Use of dental implants has become a widespread and predictable treatment modality for the restoration of missing teeth and various edentulous cases [
In addition to considering the primary implant stability a critical factor when immediate loading is planned [
One of the surgical techniques suggested to enhance the primary stability of implant in bone of low density is the undersized drilling technique, which has been introduced to locally optimize the bone density by using a final drill diameter considerably smaller compared with the implant diameter [
In addition to conventional surgical preparation techniques, the piezoelectric bone surgery [
The use of low-level lasers has also been suggested as another way of accelerating and improving the bone tissue healing process [
Nowadays, various computer-assisted systems comprising a three-dimensional virtual planning by means of a computer tomography (CT) or digital volume tomogram suggest a flapless procedure [
Different clinical methods for monitoring implant stability at various stages have been proposed, such as Periotest (Siemens AG, Bensheim, Germany), Dental Fine Tester (Kyocera, Kyoto, Japan), Osstell Mentor (Osstell AB, Stampgatan, Göteborg, Sweden), and the cutting-torque or insertion torque (IT) measurement [
Considering that the surgical technique might influence the primary and secondary stability of dental implants, the aim of this systematic review was to investigate the influence of different surgical techniques including the undersized drilling, the osteotome, the piezosurgery, the flapless procedure, and the bone stimulation by low-level laser therapy on the primary and/or secondary stability of dental implants.
The present systematic review was focused on this question: is there scientific evidence to support the influence of these surgical techniques on the primary and/or secondary stability of dental implants?
The inclusion criteria comprised observational clinical studies and randomized controlled trials (RCTs) conducted in patients who received dental implants for rehabilitation, studies that evaluated the association between the surgical technique (prognostic factor) and implant primary and/or secondary stability (outcome). Surgical techniques evaluated were the underdrilling technique, osteotome technique, piezosurgery, flapless technique, and the low-level laser therapy. Dental implant stability was evaluated by ISQ value (Osstell, Integration Diagnostics, Gothenburg, Sweden), PTV value (Periotest, Medizintechnik Gulden, Modautal, Germany), or IT measurement. Secondary implant stability should be recorded at least three months after implant placement. Studies that reported surgical technique and implant stability but did not verify their association were excluded from this systematic review.
For the identification of the clinical studies to be considered in this review, combinations of the following keywords were used: “dental implants,” “implant stability,” “primary stability,” “secondary stability,” “implant stability quotient,” “ISQ,” “resonance frequency analysis,” “RFA,” “Osstell,” “Periotest value,” “PTV,” “Periotest,” “osteotome technique,” “undersized drilling,” “piezosurgery,” “surgical technique,” “flap implant placement,” and “flapless implant placement.”
A search of health science databases (Cochrane Library and MEDLINE-PubMed) and grey literature was performed, including papers published until May 2013. The most recent electronic search was undertaken on 15 May 2013.
Only articles in English were included in this review.
The titles and abstracts (when available) of all articles identified through the electronic searches were scanned independently by at least two review authors. For studies appearing to meet the inclusion criteria, or for which there were insufficient data in the title and abstract to make a clear decision, the full report was obtained. The full reports were assessed independently by at least two review authors to establish whether they met the inclusion criteria or not. Disagreements were resolved by discussion. All studies meeting the inclusion criteria then underwent quality assessment and data extraction. Studies rejected at this or subsequent stages were recorded in the “flow diagram of literature review,” and reasons for exclusion were recorded.
Data were extracted by at least two review authors independently using specially designed data extraction form. Any disagreement was discussed and a third review author was consulted where necessary (Figure
Flow diagram of literature review.
For each study, the following data were extracted (Table Year of publishing, country of conducting the study, sample size, and number of implants. Implant dimensions, surface treatment, and implant manufacturer. Arch region of implant insertion and the surgical technique used. Primary stability ISQ or IT values and association between primary stability and surgical technique. Confounders included in analysis. Secondary stability ISQ or IT values and association between secondary stability and surgical technique.
Author and year | Geographical location | Sample | Implant dimensions (mm) and surface | Number of implants | Implant and manufacturer |
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Padmanabhan and Gupta 2010 [ |
India | Number: 5 |
Length: 13 |
10 | Uniti (Equinox Medical Technologies) |
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Shayesteh et al. 2013 [ |
Iran | Number: 30 |
length: 10, 12 |
46 | SLA oral implants (Straumann AG) |
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Marković et al. 2013 [ |
Belgrade | Number: 53 |
Length: 10 |
102 | 51 self-tapping BlueSky (Bredent), |
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Turkyilmaz et al. 2008 [ |
Turkey | Number: 22 |
Lengths: 10, 11.5 |
60 | TiUnite Mk III (Nobel Biocare) |
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Alghamdi et al. 2011 [ |
Saudi Arabia | Number: 29 |
Length: 12 |
52 | Standard Plus |
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Stacchi et al. 2013 [ |
Italy | Number: 20 |
Length: 10 mm |
40 | NanoTite Parallel Walled Certain (Biomet 3i) |
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Katsoulis et al. 2012 [ |
Switzerland | Number: 40 |
Length: 10, 13 |
195 | Replace Select Tapered (Nobel Biocare) |
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García-Morales et al. 2012 [ |
Brazil | Number: 8 |
Diameter: 3.8 |
30 | XiVE-S (Dentsply Friadent) |
Author and year | Regions of implant insertion | Surgical technique | Primary stability: ISQ, PTV and/or IT (N cm) mean (SD) | Confounders included in analysis | Association between Primary stability and surgical technique | Secondary stability: ISQ, PTV and/or IT (N cm) mean (SD) | Association between Secondary stability and surgical technique |
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Padmanabhan and Gupta |
Maxillary anterior region | Osteotome technique versus conventional drilling | ISQ: drilling 64.77 |
No confounders cited | ISQ drilling > ISQ osteotome significantly ( |
ISQ 6 months: drilling 55.40 |
No significant difference between ISQ drilling and ISQ |
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Shayesteh et al. 2013 [ |
Maxillary anterior region | Osteotome technique versus conventional drilling | ISQ: drilling 64.70 |
Implant length: cited, but not included in analysis | ISQ osteotome > ISQ drilling significantly ( |
ISQ 3 months: drilling 71.37 |
No significant difference between ISQ drilling and ISQ |
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Marković et al. 2013 [ |
Maxillary posterior region | Osteotome technique versus conventional drilling | ISQ: drilling and non-self-tapping |
Implant macrodesign (self-tapping versus non-self-tapping) influenced the stability during the entire follow-up period after bone drilling and only between the 2nd and 12th postoperative weeks, following bone condensation ( |
ISQ osteotome > ISQ drilling significantly for self-tapping and non-self-tapping implants ( |
ISQ 12th weeks: drilling and non-self-tapping |
ISQ osteotome > ISQ |
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Turkyilmaz |
Maxillary posterior region | Undersized drilling versus press-fit drilling | IT for |
Implant diameter influenced the stability |
For |
Not evaluated | Not evaluated |
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Alghamdi et al. 2011 [ |
Posterior maxilla and mandible | Undersized drilling versus press-fit drilling | ISQ: standard drilling |
Bone density and jaw position (maxilla versus mandible): cited but not included in analysis and were not accounted for to remove their confounding influence on surgical techniques between groups | No significant differences between both (ISQ and IT) |
Not evaluated | Not evaluated |
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Stacchi et al. 2013 [ |
Maxillary premolar area | Piezosurgery versus conventional drilling | ISQ: drills |
No confounders cited | No significant difference between ISQ drills and ISQ piezoelectric ( |
ISQ 3 months: drills |
ISQ piezoelectric > ISQ drills significantly during the entire period of observation (90 days): from day 14 to day 42, in particular, the difference was extremely significant ( |
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Katsoulis et al. 2012 [ |
Complete edentulous maxilla | Flapless versus flap procedure | ISQ: flap 57.7 (±1.8) |
Implant diameter and length did not influence stability |
ISQ standard > ISQ |
ISQ 3 months: Flap 56.0 (±2.0) |
ISQ flap > ISQ flapless significantly at 3 months ( |
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García-Morales et al. 2012 [ |
Mandibular posterior region | Low-level laser stimulation versus placebo | ISQ: conventional |
No confounders cited | No significant difference between ISQ conventional and ISQ laser ( |
ISQ 12 weeks: conventional |
No significant difference between ISQ conventional and ISQ laser at 12 weeks ( |
The risk of bias assessment for the included studies was considered independently and in duplicate by at least two review authors.
This was conducted using the Methodological checklist for prognostic studies developed by the National Institute for Health and Clinical Excellence of the United Kingdom (2009) [
Methodological checklist for prognostic studies developed by the National Institute for Health and Clinical Excellence from United Kingdom [
Study identification | ||||
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Circle one option for each question | ||||
(1.1) | The study sample represents the population of interest with regard to key characteristics, sufficient to limit potential bias to the results. |
Yes | No | Unclear |
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(1.2) | Loss of follow-up is unrelated to key characteristics (i.e., the study data adequately represent the sample), sufficient to limit potential bias. |
Yes | no | unclear |
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(1.3) | The prognostic factor of interest is adequately measured in study participants, sufficient to limit potential bias. |
Yes | No | Unclear |
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(1.4) | The outcome of interest is adequately measured in study participants, sufficient to limit bias. |
Yes | No | Unclear |
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(1.5) | Important potential confounders are appropriately accounted for, limiting potential bias with respect to the prognostic factor of interest. |
Yes | No | Unclear |
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(1.6) | The statistical analysis is appropriate for the design of the study, limiting potential for the presentation of invalid results. |
Yes | No | Unclear |
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It was used to perform the quality assessment and control of bias |
See (Table
The search procedure retrieved 59 articles from electronic searches. After screening the titles and abstracts (when available) independently by at least two review authors, 14 articles appeared to meet the inclusion criteria [
Of the 14 potentially eligible studies, 5 studies had to be excluded because relation between surgical technique and implant stability was not clear in one study [
Thus, a total of 9 clinical studies [
Two observational clinical studies [
A clinical study [
The other clinical study [
One RCT [
A clinical observational study [
Another clinical observational study [
One RCT [
One RCT [
One observational clinical study [
One RCT [
None of the articles was excluded from the systematic review after quality assessment, except for one article on studies [
Padmanabhan and Gupta 2010 [ |
Shayesteh et al. |
Marković et al. |
Stacchi et al. |
Turkyilmaz et al. |
Marković et al. |
Alghamdi et al. |
Katsoulis et al. |
García-Morales et al. 2012 [ | |
---|---|---|---|---|---|---|---|---|---|
(1) The study sample represents the population of interest with regard to key characteristics, sufficient to limit potential bias to the results | Unclear | Yes | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Yes |
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(2) Loss to follow-up is unrelated to key characteristics (i.e., the study data adequately represent the sample), sufficient to limit potential bias | Yes | Unclear | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
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(3) The prognostic factor of interest is adequately measured in study participants, sufficient to limit potential bias. (n these studies the prognostic factor was the surgical technique) | Yes | Yes | Yes | Yes | Yes | Unclear | Yes | Yes | Yes |
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(4) The outcome of interest is adequately measured in study participants, sufficient to limit bias. (The outcome was the primary and/or secondary stability) | Unclear | Unclear | Yes | Yes | Unclear | Yes | Unclear | Unclear | Yes |
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(5) Important potential confounders are appropriately accounted for, limiting potential bias with respect to the prognostic factor of interest. (e.g., implant dimensions and bone density) | Yes | No | Yes | Yes | Yes | Yes | No | No | Yes |
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(6) The statistical analysis is appropriate for the design of the study, limiting potential for the presentation of invalid results | Yes | Yes | Yes | Yes | Yes | Yes | Yes | yes | Yes |
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Category and situation of the article | 4 ‘‘yes:’’ moderate methodol quality included | 3 ‘‘yes:’’ Moderate methodol quality included | 5 ‘‘yes:’’ High methodol quality excluded* | 5 “yes:” High methodol quality included | 4 ‘‘yes:’’ Moderate methodol quality included | 4 ‘‘yes:’’ Moderate methodol quality included | 3 ‘‘yes:’’ Moderate methodol quality included | 3 ‘‘yes:’’ Moderate methodol quality included | 6 “yes:” high methodological quality included |
With respect to the influence of osteotome technique on secondary implant stability, there was no significant influence of using osteotome on secondary implant stability when compared with conventional drilling technique for ISQ values, in the two selected studies [
The purpose of this systematic review was to evaluate whether there was scientific evidence to support the association between different surgical techniques and primary and/or secondary implant stability. The surgical techniques that we found in the world literature evaluated by clinical studies whether they have influence on primary and/or secondary implant stability were the undersized drilling, the osteotome technique, the piezosurgery, the flapless, and the low-level laser therapy. Just three randomized controlled trials (RCTs) and five observational clinical studies were included. We selected only clinical studies that verified the association between the surgical techniques and implant stability. Laboratory or animal studies which did not report any clinical implant-related outcomes were not considered of interest since they would not be able to provide reliable clinical information for the prognosis of dental implant rehabilitation.
Because only a limited number of studies investigated the influence of different surgical techniques on stability of dental implants, the pattern of the current literature review was customized to primarily summarize the pertinent information.
When evaluating whether the undersized drilling technique could enhance the primary implant stability, the two included observational clinical studies [
When evaluating what the impact of using the osteotome in implant bed preparation on primary and/or secondary implant stability is, only one RCT [
With respect to the influence of osteotome technique on secondary implant stability, there was no significant influence of using osteotome on secondary implant stability when compared with conventional drilling technique in the two selected studies [
When evaluating whether using piezosurgery in implant bed preparation could influence the primary and/or secondary implant stability, just one RCT was found [
When assessing the influence of flapless procedure on primary and/or secondary implant stability, just one observational clinical study was selected [
When evaluating whether the use of low-level laser therapy (LLLT) to stimulate the osteotomy bone could influence the primary and/or secondary implant stability, only one RCT was conducted [
To provide objective assessment of implant stability, three methods were chosen to assess implant stability in this review: the resonance frequency method, which generated the ISQ value, the percussion method, which generates the PTV value, and the insertion torque measurement that provided the IT value in Ncm. Despite that the Periotest has been the subject of criticism as a result of its poor sensitivity [
Although this systematic review aimed to verify the influence of different surgical techniques on primary and/or secondary stability of dental implants, it was also possible to extract some data concerning the implant dimensions, implant macrodesign, and the bone density from the selected articles. Turkyilmaz et al. [
Despite the relative positive association found between primary and/or secondary implant stability and some of the aforementioned surgical techniques, the methodological quality and control of bias of the studies need to be improved to produce stronger evidences. A priori calculation for the sample size was undertaken in only two studies [
This systematic review had several limitations. First, the search was limited to English-language publications, which may have introduced a publication bias and excluded other relevant articles. However, such an exclusion may not considerably change the overall estimate of treatment effects [
These conclusions are based on few studies with small or very small sample sizes, relatively short follow-ups, moderate methodological quality, and being sometimes judged to be at moderate risk of bias, therefore they should be viewed with great caution. There is a weak evidence suggesting that undersized drilling technique could enhance the primary implant stability in sites of poor bone density. There is still a lack of evidence about the influence of undersized drilling technique on secondary implant stability. There is a weak evidence suggesting that using the osteotome technique to prepare implant beds in poor bone density could enhance the primary and secondary implant stability. There is a weak evidence suggesting that ultrasonic implant site preparation by piezoelectric inserts does not affect the primary mechanical stability but could fasten the bone healing process and increase the secondary implant stability, earlier than the traditional drilling technique. There is a weak evidence suggesting that flapless procedure could enhance the primary and secondary implant stability. There is insufficient evidence supporting or confuting the efficacy of irradiating bone osteotomies with infrared wavelengths for enhancing the primary or secondary stability of the implants.
More properly designed, RCTs with at least 1-year follow-up after implant loading are needed to understand the influence of undersized drilling, the osteotome technique, the piezosurgery, the flapless, and the low-level laser therapy on primary and secondary stability of implants placed particularly in low density bone. At this time, we could revise the existing loading protocols in this poor-quality bone dealing with these suggested surgical techniques.
The authors declare that there is no conflict of interests regarding the publication of this paper.