Outcome measures and methods of assessment of soft tissue augmentation interventions in the context of dental implant therapy: A systematic review of clinical studies published in the last 10 years

Timing of keratinized mucosa augmentation and peri-implant outcomes: A systematic review and meta-analysis

PURPOSE

This study aimed to compare different surgical timings for keratinized mucosa (KM) augmentation and assess the impact on peri-implant parameters stability.

METHODS

Electronic searches were conducted through MEDLINE (via PubMed), Scopus, Embase, and Web of Science up to June 13, 2024, which was completed with a manual search. The inclusion criteria focused on randomized and non-randomized human clinical studies that assessed outcomes of KM augmentation, with at least 3-months follow-up. The analysis included changes in KM width over time and several secondary outcomes.

RESULTS

Twenty-five studies satisfied the inclusion criteria. The studies included 855 patients and 1588 implants. The KM width significantly increased after surgery, regardless of the time or method of intervention (MD: 5.17, 95% CI: 4.59, 5.75, p<0.001). The second-stage surgery, particularly with the use of autogenous graft, indicated the lowest reduction in KM width up to 3 months after surgery, while a significant shrinkage was found when the augmentation was performed post-restoratively.

CONCLUSION

The evidence suggests that second-stage surgery is acceptable for KM augmentation, whereas the post-restorative phase is generally not the primary option. In cases where suboptimal soft tissue conditions are detected, it is advisable to either undertake KM augmentation or refer the patient for additional assessment before proceeding with the delivery of the restoration. Due to limited data, it is not possible to come to a definitive conclusion about the other surgical phases.

Soft-tissue volume augmentation during early, delayed, and late dental implant therapy: A systematic review and meta-analysis on professionally determined esthetics and self-reported patient satisfaction on esthetics

The objective of the study was to assess the effect of soft-tissue volume augmentation during early, delayed, and late dental implant therapy in terms of professionally determined esthetics and self-reported patient satisfaction on esthetics. For this, a comprehensive electronic literature search was performed to identify randomized clinical trials (RCTs) and controlled clinical trials (CCTs) reporting professionally determined esthetic outcomes and self-reported patient satisfaction on esthetics (primary outcomes) during early, delayed, and late dental implant placement comparing soft-tissue volume augmentation to the absence of soft-tissue grafting (control) (PICO 1) or comparing various soft-tissue augmentation techniques, procedures, and materials (PICO 2). Secondary outcomes were mucosal thickness (MT), intra- and postoperative complications, marginal soft-tissue-level changes, keratinized tissue width, radiographic marginal bone levels, and clinical parameters for the diagnosis of peri-implant tissue health. The standard mean differences (SMD)/weighted mean differences (WMD) were estimated for the Pink Esthetic Score (PES), self-reported patient satisfaction assessed by Visual Analog Scale (VAS) and MT gain for PICO 1 and PICO 2 by employing a random effect model. Five RCTs were included for PICO 1, whereas 7 RCTs and 1 CCT addressed PICO 2. PICO 1: The SMD for the PES between autogenous soft-tissue grafting (SCTG) and the absence of grafting (control group) was 0.47; 95% CI [-0.15, 1.09; p = 0.14] based on 5 RCTs. The SMD for the VAS values for patient-reported satisfaction on esthetics in the SCTG and control group was 0.46; 95% CI [-0.12, 1.03; p = 0.12] (2 RCTs). The WMD for gain of MT amounted to 1.06 mm; 95% CI [0.81, 1.31; p = 0.00] in favor of the SCTG group (3 RCTs). PICO 2: The SMD for the PES comparing collagen-based matrices (CM group) to the SCTG group was -0.32; 95% CI: (-0.57, -0.07; p = 0.01), in favor of the SCTG group (5 RCTs and 1 CCT). The SMD for the VAS for patient-reported satisfaction on soft-tissue esthetics was 0.24; 95% CI: (-0.31, 0.78; p = 0.40) (2 RCTs comparing CM vs. SCTG). The WMD for gain of MT was -0.27 mm; 95% CI: (-0.36, -0.17; p = 0.00), significantly favoring the SCTG group (4 RCTs). Professionally and patient-assessed outcomes showed no substantial differences between autogenous soft-tissue grafting and the absence of grafting for early, delayed, and late implant placement. However, autogenous soft-tissue grafts led to significantly improved esthetic outcomes as assessed by professionals compared to soft-tissue substitutes. Patient-assessed outcomes, nevertheless, were similar regardless of the grafting material (i.e., SCTG or soft-tissue substitute). Therefore, autogenous soft-tissue grafting, though, resulted in a considerably higher gain in mucosal thickness compared to both the absence of soft-tissue grafting and the use of soft-tissue substitutes. Complications and adverse events were rarely reported by the included studies, thus suggesting that many trials underreport harms (e.g., complications).

Characterization of the anterior maxillary region for immediate implant placement: A radiographic cross-sectional study

STATEMENT OF PROBLEM

Information regarding the influence of local phenotypical features in the context of immediate implant placement (IIP) in the anterior maxillary region is sparse.

PURPOSE

The purpose of this clinical study was to characterize key phenotypical and anatomical characteristics of the anterior maxilla related to the feasibility of virtual IIP.

MATERIAL AND METHODS

Cone beam computed tomography (CBCT) scans acquired from adult participants were used for virtual implant placement and to measure periodontal phenotypical dimensions (buccal and palatal gingival (GT) and bone thickness (BT)), the buccal gap (BG) at different apico-coronal levels, and anatomical variables nasopalatine canal and ramifications, nasal cavity, maxillary sinus). The study sample was comprised of 330 maxillary anterior teeth. Two different immediate implant modalities were examined: cingulum emergence plan (CEP) and incisal edge emergence plan (IEP).

RESULTS

A total of 660 implants were virtually placed. The mean periodontal phenotypical dimensions showed variability between and within individuals depending on the apico-coronal level, tooth type, and implant placement modality. Immediate implant feasibility was 90.1% and 93.6% for the CEP and IEP groups, respectively, and was influenced by tooth type and anatomical variables. BG distance was generally greater at the coronal aspect and in the CEP. Thick bone and gingiva (≥1 mm) were observed in 15.2% and 89.3% of the sites, respectively. A minimum of 2 mm of apical bone availability to achieve primary stability was observed in 88.8% and 91.2% of the sites in the CEP and IEP groups, respectively.

CONCLUSIONS

This study highlights the variability in periodontal phenotypical and local anatomical features at anterior maxillary sites. These observations underscore the importance of recognizing such variations that should be identified and considered during the planning and execution of therapy.

Patient-Reported Outcome Measures Following Implant Placement With Simultaneous Horizontal Bone Augmentation

OBJECTIVES

This study aimed to evaluate the impact of implant placement with simultaneous bone augmentation on patients' willingness to repeat the procedure. Secondary outcomes included assessing patient-reported outcome measures, clinical- and surgical-related factors affecting treatment outcomes.

METHODS

Subjects who were currently undergoing or have undergone implant placement with simultaneous bone augmentation in the esthetic region (maxillary second premolar to second premolar) were assigned to three groups: Group A (short-term), Group B (1-5 years post-surgery), and Group C (> 5 years post-surgery). Clinical assessments, dichotomous questions, and visual analogue scales were used to evaluate therapeutic outcomes according to the group of interest.

RESULTS

One hundred and fifty patients completed the study (n = 50 per group). In Group A, 16% experienced wound dehiscence (membrane exposure < 3 mm), and 2% had postoperative bleeding, infection, swelling, or abscess. Flaps extending beyond three teeth significantly increased early membrane exposure (p = 0.04). Patient-reported postoperative discomfort (p < 0.001) and wound healing scores (p < 0.04) decreased over time. Willingness to repeat the procedure was 100%, 88%, and 98% in Groups A, B, and C, respectively, with satisfaction rates of 98.2 ± 7.5, 91.2 ± 10.6, and 95.2 ± 10.9. No significant differences were found between Groups B and C for functional or esthetic satisfaction. However, Group C reported higher satisfaction and comfort (p < 0.001). Younger adults and women reported greater postoperative discomfort than older adults and men.

CONCLUSIONS

Implant placement with simultaneous horizontal bone augmentation in esthetic areas shows a high willingness of patients to repeat the procedure in the short-, mid-, and long-term. Additionally, this therapeutic approach yields low rates of postoperative complications and discomfort, along with high patient satisfaction related to functional performance, esthetics, and overall comfort.

Reproducibility and Reliability of Intraoral Scanners for Evaluating Peri-Implant Tissues and Implant-Supported Prostheses: A Cross-Sectional Study

OBJECTIVE

To assess the reproducibility and reliability of the pink (PES) and white esthetic scores (WES) using digital images and the intra- and inter-examiner agreement among different clinical backgrounds and assessment methods.

MATERIAL AND METHODS

Standardized intraoral images were obtained from adult subjects with an implant-supported single-tooth fixed dental prosthesis located in the maxillary esthetic zone using a digital camera and a true-color intraoral scanner. According to the PES and WES criteria, the images were evaluated by 20 calibrated evaluators, 5 prosthodontists, 5 periodontists, 5 undergraduates, and 5 oral surgeons.

RESULTS

The total number of individual PES and WES was 12600 and 9000, respectively. Similar PES and WES values were obtained with the intraoral scanner compared to the digital camera. Intra- and inter-rater variations were observed between and within evaluators' clinical backgrounds, with periodontists showing consistently lower mean PES and WES. The intraclass correlation coefficient ranges between 0.41 to 0.61 for the PES and 0.42 to 0.69 for the WES, resulting in fair to good agreement in both digital methods.

CONCLUSION

The digital assessment of the peri-implant tissues and implant-supported prostheses utilizing images provided by an intraoral scanner offers a reproducible and reliable digital method comparable with the digital camera.

CLINICAL SIGNIFICANCE

This study highlights the reliability and reproducibility of using intraoral scanners for evaluating peri-implant tissues and implant-supported prostheses. The findings suggest that intraoral scanners are a viable digital alternative to traditional digital imaging for these assessments. However, the observed intra- and inter-rater variations in pink and white esthetic scores, according to the clinical background of evaluators, emphasize the need for caution when interpreting these values in clinical decision-making and research.

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2 mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

Keratinized mucosa width assessment at implant sites using high-frequency ultrasonography

BACKGROUND

The aim of this study was to describe the application of high-frequency ultrasonography (HFUS) for assessing keratinized mucosa (KM) width at implant sites.

METHODS

KM width was measured at 28 implant sites exhibiting a peri-implant soft tissue dehiscence at baseline and 12 months after soft tissue augmentation. KM width assessment was performed with a periodontal probe [clinical assessment (clKM)] and with HFUS, based on the echointensity of the keratinized epithelium compared to the adjacent structures. KM width measurements on ultrasound scans were performed linearly (lnKM) and along the soft tissue profile [surface distance (sdKM)].

RESULTS

No statistically significant differences were observed between clKM, lnKM, and sdKM at baseline, while at 12 months, sdKM (5.313 ± 1.188 mm) was significantly higher than clKM (3.98 ± 1.25 mm) and lnKM (4.068 ± 1.197 mm) (P < 0.001 for both comparisons). A linear relationship between mucosal thickness (MT) and the difference between sdKM and lnKM was observed. In 95.2% of cases with MT > 2.51 mm, the discrepancy between sdKM and lnKM was at least 1 mm.

CONCLUSIONS

HFUS is a noninvasive and valuable tool for measure KM width at implant site. Evaluating KM width along the soft tissue profile as a surface distance may improve the accuracy of the assessment.

Alveolar ridge preservation: Complications and cost-effectiveness

Alveolar ridge preservation is routinely indicated in clinical practice with the purpose of attenuating postextraction ridge atrophy. Over the past two decades numerous clinical studies and reviews on this topic have populated the literature. In recent years the focus has primarily been on analyzing efficacy outcomes pertaining to postextraction dimensional changes, whereas other relevant facets of alveolar ridge preservation therapy have remained unexplored. With this premise, we carried out a comprehensive evidence-based assessment of the complications associated with different modalities of alveolar ridge preservation and modeled the cost-effectiveness of different therapeutic modalities as a function of changes in ridge width and height. We conclude that, among allogeneic and xenogeneic bone graft materials, increased expenditure does not translate into increased effectiveness of alveolar ridge preservation therapy. On the other hand, a significant association between expenditure on a barrier membrane and reduced horizontal and vertical ridge resorption was observed, though only to a certain degree, beyond which the return on investment was significantly diminished.

Influence of healing time on the outcomes of alveolar ridge preservation using a collagenated bovine bone xenograft: A randomized clinical trial

AIM

To evaluate the healing outcomes in non-molar post-extraction sockets filled with deproteinized bovine bone mineral with collagen (DBBM-C) as a function of time.

MATERIALS AND METHODS

Patients in need of non-molar tooth extraction were randomly allocated into one of three groups according to the total healing time (A-3 months; B-6 months; C-9 months). The effect of alveolar ridge preservation (ARP) therapy via socket filling using DBBM-C and socket sealing with a porcine collagen matrix (CM) was assessed based on a panel of clinical, digital, histomorphometric, implant-related, and patient-reported outcomes.

RESULTS

A total of 42 patients completed the study (n = 14 in each group). Histomorphometric analysis of bone core biopsies obtained at the time of implant placement showed a continuous increase in the proportion of mineralized tissue with respect to non-mineralized tissue, and a decrease in the proportion of remaining xenograft material over time. All volumetric bone and soft tissue contour assessments revealed a dimensional reduction of the alveolar ridge overtime affecting mainly the facial aspect. Linear regression analyses indicated that baseline buccal bone thickness is a strong predictor of bone and soft tissue modelling. Ancillary bone augmentation at the time of implant placement was needed in 16.7% of the sites (A:2; B:1; C:4). Patient-reported discomfort and wound healing index scores progressively decreased over time and was similar across groups.

CONCLUSIONS

Healing time influences the proportion of tissue compartments in non-molar post-extraction sites filled with DBBM-C and sealed with a CM. A variable degree of alveolar ridge atrophy, affecting mainly the facial aspect, occurs even after performing ARP therapy. These changes are more pronounced in sites exhibiting thin facial bone (≤1 mm) at baseline (Clinicaltrials.gov NCT03659617).