Comparison of Implant Stability by Means of Resonance Frequency Analysis for Flapless and Conventionally Inserted Implants

Immediate loading on two adjacent single dental implants with definitive nonsplinted restorations: A proof of concept in the posterior zone

OBJECTIVES

To evaluate clinical, clinician- and patient-reported outcomes (PROs) of two adjacent single posterior implants immediately loaded with definitive single crowns up to 1 year. Ten patients in need of two adjacent posterior single implants were included. All implants were placed applying a fully digital workflow. Definitive screw-retained single zirconia crowns were delivered within 72 h after implant placement. Clinical parameters, patient- and clinician-reported outcomes were assessed up to 1 year of follow-up.

CLINICAL CONSIDERATIONS

Clinical outcomes remained stable, with no implant failures or technical and biological complications throughout the observation period. Patient satisfaction was very high at baseline (crown delivery) and remained consistently high at 6 and 12 months of follow-up. Crown insertion 3 days after implant placement was rated as an easy procedure by clinicians.

CONCLUSIONS

Two adjacent single implants with immediate definitive restorations (<72 h) in the posterior region appear to be a viable and easy treatment option to shorten the overall treatment time and potentially enhancing patient satisfaction. However, randomized controlled trials are needed to confirm the advantages of this treatment protocol over a delayed loading approach.

CLINICAL SIGNIFICANCE

In selected cases, immediate implant loading with definitive restorations in the posterior region appears a valuable and straightforward option to shorten the overall treatment time.

Comparative evaluation of circumferential crestal bone loss after 1 year of implant placement with flapless versus flap surgery using surgical template after immediate loading in the posterior mandibular region using cone-beam computed tomography: A randomized controlled trial

Aim

The study was aimed to evaluate circumferential crestal bone level after one year of implant placement with flapless versus flap surgery using surgical template after immediate loading in the posterior mandibular region using CBCT.

Setting and Design

The study was designed as a Randomized controlled trial.

Material and Methods

32 implants were placed in single edentulous spaces in the mandibular posterior region after random allocation into two groups: Flap surgery (Group A) and Flapless surgery (Group B). Virtual implant planning was performed using Blue Sky Bio software, and static CBCT guided 3D printed surgical templates were fabricated for all participants of both the groups. Immediate non-functional temporization was performed. Circumferential crestal bone levels were assessed after surgery and one-year follow-up using CBCT and XELIS software. Vertical bone loss (VBL) and horizontal bone loss (HBL) was assessed on four sides: buccal, lingual, mesial and distal.

Statistical Analysis Used

Data was analyzed using Statistical Package for Social Sciences IBM Corp. Released 2017, IBM SPSS Statistics for Windows, Version 25.0. (Armonk, NY: IBM Corp.) and Graph Pad Prism 7.0 version. The level of significance was chosen <0.05. Chi square test was performed to assess the difference in the age in the two groups. Mann-Whitney U test was performed to compare the two groups for outcome measure. Graphically, quantile-quantile (Q-Q) plot was made using mean and standard deviation for normality verification of data.

Results

100% survival rate and patient compliance was observed along the one-year follow-up duration. By using Mann-Whitney U test, statistically significant difference was found in the vertical bone loss among participants of Flap surgery (Group A) and Flapless surgery (Group B) on all the four sides after one year of implant placement. However, significant results were not obtained for the difference in the horizontal bone level.

Conclusion

Within the limitations of this study, vertical bone loss measured circumferentially was more positively correlated with the implants placed with flap surgery compared to flapless surgery after immediate loading in the posterior mandibular region after one year.

Incidence of Peri-Implantitis, Technical and Biological Complications of Single Implants Placed with Flap or Flapless Surgery-A 10-12-Year Case-Series

BACKGROUND

Long-term follow-up of single implants and crowns is scarce, especially when inserted using flapless surgery.

AIM

Evaluate survival, peri-implantitis incidence, and technical/biologic complications of solitary implants/crowns after 10-12 years of function.

MATERIAL AND METHODS

49 patients with 53 single implants, initially operated with a one-stage flap (F) or flapless (FL) surgery and delayed loading, were recalled. Implant survival, radiographic bone-level changes compared to baseline, peri-implant health, and soft tissue aesthetics were registered. Differences in implant level between and within groups were statistically tested using the Mann-Whitney U-Test and Wilcoxon Signed Ranks Test, respectively.

RESULTS

36 patients with 40 implants were reassessed, yielding 100% implant and 97.5% crown survival. The bone loss in F (n = 19) was 0.56 mm (SD 0.89; range -0.9-2.02) and -0.85 mm (SD 0.98; range -2.84-0.53) in FL (n = 21), indicative of bone gain in FL (p = 0.003), the latter due to a difference at baseline but bone-level was comparable (p = 0.126). Groups were comparable for probing pocket depth (PPD); (3.32 vs. 3.19 mm), Bleeding Index (BI); (0.15 vs. 0.22), and gingival recession; (0.38 vs. 0.17 mm). According to international criteria, the peri-implantitis incidence was 0%, but 32.5% of the implants/crowns experienced biological or technical complications irrespective of surgical technique.

CONCLUSIONS

Solitary implants and crowns show good long-term clinical outcomes and peri-implant health. Flapless surgery is a good alternative to conventional in straightforward cases with sufficient bone volume and proper treatment planning.

Does implant placement using a minimally invasive technique increase early failures among trainees at an academic center?

PURPOSE

This study aims to identify whether dental implants placed using a flapless technique have a higher early failure rate, defined as failure within 6 months of placement, compared to implants placed with flap elevation when a surgical guide is not used.

METHODS

A retrospective cohort study was conducted to evaluate implants placed with either flapless (FL) or mucoperiosteal flap (MF) surgery between 2006 and 2012 at the Philadelphia VA Medical Center (PVAMC). Implant status after FL or MF surgery was assessed using dental encounter and radiographs at subsequent follow-up appointments to assess for early implant failures within 6 months of implant placement.

RESULTS

The FL technique was used to place 89 implants in 38 subjects, while the MF technique was used to place 381 implants in 139 subjects. Early failure occurred in 37 implants, of which 13 occurred in the FL group and 24 occurred in the MF group. FL surgery was found to be associated with a 265% increase in early implant failure (OR 2.653; 95% CL 1.287-5.469) and was statistically significant (p = 0.0064). Residents were over 200% more likely to have an early implant failure when using the FL technique (OR 2.314; 95% CL 1.112-4.816), CONCLUSIONS: Analysis revealed flapless implant placement was associated with higher early implant failure rates. In addition, early failures were more likely to occur when residents placed an implant using the flapless technique. While FL surgery can result in long-term success, it is a more technique-sensitive approach that requires greater clinical skill and stricter case selection to perform.

Accuracy of Computer-Assisted Flapless Implant Placement by Means of Mucosa-Supported Templates in Complete-Arch Restorations: A Systematic Review

The aim of this study was to systematically review the current scientific literature regarding the accuracy of fully guided flapless implant positioning for complete-arch rehabilitations in edentulous patients and to assess if there was any statistically significant correlation between linear deviation at shoulder point, at apex point and angular deviation. The electronic and manual literature search of clinical studies was carried out using specified indexing terms. A total of 13 studies were eligible for qualitative analysis and 277 edentulous patients were rehabilitated with 1556 implants patients by means of fully guided mucosa-supported template-assisted flapless surgery. Angular deviation was 3.42° (95% CI 2.82–4.03), linear deviation at shoulder point 1.23 mm (95% CI 0.97–1.49) and linear deviation at apex point 1.46 mm (95% CI 1.17–1.74). No statistically significant correlations were found between the linear and angular deviations. A statistically significant correlation was found between the two linear deviations (correlation coefficient 0.91) that can be summarized by the regression equation y = 0.03080 + 0.8254x. Computer-assisted flapless implant placement by means of mucosa-supported templates in complete arch restorations can be considered a reliable and predictable treatment choice despite the potential effects that flapless approach could bring to the overall treatment.

Comparative evaluation of crestal bone level by flapless and flap techniques for implant placement: Systematic review and meta-analysis

Aim

:To compare the crestal bone level of flapless technique of dental implant placement with the flap technique.

Setting and Design

This Systematic review and Meta-analysis was conducted according to the Preferred Reporting Items For Systematic Review and Meta-Analyses (PRISMA) Guidelines and registered with PROSPERO.

Materials and Methods

Electronic search of Medline and Google scholar databases for articles from 2010 till March 2020 was performed. Studies comparing the crestal bone level with both the techniques were included. After the collection of data, the risk of bias was assessed for each study.

Statistical Analysis Used

Meta-analysis was executed using RevMan 5 software version 5.3.

Results

23 studies were included. Statistically significant difference in crestal bone level was found between flapless and flap surgery with mean difference of -0.14 (flapless placement versus flap surgery; 95% CI: -0.24 to -0.03; P = 0.01FNx01). The difference in crestal bone level between the 2 groups was not statistically significant with a mean difference of -0.05(Guided flapless placement versus flap surgery; 95% CI: -0.10 to 0.00; P=0.06). Meta-analysis of the freehand flapless surgery with flap surgery generated a mean difference of -0.20 which was found to be statistically significant (Freehand flapless placement versus flap surgery; 95% CI: -0.37 to -0.03; P=0.02FNx01).

Conclusions

Flapless placement of implant can positively influence crestal bone loss in comparison with conventional flap technique.

Comparison of different surgical procedures on the stability of dental implants in posterior maxilla: A randomized clinical study

BACKGROUND

Stability of a dental implant is very important when planning immediate loading and design of a final restoration. The aim of this study was to compare the primary and the secondary stability of dental implants inserted by three different surgical techniques: conventional (standard) technique using a sequence of drills for implant bed preparation, osteotome technique using tapered hand instruments for creating implant sites by condensing the bone and guided flapless implant surgery with surgical templates.

MATERIAL AND METHODS

The study included 150 patients (80 males and 70 females), 46-71 years old, who required implant supported fixed partial dentures in the posterior maxilla of D3 or D4 bone density. Patients were randomly assigned into one of the three surgical insertion technique groups. All patients received tapered implants of the same manufacturer of the same length and two different widths (3.3 × 11.5 mm or 4.2 × 11.5 mm). Primary and secondary implant stability were measured by means of resonance frequency analysis (RFA) at the time of implant placement and 5 months after surgery using the Ostell ISQ device (Osstell AB, Sampgatan, Goteborg, Sweden). Statistical analysis included one-sample Kolmogorov Smirnov test, descriptive statistics, multivariate analysis (Bonferoni post-hoc tests) and paired t-tests.

RESULTS

Patients in the osteotome group exhibited higher primary stability (P < 0.01) than in the conventional and surgically guided flapless groups. There were no significant differences in the secondary stability (p >  0.05). Wider implants presented higher ISQ values (P<0.01).

CONCLUSION

The osteotome technique led to the highest implant primary stability, therefore it can be recommended when immediate loading is planned or for one-piece implant insertion.

The clinical significance of implant stability quotient (ISQ) measurements: A literature review

Implant stability quotients (ISQ values) are obtained in dental clinical practice on a non-invasive basis by resonance frequency measurement rapidly after surgical placement of implants. The ISQ-values are used as indicator for mechanical implant stability, and are believed to have predictive power for clinical outcome. It is the aim of this review to provide a synopsis of all factors described in the literature that influence ISQ measurements by performing an exhaustive literature review; moreover, this review aims at elucidating the key factors relevant for a rapid clinical predictive assessment. We searched systematically and exhaustively all major databases for publications relating to ISQ measurement methodology and for ISQ-influencing factor analyses. The reports identified were ordered in experimental (preclinical) studies and in clinical publications. We were able to identify 13 basic factors influencing ISQ-measurements. Among these, local bone quality, playing a key role in such measurements, was subdivided in four specific subfactors; thus a total of 17 individual factors was identified and reported to influence ISQ-measurements. A comprehensive list of these factors is provided in Table-form. A critical analysis points out that only 6 of these factors are of a sound predictive power useful for a rapid clinical assessment; and only two of these factors appear to have a well-documented scientific basis.

Minimally Invasive Ponto Surgery Versus the Linear Incision Technique With Soft Tissue Preservation for Bone Conduction Hearing Implants: A Multicenter Randomized Controlled Trial

OBJECTIVE

To compare the surgical outcomes of the Minimally Invasive Ponto Surgery (MIPS) technique with those of the linear incision technique with soft-tissue preservation for bone-anchored hearing systems (BAHS).

DESIGN

Sponsor-initiated multicenter, open, randomized, controlled clinical trial.

SETTING

Maastricht University Medical Centre, Ziekenhuisgroep Twente and Medisch Centrum Leeuwarden, all situated in The Netherlands.

PARTICIPANTS

Sixty-four adult patients eligible for unilateral BAHS surgery.Interventions Single-stage BAHS surgery with 1:1 randomization to the linear incision technique with soft-tissue preservation (control) or the MIPS (test) group.

PRIMARY AND SECONDARY OUTCOME MEASUREMENTS

Primary objective: compare the incidence of inflammation (Holgers Index ≥ 2) during 12 weeks' follow-up after surgery. Secondary objectives: skin dehiscence, pain scores, loss of sensibility around the implant, soft-tissue overgrowth, skin sagging, implant extrusion, cosmetic results, surgical time, wound healing and Implant Stability Quotient measurements.

RESULTS

Sixty-three subjects were analyzed in the intention-to-treat population. No significant difference was found for the incidence of inflammation between groups. Loss of skin sensibility, cosmetic outcomes, skin sagging, and surgical time were significantly better in the test group. No statistically significant differences were found for dehiscence, pain, and soft-tissue overgrowth. A nonsignificant difference in extrusion was found for the test group. The Implant Stability Quotient was statistically influenced by the surgical technique, abutment length, and time.

CONCLUSION

No significant differences between the MIPS and the linear incision techniques were observed regarding skin inflammation. MIPS results in a statistically significant reduction in the loss of skin sensibility, less skin sagging, improved cosmetic results, and reduced surgical time. Although nonsignificant, the implant extrusion rate warrants further research.

Assessment of Dental Implant Stability in Areas Previously Submitted to Maxillary Sinus Elevation

This study aimed to compare the primary and secondary stability, measured by resonance frequency analysis (RFA), in implants of different lengths installed in areas submitted to maxillary sinus lift. Correlation between RFA and implant insertion torque was also assessed. Twenty implants of 9 and 11 mm were inserted in areas submitted to maxillary sinus lift. The insertion torque was measured by the Bien Air motor. Osstell, through RFA, determined the implant stability quotient (ISQ) 2 times: the day of implant installation (T1) and 90 days after implant installation (T2). No differences were observed in the ISQ between T1 and T2 when the 20 implants were grouped, nor when the 9 mm implants were evaluated separately. In contrast, when the 11 mm values were evaluated separately, the ISQ was significantly higher in T2 than in T1 ( P < .05). In T1, 9 mm implants had a higher ISQ than 11 mm ones ( P < .05), whereas in T2, the implants of 11 mm showed a higher ISQ than did the 9 mm implants ( P < .05). There was no difference in insertion torque between 9 and 11 mm implants ( P > .05), nor was there a correlation between ISQ and insertion torque ( P > .05). In conclusion, longer implants (11 mm) presented a significant increase in ISQ values during the healing period when installed in areas previously submitted to maxillary sinus lift. This phenomenon was not observed for shorter implants (9 mm). Finally, no correlation was observed between ISQ and insertion torque.

Comparative Study on Osseointegration of Implants After Flap and Flapless Surgery in the Mandible of Dogs

PURPOSE

The objective of this study was to compare the implant stability and osseointegration of implants using a flap or flapless technique.

MATERIAL AND METHODS

Mandibular premolars and molars were extracted from both sides in 6 dogs. After 8 weeks, 4 fixtures were implanted using either a flap or flapless technique. Implant stability quotient was measured on insertion and at 2, 4, and 8 weeks later. The animals were killed while the tissues were histologically analyzed.

RESULTS

Implant stability increased for 8 weeks, and no statistically significant differences were observed between the surgical protocols. Bone-implant contact showed 60.27% ± 30.99% for flapless surgery and 59.73% ± 17.12% for flap surgery. And the results of new bone formation area from total area showed 56.07% ± 27.78% for flapless surgery and 57.00% ± 14.66% for flap surgery. There were no statistically significant differences.

CONCLUSION

This study showed no significant difference in implant stability as well as osseointegration regardless of flap or flapless technique.

Evaluation of the insertion torque, implant stability quotient and drilled hole quality for different drill design: an in vitro Investigation

OBJECTIVE

The purpose of the present study was to compare the insertion torque and implant stability quotient between different drill design for implant site preparation.

MATERIALS AND METHODS

Synthetic blocks of bone (type I density) were used for drilling procedures. Three groups were evaluated: Group G1 - drilling with a single bur for a 4.2 mm conical implant; Group G2 and Group G3 - drilling with three consecutive burs for a 4.1 mm cylindrical implant and for a 4.3 mm conical implant respectively. For each group, 15 drilling procedures were performed without irrigation for 10-mm in-depth. The drilled hole quality (HQ) after the osteotomy for implant site preparation was measured in the five-first holes through a fully automated roundness/cylindricity instrument at three levels (top, middle, and bottom of the site). The insertion torque value (ITV) was achieved with a computed torquimeter and the implant stability quotient (ISQ) values were measured using a resonance frequency apparatus.

RESULTS

The single drill (group 1) achieved a significantly higher ITV and ISQ than the multiple drills for osteotomy (groups 2 and 3). Group 1 and 3 displayed significantly better HQ than group 2.

CONCLUSIONS

Within the limitations of the study, the results suggest that the hole quality, in addition to the insertion torque, may significantly affect implant primary stability.

Does the Implant Surgical Technique Affect the Primary and/or Secondary Stability of Dental Implants? A Systematic Review

Background. A number of surgical techniques for implant site preparation have been advocated to enhance the implant of primary and secondary stability. However, there is insufficient scientific evidence to support the association between the surgical technique and implant stability. Purpose. This review aimed 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. Materials and methods. A search of PubMed, Cochrane Library, and grey literature was performed. 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 and the implant primary and/or secondary stability. The articles selected were carefully read and classified as low, moderate, and high methodological quality and data of interest were tabulated. Results. Eight clinical studies were included then they were classified as moderate or high methodological quality and control of bias. Conclusions. There is a weak evidence suggesting that any of previously mentioned surgical techniques could influence the primary and/or secondary implant stability.

Flapless versus conventional flapped dental implant surgery: a meta-analysis

The aim of this study was to test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated by dental implants being inserted by a flapless surgical procedure versus the open flap technique, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. The search strategy resulted in 23 publications. The I² statistic was used to express the percentage of the total variation across studies due to heterogeneity. The inverse variance method was used for random-effects model or fixed-effects model, when indicated. The estimates of relative effect were expressed in risk ratio (RR) and mean difference (MD) in millimeters. Sixteen studies were judged to be at high risk of bias, whereas two studies were considered of moderate risk of bias, and five studies of low risk of bias. The funnel plots indicated absence of publication bias for the three outcomes analyzed. The test for overall effect showed that the difference between the procedures (flapless vs. open flap surgery) significantly affect the implant failure rates (P = 0.03), with a RR of 1.75 (95% CI 1.07–2.86). However, a sensitivity analysis revealed differences when studies of high and low risk of bias were pooled separately. Thus, the results must be interpreted carefully. No apparent significant effects of flapless technique on the occurrence of postoperative infection (P = 0.96; RR 0.96, 95% CI 0.23–4.03) or on the marginal bone loss (P = 0.16; MD −0.07 mm, 95% CI −0.16–0.03) were observed.

Reasons for failures of oral implants

This study reviews the literature regarding the factors contributing to failures of dental implants. An electronic search was undertaken including papers from 2004 onwards. The titles and abstracts from these results were read to identify studies within the selection criteria. All reference lists of the selected studies were then hand-searched, this time without time restrictions. A narrative review discussed some findings from the first two parts where separate data from non-comparative studies may have indicated conclusions different from those possible to draw in the systematic analysis. It may be suggested that the following situations are correlated to increase the implant failure rate: a low insertion torque of implants that are planned to be immediately or early loaded, inexperienced surgeons inserting the implants, implant insertion in the maxilla, implant insertion in the posterior region of the jaws, implants in heavy smokers, implant insertion in bone qualities type III and IV, implant insertion in places with small bone volumes, use of shorter length implants, greater number of implants placed per patient, lack of initial implant stability, use of cylindrical (non-threaded) implants and prosthetic rehabilitation with implant-supported overdentures. Moreover, it may be suggested that the following situations may be correlated with an increase in the implant failure rate: use of the non-submerged technique, immediate loading, implant insertion in fresh extraction sockets, smaller diameter implants. Some recently published studies suggest that modern, moderately rough implants may present with similar results irrespective if placed in maxillas, in smoking patients or using only short implants.

Clinical advantages of computer-guided implant placement: a systematic review

OBJECTIVES

To systematically scrutinize the current scientific literature regarding the clinical advantages of computer guidance of implant placement.

MATERIALS AND METHODS

Four electronic databases were searched using specified indexing terms. The reference lists of publications were also searched manually. For inclusion, publications had to meet pre-established criteria.

RESULTS

The searches yielded 1028 titles and abstracts. After data extraction and interpretation, 28 publications and 2 systematic reviews remained for inclusion. Fifteen studies were prospective observational and four were retrospective observational. Nine studies included a control group (controlled clinical trials) of which seven were prospective and two retrospective. Only three of the prospective studies were randomized (RCT's). A total of 852 patients were treated with 4032 implants using computer-guided implant surgery. The number of patients included in each study ranged from 6 to 206. The age ranged from 16 to 92 years and the follow-up period varied between 1 and 49 months.

CONCLUSIONS

The limited scientific evidence available suggests that guided placement has at least as good implant survival as conventional protocols. However, several unexpected procedure-linked adverse events during guided implant placement indicate that the clinical demands on the surgeon were no less than those during conventional placement. A clinical advantage with flapless guided surgery is that the technique is likely to decrease pain and discomfort in the immediate postoperative period.

Evaluation of the correlation between insertion torque and primary stability of dental implants using a block bone test

PURPOSE

Implant stability at the time of surgery is crucial for the long-term success of dental implants. Primary stability is considered of paramount importance to achieve osseointegration. The purpose of the present study was to investigate the correlation between the insertion torque and primary stability of dental implants using artificial bone blocks with different bone densities and compositions to mimic different circumstances that are encountered in routine daily clinical settings.

METHODS

In order to validate the objectives, various sized holes were made in bone blocks with different bone densities (#10, #20, #30, #40, and #50) using a surgical drill and insertion torque together with implant stability quotient (ISQ) values that were measured using the Osstell Mentor. The experimental groups under evaluation were subdivided into 5 subgroups according to the circumstances.

RESULTS

In group 1, the mean insertion torque and ISQ values increased as the density of the bone blocks increased. For group 2, the mean insertion torque values decreased as the final drill size expanded, but this was not the case for the ISQ values. The mean insertion torque values in group 3 increased with the thickness of the cortical bone, and the same was true for the ISQ values. For group 4, the mean insertion torque values increased as the cancellous bone density increased, but the correlation with the ISQ values was weak. Finally, in group 5, the mean insertion torque decreased as the final drill size increased, but the correlation with the ISQ value was weak.

CONCLUSIONS

Within the limitations of the study, it was concluded that primary stability does not simply depend on the insertion torque, but also on the bone quality.