around the ...
Effects of implant thread design on primary stability—a comparison between single- and double-threaded implants in an artificial bone model
Abstract
Background
Primary implant stability is essential for osseointegration. To increase stability without changing the implant size, the thread length must be extended by reducing pitch, using a double-threaded implant, or reducing pitch/lead a...
Figure 6. Bone debris at the contact interfaces. a Numbers of debris particles. b Number and size of debris particles. Each dot indicates a debris particle, and dashes indicate median particle sizes. Particle sizes: small, < 1000 μm2; medium, 1000–10000 μm2, and large, ≥ 10,000 μm2. c Particle size distribution
Figure 5. Microscopic analysis of contact interfaces. Microscopic observations of the artificial bone-implant and number of debris particles. The small arrows in the panel indicate voids in the implant-bone interface
Figure 4. Torque kinetics. Immediately after insertion terminated, the implant was removed using the same load and rotation speed. Torque kinetics were measured during implant insertion (top) and removal (bottom)
Figure 2. Insertion torque (IT), removal torque (RT), and implant stability quotient (ISQ)
Table 2. Implants. Implant code 12S is similar to a commercially available standard single-threaded implant with equal thread pitch and a 1.2-mm lead. The thread length of implant code 06D is doubled by adding the second thread (light blue). The thread length of implant code 06S is doubled by a 50% reduction in pitch and lead angles. Characteristics of each implant are summarized in Table 1....
Code
IT(N•cm)
RT(N•cm)
ISQ
12S
13.67 (1.88)
11.68 (1.06)
51.40 (2.95)
06D
20.19 (1.61)
17.45 (1.28)
53.77 (2.73)
06S
22.30 (1.78)
20.25 (2.47)
55.66(1.62)
Implant code
Thread type
Pitch (mm)
Lead (mm)
Lead angle (degree)
Total thread length (mm)
12S
Single-threaded
1.2
1.2
8.1
64
06D
Double-threaded
0.6
1.2
8.1
129
06S
Single-threaded
0.6
0.6
4.65
129
The question of placement speed warrants further consideration. Indeed, another advantage of double-threaded implants is placement speed. The implantation speed of 06D was twice that of 06S, and implantation was completed twice as fast. Nevertheless, while plastic bottles and emergency valves have double-threaded screws for faster opening and closing, the effect...
Here, the RT value of each implant was lower compared with their respective IT values, consistent with other reports. The IT and RT values of 06S were highest, followed by 06D and 12S. In contrast, the differences between RT and IT values were highest for 12S, followed by 06D, and in 06S. We reported that the RT decreased more than IT. Thus, 06S had the lowest rate of decline (IT...
In the artificial bone adjacent to 06D, there were more voids compared with those associated with 06S or 12S, which accounts for the increase in torque. The highest numbers and larger sizes of debris particles were associated with 06D, followed by 0S and 12S, indicating the potential for greater tissue damage. These results likely explain the lower (50%) torque value of 06S compared wi...
In the artificial bone adjacent to 06D, there were more voids compared with those associated with 06S or 12S, which accounts for the increase in torque. The highest numbers and larger sizes of debris particles were associated with 06D, followed by 0S and 12S, indicating the potential for greater tissue damage. These results likely explain the lower (50%) torque value of 06S compared wi...
Discussion
We show here that increasing thread length and reducing pitch can increase primary implant stability without changing the size of an implant. Compared with the standard single-threaded implant with a 1.2-mm pitch/lead (12S), torque values and ISQ were significantly increased by doubling the thread length by adding the second thread (06D) or by reducing pitch/lead and lead angle o...
Results
The IT, RT, and ISQ values revealed significant differences among the implants (Table 2).
The IT and RT values of 12S were not significantly different compared with published data (IT, 13.13 ± 1.763 N cm; RT, 12.37 ± 1.746 N cm) (Student t test, df = 9, t = 2.91, p < .017). Compared with 12S, the IT and RT values of 06D and 06S were significantly different (147% and 150%, a...
Implants
Three types of grade-4 titanium cylindrical nonself-tapping implants (codes 12S, 06D, and 06S) were specially designed and manufactured (Suwa Co., Ltd., Fujiyoshida, Yamanashi, Japan) (Fig. 1 and Table 1). The code 12S single-threaded implant served as a reference. Codes 06D and 06S were designed to double the thread length compared to 12S. Code 06D was a double-threated implant with t...
Unfortunately, the effects of double- or triple-threaded implants on primary stability are known for only a few procedures, such as finite element analysis. An excessive lead angle for these implants may jeopardize their ability to sustain axial load despite faster insertion. Further, when micromotion is compared among implants with different lead angles with the same thread pitch, single-threaded...
Introduction
Secure primary stability is positively associated with successful long-term implant integration to ensure a successful clinical outcome. Initial implant stability is defined as biomechanical stability upon insertion, which is influenced by factors such as bone quantity and quality, geometry of the implant, surgical technique, and insertion torque (IT). New bone develops around the ...
Abstract
Background
Primary implant stability is essential for osseointegration. To increase stability without changing the implant size, the thread length must be extended by reducing pitch, using a double-threaded implant, or reducing pitch/lead and lead angle to half that of a single-threaded implant.
Materials and methods
We tested the stabilities of these configurations using artificial...