Soft tissue augmentation at immediate implants using a novel xenogeneic collagen matrix in conjunction with immediate provisional restorations: A prospective case series

Local delivery of pamidronate with collagen matrix mitigates buccal bone resorption following immediate implant placement - An experimental in vivo study

AIMS

The aim of this experimental in vivo pilot study was to evaluate the effect of the local delivery of pamidronate within a collagen membrane on the changes in the buccal soft and hard tissue dimensions at the time of immediate implant placement and whether this effect was influenced by the placement of bone substitutes.

METHODS

In six beagle dogs, the distal roots of the third and fourth premolars were extracted, and immediate implants were placed. Treatment groups were randomly allocated to each socket: (i) covering the buccal bone with pamidronate-soaked collagen membrane (BP group), (ii) filling the gap defect with synthetic bone substitute (BS group), (iii) filling the gap defect with synthetic bone substitute and covering the buccal bone with pamidronate soaked collagen membrane (BP/BS group), (iv) no treatment (control group). Intraoral scanning was performed immediately after the surgery and at 20 weeks. Histomorphometric and micro-computed tomography (CT) outcomes were evaluated at 20 weeks.

RESULTS

The micro CT analysis demonstrated that the BP group showed no apparent difference in vertical bone level with residual mesial root area, while control group showed significant buccal bone resorption at the implant site. The histomorphometric analysis demonstrated that the vertical bone level of buccal plate was significantly differed between the BP and control group (0.34 ± 0.93 and 1.27 ± 0.56 mm, respectively; p = .041). There was no statistically significant difference in the horizontal ridge width (HRW 1, 2, 3) among the groups. Also, the thickness, height and buccal contours of the soft tissue did not reveal significant changes among the groups.

CONCLUSION

The local delivery of pamidronate to the outer surface of the buccal wall at the time of immediate implant placement effectively limits buccal bone resorption. The results from the present investigation should be interpreted with caution, as well as its clinical translatability. Further investigation is needed to understand the pamidronate binding and releasing kinetic, as well as the ideal carrier of this drug for its topical application.

Effects of implant placement timing and type of soft-tissue grafting on histological and histomorphometric outcomes in a preclinical canine model

AIM

To determine the effects of implant timing and type of soft-tissue grafting on histological and histomorphometric outcomes in a preclinical model.

MATERIALS AND METHODS

Four implant placement protocols were randomly applied at the mesial root sites of the third and fourth mandibular premolars in 10 mongrel dogs: immediate placement (group IP), early placement (group EP), delayed placement with/without alveolar ridge preservation (groups ARP and DP, respectively). A connective-tissue graft (CTG) or porcine-derived volume-stable collagen matrix (VCMX) was applied to enhance the ridge profile (simultaneously with implant placement in group IP and staged for others), resulting in five sites for each combination. All dogs were sacrificed 3 months after soft-tissue grafting. Histological and histomorphometric analyses were performed, and the data were analysed descriptively.

RESULTS

CTG and VCMX were difficult to differentiate from the augmented area. The median total tissue thickness on the buccal aspect of the implant was largest in group IP/CTG (between 2.78 and 3.87 mm). The soft-tissue thickness was generally favourable with CTG at all implant placement timings. Within the DP groups, CTG yielded statistically significantly larger total and soft-tissue thickness than VCMX (p < .05). Among the groups with VCMX, group EP/VCMX showed the largest soft-tissue thickness at apical levels to the implant shoulder.

CONCLUSIONS

CTG generally led to greater tissue thickness than VCMX.

The facial-coronal ridge crest alterations after single immediate implant placement and provisionalization with thin buccal plate phenotype in anterior maxilla: A radiographic case-series study

AIM

To explore the features of and potential landmarks that predict crestal ridge remodeling after immediate implant placement and provisionalization (IIPP) with thin buccal plate phenotype in the anterior maxilla.

MATERIALS AND METHODS

Patients requiring IIPP of single maxillary incisor with thin buccal bone plate (<1 mm) were recruited. Cone-beam computed tomography (CBCT), performed before and 6 months after the intervention, were three-dimensionally superimposed. A virtual line connecting the bony emergence points of adjacent teeth was drawn as a reference. The facial-coronal alveolar crest of the extraction socket and healed ridge were located in mesial, middle and distal cross-sectional planes, and linear ridge reductions were measured. The correlation between ridge reduction and local factors was analyzed.

RESULTS

Fifty patients were included. From the extraction socket to healed ridge, the alveolar crest underwent linear bone reduction of 1.50 ± 0.50, 1.54 ± 0.66 and 1.65 ± 0.73 mm in the mesial, middle, and distal regions in an apical-palatal direction. The middle region had significantly higher horizontal (facial-palatal) but lower vertical (coronal-apical) bone reduction than the mesial and distal areas (P < 0.01). The facial-coronal ridge crest of the healed ridge located close to the reference line. Ridge reduction positively correlated with the distance between the initial facial-coronal crest of the extraction socket and the reference line (P < 0.01).

CONCLUSIONS

Alveolar crest of the socket lost its curvature and tended to attain a flat profile after IIPP due to inconsistent ridge reduction in middle, mesial and distal areas. The reference line may be a potential landmark for predicting the ridge crest after remodeling.

A biologically oriented preparation technique (BOPT) for immediate posterior implant placement, immediate provisionalization, and definitive implant crown fabrication: A complete digital workflow

OBJECTIVE

Immediate implants and immediate alveolar sealing have been a widely utilized treatment with high predictability and biological advantages. The improvement in technology has made it possible to simplify clinical processes. The aim of the present report was to describe the complete digital workflow of the Biologically oriented preparation technique for immediate posterior implant, immediate provisionalization and fabrication of definitive implant crowns.

CLINICAL CONSIDERATIONS

The surgical process and prosthetic management to preserve the gingival contours of the extracted natural tooth during immediate implant placement and provisionalization are described. Additionally, during the same clinical intervention, the definitive intraoral digital implant scans for capturing the implant position, peri-implant tissue contours, adjacent and antagonist dentition, and profile emergence of the interim implant crown are captured for the fabrication of the definitive crown.

CONCLUSIONS

Based on the technique described, the immediate implant placement and provisionalization in the posterior area provides biological and clinical advantages, reducing the number of abutment-implant disconnections and the number of clinical appointments, as well as increases patient comfort.

CLINICAL SIGNIFICANCE

The present article describes a technique for an immediate implant placement and provisionalization in the posterior region for maintaining the gingival architecture of the extracted tooth. During the same appointment, the implant position, peri-implant tissue contours, and adjacent and antagonist dentition, and profile emergence of the interim implant crown are captured by using an intraoral scanner and used for the fabrication of the definitive crown. This technique aims to reduce the number of abutment-implant disconnections and clinical appointments.

Marginal bone level change of immediately restored implants with simultaneous guided bone regeneration: A systematic review

AIM

To assess marginal bone level change (MBLc), clinical outcomes for soft tissue, and survival rates for immediately restored implants with simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS

Electronic and manual searches were conducted in PubMed/MEDLINE, EMBASE, and CENTRAL for studies that investigated immediately restored implants in simultaneously grafted sites with a mean follow-up of over 12 months. MBLc was the primary outcome. Soft tissue clinical parameters and implant survival rate (ISR) were the secondary outcomes.

RESULTS

Twenty-five studies (5 randomized controlled trials, 6 prospective studies, 2 retrospective studies, and 12 case series) were included, from which 692 immediately restored implants were analyzed. For studies that investigated bone grafts in the gap between the implant and the peripheral bone wall, the weighted mean MBLc was -0.73 ± 1.52 mm (range: -1.50 to 0.26 mm) for 475 implants. Pink esthetic score (PES) was improved in eight studies and the weighted cumulative ISR was 98.99% (Median: 100%) in 622 implants. Mean MBLc was -1.19 ± 0.26 mm for 30 implants in studies that reported gap with dehiscence and/or fenestration augmentation. Weighted cumulative ISR was 97.25% in 70 implants. A meta-analysis was not possible due to the lack of studies with an eligible control group. Therefore, the data should be interpreted with caution.

CONCLUSION

Less marginal bone loss and more predictable soft tissue parameters can be achieved for immediately restored implants with simultaneous peri-implant gap filling compared with gap with dehiscence/fenestration grafting. Increased ISR for implants with gap filling was observed. However, more evidence is needed to confirm whether immediate provisional prostheses should be utilized when bone defects are simultaneously augmented around the implants.

Efficacy of a collagen matrix for soft tissue augmentation after implant placement compared to connective tissue grafts: A multicenter, noninferiority, randomized controlled trial

OBJECTIVES

To test whether soft tissue volume augmentation using a collagen matrix (VCMX) leads to noninferior results in terms of gain of mucosal thickness at single implant sites, compared to connective tissue grafts (SCTG).

METHODS

The study was designed as a multi-center randomized controlled clinical trial. Subjects in need of soft tissue volume augmentation at single tooth implant sites were consecutively recruited at nine centers. The deficient mucosal thickness at the implant sites (one per patient) was augmented by applying either a VCMX or a SCTG. Patients were examined at 120 days (abutment connection = primary endpoint), 180 days (final restoration), and 360 days (1-year after insertion of the final restoration). Outcome measures included: transmucosal probing of the mucosal thickness (crestal = primary outcome), profilometric measurements of the tissue volume, and patient-reported outcome measures (PROMs).

RESULTS

Out of the 88 patients, 79 attended the one-year follow-up. The median increase of the crestal mucosal thickness between pre-augmentation and 120 days was 0.3 ± 2.1 mm in the VCMX group and 0.8 ± 1.6 mm in the SCTG group (p = .455). Non-inferiority of the VCMX compared to the SCTG was not observed. The respective numbers at the buccal aspect amounted to 0.9 ± 2.0 mm (VCMX) and 1.1 ± 1.4 mm (SCTG; p = .431). PROMs including pain perception favored the VCMX group.

CONCLUSION

It remains inconclusive whether soft tissue augmentation using a VCMX is noninferior to SCTG in terms of crestal mucosal thickening at single implant sites. However, the use of collagen matrices favors PROMs especially pain perception, while achieving similar buccal volume gains along with comparable clinical and aesthetic parameters to SCTG.

Efficacy of the application of leukocyte and platelet-rich fibrin (L-PRF) on alveolar ridge preservation. A randomized controlled clinical trial

INTRODUCTION

Alveolar ridge preservation (ARP) is a well-defined treatment performed to reduce bone dimensional changes occurring during the healing of post-extraction sockets to allow for adequate implant placement. Leukocyte and platelet-rich fibrin (L-PRF) has been showing to potentially promote bone and tissue regeneration during wound healing. Therefore, the aim of this study is to evaluate its efficacy for ARP when applied to fresh extraction sockets, in comparison with spontaneous healing.

MATERIALS AND METHODS

Twenty-seven patients with hopeless non-molar teeth were treated. After randomization, fresh extraction sockets were either filled with L-PRF or allowed to heal spontaneously. CBCTs and intraoral scans were obtained immediately after extraction and at 4 months. Through superimposition of the obtained images, changes in the horizontal ridge width, height, buccal volume, and ridge contour changes were measured, as well as patient-reported outcome measures (PROM's).

RESULTS

The ridge dimensions changed similarly in both groups. Although less reduction occurred in the test group at 1 mm from the bone crest, differences were not statistically significant (p > 0.05). Application of L-PRF did not prevent reductions of ridge contours, neither in the linear vertical aspect nor in volumetric changes. There were no differences between groups in the need for bone regeneration when placing implants. Patients in both groups reported similar outcomes in terms of bleeding, pain, inflammation, and function at 1 and 4 weeks postoperatively.

CONCLUSION

Alveolar preservation with L-PRF neither minimized bone resorption occurring after tooth extraction in non-molar sites nor reduced the need for bone regeneration when placing implants. Furthermore, its use did not improve PROM's.

Tissue integration and biodegradation of soft tissue substitutes with and without compression: an experimental study in the rat

OBJECTIVES

To analyze the influence of compression on tissue integration and degradation of soft tissue substitutes.

MATERIAL AND METHODS

Six subcutaneous pouches in twenty-eight rats were prepared and boxes made of Al₂O₃ were implanted and used as carriers for soft tissue substitutes: a collagen matrix (MG), two volume-stable collagen matrices (FG/MGA), and a polycaprolactone scaffold(E). The volume-stable materials (FG/MGA/E) were further implanted with a twofold (2) and a fourfold (4) compression, created by the stacking of additional layers of the substitute materials. The samples were retrieved at 1, 2, and 12 weeks (10 groups, 3 time points, n = 5 per time point and group, overall, 150 samples). The area fraction of infiltrated fibroblasts and inflammatory cells was evaluated histologically. Due to within-subject comparisons, mixed models were conducted for the primary outcome. The level of significance was set at 5%.

RESULTS

The area fraction of fibroblasts increased in all groups over time. At 12 weeks, the densely compressed materials FG4 (1.1%), MGA4 (1.7%), and MGA2 (2.5%) obtained lower values as compared to the other groups, ranging between 4.7 (E2) and 6.5% (MG). Statistically significant differences (p ≤ 0.05) were observed between groups FG4 vs MG/FG2/E/E4 as well as between MGA4 vs MG/FG2/E/E4 and E vs MGA2.

CONCLUSIONS

Higher levels of compression led to delayed tissue integration. The effect of different compression levels was more distinct when compared to the differences between the materials.

CLINICAL RELEVANCE

All biomaterials demonstrated tissue integration and a minimal concomitant inflammatory reaction. Clinically, it might be more favorable to obtain a sufficient flap release or to reduce the material size to improve the tissue integration processes.

Minimal invasiveness in soft tissue augmentation at dental implants: A systematic review and meta-analysis of patient-reported outcome measures

The aim of this study was to compare patient-reported outcome measures (PROMs) of soft tissue substitutes versus autogenous grafts for soft tissue augmentation procedures at implant sites. Comprehensive and systematic literature searches were performed until December 2021. A focused question was formulated based on the Population, Intervention, Comparison and Outcome criteria (PICO): In patients with dental implants undergoing soft tissue augmentation (P), do soft tissue substitutes (I) compared to autogenous soft tissue graft (SCTG [subepithelial connective tissue graft]) (C) limit the post-operative morbidity and other patient reported-outcomes measures (O). Randomized controlled clinical trials, prospective-, retrospective- and case-series studies were included. Meta-analyses were performed whenever possible and the results were expressed as weighted mean differences (WMD). A total of 29 clinical studies were included. For mucosal thickness gain, soft tissue substitutes significantly reduced the pain perception compared to SCTG (n = 4; WMD = 14.91 Visual Analog Scale [VAS] units; 95% confidence interval [CI] 6.42-23.40; P < .0006) based on a 0-100 VAS scale. Based on a 0-10 VAS scale, a borderline significance of pain reduction was found when soft tissue substitutes were applied (n = 4; WMD = 1.62 VAS units; 95% CI 0.01-3.23; P = .05). For keratinized tissue gain, soft tissue substitutes significantly reduced the pain perception after keratinized tissue augmentation compared to SCTG based on a 0-100 VAS scale (n = 2; WMD = 21.43 VAS units; 95% CI 12.58-30.28; P < .0001). Based on the 0-10 VAS scale, soft tissue substitutes significantly reduced the pain as compared to SCTG (n = 4; WMD = 1.65 VAS units; 95% CI 0.66-2.64; P = .001). Regarding pain medication, soft tissue substitutes required less painkillers (n = 6; WMD = 1.56 tablets; 95% CI 1.22-1.91; P < .00001) after soft tissue augmentation. The surgery time was significantly reduced when soft tissue substitutes were used (n = 5; WMD = 10.9 minutes; 95% CI 4.60-17.19; P < .00001). There were no significant differences in satisfaction, aesthetics, and quality of life (OHIP-14) between soft tissue substitutes and autogenous grafts following soft tissue augmentation at implants sites. Soft tissue substitutes, compared to autogenous grafts, significantly improve PROMs following soft tissue augmentation at implant sites. Soft tissue substitutes can reduce pain perception, amounts of painkillers and surgery time while achieving similar levels of patient´s satisfaction as autogenous grafts without impairing the clinical outcomes. The current evidence indicates that they constitute a valid and reliable alternative to minimize the invasiveness in soft tissue augmentation procedures at implant sites.

Soft and hard tissue changes after immediate implant placement with or without a sub-epithelial connective tissue graft: results from a 6-months pilot randomized controlled clinical trial

AIM

The present pilot RCT aimed to investigate the influence of a connective tissue graft (CTG) in combination with the immediate implant placement (IIP) on hard and soft tissues healing, without a bone replacement graft in the gap between the implant and the socket walls.

MATERIAL AND METHODS

Thirty patients requiring extraction of one anterior tooth (from premolar to premolar) were randomly assigned to one of the two treatment groups (test: IIP+CTG; control: IIP). Cone-beam computed tomography (CBCT) and optically scans were performed before tooth extraction and at 6-months follow-up. Then, DICOM files were superimposed in order to allow the evaluation of osseous ridge and buccal bone changes, while the superimposition of DICOM and STL (Standard Tessellation Language) files allowed for evaluating of soft tissue contour. For testing the differences between the two groups, the non-parametric test as Wilcoxon rank-sum test, was used.

RESULTS

Twenty-six out of the thirty enrolled patients, attended the 6-month follow-up visit. The 4 patients of control group that were lost to follow-up, were analyzed under the intention-to-treat principle. No statistically significant differences between the groups were observed for the vertical buccal bone resorption (p=0.90), as well as for the horizontal buccal bone resorption at all measured levels. Significant differences were found between test and control groups in the horizontal dimensional changes of osseous ridge at the most coronal aspect (p=0.0003 and p=0.02). Changes of tissue contour ranged between -0.32 and -0.04 mm in the test group, and between -1.94 and -1.08 mm in the control group, while changes of soft tissue thickness varied between 1.33 and 2.42 mm in the test group, and between -0.16 and 0.88 mm in the control group, with statistically significant differences for both variables at all measured levels. At 6 months, the mean volume increase was 6.76±8.94 mm³ and 0.16±0.42 mm³ in the test and control groups, respectively, with statistically significant difference.

CONCLUSIONS

The findings of the present study indicate that the adjunct of a connective tissue graft at the time of immediate implant placement, without bone grafting, does not influence vertical bone resorption. Within the limits of the present study, it can be suggested that the adjunct of a connective tissue graft at the time of immediate implant placement, without bone grafting, reduces the horizontal changes of the alveolar ridge. Moreover, it allows maintenance of the tissue contour due to an increase in soft tissue thickness.

The influence of thin as compared to thick peri-implant soft tissues on aesthetic outcomes: A systematic review and meta-analysis

Objectives

In systematically healthy patients with an implant‐supported fixed restoration (P), what is the influence of thin (E) as compared to thick (C) peri‐implant soft tissues on aesthetic outcomes (O)?

Methods

Following an a priori protocol, a literature search of six databases was conducted up to August 2020 to identify prospective/retrospective clinical studies on healthy patients with an implant‐supported fixed reconstruction. Measurement of the buccal soft tissue thickness and an aesthetic outcome was a prerequisite, and sites presenting with a buccal soft tissue thickness of <2 mm or shimmering of a periodontal probe were categorized as a thin phenotype. After study selection, data extraction, and risk of bias assessment, random‐effects meta‐analysis of Mean Differences (MD) or Odds Ratios (OR) with their corresponding 95% Confidence Intervals (CI) were conducted, followed by sensitivity analyses and assessment of the quality of evidence.

Results

Thirty‐four unique studies reporting on 1508 patients with 1606 sites were included (9 randomized controlled trials, one controlled trial, 10 prospective cohort studies, 8 cross‐sectional studies, and 6 retrospective cohort studies). The mean difference of the pink aesthetic score (PES) after the follow‐up was not significantly different between thin (<2.0 mm) or thick soft tissues (≥2.0 mm) or phenotypes (12 studies; MD = 0.15; [95% CI = −0.24, 0.53]; p = .46). PES changes during the follow‐up, however, were significantly in favour of thick soft tissues (≥2.0 mm) or phenotypes (p = .05). An increased mean mucosal thickness was associated with an increased papilla index (5 studies; MD = 0.5; [95% CI = 0.1, 0.3]; p = .002) and an increase in papilla presence (5 studies; OR = 1.6; [95% CI = 1.0, 2.3]; p = .03). Thin soft tissues were associated with more recession, −0.62 mm (4 studies; [95% CI = −1.06, −0.18]; p = .006). Patient‐reported outcome measures (patient satisfaction) were in favour of thick soft tissues −2.33 (6 studies; [95% CI = −4.70, 0.04]; p = .05). However, the quality of evidence was very low in all instances due to the inclusion of non‐randomized studies, high risk of bias and residual confounding.

Conclusion

Within the limitations of the present study (weak study designs and various soft tissue measurements or time‐points), it can be concluded that increased soft tissue thickness at implant sites was associated with more favourable aesthetic outcomes.

Clinical evaluation of the buccal aspect around immediate implant using dual zone therapeutic concept versus buccal gap fill to bone level: A randomized controlled clinical trial

OBJECTIVE

Soft tissue esthetics for immediate implant is considered challenging when restoring a tooth in an esthetic zone. This study aimed to evaluate the buccal aspect after immediate implant using the dual-zone therapeutic concept compared to grafting the buccal gap to the bone crest.

MATERIALS AND METHODS

Twenty-four patients were randomly assigned into either immediate implant with the dual-zone therapeutic concept (DZ, test group) or with bone grafting till buccal bone crest with immediate temporization (BCG, control group). Pink esthetic score (PES), buccal bone loss (BBL), mid-facial recession (MFR), soft tissue thickness (STT), keratinized tissue width (KTW), post-operative swelling (POS), and patient satisfaction (PS) were evaluated for 1 year.

RESULTS

At 12 months the PES in the test group was 11.36 ± 1.69, and 10.80 ± 1.55 in the control group, with no statistically significant difference (p = 0.45). MFR in the DZ and BCG groups was 0.27 ± 0.34 and 0.45 ± 0.44 after 12 months with no statistical significance difference (p = 0.195). The STT assessment showed a statistically significant increase in both groups, however the intergroup comparison was statistically not significant (p = 0.23). The mean KTW in the DZ and BCG groups was 4.55 ± 1.08 and 4.20 ± 0.82 mm, respectively with no statistical significance (p = 0.42). There was no statistical significant difference in patient satisfaction between the two groups except in question number 10 concerning the post-operative swelling which was higher in the DZ group (p = 0.009).

CONCLUSIONS

Both treatment modalities are considered reliable methods to achieve good soft tissue esthetics. However, both treatment modalities were not effective in preventing facial bone resorption despite the use of bone graft.

Dimensional ridge changes in conjunction with four implant timing protocols and two types of soft tissue grafts: A pilot pre-clinical study

AIM

To determine the effect of (1) implant placement timing and (2) the type of soft tissue graft in terms of ridge profile changes.

MATERIALS AND METHODS

Four implant treatment modalities were applied in the mesial root areas of the third and fourth mandibular premolars of 10 mongrel dogs alongside connective-tissue graft (CTG) and volume-stable cross-linked collagen matrix (VCMX): immediate, early, and delayed placement (DP), and DP following alveolar ridge preservation (ARP). All dogs were sacrificed 3 months after soft tissue augmentation. Standard Tessellation Language files from designated time points were analysed.

RESULTS

Compared with the pre-extraction situation, the median width of the ridge demontstrated a linear increase only in group ARP/CTG (0.07 mm at the 2-mm level), whereas all other groups showed a reduction (between -1.87 and -0.09 mm, p > .05). Groups ARP/CTG (0.17 mm) and DP/CTG (0.05 mm) exhibited a profilometric tissue gain in a set region of interest (p > .05). The net effect of CTG and VCMX ranged from 0.14 to 0.79 mm.

CONCLUSIONS

Dimensional ridge changes varied between treatment protocols. ARP with CTG led to the smallest difference in ridge profile between the pre-extraction and the study end time point. Both CTG and VCMX enhanced the ridge contour.

Does simultaneous soft tissue augmentation around immediate or delayed dental implant placement using sub-epithelial connective tissue graft provide better outcomes compared to other treatment options? A systematic review and meta-analysis

OBJECTIVE

The clinical benefits of simultaneous implant placement and soft tissue augmentation using different treatment modalities are unclear. The current meta-analysis aimed to compare the effect of simultaneous soft tissue augmentation using subepithelial connective tissue graft (SCTG) around immediate or delayed dental implant placement with other treatment modalities on the peri-implant tissue health and esthetic.

METHODS

Up to May 2021, four databases (PubMed, EMBASE, Cochrane Central, and Google Scholar) were searched. Randomized control trials with follow-up >3 months, evaluating simultaneous implant placement (immediate or delayed) and soft tissue augmentation using SCTG compared with other treatment modalities were included. The predictor variables were SCTG versus no augmentation with/without guided bone regeneration (GBR) or other augmentation techniques (Acellular dermal matrix (ADM), Xenogeneic collagen matrix (XCM). The outcome variables were buccal tissue thickness (BTT), mid-buccal gingival level (MGL), marginal bone loss (MBL), and pink esthetic scores (PES). Cumulative mean differences (MD) and 95% confidence interval (CI) were estimated.

RESULTS

Twelve studies were included. SCTG along with immediate implant placement (IIP) or delayed implant placement (DIP) showed a statistically significant improvement in BTT (Fixed; MD, 0.74; 95% CI, 0.51; 0.97), MGL (Fixed; MD, 0.5; 95% CI, 0.21; 0.80), PES (Fixed; MD, 0.79; 95% CI, 0.29; 1.29), and less MBL (Fixed; MD, -0.11; 95% CI, -0.14; -0.08) compared to no graft (P<0.05). A statistically insignificant differences in BTT (Random; MD, 0.62; 95% CI, -0.41; 1.65), MGL (Fixed; MD, -0.06; 95% CI, -0.23; 0.11), MBL (Fixed; MD, 0.36; 95% CI, -0.05; 0.77) and PES (Fixed; MD, 0.28; 95% CI, -0.10; 0.67) was observed when SCTG along with DIP was compared with no augmentation plus GBR. Similarly, no statistically significant difference was observed when comparing SCTG along with DIP with acellular dermal matrix (ADM) concerning BTT (MD:0.71, P = 0.18) and KMW (MD: 0.6, P = 0.19).

CONCLUSION

There is a very low quality of evidence to provide recommendations on whether simultaneous dental implant placement (IIP or DIP) and soft tissue augmentation using SCTG is superior to no augmentation or is comparable to the other tissue augmentation materials in improving the quality and quantity of peri-implant tissues. Therefore, further, well-designed RCTs with larger sample sizes and long follow-up times are still needed.

Buccal bone dimensional changes at immediate implant sites in the maxillary esthetic zone within a 4-12-month follow-up period: A systematic review and meta-analysis

OBJECTIVE

To evaluate the changes in buccal bone dimensions (CBD) following immediate implant placement in the maxillary esthetic zone and to identify the factors influencing the degree of buccal bone resorption for different placement and restoration protocols.

MATERIAL AND METHODS

An electronic search was conducted using the EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and MEDLINE (PubMed) databases, combined with a manual and gray literature search, up to January 2021. Selected clinical studies had to report the changes in horizontal buccal bone dimension in maxillary immediate implantation sites (premolar to premolar) at baseline and at follow-up visits within a year of implantation. A meta-analysis was conducted to calculate the mean value of the changes in horizontal and vertical buccal bone dimensions (CHBD and CVBD) around implants. To further investigate the heterogeneity and identify factors associated with buccal bone loss after immediate implant placement, subgroup analysis and univariate meta-regression were performed.

RESULTS

From a total of 3498 articles, 4 randomized controlled trials and 12 nonrandomized controlled trials were included for analysis. The mean survival rate of 568 implants was 99.6%. The mean CHBD and CVBD values were 0.71 mm (95% confidence interval: [0.56, 0.86]) and 0.58 mm (95% confidence interval: [0.43, 0.72]), respectively. For possible factors that related to bone resorption, including buccal bone thickness, flap design, bone grafting, horizontal defect dimension, and restoration protocol, bone grafting was the only variable that significantly influenced CHBD.

CONCLUSIONS

This study demonstrated that immediate implant placement in the esthetic zone does not prevent buccal bone from resorption. Due to data heterogeneity and the small sample size of the studies included in the analysis, further well-conducted, randomized controlled trials with homogeneous samples are required to investigate the correlation of CBD with different variables.

A multi-centre randomized controlled trial comparing connective tissue graft with collagen matrix to increase soft tissue thickness at the buccal aspect of single implants: 3-month results

AIM

To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of changes over time in buccal soft tissue profile (BSP) when applied at single implant sites.

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal mucosa defect were enrolled in a multi-centre randomized controlled trial. All sites had a bucco-palatal bone dimension of at least 6 mm and received a single implant and immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX: Geistlich Fibro-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) to increase buccal soft tissue thickness. Primary outcome was increase in BSP at T1 (immediately after operation) and T2 (3 months) based on superimposed digital surface models. Secondary parameters included patient-reported clinical and aesthetic outcomes.

RESULTS

Thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48). Even though surgeons applied thicker grafts when using CMX, sites treated with CMX demonstrated 0.78 mm (95% CI 0.41-1.14) more shrinkage between T1 and T2 than sites treated with CTG. The final increase in BSP was 1.15 mm (95% CI 0.88-1.43) for CTG and 0.85 mm (95% CI 0.58-1.13) for CMX. The mean difference of 0.30 mm (95% CI -0.01 to 0.61) at T2 in favour of CTG was of borderline significance (p = .054). There were no significant differences between the groups in terms of post-operative bleeding (p = .344), pain (p = .331), number of analgesics taken (p = .504), oedema (p = .227), and pink aesthetic score (p = .655). VAS for post-operative haematoma was 6.56 (95% CI 0.54-12.59) lower for CMX, and surgery time could be reduced by 9.03 min (95% CI 7.04-11.03) when applying CMX. However, CMX resulted in significantly more marginal bone loss (0.38 mm; 95% CI 0.15-0.60), deeper pockets (0.30 mm; 95% CI 0.06-0.54), and more mid-facial recession (0.75 mm; 95% CI 0.39-1.12) than CTG.

CONCLUSIONS

CTG remains the gold standard for increasing soft tissue thickness at the buccal aspect of implants.

Does the timing of implant placement and loading influence biological outcomes of implant-supported multiple-unit fixed dental prosthesis-A systematic review with meta-analyses

OBJECTIVE

To investigate the impact of timing of implant placement and loading on implant survival and biological outcomes of multiple-unit implant-supported fixed dental prosthesis (FDPs).

MATERIAL AND METHODS

A literature search was performed by three independent reviewers for studies reporting on ≥10 patients with FPDs supported by ≥two implants over ≥3 years of follow-up. Data were analyzed on implant survival and biological complications as primary outcomes and biological events, including changes in peri-implant marginal bone level (MBL), probing depth, soft-tissue level, and health condition as secondary outcomes.

RESULTS

7002 titles were identified, 360 full-texts were screened, and 14 studies were included. These comprised 6 randomized controlled studies (RCTs), 5 cohort studies, and 3 case series with identifiable implant placement and loading protocols in five of 09 possible combinations. All groups but one (IPIL) showed implant survival rates >90%. A meta-analysis based on 3 RCTs found no differences in survival rate between DPIL and DPDL (p = .227).

CONCLUSIONS

High survival rates for all studied implant placement and loading combinations were shown for FPDs over ≥3 years of follow-up. When a delayed implant placement protocol is applied, immediate or delayed loading demonstrated similar survival rates. The heterogeneity of the data did not allow to draw any further conclusions on the occurrence of biological complications related to timing of implant placement/loading.

Immediate implant placement combining socket seal abutment and peri-implant socket filling: A prospective case series

OBJECTIVES

The aim of this prospective case series was to assess the implant outcomes as well as hard and soft tissue dimensional changes of immediate implant placement in posterior sites using a custom-made sealing socket abutment (SSA) combined to peri-implant socket filling (PISF).

MATERIAL AND METHODS

Twenty patients were considered for single extraction and immediate implant in upper or lower posterior regions. The remaining peri-implant sockets were filled with Deproteinized Bovine Bone Mineral. Based on intra-oral scans (IOS), custom-made SSAs were placed the same day. Implant survival rate, peri-implant bone changes, peri-implant health and pink esthetic score (PES) were recorded up to 1 year post-implant placement. Moreover, CBCT and IOS were performed to monitor hard and soft tissue dimensional changes.

RESULTS

One implant failed to osseointegrate leading to an implant survival rate of 95% after 1 year. Peri-implant bone changes yielded 0.19 ± 0.31 mm and 84.2% of the implants displayed no or mild bleeding on probing. Horizontal bone remodeling was not significant from baseline to 1 year at any levels. Finally, soft tissue profile was stable in the most cervical area while minor changes occurred during the first 6 months below the gingival margin. The absence of mid-buccal recession (0.07 mm) and good PES were found after 1 year.

CONCLUSION

Despite its limitations, this study showed that immediate implants in the posterior region using the SSA + PISF protocol resulted in promising implant outcomes with limited hard and soft tissue dimensional changes while decreasing the overall treatment time.

The effect of soft tissue augmentation on the clinical and radiographical outcomes following immediate implant placement and provisionalization: a systematic review and meta-analysis

Background

Nowadays, due to the esthetic and social demands of patients, conventional staged protocols seem to be increasingly replaced by faster, one-step protocols. The purpose of the present systematic review is to assess the peri-implant soft tissue changes after immediate implant placement and provisionalization (IIPP) comparing patients treated with or without a sub-epithelial connective tissue graft (SCTG) when replacing a single tooth in the esthetic region.

Methods

The present systematic review was written following the PRISMA checklist. Immediate implants placed with a connective tissue graft and without one were compared. The researched primary outcomes were the mid-buccal mucosa level (MBML) facial soft tissue thickness (FSTT) and marginal bone loss (MBL). The weighted mean differences (WMD) were estimated for all three outcomes.

Results

The change in the mid-buccal mucosa level in the intervention group was significantly higher (WMD 0.54; 95% CI 0.33–0.75), with no indication of heterogeneity (I² = 16%). The facial soft tissue thickness increased significantly in the intervention group (WMD 0.79; 95% CI 0.37–1.22). The marginal bone loss was significantly higher in the control group (WMD 0.13; 95% CI 0.07–0.18), with no indication of heterogeneity (I² = 0%).

Conclusions

The results of the meta-analyses showed a statistically significant reduced change of the marginal bone loss and vestibular recession, as well as higher soft tissue thickness, when a graft was used. The included studies had a short observation time; therefore, studies with longer follow-ups are needed to confirm these findings.

Clinical and Histological Differences between Guided Tissue Regeneration with Acellular Dermal Matrix of Porcine Origin and Autologous Connective Tissue: An Animal Study

This research aims to evaluate the clinical and histological parametric differences concerning keratinized tissue that result from two regeneration techniques, the subepithelial autologous connective tissue graft (ACTG) and the acellular dermal matrix (MD) of porcine origin, performed on surgical beds on edentulous spaces in an animal model. The parameters of the MD and ACTG groups were compared with samples of the control group (CG) after 15, 45, and 90 days. Nine female white pigs (Sus scrofa domestica) were used, and each animal provided 20 study areas (12 MD and 8 ACTG). At 15 days, the keratin layer thickness in the MD group was greater than those of the ACTG (25.27 vs. 19.95 μm) and the CG (21.2 μm). After 45 days, the MD and ACTG thickness values decreased but were higher than the CG. At 90 days, MD (19.46 μm) obtained a value close to that of CG, and the ACTG decreased to CG (15.53 μm, p < 0.001). The use of an MD may be a viable alternative to the ACTG because of its ability to provide increased keratinized tissue in comparison to the ACTG.

Clinical comparison of a xenogeneic collagen matrix versus subepithelial autogenous connective tissue graft for augmentation of soft tissue around implants

Dental implant placement is a predictable therapy for replacing teeth. Nevertheless, mechanical, biological, and aesthetic complications frequently occur. The aim of this study was to compare the clinical outcomes of a xenogeneic collagen matrix (XCM) used at the time of implant placement as an alternative to a subepithelial connective tissue graft (SCTG), for soft tissue augmentation. This was a prospective clinical trial with 12 months of follow-up. In the control group, soft tissue augmentation at the time of implant placement was performed with a SCTG, while in the test group, a XCM was employed. At 12 months postoperative, all xenografts showed no postoperative complications. In both groups, a significantly greater thickness was observed on the buccal and occlusal sides from preoperative to 3 months postoperative (P<0.05). No statistically significant difference in pink aesthetic score (P=0.379, 6 months postoperative) or marginal bone loss (P=0.449 at 3 months postoperative, P=0.778 at 6 months postoperative) was observed between the groups. Statistically significant differences in pain perceived by the patients (P<0.0001) and the time to complete the surgical procedure (P=0.0008) were detected. At 12 months after surgery, XCM provided similar clinical results in terms of soft tissue augmentation on the buccal and occlusal sides as compared with the SCTG.

The effect of immediate implant placement on alveolar ridge preservation compared to spontaneous healing after tooth extraction: Soft tissue findings from a randomized controlled clinical trial

AIM

To compare soft tissue dimensional changes and relative differences in soft and hard tissue volumes 4 months after single-tooth extraction and three different treatment modalities: spontaneous healing (SH) and alveolar ridge preservation by means of a deproteinized bovine bone mineral and a collagen matrix, with (IMPL/DBBM/CM) or without (DBBM/CM) immediate implant placement.

MATERIALS AND METHODS

STL files from study casts obtained at baseline and after 4 months were matched to calculate buccal soft tissue linear and volumetric changes. DICOM files from CBCTs were superimposed to STL files allowing the evaluation of soft tissue thickness at baseline and 4 months.

RESULTS

Mean horizontal reduction accounted for 1.46 ± 0.20 (SH), 0.85 ± 0.38 (DBBM-CM) and 0.84 ± 0.30 IMPL/DBBM-CM, with no statistical differences. Soft tissue thickness had a significant mean increase of 0.95 for SH group, compared to a non-significant mean decrease for DBBM-CM (0.20) and IMPL/DBBM-CM groups (0.07).

CONCLUSION

A preservation technique with DBBM-CM, with or without immediate implant placement, did not reduce the horizontal linear and volumetric changes at the buccal soft tissue profile significantly at 4 months after tooth extraction when compared to spontaneous healing. This is due to a significant increase in soft tissue thickness in spontaneously healing sites.

Volumetric changes at implant sites: A systematic appraisal of traditional methods and optical scanning-based digital technologies

AIM

To evaluate techniques for assessing soft tissue alterations at implant sites and compare the traditionally utilized methods to the newer three-dimensional technologies emerging in the literature.

MATERIALS AND METHODS

A comprehensive search was performed to identify interventional studies reporting on volumetric changes at implant sites following different treatments.

RESULTS

Seventy-five articles were included the following: 30 used transgingival piercing alone, one utilized calliper, six with ultrasonography, six on cone-beam computed tomography, and 32 utilized optical scanning and digital technologies. Optical scanning-based digital technologies were the only approach that provided 'volumetric changes,' reported as volumetric variation in mm³ , or the mean distance between the surfaces/mean thickness of the reconstructed volume. High variability in the digital analysis and definition of the region of interest was observed. All the other methods reported volume variation as linear dimensional changes at different apico-coronal levels. No studies compared volumetric changes with different approaches.

CONCLUSIONS

Despite the emergence of optical scanning-based digital technologies for evaluating volumetric changes, a high degree of variation exists in the executed workflow, which renders the comparison of study results not feasible. Establishment of universal guidelines could allow for volumetric comparisons among different studies and treatments.

Clinical and volumetric analysis of peri-implant soft tissue augmentation using an acellular dermal matrix: A prospective cohort study

BACKGROUND

The role of keratinized mucosa in promoting peri-implant health is controversial, however recent evidence support the use of soft tissue augmentation procedures around dental implants. Soft tissue substitutes have been proposed to replace autogenous connective tissue grafts, therefore the aims of this study are to report clinical and volumetric three-dimensional changes in mucosal thickness (MT) 1 year after treatment with an acellular dermal matrix (ADM).

METHODS

Soft tissue augmentation was performed at second-stage surgery in the premolar maxillary area with an ADM. MT was assessed prior to implant placement and 1, 6, and 12 months after treatment. Digital linear and volumetric measurements were recorded at baseline and after 1 and 12 months. Furthermore, clinical parameters (Probing Pocket Depths, Bleeding On Probing, Plaque Index) and marginal bone loss were also recorded. Esthetic outcomes of treatment were evaluated objectively using the Pink Esthetic Score and through patient reported outcomes.

RESULTS

Twelve patients were enrolled in this prospective study. Post-hoc analysis of the assessments with Tukey's honestly significant difference adjustment revealed that the MT had increased significantly from baseline to 1 month (P < 0.001), 6 months (P < 0.001) and 12 months (P < 0.001), and remained stable between 6 months and 12 months (P > 0.05). Based on the volumetric evaluation, a shrinkage of 23.31% occurred from 1 month to 12 months (P > 0.05).

CONCLUSIONS

A significant increase in MT was reported after 1 year, with a mean gain of 1.25 mm. Soft tissues were stable, with no statistically significant differences between 6 months and 1 year.