Comparison of Crestal Bone Loss Around Dental Implants Placed in Healed Sites Using Flapped and Flapless Techniques: A Systematic Review

Biomechanical influence of narrow-diameter implants placed at the crestal and subcrestal level in the maxillary anterior region. A 3D finite element analysis

PURPOSE

To evaluate the tendency of movement, stress distribution, and microstrain of single-unit crowns in simulated cortical and trabecular bone, implants, and prosthetic components of narrow-diameter implants with different lengths placed at the crestal and subcrestal levels in the maxillary anterior region using 3D finite element analysis (FEA).

MATERIALS AND METHODS

Six 3D models were simulated using Invesalius 3.0, Rhinoceros 4.0, and SolidWorks software. Each model simulated the right anterior maxillary region including a Morse taper implant of Ø2.9 mm with different lengths (7, 10, and 13 mm) placed at the crestal and subcrestal level and supporting a cement-retained monolithic single crown in the area of tooth 12. The FEA was performed using ANSYS 19.2. The simulated applied force was 178 N at 0°, 30°, and 60°. The results were analyzed using maps of displacement, von Mises (vM) stress, maximum principal stress, and microstrain.

RESULTS

Models with implants at the subcrestal level showed greater displacement. vM stress increased in the implant and prosthetic components when implants were placed at the subcrestal level compared with the crestal level; the length of the implants had a low influence on the stress distribution. Higher stress and strain concentrations were observed in the cortical bone of the subcrestal placement, independent of implant length. Non-axial loading influenced the increased stress and strain in all the evaluated structures.

CONCLUSIONS

Narrow-diameter implants positioned at the crestal level showed a more favorable biomechanical behavior for simulated cortical bone, implants, and prosthetic components. Implant length had a smaller influence on stress or strain distribution than the other variables.

Same-Day Digital Dentistry Restorative Workflow for Single Immediate Provisionalization of Narrow-Diameter Implants: An Exploratory Prospective Study

This study evaluated the two-year clinical outcomes of 3.1 mm diameter dental implants, immediately provisionalized and later restored using same-day dentistry, in 10 patients receiving 11 narrow-diameter (3.1 mm) single implants. Each implant was placed and immediately restored with a provisional crown after placement. At least 2 months after placement, the implant was restored with a prefabricated titanium abutment and an all-ceramic crown using a same-day dentistry protocol. Clinical outcomes, including apical bone loss, probing depths, gingival index, and surgical and prosthetic complications, were documented. There was no implant failure over the course of two years. No surgical complications were reported. Two cases lost provisional crowns. One crown needed to be remade due to esthetic concern. The cumulative two-year survival rate of the implants was 100%. Implant bone loss after two years of functional loading was −0.56 ± 0.54 mm and −0.32 ± 0.68 mm for mesial and distal crestal bone, respectively. Two prosthetic complications included recementation of a crown and remaking of a crown. This exploratory study suggests that immediate provisionalization and a same-day restorative dentistry digital workflow protocol for narrow-diameter implants appear to be predictable clinical procedures with no reported surgical complications and minimal prosthetic complications.

Comparison between flapless-guided and conventional surgery for implant placement: a 12-month randomized clinical trial

OBJECTIVES

The study was aimed at comparing implants installed with guided and conventional surgery.

MATERIAL AND METHODS

Twenty-nine total edentulous patients were selected, and maxillary contralateral quadrants were randomly assigned to static computer-aided implant surgery (S-CAIS): flapless computer-guided surgery, and conventional surgery (CS): flap surgery with conventional planning. Tomography scans were performed at baseline and 10 days after the surgery for deviation measurement, and radiography was done at baseline and after 6 and 12 months, for peri-implant bone level (PIBL) analysis. Peri-implant fluid and subgingival biofilm were collected to evaluate bone markers and periodontal pathogens.

RESULTS

S-CAIS showed less linear deviation at the apical point and the midpoint and less angular deviation (p < 0.05), with greater depth discrepancy in the positioning of the platform (p < 0.05). Higher values of vertical PIBL were observed for the S-CAIS group at baseline (p < 0.05), while lower values of horizontal PIBL were observed for CS (p < 0.05). Bone markers and Tf presented higher levels in CS (p < 0.05). Flapless S-CAIS allowed smaller linear and angular deviations than the conventional technique.

CONCLUSION

However, PIBL was higher in S-CAIS; the conventional technique led to a greater angiogenic and bone remodeling activity by elevating the angiogenic levels and bone markers.

CLINICAL RELEVANCE

Evaluating the different implant insertion techniques can guide clinical and surgical regarding the accuracy, the release pattern of bone markers, and the peri-implant bone level.

TRIAL REGISTRATION

ReBEC-RBR-8556fzp.

Accuracy of dental implant placement with computer-guided surgery: a retrospective cohort study

Background

The aim of this study was to assess the accuracy of virtual planning of computer-guided surgery based on the actual outcomes of clinical dental implant placement.

Methods

This retrospective study enrolled patients among whom implant treatment was planned using computer-guided surgery with cone beam computed tomography (CBCT). The patients who received implant according to the guide with the flapless and flapped approach were classified as group 1 and 2, respectively, and the others who could not be placed according to the guide were allocated to the drop-out group. The accuracy of implant placement was evaluated with the superimposition of CBCT.

Results

We analyzed differences in the deviated distance of the entrance point and deviated angulation of the insertion of implant fixtures. With regard to the surgical approach, group 2 exhibited greater accuracy compared to group 1 in deviation distance (2.22 ± 0.88 and 3.18 ± 0.89 mm, respectively, P < 0.001) and angulation (4.27 ± 2.30 and 6.82 ± 2.71°, respectively, P = 0.001). The limitations of guided surgery were discussed while considering the findings from the drop-out group.

Conclusions

Computer-guided surgery demonstrates greater accuracy in implant placement with the flapless approach. Further research should be conducted to enhance the availability of guides for cases with unfavorable residual bone conditions.

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.

A 5 to 7-year case series on single angulated implants installed following papilla-sparing flap elevation

BACKGROUND

Bony concavities at the buccal aspect may cause a distortion between the implant axis and ideal prosthetic axis. Angulated implants can overcome this problem, yet long-term data are lacking. In addition, papilla-sparing incisions have been proposed to reduce tissue loss, yet aesthetic outcomes have not been published.

PURPOSE

To evaluate the 5 to 7-year outcome of single angulated implants installed following papilla-sparing flap elevation.

MATERIALS AND METHODS

Patients who had been consecutively treated with a single angulated implant (Co-axis®, Southern Implants, Irene, South Africa) in the anterior maxilla were re-examined after 5 to 7 years. Available data at 1 year (T1) were compared to those obtained at 5 to 7 years (T2).

RESULTS

Twenty out of 22 treated patients (11 females, 9 males, mean age of 52) with 22 implants attended the 5 to 7-year reassessment. All implants survived and stable clinical conditions could be reached with mean marginal bone loss of 1.28 mm at T2. Papilla-sparing flap elevation resulted in Pink Esthetic Score of 9.83 at T1 and 8.23 at T2 (p = 0.072). Mucosal Scarring Index was 4.61 at T1 and 3.50 at T2 (p = 0.165). The overall appearance of scarring significantly improved over time (p = 0.032), yet 59% of the cases still demonstrated scarring at T2.c CONCLUSIONS: Within the limitations of the study, angulated implants (Co-axis®, Southern Implants) reached stable clinical conditions. Papilla-sparing incisions may not be recommended in aesthetically demanding patients due to high risk of scarring.

Clinical comparison between crestal and subcrestal dental implants: A systematic review and meta-analysis

STATEMENT OF PROBLEM

How the performance of dental implants is related to their occlusogingival placement, crestal or subcrestal, is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate marginal bone loss, implant survival rate, and peri-implant soft tissue parameters between implants placed at the crestal and subcrestal bone level.

MATERIAL AND METHODS

Two independent reviewers searched the PubMed/MEDLINE, Embase, and Cochrane Library databases for randomized clinical trials published up to September 2020. The meta-analysis was based on the Mantel-Haenszel and the inverse variance methods (α=.05).

RESULTS

The search identified 928 references, and 10 studies met the eligibility criteria. A total of 393 participants received 709 implants, 351 at crestal bone levels and 358 at subcrestal bone levels. Meta-analysis indicated that crestal bone level implants showed similar marginal bone loss to that seen with subcrestal bone level implants (mm) (P=.79), independent of the subcrestal level (P=.05) and healing protocol (P=.24). The bone level implant placement did not affect the implant survival rate (P=.76), keratinized tissue (mm) (P=.91), probing depth (mm) (P=.70), or plaque index (%) (P=.92).

CONCLUSIONS

The evidence suggests that both approaches of implant placement are clinically acceptable in terms of peri-implant tissue parameters and implant-supported restoration survival.

Narrative review regarding the applicability, accuracy, and clinical outcome of flapless implant surgery with or without computer guidance

Background

The advent of computer‐guided surgery removed the need for complex surgical interventions such as extensive flap elevations, second stage implant exposure, and complications usually associated with conventional protocols.

Purpose

(a) Analyze available literature reporting on applicability, accuracy, clinical outcome of flapless surgery with or without computer guidance. (b) Evaluate quality of studies, in terms of scientific level of evidence and ethical committee approval.

Materials and methods

A PUBMED search was performed in July 2018. A first search was based on a general search string limited to “Dental Implants” and “flapless surgery.” A second search focused on accuracy of computer‐guided surgery using search string “Surgery, Computer‐Assisted” or “guided surgery,” and “Dental implants.” The following inclusion criteria were applied: (a) studies in English; (b) human studies (excluding cadaver); (c) systematic reviews; (d) systematic reviews with meta‐analysis. Reviews not mentioning accuracy were excluded in search 2.

Results

Nine reviews included in total. Implant survival ranged between 89% and 100%. Early surgical and prosthetic complications reported in 9.1% to 36.4% of reviewed papers. Tooth‐supported guides show more accuracy than bone or mucosa‐supported guides. Fully guided surgery yields higher accuracy, with lower values for horizontal coronal, horizontal apical and angular deviation (1.00, 1.23, and 3.13°mm, respectively) than those placed with half guided surgery (1.44, 1.91, and 4.30 mm, respectively). Thirty‐four of 71 human studies included in nine reviews, mentioned ethical committee approval or compliance with Declaration of Helsinki.

Conclusions

Guided flapless surgery is comparable to free‐hand surgery in terms of implant survival, marginal bone remodeling, and peri‐implant variables. Clinicians advised to take care in all steps of the protocol, and include safety margins around virtually planned implants. Regarding compliance with research ethics, we should question whether scientific reports of clinical trials performed without an ethical umbrella are trustworthy. Compliance of ethics standards is imperative for submitted research papers.

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.

Evaluation of crestal bone resorption around cylindrical and conical implants following 6 months of loading: A randomized clinical trial

OBJECTIVE

The purpose of this clinical study was to evaluate the effect of implant body form (cylindrical and conical implants) on crestal bone levels during 6 months' follow-up after loading.

MATERIALS AND METHODS

A total of 32 SPI implants (19 conical implants/13 cylindrical implants) were randomly placed in 12 male patients using a submerged approach. None of the patients had compromising medical conditions or parafunctional habits. Periapical radiographs using the parallel technique were taken after clinical loading and 6 months later. Clinical indices including pocket depth and bleeding on probing (BOP) were recorded on 6-month follow-up. Data were analyzed by independent samples t-test and Chi-square test with a significance level of 0.05.

RESULTS

Six months after loading, crestal bone loss was 0.84 (±0.29) mm around the cylindrical implants and 0.73 (±0.62) mm around the conical types, which was not significantly different (P = 0.54). Pocket depth around the cylindrical and conical implants was 2.61 (±0.45) mm and 2.36 (±0.44) mm, respectively (P = 0.13). BOP was observed among 53.8% and 47.4% of the cylindrical implants and conical (P = 0.13). Bone loss and pocket depth in the maxilla and mandible had no significant difference (P = 0.46 and P = 0.09, respectively).

CONCLUSION

In this study, although bone loss and clinical parameters were slightly higher in the cylindrical implants, there was no significant difference between the conical- and cylindrical-shaped implants.

Dimensional changes of buccal bone plate in immediate implants inserted through open flap, open flap and bone grafting and flapless techniques: A cone-beam computed tomography randomized controlled clinical trial

OBJECTIVES

To assess through cone-beam computed tomography (CBCT) buccal alveolar bone alterations after immediate implant placement using the following techniques: open flap and grafting (flap-graft), open flap and no grafting (flap-nograft) and flapless and no grafting (noflap-nograft).

MATERIALS AND METHODS

This was a three-armed parallel group randomized clinical trial with allocation ratio 1:1:1. Patients were eligible in case they needed immediate implant replacing teeth in maxillary premolar area, with sufficient buccal bone support. CBCT was performed immediately after the intervention and 6 months later. The main outcomes were CBCT measurements performed at apical (A-EA), medial (M-EM) and external and internal implant bevel level (B-EB, B-IB) and vertical defect depth (DP). Pain and discomfort, time of surgery and complications were recorded. Differences between groups were estimated through ANOVA tests and post-hoc Scheffe's analysis for pairwise comparisons. Multiple regressions were conducted to estimate influence of gingival biotype and baseline marginal gap dimension.

RESULTS

Forty-five patients were recruited and randomized to treatments with one lost to follow-up. Analysis of variance showed that the effect of treatment technique was not relevant for all horizontal and vertical outcomes. The three techniques exhibited almost complete fill of marginal gap, with a mean residual vertical gap of 0.27 mm and horizontal gap of 0.5 mm. Regression models indicated a positive effect of thick biotype on gap filling and dimensional bone reduction. The noflap-nograft technique resulted less painful.

CONCLUSIONS

The option of noflap-nograft surgery in post-extraction implants allows for minimal surgical intervention with comparable buccal bone changes and gap filling after a follow-up of 6 months in sites with sufficient buccal bone support.

The Accuracy of Computer-Assisted Implant Surgery Performed Using Fully Guided Templates versus Pilot-Drill Guided Templates

Purpose. Computer-assisted stereolithographically guided surgery allows an ideal implant placement for prosthetic restoration. Two types of stereolithographic templates are currently available: a fully guided template and a pilot-drill guided template. The purpose of this study was (i) to evaluate the accuracy of implant insertion using these types of surgical templates and (ii) to define parameters influencing accuracy. Materials and Methods. 20 patients were enrolled and divided into 2 study groups: in group A, implants were placed using CAD-CAM templates with fully guided sleeves; in group B, implants were placed with a template with only pilot-drill guided sleeves. Pre- and postoperative computed tomographies were used to measure differences between final positions of implants and virtually planned positions. Three linear discrepancies (coronal, apical, and depth) and two angular ones (buccolingual and mesiodistal) were measured. Correlations between accuracy and jaws of interest, implant length and diameters, and type of edentulism were also analysed. Results. A total of 50 implants were inserted in 15 patients using CAD-CAM templates: 23 implants in group A and 27 in group B. The mean coronal deviations were 1.16 and 1.11 mm (P = 0.35), respectively; the mean apical deviations were 1.65 and 1.71 mm (P = 0.22); the mean depth deviations were 0.95 and −0.68 mm (P = 0.032); the mean buccolingual angular deviations were 4.16° and 6.72° (P = 0.042); and the mean mesiodistal ones were 2.81° and 5.61° (P = 0.029). In addition, the accuracy was statistically influenced only by implant diameter for coronal discrepancy (P = 0.035) and by jaw of interest for mesiodistal angulation (P = 0.045). Conclusion. Fully guided implant surgery was more accurate than pilot-drill guided surgery for different parameters. For both types of surgery, a safety margin of at least 2mm should be preserved during implant planning to prevent damage to nearby anatomical structures.

Comparative evaluation of soft and hard tissue changes following endosseous implant placement using flap and flapless techniques in the posterior edentulous areas of the mandible-a randomized controlled trial

BACKGROUND

Dental implant-supported restorations have long been used as a successful modality for replacing missing teeth. There are two well-established methods of implant placement. The traditional approach to implant surgery involves raising a mucoperiosteal flap and the alternative approach does not involve reflecting a flap, each having its own advantages and disadvantages. The purpose of the present study was to compare and evaluate the soft and hard tissue changes around endosseous implants placed using flap and flapless surgery in mandibular posterior edentulous sites over a period of time.

MATERIALS AND METHODS

A total of 20 systemically healthy patients with a single edentulous site in the posterior mandible were enrolled in this study and 20 endosseous implants were placed (10 in the flap group and 10 in the flapless group). The peri-implant probing depth was assessed. Radiographic assessment was done for changes in the marginal bone levels at the mesial and distal side of the implant with measurements made at baseline, 6 months, and 12 months. Patient-centered outcomes were assessed by using the visual analogue scale (VAS). All these parameters were statistically analyzed using the Wilcoxon signed-rank test, paired Student t test, and two-way ANOVA test and were considered to be significant if the p value was ≤ 0.05.

RESULTS

Twenty patients were enrolled in the present study and endosseous implants were placed. Eighteen subjects were followed up throughout the study period and two patients were excluded from the study. The mean PD in the flapless group was comparatively less than the flap group at 12 months and was found to be statistically significant. During the observation period of 12 months, reduction of crestal bone height around the implants placed by flapless and flap surgery were statistically significant. The flapless group showed less change in the crestal bone height which was statistically significant compared to the flap group. The mean VAS score on day 0 in the flap and flapless group was statistically significant. The flapless group showed significantly less pain when compared to the flap group.

CONCLUSION

Although the flapless technique of endosseous implant placement had statistically significant less PD, bone loss, and pain than the flap technique, the difference was found to have uncertain clinical significance.

Clinical parameters of implants placed in healed sites using flapped and flapless techniques: A systematic review

BACKGROUND

Dental implant placement using flapless surgery is a minimally invasive technique that improves blood supply compared with flapped surgery. However, the flapless technique does not provide access to allow bone regeneration.

OBJECTIVE

The aim of this systematic review was to evaluate the clinical parameters following implant surgery in healed sites, using two procedures: flapped vs. flapless surgery.

MATERIALS AND METHODS

A detailed electronic search was carried out in the PubMed/Medline, Embase and Cochrane Library databases. The focused question was, "How do flapped and flapless surgical techniques affect the clinical parameters of dental implants placed in healed sites?". All the studies included with a prospective controlled design were considered separately, depending on whether they had been conducted on animals or humans. The following data were recorded in all the included studies: number of implants, failures, location (maxilla, mandible), type of rehabilitation (partial or single), follow-up and flap design. The variables selected for comparison in the animal studies were the following: flap design, gingival index, mucosal height, recession and probing pocket depth. In humans studies the variables were as follows: flap design, plaque index, gingival index, recession, probing pocket depth, papilla index and keratinized gingiva.

RESULTS

Ten studies were included, six were experimental studies and four were clinical studies. Studies in animals showed better results using the flapless technique in the parameters analyzed. There is no consensus in the clinical parameters analyzed in human studies, but there is a trend to better results using flapless approach.

CONCLUSION

The animal studies included in the present review show that implants placed in healed sites with a flapless approach have better clinical parameters than the flapped procedure in a short-term follow-up. In human studies, there is no consensus about which technique offer better results in terms of clinical parameters. Therefore, more research in humans is required in order to overcome the limitations and contrast these results.

Immediate loading of implants in the edentulous mandible: a multicentre study

PURPOSE

The aim of this prospective study was to investigate the two-year outcomes following immediate loading of mono-cortically engaged implants.

MATERIALS AND METHODS

Thirty healthy mandible edentulous patients with an average age of 67.3 years and presenting with sufficient bony ridge at the mandible symphysis were included in the study. Four Astra Tech, Ti-Oblast^® implants were installed between the mental foramina using the mono-cortical anchorage technique. The primary stability of the implants was assessed by resonance frequency analysis (RFA). After uni-abutments were placed, a temporary bridge was constructed and fixed the same day. The definitive bridges were installed 6 weeks after implant surgery. Five of 120 placed implants were lost in four patients during the first 6 weeks and these patients were excluded from the follow-up. The changes in marginal bone level (n = 20) were evaluated in Brazilian and Swedish groups at baseline, 6 weeks, 6 months, 12 months and 24 months. The RFA (n = 30) was evaluated at baseline, 6 weeks, 6 months, 12 months and 24 months postoperatively.

RESULTS

Compared with baseline measurements, the postoperative values for marginal bone level (6 weeks, 6 months, 12 months and 24 months) were significantly reduced (p < 0.05), while no differences were observed in the RFA analysis (12 months and 24 months).

CONCLUSIONS

The immediate loading of mono-cortically engaged implants in the edentulous mandible is safe and predictable and implant stability remains excellent after 2-year follow-up.

A New Detection Method for Submerged Implants: Oral Tattoo

PURPOSE

To evaluate the marking potential of tattoo ink in determining the definitive locations of submerged implants at the time of surgical exposure of the implants.

MATERIALS AND METHODS

In total, 104 implants in 32 patients were included in this study. After placement of the implants, cover screws were inserted. Overlying mucosa was marked with tattoo ink using a 20 g needle through the center of the cover screw. At the time of surgical exposure the tattoo marks were evaluated relative to visibility.

RESULTS

At the time of the surgical exposures, tattoo ink was clearly visible at 91 implants, slightly visible at 8 implants, and not visible at 5 implants. After detection and classification of tattoo ink, the overlying mucosa was gently removed by tissue punch under local anesthesia.

CONCLUSION

The results of this study seemed to indicate that marking the location of implants with tattoos at the time of implant placement can be an inexpensive, easy, healthy, and practical way to identify the location of marked submerged dental implants.

Immediate implant placement and provisionalization in the aesthetic zone using a flapless or a flap-involving approach: a randomized controlled trial

AIM

We conducted a randomized controlled trial to compare the effect of flapless (FLS) or flap-involving (F) immediate placement and provisionalization of single-tooth implants in the aesthetic zone.

MATERIALS AND METHODS

Thirty-nine patients were randomized following extraction of a non-restorable tooth to a FLS or F group. All implants were immediately placed and provisionalized. We monitored prospectively changes in the peri-implant mucosal margin, the interproximal bone and buccal horizontal ridge at 3, 6 and 12 months.

RESULTS

At 3 months post-surgery, the mean ± SD [median (interquartile range)] mesiobuccal peri-implant gingival margin recession from the pre-surgical soft tissue position amounted to 0.11 ± 0.32 mm [0 (0, 0.5)] in the FLS treatment arm versus 0.43 ± 37 mm [0.5 (0, 0.5)] in the F treatment arm (p = 0.02); corresponding values at the distobuccal surface were 0.11 ± 32 mm [0 (0, 0)] in the FLS arm versus 0.48 ± 0.44 mm [0.5 (0, 1)] in the F arm (p = 0.01). No other significant differences in soft or hard tissue remodelling between the treatment arms were observed at 3, 6 or 12 months.

CONCLUSIONS

Flapless and a flap-involving immediate implant placement and provisionalization in the aesthetic zone resulted in comparable remodelling of the peri-implant mucosa, interproximal bone and buccal ridge at 6 and 12 months.

Crestal Bone Loss under Delayed Loading of Full Thickness Versus Flapless Surgically Placed Dental Implants in Controlled Type 2 Diabetic Patients: A Parallel Group Randomized Clinical Trial

PURPOSE

To compare crestal bone loss around dental implants using a delayed loading protocol. Bone loss was compared in patients following conventional full thickness flap and flapless surgery in controlled type 2 diabetic patients.

MATERIALS AND METHODS

Eighty-eight type 2 diabetic patients satisfying predetermined inclusion and exclusion criteria were selected for this single center, parallel group study after obtaining institutional review board approval and informed consent. These patients were randomly divided into two groups. Group I consisted of patients undergoing full thickness flap surgery for implant placement, and group II consisted of patients undergoing flapless surgery for implant placement. The mean age, duration of diabetes, glycosylated hemoglobin levels, and male-to-female ratio in both groups were matched and compared statistically. Dental implants were placed followed by delayed loading (4 months) in both groups. Crestal bone loss was assessed with intraoral periapical radiographs with the help of computer software (DBSWIN viewer). Actual implant length acted as the radiographic index, and implant-abutment junctions were used as a reference point for all measurements. Mesial and distal bone levels at baseline, 6, and 12 months post implant placement of the two groups were determined. Mesial and distal crestal bone loss from baseline to 6 and 12 months were calculated and compared with Tukey test using SPSS v15.0 statistical analysis software.

RESULTS

Tukey test revealed similar (not statistically different) mean mesial crestal bone loss between the two groups after 6 months (0.47 ± 0.08 mm vs. 0.36 ± 0.13 mm, p = 0.576) and after 12 months (1.56 ± 0.25 mm vs. 1.50 ± 0.22 mm, p = 0.891). The mean distal bone loss resulting between the two groups was not statistically different at 6 months (0.44 ± 0.08 mm vs. 0.35 ± 0.12 mm, p = 0.687) and at 12 months (1.57 ± 0.23 mm vs. 1.61 ± 0.22 mm, p = 0.947).

CONCLUSIONS

The results of this clinical randomized control trial indicated that in controlled type 2 diabetic patients, levels of crestal bone loss around dental implants placed following conventional full thickness flap surgery was comparable to crestal bone loss around dental implants placed with the flapless surgical technique. More clinical studies are required regarding controlled type 2 diabetics with larger sample sizes, for long time periods to obtain more predictable results.

Flap Designs for Implant-Related Surgical Procedures: A Review

PURPOSE

The objective of this study was to compare the reliability and results of 2 flap techniques, flapless (FL) and full-thickness (FT) flap, during implant placement.

MATERIALS AND METHODS

Online and hand searches of the literature published were conducted to identify studies examining different flap techniques on clinical and histological outcomes. The search terms used, alone or in combination, were "flapless," "full-thickness flap," "crestal bone resorption," "gingival blood circulation," and "biological width."

RESULTS

Fifty studies were selected for comparison and to address the points highlighted in this study. Fourteen articles and 1 book were not directly related to flap design but were included for understanding the process of soft tissue healing. Five articles discussed the principles of oral surgery and flap design.

CONCLUSION

This review revealed that the FL technique might be more appropriate in immediate implant loading cases. This specific technique results in shallower biological width, reduced inflammation, less morbidity with guided implant placement, and better esthetics in comparison with the FT technique. The implant survival rates are not significantly different between the 2 flap techniques. With respect to crestal bone resorption in FL and FT, it is inconclusive, depending on the study type (human or animal).

Three-Year Outcome of Fixed Partial Rehabilitations Supported by Implants Inserted with Flap or Flapless Surgical Techniques

PURPOSE

The aim of this prospective clinical study was to evaluate the 3-year outcome of fixed partial prostheses supported by implants with immediate provisionalization without occlusal contacts inserted in predominantly soft bone with flap and flapless protocols.

MATERIALS AND METHODS

Forty-one patients partially rehabilitated with 72 NobelSpeedy implants (51 maxillary; 21 mandibular) were consecutively included and treated with a flapless surgical protocol (n = 20 patients; 32 implants) and flapped surgical protocol (n = 21 patients; 40 implants). Primary outcome measure was implant survival; secondary outcome measures were marginal bone resorption (comparing the bone levels at 1 and 3 years with baseline) and the incidence of biological, mechanical, and esthetic complications. Survival was computed through life tables; descriptive statistics were applied to the remaining variables of interest.

RESULTS

Eight patients with eight implants dropped out of the study. One implant failed in one patient (flapless group) giving an overall cumulative survival rate (CSR) of 98.6%. No failures were noted with the flapped protocol (CSR 100%), while for the implants placed with the flapless surgical technique, a 96.9% CSR was registered. The overall average marginal bone resorption at 3 years was 1.37 mm (SD = 0.94 mm), with 1.14 mm (SD = 0.49 mm) and 1.60 mm (SD = 1.22 mm) for the flap and flapless groups, respectively. Mechanical complications occurred in nine patients (n = 5 patients in the flapless group; n = 4 patients in the flap group). Implant infection was registered in three implants and three patients (flapless group), who exhibited inadequate oral hygiene levels.

CONCLUSIONS

Partial edentulism rehabilitation through immediate provisionalization fixed prosthesis supported by dental implants inserted through flap or flapless surgical techniques in areas of predominantly soft bone was viable at 3 years of follow-up. The limitations and risks of the "free-hand" method in flapless surgery should be considered when planning implant-supported fixed prosthetic reconstructions.

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.

Crestal bone loss and periimplant inflammatory parameters around zirconia implants: A systematic review

STATEMENT OF PROBLEM

Zirconia implants have been used for oral rehabilitation; however, evidence of their ability to maintain crestal bone and periimplant soft tissue health is not clear.

PURPOSE

The purpose of this systematic review was to evaluate crestal bone loss (CBL) around zirconia dental implants and clinical periimplant inflammatory parameters.

MATERIAL AND METHODS

The focus question addressed was, "Do zirconia implants maintain crestal bone levels and periimplant soft tissue health?" Databases were searched for articles from 1977 through September 2014 with different combinations of the following MeSH terms: "dental implants," "zirconium," "alveolar bone loss," "periodontal attachment loss," "periodontal pocket," "periodontal index." Letters to the editor, case reports, commentaries, review articles, and articles published in languages other than English were excluded.

RESULTS

Thirteen clinical studies were included. In 8 of the studies, the CBL around zirconia implants was comparable between baseline and follow-up. In the other 5 studies, the CBL around zirconia implants was significantly higher at follow-up. Among the studies that used titanium implants as controls, 2 studies showed significantly higher CBL around zirconia implants, and in 1 study, the CBL around zirconia and titanium implants was comparable. The reported implant survival rates for zirconia implants ranged between 67.6% and 100%. Eleven studies selectively reported the periimplant inflammatory parameters.

CONCLUSIONS

Because of the variations in study design and methodology, it was difficult to reach a consensus regarding the efficacy of zirconia implants in maintaining crestal bone levels and periimplant soft tissue health.