Flapless dental implant surgery enabled by haptic robotic guidance: A case report

This case report presents the use of haptic robotic technology in one patient with six implants placed in the maxilla and five implants in the lower mandible with the goal of individual single implant supported crowns to be placed over each implant after 6 months. All implants were placed using a flapless technique, with one immediate implant placement after extraction. All implants were placed with a high degree of accuracy relative to the pre-operative plan as determined by post-op CBCT analysis with an average angular deviation of 2.58° and positional deviations at the coronal and apical aspects of the implant around 1 mm (0.93 and 1.06 mm, respectively). Total surgical time of less than 2 h. Haptic robotics physically guides the location, orientation, and depth of the tools during both drilling and implantation and thus allows for accurate placement as well as the intra-operative flexibility to change the plan as necessary while providing excellent visualization and irrigation. This robotic technology provides a treatment that focuses on accuracy and safety providing the best chance at excellent surgical outcomes for the patient.

The Clinical Evaluation of the Dynamically Navigated Flapless Placement of Zygomatic Implants: A Randomized Controlled Trial

PURPOSE

To assess the pain, swelling, infection, and alteration in sensation following the flapless placement of zygomatic implants guided by dynamic navigation.

MATERIALS AND METHODS

A randomized controlled trial was conducted on 20 patients. In group 1, the placement of the zygomatic implants was carried out without reflecting a mucoperiosteal flap (flapless). In group 2, a mucoperiosteal flap was raised (flapped). Two zygomatic implants were placed in each patient (one on each side) under local anesthesia, guided by dynamic navigation. Postoperative evaluations included pain (using the visual analogue scale [VAS]), swelling (using standard measurements), maxillary sinus infection, and alteration of sensation (using mechanical stimuli, thermal threshold detection, and a two-point discrimination test). The assessments were carried out at 2 days, 1 week, and then 1, 2, and 3 months postoperatively.

RESULTS

In group 1, all implants except for one were successfully osseointegrated. Immediate postoperative pain and swelling were both significantly greater in group 2 (P < .01). No alteration in sensation was detected in any case in the two groups. There were a total of three cases of chronic sinusitis: one in group 1 and two in group 2.

CONCLUSIONS

The flapless placement of zygomatic implants guided by dynamic navigation and under local anesthesia improves postoperative recovery.

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.

Flap versus Flapless Immediate Implants with Bone Augmentation: A Novel Study

Background

This study aimed to equate implants placed using a traditional flap elevation technique with implants placed using a flapless process regarding bone healing and success in clinical conditions.

Materials and Methods

Sixty subjects were included in this research work. The participants were randomly divided into two groups. Patients in group A underwent implant placement with the flap elevation technique. Similarly, group B patients underwent implant placement without flap reflection. Parameters such as plaque index, wound healing index, crestal bone loss, and radiograph were considered to estimate the effectiveness of the two techniques.

Results

Plaque indexes were improved in both groups. The modified gingival index also improved in all the phases of healing. The flapless method showed a better crestal bone.

Conclusion

It can be concluded that this study showed that with the right augmentation techniques, implants could be successfully performed immediate extraction sockets, both with and without elevation of the mucoperiosteal flap.

Clinical study of dynamic real-time navigation assisted immediate implant without flapping in the esthetic zone

OBJECTIVE

The purpose of this study is to investigate the clinical effect of Dynamic real-time navigation to assist immediate implant without flapping in the esthetic zone.

METHODS

Eight patients who underwent immediate implantation in the aesthetic area were included. A total of 11 implants were implanted using dynamic real-time navigation system combined with non-flap technology. Clinical indicators including implant deviation, initial stability, alveolar bone absorption, implant success rate, pink esthetic score (PES), Papilla index score (PIS), and the thickness of labial side bone plate of the implant were recorded.

RESULTS

The deviation between the actual implant position and the preoperative design was (0.76±0.08) mm at the top, (1.11±0.18) mm at the root, (0.90±0.16) mm at the depth, and (1.48±0.91)°at the Angle. ISO values of all implants were greater than 59. PES was greater than 8. PIS index was 2 or 3. The average alveolar bone absorption was (0.34±0.09) mm and the thickness of bone plate on the lip of implant was greater than 1.6 mm. The success rate of implantation was 100%.

CONCLUSION

The use of dynamic real-time navigation assisted non-flap implantation in the aesthetic area can effectively reduce implant deviation and improve the aesthetic effect.

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.

Evaluation of Bone Regeneration around Implants with and Without Flap Elevation

Background:

The aim of this study is to clinically evaluate and compare the clinical success and the relative bone healing of the implants which are placed using a flapless procedure and compare it to those placed by the conventional flap technique.

Materials and Methods:

This study was conducted with ten patients that were randomly divided into two groups. Group A included patients with immediately placed implants after extraction with flap elevation. Group B included patients with immediately placed implants after extraction without any flap elevation. The clinical parameters recorded were Plaque index, Modified Gingival Index, Early Wound Healing Index, Buser's criteria, Distance between implant shoulder and the crestal bone (DIB), and Radiographic Examination in a standardized manner to evaluate changes for the DIB values.

Results:

There was an improvement in Plaque Score from baseline to 1 month and baseline to abutment placement (6 months), which was statistically significant, but the plaque score from 3 months to abutment placement (6 months) was statistically nonsignificant in both the group. There was an increase in modified gingival score from baseline to 3 months, baseline to abutment placement (6 months), and 3 months to abutment placement (6 months), which was statistically significant in both the groups. The DIB scores in Group A recorded at baseline to 6 months were 2.80 ± 0.57 and 1.90 ± 0.42, respectively, showing a mean difference of −0.90 and P = 0.001 in comparison. Whereas, the DIB scores in Group B at baseline to 6 months were 3.20 ± 0.57 and 2.50 ± 0.50, respectively, showing a mean difference of −0.70 and P = 0.001 in comparison. The DIC scores in Group A at baseline to 6 months were 1.60 ± 0.54 and 0.00 ± 0.00, respectively, showing a mean difference of −1.60 and P = 0.003 in comparison, Whereas the DIC scores in Group B at baseline to 6 months were 1.40 ± 0.54 and 0.00 ± 0.00, respectively, showing a mean difference of −1.40 and P = 0.005 in comparison.

Conclusion:

Implants placed in fresh extraction sockets with and without mucoperiosteal flap elevation can be successfully done with augmentation procedures. Short-term survival rates and clinical outcomes of both groups were similar and appeared to be predictable treatment modalities.

Natural Bone Healing In Compromised Sockets After Tooth Extraction: Digital Measurement Methods With Cone-Beam Computed Tomography

This study aimed to evaluate bone regeneration within infected extraction sockets with bone defects using cone-beam computed tomography (CBCT) at a 1-year follow-up after implant placement in a prosthetically driven implant position. Forty-eight patients requiring premolar or molar tooth extraction due to bone defects caused by periodontal diseases were included. Vertical and horizontal bone volumes were assessed by overlapping the CBCT scan images with the full digital process. At 1-year post-extraction, a prosthetically-driven implant was planned using virtual implant planning software. At 1 year after extraction, CBCT revealed significant horizontal and vertical bone gains; an overall mean buccolingual bone width gain of 5.46 ± 2.87 mm, and an overall mean vertical bone gain of 0.27 ± 1.28 mm for the lingual bone plate level and 3.50 ± 1.81 mm for the buccal bone plate level were observed. Except for 4 (out of 48) sites, implants were virtually positioned in the center of the edentulous spaces. In summary, despite the dimensional changes after tooth extraction in compromised posterior sockets, there was sufficient bone for placing an implant using the prosthetically driven approach.

[Comprehensive Digital Workflow and Computer-Assisted Implant Surgery in a Patient with Reduced Crest Width. Case Report of a Split-Mouth Approach]

Modern treatment protocols in implant dentistry focus on lower morbidity and patient-centered outcomes, in addition to commonly applied treatment success criteria. Prosthetically-driven digital planning followed by static computer-assisted implant surgery (sCAIS) may minimize the need for bone augmentation by ideally utilizing the residual crest and thereby improve patient satisfaction. A healthy 37-year-old female suffered from agenesis of both second mandibular premolars and presented wide single-tooth gaps on both sides of the mandible with a moderate (left) and pronounced (right) horizontal bone deficiency. 3D implant planning allowed ideal implant positioning in the residual bone volume while respecting critical anatomical structures. This enabled a flapless sCAIS procedure without bone grafting in the left mandible. On the right side, the insufficient bone volume was augmented simultaneously to the sCAIS using GBR. The clinical and radiographic parameters showed a good oral health status in the 1-year postop examination. The final implant position presented a minimal angular and horizontal deviation from the initial planning. The patient was highly satisfied with the two applied methods but preferred the flapless procedure.

Accuracy, Labor-Time and Patient-Reported Outcomes with Partially versus Fully Digital Workflow for Flapless Guided Dental Implants Insertion-A Randomized Clinical Trial with One-Year Follow-Up

(1) Background: Prosthetically-driven implant positioning is a prerequisite for long-term successful treatment. Transferring the planned implant position information to the clinical setting could be done using either static or dynamic guided techniques. The 3D model of the bone and surrounding structures is obtained via cone beam computed tomography (CBCT) and the patient’s oral condition can be acquired conventionally and then digitalized using a desktop scanner, partially digital workflow (PDW) or digitally with the aid of an intraoral scanner (FDW). The aim of the present randomized clinical trial (RCT) was to compare the accuracy of flapless dental implants insertion in partially edentulous patients with a static surgical template obtained through PDW and FDW. Patient outcome and time spent from data collection to template manufacturing were also compared. (2) Methods: 66 partially edentulous sites (at 49 patients) were randomly assigned to a PDW or FDW for guided implant insertion. Planned and placed implants position were compared by assessing four deviation parameters: 3D error at the entry point, 3D error at the apex, angular deviation, and vertical deviation at entry point. (3) Results: A total of 111 implants were inserted. No implant loss during osseointegration or mechanical and technical complications occurred during the first-year post-implants loading. The mean error at the entry point was 0.44 mm (FDW) and 0.85 (PDW), p ≤ 0.00; at implant apex, 1.03 (FDW) and 1.48 (PDW), p ≤ 0.00; the mean angular deviation, 2.12° (FDW) and 2.48° (PDW), p = 0.03 and the mean depth deviation, 0.45 mm (FDW) and 0.68 mm (PDW), p ≤ 0.00; (4) Conclusions: Despite the statistically significant differences between the groups, and in the limits of the present study, full digital workflow as well as partially digital workflow are predictable methods for accurate prosthetically driven guided implants insertion.

Comparison between flapless and open-flap implant placement: a systematic review and meta-analysis

No consensus has been reached regarding the influence of the flapless and open-flap surgical techniques on the placement of dental implants. This systematic review compared the effects of flapless implant placement and implant placement with elevation of the mucoperiosteal flap in terms of marginal bone loss, implant survival rate and complications rates. This review followed PRISMA guidelines and was registered in PROSPERO with the registration number CRD42017071475. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published until December 2017. The search identified 559 references. After a detailed review, 24 studies were assessed for eligibility. A total of 1025 patients who had received a total of 1873 dental implants were included. There were no significant differences between the flapless and open-flap surgical techniques in terms of implant survival rates (P=0.34; risk ratio (RR): 1.36; confidence interval (CI): 0.72-2.56), marginal bone loss (P=0.23; MD: -0.20; CI: -0.52-0.13), or complication rates (P=0.67; RR: 1.10; CI: 0.70-1.73). The current meta-analysis showed that the implant survival rate, marginal bone levels, and complications of flapless surgery were similar to those of open-flap surgery over a mean follow-up period of 21.62 months.

Comparison between flapless and open-flap implant placement: a systematic review and meta-analysis

No consensus has been reached regarding the influence of the flapless and open-flap surgical techniques on the placement of dental implants. This systematic review compared the effects of flapless implant placement and implant placement with elevation of the mucoperiosteal flap in terms of marginal bone loss, implant survival rate and complications rates. This review followed PRISMA guidelines and was registered in PROSPERO with the registration number CRD42017071475. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published until December 2017. The search identified 559 references. After a detailed review, 24 studies were assessed for eligibility. A total of 1025 patients who had received a total of 1873 dental implants were included. There were no significant differences between the flapless and open-flap surgical techniques in terms of implant survival rates (P=0.34; risk ratio (RR): 1.36; confidence interval (CI): 0.72-2.56), marginal bone loss (P=0.23; MD: -0.20; CI: -0.52-0.13), or complication rates (P=0.67; RR: 1.10; CI: 0.70-1.73). The current meta-analysis showed that the implant survival rate, marginal bone levels, and complications of flapless surgery were similar to those of open-flap surgery over a mean follow-up period of 21.62 months.

Angulated screw-retained and cemented implant crowns following flapless immediate implant placement in the aesthetic region: A 1-year prospective cohort study

PURPOSE

To compare the short-term clinical and radiographic outcomes of angulated screw-retained and cemented implant crowns following flapless immediate implant placement.

MATERIALS AND METHODS

The study was designed as a prospective cohort study with 1-year follow-up. Eligible patients were divided into two groups according to restoration type: the angulated screw group (AG) and the cemented group (CG). Implant survival, marginal bone loss, mechanical complications, probing depth, bleeding on probing% and pink aesthetic score were evaluated.

RESULTS

After 1 year of loading, the implant survival rate was 100% in both groups (AG, n = 23; CG, n = 20). A significantly lower bleeding on probing% was found in the AG than in the CG (11.6 ± 19.1% vs. 33.3 ± 33.8%, P = 0.04). No significant differences in marginal bone loss, probing depth and mechanical complication rates were found between the two groups (P = 0.53, 0.48, 0.41, respectively). The overall pink aesthetic score value was 8.96 ± 0.88 in the AG and 8.98 ± 0.62 in the CG at 1-year examination (P = 0.96). The percentage of excellent pink aesthetic scores (≥ 9) value increased from 48% at baseline to 83% at 1 year in the AG, and from 45% at baseline to 85% at 1 year in the CG.

CONCLUSION

Based on the 1-year results, both treatment options provide high implant survival, a stable marginal bone level and excellent aesthetic outcomes in the short term. Angulated screw-retained crowns might benefit the long-term peri-implant conditions.

Changes in alveolar process dimensions following extraction of molars with advanced periodontal disease: A clinical pilot study

OBJECTIVE

To use cone beam computed tomography (CBCT) to assess the alterations of socket dimensions after a 6-month healing period following molar extraction.

MATERIALS AND METHODS

Seventeen molars were extracted due to advanced periodontitis. CBCT scans were taken immediately after extraction and once more 6 months later. Superimposition of CBCT images was used to measure the following: horizontal changes at extraction sites at three corono-apical levels (-1, -3, and -5 mm) below the bone crest, three mesio-distal levels (mesial, central, and distal), vertical changes at nine regions of the alveolar crest, and alveolar bone volume.

RESULTS

The width of the central crests at -1 mm decreased by 0.59 and 0.72 mm in the buccal and 0.27 and 0.02 mm in the lingual, in the maxilla and mandible, respectively. No statistically significant decreases in the ridge height were observed except in the disto-palatal region with a 1.11 mm decrease in the maxilla (p < 0.05). Heights of the buccal and lingual bone plates decreased significantly and ranged from 0.56 to 1.38 mm in the mandible after 6 months of healing (p < 0.05). Overall, ridge height changes were not significantly different between the maxilla and mandible (p > 0.05) and no significant volumetric bone loss occurred in either maxillary or mandibular sockets after 6 months of healing.

CONCLUSIONS

Socket dimensions of molars with advanced periodontal disease showed a significant increase at the middle-central portion, although there were no significant changes of horizontal width 6 months following the procedures.

Immediate loading of one (fixed-on-1) versus two (fixed-on-2) implants placed flapless supporting mandibular screw-retained cross-arch fixed prostheses: 10-month results from an explanatory randomised controlled trial

PURPOSE

To evaluate the outcome of one (fixed-on-1, Fo1) versus two (fixed-on-2, Fo2) implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses.

MATERIALS AND METHODS

Twenty patients with edentulous or to be rendered edentulous mandibles were randomised to the Fo1 group (10 patients who received three intraforaminal implants but only the mesial implant was actually loaded) and to the Fo2 group (10 patients who received two intraforaminal implants) according to a parallel-group design. To be immediately loaded implants had to be inserted with a minimum torque of 60 Ncm. Outcome measures were prosthesis and implant failures, complications and patient satisfaction for function and aesthetics evaluated up to 10 months post-loading.

RESULTS

Flaps were raised in three patients of the Fo1 group and one of the Fo2 group. Two prostheses in each group were delayed loaded at 2 and 3 months, because implants could not be inserted with a torque superior to 60 Ncm. Patients of the Fo2 group received prostheses with 12 teeth whereas Fo1 patients with 8 or 10 teeth. Ten months after loading no drop-out or implant failure occurred, but one Fo2 prosthesis had to be remade because the patient complained it was too short (risk difference = 0.1; 95% CI: -0.19 to 0.40; Fisher's exact test P = 1.000). Three patients were affected by complications in each group (risk difference = 0.0; 95% CI: -0.359 to 0.359; Fisher's exact test; P = 1.000). There were no statistically significant differences for prosthetic failures and complications between groups. Four months after loading, patients of the Fo1 group were less satisfied for function than those of the Fo2 group (difference between the medians [Hodges-Lehmann estimation] = 1; 95% CI: 0 to 2; P = 0.043). No differences were observed for aesthetics (difference between the medians [Hodges-Lehmann estimation] = 0; 95% CI: -1 to 0; P = 0.481), and two Fo1 patients would not undergo the same procedure again (difference in proportions: 0.2; 95% CI: -0.11 to 0.51; P = 0.474).

CONCLUSIONS

Preliminary results suggest that immediately loaded cross-arch screw-retained fixed prostheses with 8 to 10 teeth can be supported by only one dental implant at least up to 10 months post-loading; however, the clinical application and usefulness of such a procedure remains questionable.

Immediate and flapless implant insertion and provisionalization using autogenous bone grafts in the esthetic zone: 5-year results

OBJECTIVES

As the 2-year results for immediately inserted and provisionalized implants have been reported, it remained an open issue, whether the initially high success rates and the esthetic outcome remain stable for longer observation periods. Therefore, this prospective study examines the 5-year hard and soft tissue changes at implants placed in the anterior maxilla.

MATERIAL AND METHODS

Meanwhile, 37 microthreaded implants were placed in 21 patients into extraction sockets with and without facial bone deficiencies by a flapless approach. Facial gaps and bony defects were grafted with autogenous bone chips. The implants were immediately provisionalized. The primary outcome parameters were the interproximal marginal bone level and the thickness of the facial bony wall. Implant success and Pink Esthetic Score (PES) were considered as secondary outcome parameters.

RESULTS

Two patients with four implants withdrew from the study (dropouts), and the remaining 33 implants were still in function at a follow-up period of 68 months. Marginal bone height averaged 0.04 mm coronal to the implant shoulder. The thickness of the facial bony lamellae increased significantly between pre-op examination and 1-year follow-up (p = .002) and thereafter remained stable. Within 5 years of follow-up, 24 of 33 implants were clinically stable, free of signs and symptoms, and showed bone loss less than 1 mm. The mean PES ratings improved slightly from 10.7 pre-operatively to 11.7 at the last follow-up (p = .02).

CONCLUSIONS

Interproximal marginal bone levels, survival rates, and esthetic results remain stable at the 5-year follow-up in implants used in an immediate insertion, reconstruction, and provisionalization concept. Facial marginal bone levels decreased slightly; however, this reduction did not affect the PES so far.

Flapless boning to increase space by piezosurgery: A novel mini-invasive strategy for teeth extraction. A retrospective study

This study aimed to investigate the application of piezosurgery-associated flapless surgery for increasing bone space during teeth extraction and evaluate its success rate, postoperative outcomes, and incidence of major complications.From January 2014 to December 2016, patients who experienced teeth extraction via piezosurgery-associated flapless surgery were enrolled in this study. The positions, diagnosis, dental medical history, and radiographic examination of teeth were recorded before the treatment. During the surgery, the fracture or displacement of root, injuries of soft tissue, and fractures of the alveolar process were noted.A total of 140 patients fulfilled the eligibility criteria in the present study. All these teeth were classified into 4 groups based on diagnosis: residual roots that underwent root canal therapy (28 cases), teeth with root fracture (37 cases), teeth extraction because of orthodontics needed (31 cases), and the vertically impacted lower third molar (44 cases). The radiographic presentation revealed about 50% ankylosed teeth. No root fracture and root displacement emerged, and all roots were removed intact. Moreover, fracture of the alveolar process did not occur. Two cases with buccal mucosal injury were noted, which were because of heat injuries caused by the basement of the tip while cool water was used out.This study introduced a novel mini-invasive strategy for increasing space during teeth extraction. The advantage of this piezosurgery-associated flapless surgery included maximal preservation of the alveolar bone, minimal injury to soft tissues, and prevention of root fracture during the surgery. Furthermore, the cool water used during the surgery must be carefully checked before the procedure.

Minimally invasive transgingival implant therapy: A literature review

Transgingival (flapless) implant placement procedure is a minimally invasive surgical technique in which implant is placed without reflecting mucoperiosteal flap and hence the blood supply of bone is not hampered which is advantageous in many ways. To compare the outcomes of various implant placement techniques, an electronic database of various journals from January 1990 to March 2017 were analyzed and only human clinical trials with 6 months follow-up and at least five implants in each group were reviewed. The present literature review focuses on the comparative aspects of flapped versus flapless implants in terms of their survival, marginal bone loss, soft-tissue parameters, and patient-centered outcomes. When the proper protocol is followed by experienced surgeons, no significant difference was observed in survival rate, marginal bone loss, and keratinized mucosal width between flapless and conventional flap technique. Although transgingival approach for implant placement is reported to significantly reduce the surgical time, increased patient comfort and acceptance, i.e. the patient centered outcomes such as postoperative pain, swelling, and visual analog score, are minimized. Hence, it is concluded that transgingival (flapless) implant placement technique is well accepted by the patient with potential outcomes as compared to the conventional implant placement approach.

Histopathological comparative analysis of periimplant bone inflammatory response after dental implant insertion using flap and flapless surgical technique. An experimental study in pigs

AIM

To evaluate by histopathological analysis the peri-implant bone inflammation degree, in certain time intervals (7, 14, 21 and 28 days), following mini-incision flapless and flap implant placement.

MATERIAL AND METHODS

The experiment was conducted on four domestic pigs. Nine weeks prior to implant insertion, second and third mandibular premolars were extracted. Each animal received six implants in lower jaw. On one randomly chosen side of jaw flapless technique using mini-incision was performed, while on the other side implants were inserted after flap raising. After 7, 14, 21, and 28 days, the experimental animals were sacrificed. Following mandibular resection and decalcification, the samples for histopathological analysis of the peri-implant bone were obtained in the empty implant bed area, from the buccal side of the mandible, adjacent to implant neck region and parallel to crestal edge of implant bed. The degree of inflammatory response of the peri-implant bone was estimated through ordinal scores from 0 to 2.

RESULTS

Seven days after the surgery all samples in the flap group had score 2 indicating high inflammation degree, in contrast to lower inflammatory reaction in flapless group. On the 14th and 21st postoperative day decreasing of inflammation degree was noted in all samples of the flapless group (score 1), while in flap group samples presented scores 1 and 2. Twenty-eight days after the implant placement, further reduction of inflammation in the flapless group (33% of samples had score 0) was observed.

CONCLUSION

Flapless technique in comparison to conventional flap procedure minimizes postoperative bone inflammatory reactions.

Minimally invasive flapless vs. flapped approach for single implant placement: a 2-year randomized controlled clinical trial

PURPOSE

The purpose of this 2-year randomized controlled clinical trial was to assess the differences in implant survival rates, soft tissue preservation, patient centered outcome and crestal bone changes applying the minimally invasive (MI) flapless approach for single implant placement compared to flapped implant surgery (FS).

MATERIALS AND METHODS

Subjects eligible for this study were randomly assigned into two groups: MI or FS. Items of evaluation were the following: implant installation position, soft tissue healing, post-surgical pain, soft tissue outcome, marginal bone loss (MBL), and implant survival rate.

RESULTS

Forty subjects (14 women and 26 men, 20 in MI group and 20 in FS group with a mean of 39 ± 13.2 years old) were included in the study. None of the implants demonstrated dehiscence or loss during the follow-up. Subjects in MI group showed significantly lower post-surgical pain and significantly less wound healing index scores at 1-week follow-up. The width of keratinized mucosa decreased from a mean of 4.2 ± 1.6 mm pre-surgically to 3.7 ± 1.1 mm at crown delivery but remained stable at 2-year follow-up in MI group. At every appointment in the study, no statistical significant difference of PD and MBL was found between the two groups.

CONCLUSION

Compared with FS, single implants placed applying the MI technique in selected subjects showed advantages in improving patient comfort and decreasing post-implant placement soft tissue reaction. Meanwhile, implants with MI approach have the same level of MBL and high success rates as FS procedure at 2-year follow-up. The deduction of keratinized mucosa is very limited and the width of KM remained stable with MI approach at 2-year follow-up.

Submerged flapless technique vs. conventional flap approach for implant placement: experimental domestic pig study with 12-month follow-up

OBJECTIVES

The aim of our study was to compare osseointegration and peri-implant crestal bone resorption in submerged flapless and conventional flap surgery over a 12-month follow-up.

MATERIALS AND METHODS

The study used five domestic pigs. Implants were inserted 9 weeks after tooth extraction. Each animal received six implants in the mandible, following a split-mouth design: one side was treated using a flapless technique using mini-incisions, while a flap was raised on the other. The animals were sacrificed at 2 weeks, 1, 3, 6 and 12 months after implant placement. Radiographic images were taken to analyze crestal bone loss, and samples were extracted for histopathological and bone-to-implant contact (BIC) analyses.

RESULTS

Significantly, greater crestal bone loss (P = 0.005) was obtained in the flap group compared with the flapless group. The flapless group presented significantly higher percentages of BIC (P < 0.05) at 3, 6 and 12 months compared with the conventional flap group.

CONCLUSIONS

Within the limitations of this experimental animal study, it may be concluded that the type of surgery (flap or flapless) affects peri-implant bone preservation and osseointegration of regular platform implants. Flapless surgery is associated with peri-implant crestal bone preservation. Flapless surgery in combination with submerged implants allows higher osseointegration values.

Histopathological comparative analysis of peri-implant soft tissue response after dental implant placement with flap and flapless surgical technique. Experimental study in pigs

AIM

The aim of this study was comparing the effect of flapless vs. flap technique of implant placement on inflammation degree of peri-implant soft tissue, through histopathological analysis.

METHOD

The experiment was conducted on five domestic pigs. Nine weeks after tooth extraction, implants were installed. Each animal received six implants in mandible. According to split-mouth design, randomly one side was used for flapless technique using mini-incision, while on the other side, flap was raised. After 7, 14, 21, 28, and 90 days, the experimental animals were sacrificed. Samples for histopathological analyzes were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The degree of inflammatory response in the peri-implant soft tissue was estimated through ordinal scores from 0 to 3.

RESULTS

In the flap group Score 3 indicating high degree of inflammation was present from day 7 to day 21, in contrast to flapless group where Score 3 was not recorded during the entire follow-up. Three months after implantation, there were no signs of inflammation neither around flap nor around flapless implants.

CONCLUSION

Flapless surgical implantation technique using mini-incision decreases peri-implant soft tissue inflammatory reaction compared with flap surgery.

Immunohistochemical analysis of blood vessels in peri-implant mucosa: a comparison between mini-incision flapless and flap surgeries in domestic pigs

AIM

The aim of this experimental study is to compare the effect of mini-incision flapless versus flap technique of implant placement on the amount of vascular structures and blood vessel elements in peri-implant soft tissue, using immunohistochemical analysis.

METHOD

The experiment was conducted on five domestic pigs. Each animal received six implants in mandible according to the split-mouth design. On one randomly chosen jaw side, mini-incision flapless surgery was performed, whereas on the opposite jaw side, flap was raised. After 3 months of implant healing through submerged approach, the experimental animals were sacrificed and samples for immunohistochemical analyses were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The study outcome was the presence of vascular structures and elements of the blood vessels in the peri-implant mucosa per microscopic field, estimated through ordinal scores from 0 to 2. Effects of surgical approach, site of implantation, and their interaction on vascular scores of peri-implant mucosa were assessed by Brunner and Langer nonparametric analysis of longitudinal data.

RESULTS

Statistically significant effect of surgical approach on vascularity of peri-implant mucosa has been revealed in the second mucosal layer, where flapless approach provided higher vascularity compared with flap approach (P = 0.002). In the remaining two layers, surgical approach did not affect mucosal vascularity significantly (layer 1: P = 0.071; layer 3: P = 0.433).

CONCLUSION

The flapless surgical implant placement approach using mini-incision provides better vascularization of peri-implant mucosa after 3 months of healing compared with flap surgery.

Immediate placement and restoration of implants in the aesthetic zone with a trimodal approach: soft tissue alterations and its relation to gingival biotype

PURPOSE

The aim of this prospective study was to evaluate the soft tissue changes around implants in the aesthetic zone, placed under a trimodal approach (immediate post-extraction placement, flapless, and immediate provisional restoration) and its relationship to gingival/periodontal biotype of the patient.

MATERIALS AND METHODS

The sample consisted of 14 patients from two private practices that were in need of a tooth extraction in the anterior maxillary region (cuspid to cuspid) and were candidates to a replacement with a dental implant. An initial measurement (baseline) of the position or the mesial and distal papillae and gingival zenith was made at this time, with a rigid dental-supported stent and an electronic precision caliper, able to the second tenth of a millimeter; after careful tooth extraction, the periodontal thickness, at a point 5 mm apical to de gingival buccal margin, with an analogical thickness gauge, able to one tenth of a millimeter. Once the implant was inserted an immediate provisional restoration was delivered. To evaluate the soft tissue changes measurements were repeated at 3, 6, and 12 months. A statistical analysis was performed to evaluate the changes in the gingival margin around the implant restorations and to identify a possible correlation to patient's periodontal thickness.

RESULTS

All 14 patients received Straumann (®) implants (9 Tissue Level [TL] Regular Neck [RN], 2 TL Narrow Neck [NN], 2 Bone Level [BL] Narrow Crossfit [NC], and 1 BL Regular Crossfit [RC]). All implants integrated and none had any biological complications. Three provisional restorations presented screw loosening and retightened once and one loss retention and was recemented once. In one patient, with a severe bruxing habit, the final restoration suffered screw loosening and was retightened. Of the final restorations, 12 were screw-retained and 2 cemented on custom-made Zirconia abutments. A mean recession of the buccal margin of 0.45 mm was recorded at 12 months ( ± 0.25 mm). An acceptable papilla level was present in all cases at 1 year, with mean changes of 0.38 mm ( ± 0.60) for the mesial and 0.80 mm ( ± 0.90) of the distal papilla, respectively. No correlation could be established between the soft tissue changes and the periodontal biotype of the patient.

CONCLUSIONS

Within the limitations of this study, the good aesthetic outcome and minimal complications seem to validate the trimodal approach protocol as a reliable and simple protocol to place and restore immediate implants in the aesthetic zone. No correlation between the patient's gingival biotype and the soft tissue alterations could be established. Additional studies are needed to verify long-term aesthetic results with this approach and to better define and quantify biotypes.