Long-term stability of early implant placement with contour augmentation

Bone alteration and esthetics associated with implant-supported prostheses in the anterior maxilla under different implant placement timing: A retrospective clinical study of 1 to 3 years

STATEMENT OF PROBLEM

Different factors influence alterations in facial bone thickness and esthetic outcomes after implant placement. Whether the timing of implant placement influences alterations in the bone dimensional and esthetic outcomes is unclear.

PURPOSE

The purpose of this retrospective clinical study was to assess the influence of the timing of implant placement on alveolar bone alterations and esthetic outcome.

MATERIAL AND METHODS

Data were collected from 40 patients who had received guided bone regeneration (GBR) performed simultaneously with immediate, early, or delayed single-tooth implant placement in the anterior maxilla. Facial and palatal horizontal bone thicknesses (FHBT, PHBT) and vertical bone level (FVBL, PVBL) immediately after surgery (T0), at 6 months after implant placement (T1), and at 1 to 3 years follow-up (T2) were measured, and the changes calculated. The pink esthetic score (PES) and white esthetic score (WES) were evaluated at the 1- to 3-year follow-up. The Kruskal-Wallis followed by the Dunn t test was applied to evaluate bone alteration among groups, and the Bonferroni method was used for adjusting multiple comparisons. The 1-way ANOVA test was used to determine any significance in the esthetic outcome in the 3 groups (α=.05).

RESULTS

The reduction in the FHBT0 of the immediate, early, and delayed implant placement group (T2-T0) was -1.17 (-1.70, -0.61) mm, -1.53 (-1.69, -0.49) mm, and -1.47 (-2.30, -0.20) mm, respectively. The FHBT around the implant apices remained basically stable. No obvious changes in the PHBT around the implants of the immediate and delayed implant placement group were noted. The FVBL significantly decreased in each group during the follow-up period (-1.34 (01.88, -0.56) mm, immediate; -2.88 (-3.79, -1.07) mm, early; -1.26 (-2.52, -0.48) mm, delayed). The PVBL change in the early implant placement group (-2.18 (-3.26, -0.86) mm) was more significant than that in the immediate (-0.55 (-2.10, -0.17) mm) and delayed (-0.51 (-1.29, 0.02) mm) implantation groups (P =.013). The mean ±standard deviation PES/WES score of the immediate (15.6 ±1.84) and early (15.00 ±1.13) implant placement groups was higher than that of the delayed implant placement group (13.92 ±2.10) without significant difference.

CONCLUSIONS

Similar bone changes and esthetic outcomes were found around implants of the immediate, early, and delayed implant placement groups.

Autonomous robotic system for the assisted immediate placement of a maxillary anterior implant: A clinical report

Precise reproduction of the preoperatively designed 3-dimensional (3D) implant position is key to seating a prefabricated restoration and restoring esthetics. Static and dynamic computer-aided implant surgery (CAIS) based on the fusion of 3D imaging files have been used to improve implant accuracy. However, both techniques have shortcomings that can be remedied by a robotic system. This clinical report describes the immediate placement of an implant in the anterior esthetic zone by using an autonomous dental implant robotic system (ADIR).

Immediately versus early placed bone-level-tapered implants supporting all-ceramic crowns on titanium base abutments: 1-year radiographic and pink esthetic outcomes of a multicenter pilot RCT

OBJECTIVES

Aim of this study was to assess survival rates, radiographic, and pink esthetic outcomes of a bone-level-tapered (BLT) implant following immediate or early implant placement.

MATERIALS AND METHODS

Patients in need of tooth extraction and one implant in the anterior or premolar area were recruited in five centers. Patients were randomly assigned to the immediate or early placement protocol. Implants were restored with all-ceramic crowns cemented to titanium-base-abutments. Radiographic bone levels, implant stability quotient (ISQ), and pink esthetic outcomes were assessed. Data were analyzed descriptively. Level of significance was set at 0.05. Differences between groups were tested using Wilcoxon-signed-rank and Mann-Whitney-U test as nonparametric tests.

RESULTS

A total of 60 patients received 60 BLT implants (Institut Straumann). At 12-months, 59 implants (98.3%) were osseointegrated. The mean distance from implant shoulder to first bone-to-implant contact was 0.15 ± 0.59 mm without significant differences between the groups. Median ISQ values increased from 75.5 to 78.5. A mean buccal recession of 0.1 ± 0.70 mm occurred with no difference between groups. The mean papilla height gain in both groups was 0.5 ± 1.47 mm mesially and 0.4 ± 1.36 mm distally.

CONCLUSIONS

After 1 year, immediately and early placed BLT implants exhibit similar bone level changes, ISQ values, and pink esthetic outcomes.

CLINICAL SIGNIFICANCE

The present research contributes to the knowledge on clinical outcomes of immediately and early placed BLT implants restored with buccally microveneered ceramic single crowns out of two different ceramic materials. The research shows that similar esthetic and radiographic outcomes can be reached by means of immediate implant placement compared to the conventional early placement protocol. The improvement of esthetic soft-tissue parameters over time was shown for both implant placement protocols.

Optimized bone grafting

Bone grafting is routinely performed in periodontology and oral surgery to fill bone voids. While autogenous bone is considered the gold standard because of its regenerative properties, allografts and xenografts have more commonly been utilized owing to their availability as well as their differential regenerative/biomechanical properties. In particular, xenografts are sintered at high temperatures, which allows for their slower degradation and resorption rates and/or nonresorbable features. As a result, clinicians have combined xenografts with other classes of bone grafts (most notably allografts and autografts in various ratios) for procedures requiring better long-term stability, such as contour grafting, sinus elevation procedures, and vertical bone augmentations. This review addresses the regenerative properties of each class of bone grafts and then highlights the importance of understanding each of their biomechanical and regenerative properties for clinical applications, including extraction site management, contour augmentation, sinus grafting, and horizontal and vertical augmentation procedures. Thereafter, an introduction toward the novel production of nonresorbable bone allografts (NRBAs) via high-temperature sintering is presented. These NRBAs not only pose the advantage of being more biocompatible than xenografts owing to their origin (human vs. animal bone) but also display nonresorbable properties similar to those of xenografts. Thus, while packaging allografts with xenografts in premixtures specific to various clinical indications has never been permitted owing to cross-species contamination and FDA/CE requirements, the discovery and production of NRBAs allows premixing with standard allografts in various ratios without regulatory restrictions. Therefore, premixtures of allografts with NRBAs can be produced in various ratios for specific indications (e.g., a 1:1 ratio similar to an allograft/xenograft mixture for sinus grafting) without the need for purchasing separate classes of bone grafts. This optimized form of bone grafting could theoretically provide clinicians more precise ratios without the need to purchase separate bone grafts. This review highlights the future potential for simplified and optimized bone grafting in periodontology and implant dentistry.

Simultaneous or staged lateral ridge augmentation: A clinical guideline on the decision-making process

Lateral ridge augmentation is a standard surgical procedure that can be performed prior to (staged) or simultaneously with implant placement. The decision between a simultaneous or staged approach involves considering multiple variables. This paper proposed a decision-making process that serves as a guideline for choosing the best treatment choice based on the available evidence and the author's clinical experience.

Three-Dimensional Peri-Implant Tissue Changes in Immediately vs. Early Placed Tapered Implants Restored with Two Different Ceramic Materials-1 Year Results

BACKGROUND

A prospective multi-center randomized controlled clinical trial was performed to digitally analyze tissue volume changes in immediately and early placed implants with simultaneous bone augmentation restored with two different all-ceramic materials.

METHODS

A total of 60 patients received 60 bone-level tapered implants (BLT, Straumann AG) immediately (n = 30) or early placed, 8-10 weeks after tooth extraction, (n = 30). Implants were restored with all-ceramic single crowns fabricated out of zirconia (Lava Plus, 3M), or lithium disilicate (E.max CAD, Ivoclar Vivadent AG) bonded to titanium base abutments (Variobase for Cerec, Straumann AG). Impressions were taken at baseline (BL), 6 and 12 months, and STL data were used to define an area of interest (AOI) to analyze peri-implant volume changes and midfacial recessions.

RESULTS

For immediate placement, a mean volume loss of -5.56 mm3 (±5.83 mm3) was found at 6 months, and of -6.62 mm3 (±6.56 mm3) at 12 months. For early placement, a mean volume loss of -1.99 mm3 (±5.82 mm3) at 6 months, and of -3.7 mm3 (±5.62 mm3) at 12 months was found. The differences in volume loss at 12 months between the two implant placement protocols were significant (p = 0.005). In both groups, mean midfacial recessions of 0.48 mm (±0.52) occurred.

CONCLUSIONS

A more pronounced peri-implant volume loss can be expected 12 months after immediate implant placement compared with early placement.

The Influence of the Clinicians' Experience on the Outcome of Dental Implants: A Clinical Audit

The purpose of this outcome audit is to evaluate the influence of the clinicians' experience on the outcome of dental implants. In addition, it is to identify the associated risk factors that might influence the success and survival of these implants.

METHODOLOGY

The records of patients treated with SLA/SLActive Straumann implants were screened. This enabled us to have a minimum of 12 months of follow-up. Eligible patients, according to the inclusion criteria, were contacted and invited to undergo a follow-up assessment. Success was accounted for and defined in a comprehensive manner by considering four different categories: implant perspective, peri-implant soft tissue perspective, prosthetic perspective, and patient satisfaction. The patient investigations included a clinical examination of the implant mobility, suppuration, width of keratinized mucosa, probing depth, plaque accumulation, prosthetic complications, and patient satisfaction. In addition, a periapical radiograph was taken to evaluate bone loss and peri-implant radiolucency. The data were analysed using SPSS version 26.

RESULTS

Thirty-eight patients with 84 SLA/SLActive Straumann implants were available for the assessment. The mean age of the patients at implant surgery was 49.05 ± 13.19 years. Over the mean follow-up period of 26 months, no implant fractures were noted. Overall, eight implants were considered failures (9.5%). Two out of six patients with a history of periodontitis (HoP) and two out of five smokers exhibited failed implants. The patients' satisfaction responses showed that all the responses were statistically higher than the test median value of three. The median value of general satisfaction using a visual analogue scale was 9 out of 10.

CONCLUSIONS

The implants placed on partially and fully edentulous patients revealed high survival and success rates (100% and 90.5%, respectively) at a mean follow-up time of 26 months. It can be concluded that the implant practise among trainees in the programme is satisfactory. A history of periodontitis and a lack of patient compliance with supportive periodontal therapy in some cases have been shown to be risk factors associated with increased implant failure, mainly peri-implantitis.

Stability of guided bone regeneration with two ratios of biphasic calcium phosphate at implant sites in the esthetic zone: A randomized controlled clinical trial

AIMS

The aim of this randomized, double-blind, clinical trial was to compare the stability of the horizontal dimensions (facial bone thickness) of augmented bone using biphasic calcium phosphate (BCP) with hydroxyapatite/β-tricalcium phosphate ratio of either 60/40 or 70/30.

MATERIALS AND METHODS

Sixty dental implants placed with contour augmentation in the esthetic zone were randomized to 60/40 BCP (n = 30) or 70/30 BCP (n = 30). Cone-beam computed tomographic was used to assess facial bone thickness post-implantation and 6 months later at implant platform and 2, 4, and 6 mm apical to it.

RESULTS

The percentage of horizontal dimension reduction was 23.64%, 12.83%, 9.62%, and 8.21% in 70/30 BCP group, while 44.26%, 31.91%, 25.88%, and 21.49% in 60/40 BCP group at the level of the implant platform and 2, 4, and 6 mm apical, respectively. Statistically significant difference was found at 6 months at all levels of measurement (p-value < .05).

CONCLUSIONS

BCP bone grafts with HA/β-TCP ratio of 60/40 and 70/30 showed comparable outcomes for contour augmentation simultaneously with implant placement. Interestingly, the 70/30 ratio was significantly superior in maintaining facial thickness and showed more stable horizontal dimensions of the augmented site.

How to avoid intraoperative and postoperative complications in maxillary sinus elevation

Maxillary sinus floor elevation, via the lateral approach, is one of the most predictable bone augmentation procedures performed in implant dentistry. but both intra- and postoperative complications can occur, and some of them are severe. Our aim is as follows: To review the pertinent literature on the topic, especially assessing the risk factors related to complications. To give clinical recommendations to minimize intra- and postoperative complications with the ultimate scope of improving the standard of clinical care and patient safety.

Factors Associated with Esthetic Outcomes of Flapless Immediate Placed and Loaded Implants in the Maxillary Incisor Region—Three-Year Results of a Prospective Case Series

Flapless immediate implant placement and provisionalization (FIIPP) is often associated with an increased risk of buccal soft-tissue recession. This study aims to assess the 3-year esthetic outcome. In 100 consecutive patients, one maxillary incisor, with or without a pre-extraction buccal bone defect (≤5 mm), was replaced by an implant installed in a maximal palatal position (buccal gap ≥2 mm). The created gaps were filled with bovine bone substitute. Patient satisfaction (PS), pink esthetic scores (PES/modPES), and white esthetic score (WES) were calculated at different time points. A multilevel regression analysis (MRA) was performed to analyze which factors may be associated with the esthetics. After three years, PS scored 8.9 ± 0.84 on a scale of 10 (n = 83), and the soft-tissue esthetics were high (PES = 12.2; modPES = 8.5), as was the WES (8.2), showing no decrease from one year. Buccal bone defect size and smoking could not be associated with the soft-tissue outcome; however, implant location, gap size, and emergence profiles could. Performing FIIPP, the final crown (WES) scored highest when it was cemented, the soft tissue (PES/modPES) in central-incisor positions, and all (WES/PES/modPES) with concave emergence profiles.

In vitro and in vivo evaluation of a modified porcine acellular dermal matrix for soft tissue augmentation

OBJECTIVES

To evaluate the effects of a modified porcine acellular dermal matrix (P-ADM), subepithelial connective tissue graft (SCTG) and other commercial bovine acellular dermal matrix membrane materials (B-ADM) on gingival soft tissue augmentation in the oral esthetic zone.

MATERIAL AND METHODS

The characteristics of P-ADM were observed by scanning electron microscope (SEM), Hematoxylin and eosin (H&E) and Masson's trichrome staining (Masson staining). The biocompatibility of P-ADM was verified by CCK8, phalloidin and living/dead cell staining. Beagle dog models were constructed and the thickness of gingiva was analyzed by the intraoral scanner. The morphology was observed by H&E and Masson staining.

RESULTS

Scanning electron microscopy, H&E and Masson staining showed that the P-ADM was mainly composed of collagen fibers, with no component of nuclear. The results of CCK8, phalloidin and living/dead cell staining indicated that the P-ADM had good cytocompatibility and no cytotoxicity. Human gingival fibroblasts were able to adhere and stretch on the surface of the material with pseudopodia. The SCTG group outperformed the B-ADM and P-ADM groups in terms of effectiveness, according to the analysis of digital oral scanning data at various time points following incremental soft tissue surgery. Compared with the B-ADM group, the effect of soft tissue increment was better in the P-ADM group.

CONCLUSIONS

P-ADM, as a biocompatible biomaterial, can be used as an alternative biomaterial for oral soft tissue thickening. However, the results of this study need to be verified by more clinical trials.

Characterization of eggshell as a bio-regeneration material

Objective

The objective of this study was to identify and summarize the characteristic features of eggshell for regeneration purpose in oral surgery procedures.

Methods

A review of literature was undertaken based on the PubMed database. A search to reveal the current state of knowledge and the current uses of the eggshell as a biomaterial was performed. The characteristics of the materials, the specific use, the procedure and the outcome were extracted from the articles.

Results

The materials have been found to be used in humans, animals, and in vitro studies. There is a wide use regarding oral surgery especially in experimental models. There have also been attempts to enhance certain properties and improve the capabilities of eggshell as a biomaterial. There is yet a commercial product to be developed and approved for human use.

Conclusions

Eggshell can be an important biowaste which can be of use in guided bone regeneration procedures, but it has not yet entered the commercial phase and approval through official regulation channels.

Enhanced osteogenesis by addition of cancellous bone chips at xenogenic bone augmentation: In vitro and in vivo experiments

OBJECTIVES

To investigate and compare the influence of deproteinized bovine bone mineral (DBBM) combined with autologous cortical (CorBC) or cancellous bone chips (CanBC) as bone grafts on guided bone regeneration (GBR) in vivo and in vitro.

MATERIALS AND METHODS

Defects were created in the mandibular buccal alveolar ridges in dogs and randomly filled with 3 groups of bone grafts: DBBM, DBBM + CorBC, or DBBM + CanBC. Osteogenesis was evaluated by sequential fluorescent labeling and histological analysis. Moreover, rat bilateral calvaria defects were randomly grafted with DBBM, DBBM + CorBC, or DBBM + CanBC. A blank group was included as control. Defect healing was assessed by histological staining, micro-CT, and quantitative polymerase chain reaction. In vitro migration, proliferation, and osteogenic differentiation assays were performed by stimulating rat bone marrow mesenchymal stem cells (rBMSCs) with cortical (CorBCM) or cancellous bone conditioned medium (CanBCM) to unveil the cellular mechanism.

RESULTS

In the canine model, the augmented sites of DBBM + CanBC exhibited higher mineralized tissue proportion than the other two groups (DBBM: 0.61 ± 0.03 versus DBBM + CorBC: 0.69 ± 0.07 versus DBBM + CanBC: 0.86 ± 0.06; p < .05). In the rat model, the BV/TV value of DBBM + CanBC (0.51 ± 0.01) was higher than those of DBBM + CorBC (0.41 ± 0.02), DBBM (0.31 ± 0.01), and Control (0.10 ± 0.01; p < .01). Further radiological, histological and transcriptional results showed similar trends. In vitro experiments revealed that CorBCM and especially CanBCM could enhance rBMSCs migration, proliferation, and osteogenic differentiation.

CONCLUSION

In vivo and in vitro experiments verified favorable synergistic effect of mixing autologous bone chips with DBBM on osteogenesis. Furthermore, CanBC presented more powerful osteogenic effect than CorBC.

Polycaprolactone versus collagen membrane and 1‐year clinical outcomes: A randomized controlled trial

BACKGROUND

Polycaprolactone (PCL) is a synthetic aliphatic polyester widely used in biomedical applications with biodegradability in the body and promotes cell proliferation and differentiation. A newly developed bilayered PCL membrane was developed for possibly being used as a membrane in guided bone regeneration (GBR).

PURPOSE

To compare the clinical efficacy between a newly developed bilayered PCL membrane with a Cytoplast™ RTM collagen membrane for GBR with simultaneous implant placement.

MATERIALS AND METHODS

Twenty-four patients were randomized to PCL or RTM group, and a total of 24 dental implants were placed. Primary outcomes were patient mean buccal bone thickness (BBT) immediately postimplantation and at 6 months using cone-beam CT and soft tissue surface dimensional changes (STC) at crown insertion, 6 months, and 1 year after loading using intraoral scanner. Secondary outcomes included success rate, clinical parameters, healing index, implant stability, pink esthetic score, and marginal bone levels.

RESULTS

The percentage of reduced BBT at 6 months was 32.38%, 25.94%, and 23.96% in the test group and 34.42%, 14.75%, and 6.34% in the control group at the corresponding levels. The mean difference of changed BBT associated with PCL membrane, when compared to collagen membrane, at 6 months was -0.02 ± 0.18 mm (95% confidence interval [CI]: -0.40 to 0.35), 0.29 ± 0.28 mm (95% CI: -0.29 to 0.87), and 0.62 ± 0.38 mm (95% CI: -0.17 to 1.42) at 0, 2, and 4 mm from implant shoulder. Minimal loss of STC was observed in both groups up to 1 year of loading. The mean difference loss of surface dimensional change associated with PCL membrane, when compared to collagen membrane, at 1 year of loading was 0.31 ± 0.19 mm (95% CI: -0.07 to 0.70), 0.22 ± 0.26 mm (95% CI: -0.33 to 0.76), and 0.17 ± 0.30 mm (95% CI: -0.45 to 0.78) at 0, 2, and 4 mm from implant shoulder. None of these differences were statistically significant (unpaired t-test, degrees of freedom [df] = 22; p > 0.05).

CONCLUSION

Within the limits of this trial, both barrier membranes resulted in comparable outcomes for GBR with implant placement after 1 year in function. Further research is necessary with a larger sample size.

Use of Connective Tissue Graft and Coronally Advanced Flap in Areas of Buccal Contour Concavities for Nonsubmerged Implant Placement

There is a lack of scientific evidence concerning the best timing of soft tissue management around implants, as well as a divergence of topics concerning optimal procedures. The objective of this study is to evaluate the gain in buccal contour and soft tissue stability after a surgical technique combining nonsubmerged implant placement with submarginal connective tissue graft (CTG) and coronally advanced flap (CAF). Seven patients (4 males and 3 females) underwent surgery for transmucosal implant placement in partially edentulous areas showing mild to moderate buccal contour concavities using a technique combining CTG and CAF. The following parameters were evaluated: keratinized tissue height (KTH), soft tissue thickness (STT), and vertical soft tissue level (VSTL) at T0 (before surgery), T1 (6 months after surgery), T2 (12 months after surgery) and T3 (2 years after surgery). After two years, we observed an increase of 78.5% in buccal KTH, 64% in STT, and 24% in VSTL. No implant presented any sign of mucositis or bone loss. Non-submerged implant placement using an "envelope flap design" in addition to CTG and CAF is beneficial.

Addition of Synthetic Biomaterials to Deproteinized Bovine Bone Mineral (DBBM) for Bone Augmentation-A Preclinical In Vivo Study

(1) Aim: To investigate the effect of synthetic bone substitutes, α-tricalcium phosphate (α-TCP) or bi-layered biphasic calcium-phosphate (BBCP) combined with deproteinized bovine bone mineral (DBBM), on bone formation. (2) Methods: Thirty critical size defects were randomly treated with the following five different treatment modalities: (1) negative control (NC, empty), (2) DBBM, (3) α-TCP + DBBM (1:1), (4) BBCP 3%HA/97%α-TCP + DBBM (1:1), and (5) BBCP 6%HA/94%α-TCP + DBBM (1:1). The samples, at four weeks post-surgery, were investigated by micro-CT and histological analysis. (3) Results: A similar level of new bone formation was demonstrated in the DBBM with α-TCP bone substitute groups when compared to the negative control by histomorphometry. DBBM alone showed significantly lower new bone area than the negative control (p = 0.0252). In contrast to DBBM, the micro-CT analysis revealed resorption of the α-TCP + DBBM, BBCP 3%HA/97%α-TCP + DBBM and BBCP 6%HA/94%α-TCP + DBBM, as evidenced by a decrease of material density (p = 0.0083, p = 0.0050 and p = 0.0191, respectively), without changing their volume. (4) Conclusions: New bone formation was evident in all defects augmented with biomaterials, proving the osteoconductive properties of the tested material combinations. There was little impact of the HA coating degree on α-TCP in bone augmentation potential and material resorption for four weeks when mixed with DBBM.

Testosterone Enanthate: An In Vitro Study of the Effects Triggered in MG-63 Cells

The aim of this study was to investigate the effects of the androgenic hormone testosterone enanthate (TE) on human MG-63 cells. MG-63 were cultured for 24 h in the presence of TE at increasing concentrations to assess its lethal dose. Therefore, the suitable concentration for a prolonged use of TE in vitro was assessed by viability assay over 9 days. Finally, MG-63 were exposed to TE for 14 days and assayed for differentiation by qPCR and Alizarin Red S staining. TE in the amount of 100 µM resulted as the maximum dose tolerated by MG-63 cells after 24 h. However, a prolonged exposure in culture TE in the amount of 100 µM showed a cytostatic effect on cell proliferation. On the contrary, TE 10 µM was tolerated by the cells and did not boost cell proliferation, but did enhance new bone formation, as revealed by COL1A1, ALPL, BGLAP, and IBSP gene expression after 3, 7, and 14 days, and calcium deposition by Alizarin Red S staining after 14 days. Based on the current study, 10 µM is the critical dose of TE that should be used in vitro to support bone differentiation of MG-63 cells.

A Randomized Controlled Trial of Guided Bone Regeneration for Peri-Implant Dehiscence Defects with Two Anorganic Bovine Bone Materials Covered by Titanium Meshes

The aim of this study is to compare two low-temperature sintered anorganic bovine bone materials (ABBMs), Bio-Oss (Geistlich, Wolhusen, Switzerland) and A-Oss (Osstem, Seoul, Korea), for GBR in dehiscence defects. A single implant was placed simultaneously with GBR in the buccal or bucco-proximal osseous defect by double-layering of inner allograft and outer ABBM, covered by a preformed ultrafine titanium mesh and an absorbable collagen membrane. Grafted volume changes were evaluated by cone-beam computed tomography, taken preoperatively (T0), immediately after implant surgery (T1), after re-entry surgery (T2), and after delivery of the final restoration (T3). The density of the regenerated bone was assessed by measuring the probing depth on the buccal mid-center of the mesh after removing the mesh at T2. Postoperative sequelae were also recorded. Grafted volume shrinkage of 46.0% (0.78 ± 0.37 cc) and 40.8% (0.79 ± 0.33 cc) in the Bio-Oss group (8 patients) and A-Oss group (8 patients), respectively, was observed at T3 (p < 0.001). There were no significant differences in grafted volume changes according to time periods or bone density between the two groups. Despite postoperative mesh exposure (3 patients), premature removal of these exposed meshes and additional grafting was not necessary, and all implants were functional over the 1-year follow-up period. Both ABBMs with titanium meshes showed no significant difference in the quantity and density of the regenerated bone after GBR for peri-implant defects.

Vertical Bone Implant Contact Around Anterior Immediate Implants and Their Stability After Using Either Alloplast or L-PRF or Both in Peri-Implant Gap: A Prospective Randomized Trial

Purpose

Various graft materials have been studied for filling peri-implant gap (PIG), but there was no similar randomized clinical trial to evaluate the effect of Platelet-rich fibrin or alloplast or their combination on vertical bone implant contact (BIC) around immediate implants and their stability over a period of 1 year.

Methods

Immediate implants were placed in maxillary anterior region of 30 subjects (n = 10). Either alloplast (group I) or L-PRF (group II) or both (group III) were used to fill the PIG following randomization chart. Vertical BIC was measured on peri-apical radiographs which were taken immediately after placement, after 3, 6 and 12 months using Image J software. Periotest was used to measure the implant stability at the time of implant placement, at 3, 6 and 12 months after implantation.

Results

The comparison of distance from implant shoulder to the first visible bone-to-implant contact (IS-BIC) in each group showed statistically significant bone formation on mesial and distal sides over a 1 year period (p < 0.05). There was no significant difference in IS-BIC distance among the three groups at 1 year (p > 0.05). Periotest values showed that there was significant improvement in implant stability in all groups in 1-year period. On intergroup comparison, the mean difference of periotest values was statistically non-significant among three groups (p > 0.05).

Conclusions

All the graft materials were effective in promoting osseointegration when used as PIG filling materials alone or in combination around immediate implants in maxillary anterior region.

CTRI No

REF/2015/06/009200.

Stability of contour augmentation of implant-supported single crowns in the esthetic zone: One-year cone-beam computed tomography results of a comparative, randomized, prospective, two-center clinical study using two different bone grafting techniques in early implant placement

BACKGROUND

Early implant placement with contour augmentation could provide support and volume to the hard and soft tissues. Herein, we aimed to ascertain whether freeze-dried bone allograft (FDBA) shares with deproteinized bovine bone material (DBBM) the results for esthetic outcomes for anterior teeth and stability of peri-implant facial bone thickness and height by conducting guided bone regeneration.

METHODS

Forty-eight patients were randomly assigned into two groups. In the control group, autogenous bone chips was used to cover the exposed implant surface, followed by a layer of DBBM. This graft combination was then covered with two layers of collagen membrane. In the test group, the exposed implant surface was covered with FDBA, combined with the collagen membrane. During this study, the hard tissue dimensional changes were measured at 12-months post-implant loading by using cone-beam computed tomography.

RESULTS

At 12 months postoperatively, all 48 implants were clinically successful. The mean thickness of facial bone walls ranged from 1.6 to 2.45 mm at the three levels of measurement in the control group and ranged from 1.6 to 2.10 mm in the test group. The mean facial vertical bone wall peak (IP-FC) after loading 1 year presented with values of 0.8 mm (range, 0.0 to 1.25 mm) and 0.5 mm (range, 0.1 to 1.1 mm) coronal to the implant platform in control and test implants, respectively. There were no significant differences in facial bone wall thickness and IP-FC between groups.

CONCLUSIONS

This study demonstrated that autogenous bone chips plus DBBM or FDBA showed similar outcome of peri-implant buccal bone stability in early implant placement after 1 year.

Bone remodeling around dental implants after 1-1.5 years of functional loading: A retrospective analysis of two-stage implants

OBJECTIVES

This study aims to retrospectively assess to what extent peri-implant bone level changes occur from exposing the implant to the oral environment at the second stage of surgery (SSS) to the baseline assessment and, additionally, after 1-1.5 years of functional loading. Further, this study aims to examine the role of the emergence angle in marginal bone changes.

MATERIAL AND METHODS

This retrospective study included 46 patients treated between 2012 and 2019. These patients received 64 bone-level dental implants. After implant placement, SSS, and baseline assessment, relevant clinical peri-implant conditions and radiographical data were collected. A radiographic examination of the marginal bone level was performed after SSS, the baseline assessment, and 1-1.5 years of follow-up.

RESULTS

The peri-implant periodontal probing depth increased significantly from 3.08 ± 0.7 mm at the baseline to 3.27 ± 0.81 mm at the 1-1.5-year follow-up. The mean marginal bone level at the implant level was 0.12 ± 0.23, 0.35 ± 0.43, and 0.47 ± 0.47 mm at the SSS, baseline, and the 1-1.5-year follow-up, respectively. Most changes occurred at the implant's distal site. A significant relationship was found between the emergence angle and the extent of change in the marginal bone level between the SSS and baseline (r = .430, p ≤ .001).

CONCLUSIONS

Most changes in the marginal bone level occurred between SSS and baseline assessments. For diagnostic purposes, it is advised to obtain a standardized radiograph after SSS to monitor peri-implant bone-level alterations.

Classification Based on Extraction Socket Buccal Bone Morphology and Related Treatment Decision Tree

Background: Alveolar ridge preservation (ARP) can successfully reduce volumetric ridge changes. However, there is still no consensus on what technique is the most advantageous for each specific clinical scenario. Hence, the aim of the present paper was to provide a treatment decision tree to guide the choice of predictable ARP procedures based on extraction socket buccal bone morphology and integrity. Material and Methods: Three socket types (ST) are proposed and discussed based on buccal bone morphology (intact, dehiscence or fenestration). Results: A decision tree for ARP was developed in order to merge ST classification with suitable treatment modalities. In the decision tree, the issue of when to allow unassisted healing or ARP was discussed. Described methods included bone grafting and collagen plug, and absorbable membrane or non-resorbable membrane, with or without flap elevation. Conclusion: A decision tree for ARP procedures was provided to guide clinicians towards the most conservative and predictable treatment approach based on remaining socket anatomical structures after extraction.

Healing complications and their detrimental effects on bone gain in vertical-guided bone regeneration: A systematic review and meta-analysis

PURPOSE

Guided bone regeneration (GBR) utilizes a barrier membrane to allow osteogenic cells to populate a space by excluding epithelial and connective tissue cells. The purpose of this systematic review was to investigate the ratio of means (RoM) of vertical bone gained (Outcome) in vertical GBR procedures with healing complications (Intervention) and in vertical GBR procedures without healing complications (Comparison) in patients with vertically resorbed edentulous ridges that require dental implant placement (Population). A further aim was to investigate the incidence of complications after vertical GBR, and the influence of the timing of implant placement and regenerative devices on complications.

MATERIALS AND METHODS

MEDLINE (through PubMed), EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched in duplicate up to, and including, November 2020 for randomized and controlled clinical trials and prospective and retrospective case series. Outcomes included patient-level and site-level RoM of vertical bone gain between healing complications and uneventful healing, and incidences of complications that occurred after vertical GBR. Random-effects and fixed-effects meta-analyses were performed where appropriate. This study was registered on PROSPERO (CRD42021226432).

RESULTS

A total of 31 publications were selected for the qualitative and quantitative analyses. The RoM of vertical bone gained was 0.65 [95% CI = 0.47, 0.91] and 0.62 [95% CI = 0.45, 0.85] when membrane exposure without suppuration and abscess formation without membrane exposure occurred respectively, in comparison to uneventful healing. The overall incidence proportion of healing complications occurring at the augmented site at a site- and patient-level was 11.0% [95% CI = 7.0, 15.6] and 10.8% [95% CI = 6.6, 15.7]. At a patient-level, there were no significant differences between a simultaneous or staged approach, or with the regenerative device used. The site-level incidence proportion of membrane exposure without suppuration, membrane exposure with suppuration, and with abscess formation without membrane exposure was 8.7% [95% CI = 4.2, 14.2], 0.7% [95% CI = 0.0, 2.9], and 0.5% [95% CI = 0.0, 1.7], respectively. The site-level weighted mean incidence proportion of neurologic complications occurring at the donor site was 0.8% [95% CI = 0.0, 5.3].

CONCLUSIONS

There is a significant reduction in bone gain when healing complications occur. However, healing complications are relatively uncommon surgical complications after vertical GBR.

Patient-reported outcome measures comparing static computer-aided implant surgery and conventional implant surgery for single-tooth replacement: A randomized controlled trial

OBJECTIVE

To compare static computer-aided implant surgery (s-CAIS) and conventional implant surgery (CIS) for single-tooth replacement in posterior sites in terms of patient-reported outcome measures (PROMs).

METHODS

Forty patients were divided into two groups for treatment with s-CAIS (Test) and CIS (Control). Patients' anxiety level was measured using the modified dental anxiety score before implant surgery. After surgery, patients completed two questionnaires for 7 days. The first questionnaire assessed pain level using a visual analog scale (VAS) and the incident rate of pain using a 5-point Likert scale; analgesic intake was also recorded. The second questionnaire investigated patients' oral health-related quality of life (OHRQoL) including postoperative symptoms, oral function, and daily activity. The difference between data was compared at significance level (α = 0.05).

RESULTS

There was no statistically significant difference in pretreatment dental anxiety level, postoperative pain scores, and OHRQoL between treatment groups. Overall, mild or moderate dental anxiety was reported by 70% and 20% of patients, respectively. Pain score was significantly reduced by postoperative Day 3 in the test group and Day 4 in the control group, compared with baseline. Both groups significant reduced analgesic intake by postoperative Day 5. Most OHRQoL-related complaints subsided approximately 3 days after surgery.

CONCLUSIONS

Overall, PROMs between s-CAIS and CIS were not significantly different for the single-tooth implant surgery in the posterior area. Postoperative symptoms after implant surgery still inevitably occurred, reflecting the normal process of oral wound healing.

Comparison of quality of bone and insertion torque values of early implants placed at 6 and 8 weeks in sockets preserved with advanced platelet-rich fibrin: A randomized controlled trial

Aim

Successful functional and esthetic rehabilitation of edentulous jaws with implants depends on the optimal timing of placement, surgical protocol, materials used, cost-effectiveness, and satisfying patient needs. Increasing demand for shorter treatment times necessitates the immediate placement protocol. However, researchers have demonstrateda higher failure rate. A-PRF (Advanced platelet-rich fibrin) has exhibited accelerated bone regeneration potential. Early implant placement with a limited healing period, along with A-PRF, can be beneficial over conventional and immediate implant placement.

Settings and Design

This prospective randomized clinical trial aims to assess the outcome of early implant placement in sockets preserved using A-PRF at six weeks and eight weeks of post-extraction. Two groups of 10 participantseach were formed. All patients underwent atraumatic extraction and socket preservation using A-PRF.

Materials and Methods

A Partial-thickness pedicle graft was raised, and the extraction socket wasclosed. Implants wereplaced in at six and eight weeks of post-extraction in group A group B, respectively. The histomorphometric analysisassessedthe bone quality present at the timeof surgery. The insertion torque values were recorded during implant placement.

Statistical Analysis Used

The obtained data were statistically analyzed using parametric tests, namely independent T-test for intergroup comparison.

Results

T-test for torque values indicated a significantly higher torque value at eight weeks. The meanhistomorphometric value showeda significantly higher percentage of bone formation at eight weeks than at six weeks (P = 0.03).

Conclusion

Within the study's limitations, early implant placement in extraction sockets preserved with A-PRF had significantly higher insertion torque values and predictable bone at eight weeks compared to six weeks.

Dimensional changes of buccal bone in the edentulous maxilla with telescopic-retained implant-supported fixed dental prostheses

STATEMENT OF PROBLEM

The buccal bone in an edentulous maxilla loses thickness over time because of physiological changes. However, the dimensional changes of the buccal bone in an edentulous maxilla with an implant-supported fixed dental prosthesis are unknown.

PURPOSE

The purpose of this retrospective clinical study was to evaluate cone beam computed tomography (CBCT) images of the dimensional changes of the buccal bone in edentulous maxillae with complete-arch telescopic-retained implant-supported fixed dental prostheses (CTI-FDPs) after 6 years by using a professional retrieval system.

MATERIAL AND METHODS

This study included 17 participants with edentulous maxillae who had been provided with CTI-FDP with 121 taper joint implants. A three-dimensional radiographic analysis by using CBCT was performed at implant insertion (0 years) and after 6 years. Vertical and horizontal bone measurement values were evaluated. During horizontal bone thickness measurement, 4 different levels, 0, 2, 4, and 6 mm apical to the implant shoulder, were evaluated as bone value (BV)_0mm, BV_2mm, BV_4mm, and BV_6mm, respectively. The BVs were compared with the Wilcoxon signed-rank test and Kruskal-Wallis test (α=.05). In addition, the Spearman rank correlation coefficient was used to identify 0yBV factors that influence the 6yBVs. A nonlinear regression analysis was used to clarify the slopes of 0yBVs and 6yBV_0mm.

RESULTS

Significant decreases in vertical and horizontal BVs were found between 0 years and 6 years (P<.05). However, no significant difference was observed in bone loss at 6 years at any of the vertical and horizontal measurement points (P≥.05). When 0yBVs related to 6yBV_0mm were analyzed, 0yBV_0mm and 0yBV_2mm showed strong correlations with 6yBV_0mm (|r|≥.7). In the regression analysis, a 0yBV_0mm of 0.58 mm and 0yBV_2mm of 0.78 mm could be critical factors associated with a 6yBV_0mm of 0 mm. A 6yBV_0mm of 0yBV_0mm more than 0.58 mm was significantly higher than a 6yBV_0mm of 0yBV_0mm less than 0.58 mm (P<.001). Moreover, a 6yBV_0mm of 0yBV_2mm more than 0.78 mm was significantly higher than a 6yBV_0mm of 0yBV_2mm less than 0.78 mm (P<.001).

CONCLUSIONS

The buccal bone in an edentulous maxilla with fixed implant-supported prostheses lost significant vertical and horizontal bone thicknesses after 6 years. At implant insertion, both a 0.58-mm buccal bone on the platform and a 0.78-mm buccal bone at 2 mm apical to the implant shoulder are necessary for longer term maintenance of bone on the platform of implants specifically supporting CTI-FDPs.

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.

Clinical and radiographical performance of implants placed with simultaneous guided bone regeneration using resorbable and nonresorbable membranes after 22-24 years, a prospective, controlled clinical trial

Aim

The aim was to evaluate the performance of implants placed with simultaneous guided bone regeneration (GBR) using resorbable or nonresorbable membranes compared to implants placed in pristine bone without bone regeneration after an observation period of 22–24 years.

Material and Methods

The patient cohort of this clinical trial was treated from 1994 to 1996. Dehiscence defects were treated with GBR by either using resorbable collagen membranes (BG) or nonresorbable ePTFE membranes (GT). Implants placed in pristine bone served as a control (CT). Clinical parameters, marginal bone levels, and technical outcomes were evaluated following restoration placement and at the present follow‐up. A 3D radiographic analysis was conducted in order to assess buccal and oral bone dimensions. Implant survival was assessed with Kaplan–Meier analysis and a frailty model (level of significance 5%).

Results

Out of the originally 72 patients (mean age 75.4 ± 15.70 years) with 265 implants, 39 patients with 147 implants were included in the study after a median period of 23.5 years. Implant survival was 89.3% in group BG (n = 100), 90.2% in group GT (n = 37), and 93.8% in group CT (n = 105), without significant differences (Frailty proportional hazard model p = .79). Smoking had a negative effect on survival (p = .0122). Mean vertical marginal bone levels were −2.3 ± 1.4 mm (BG, n = 59), −3.0 ± 1.5 mm (GT, n = 21), and −2.3 ± 1.6 mm (CT, n = 52). The vertical buccal bone levels were −3.0 ± 1.9 mm (BG, n = 57), −3.5 ± 2.2 mm (GT, n = 21), and −2.6 ± 1.8 mm (CT, n = 49), without significant differences.

Conclusion

Implant placement with GBR procedures provides treatment outcomes with favorable implant survival rates (89.3%–93.8%) after 23.5 years. Smoking, however, affected implant survival negatively.

Evaluation of Bone Regeneration around Implants with and Without Flap Elevation

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

The effect of acemannan in implant placement with simultaneous guided bone regeneration in the aesthetic zone: a randomized controlled trial

Acemannan, a linear polysaccharide produced by Aloe vera, has been shown to have important biological effects promoting wound healing and tissue regeneration. The aim of this randomized clinical trial was to investigate the impact of acemannan in guided bone regeneration (GBR) with simultaneous implant placement. Twenty patients were randomly allocated to a test group (deproteinized bovine bone with particulate acemannan (mean size 32.45 μm)) and a control group (deproteinized bovine bone only). Twenty implants were placed with simultaneous GBR. Radiographic measurements were conducted on cone beam computed tomography (CBCT) scans immediately post-surgery and at 3 and 6 months. Vertical and horizontal dimensions of the buccal bone were measured at the implant platform (0) and at points 2, 4, 6, and 8 mm apically. The dimensional reduction of vertical and horizontal buccal bone was significantly smaller in the test group at 3 months postoperative (P < 0.05) at every position measured (0, 2, 4, 6, 8 mm), but the difference was not statistically significant at 6 months. Acemannan was found to be a safe and predictable biomaterial for GBR, which resulted in enhanced dimensional stability of the regenerated tissue at 3 months. However, these results were not replicated at 6 months. Further studies are required to document the long-term efficacy and potential of acemannan use as a supplement in bone regeneration.

Implants sites with concomitant bone regeneration using a resorbable or non-resorbable membrane result in stable marginal bone levels and similar profilometric outcomes over 5 years

OBJECTIVES

To assess clinical and radiographic outcomes as well as the profilometric contour alterations of peri-implant hard and soft tissues around single implants treated with simultaneous guided bone regeneration (GBR) at 5 years.

MATERIALS AND METHODS

Twenty-seven patients presenting with a single tooth gap in the esthetic zone received a two-piece implant. GBR was randomly performed using a resorbable (RES) or a non-resorbable membrane (N-RES) combined with a bone substitute material. Follow-up examinations were performed at baseline (BL = crown insertion), 1 year (FU-1), 3 years (FU-3), and at 5 years (FU-5) including clinical and radiographic parameters as well as profilometric changes. Statistics were performed by means of parametric and nonparametric tests.

RESULTS

At 5 years, 20 out of 27 patients (9 RES, 11 N-RES) were re-examined. Median values for probing depth changed insignificantly between BL and FU-5 in both groups. The median marginal bone levels were located 0.23 mm (0.06; 0.46; RES) and 0.17 mm (0.13;0.28; N-RES) below the implant shoulder at FU-5 (changes over time p < .05). The calculated median profilometric change between BL and FU-5 was -0.28 mm (-0.53;-0.20; RES; p = .016) and -0.24 mm (-0.43;0.08; N-RES; p = .102; intergroup p = .380). The horizontal bone thickness decreased significantly between re-entry and FU-5 for group RES at all measured levels (p < .05) measuring 0.87 mm (0.0; 2.05) at the implant shoulder, whereas the decrease for group N-RES was insignificant (p = .031) with 0 mm (0; 0.84) at the implant shoulder at 5 years.

CONCLUSIONS

Implants sites with concomitant GBR using a resorbable or non-resorbable membrane revealed stable marginal bone levels and clinical outcomes. Profilometric changes were clinically negligible over 5 years. The observed change in hard tissue thickness was partially compensated by an increase in soft tissue thickness.

Peri-Implantitis: A Clinical Update on Prevalence and Surgical Treatment Outcomes

Dental implants may be considered a reliable routine procedure in clinical practice for the replacement of missing teeth. Results from long-term studies indicate that implant-supported dental prostheses constitute a predictable treatment method for the management of fully and partially edentulous patients. Implants and their restorations, however, are not free from biological complications. In fact, peri-implantitis, defined as progressive bone loss associated to clinical inflammation, is not a rare finding nowadays. This constitutes a concern for clinicians and patients given the negative impact on the quality of life and the sequelae originated by peri-implantitis lesions. The purpose of this narrative review is to report on the prevalence of peri-implantitis and to overview the indications, contraindications, complexity, predictability and effectiveness of the different surgical therapeutic modalities to manage this disorder.

Vertical eruption of anterior maxillary teeth adjacent to single-implant-supported crowns: An assessment after a 3-year follow-up period

STATEMENT OF PROBLEM

Vertical eruption of teeth adjacent to an implant has been reported clinically and might affect the esthetic outcome over time. The prevalence of the problem is unclear.

PURPOSE

The purpose of this prospective clinical trial was to evaluate the vertical eruption of anterior maxillary teeth adjacent to single-implant crowns after a 3-year follow-up period.

MATERIAL AND METHODS

Thirty single dental implants were inserted in maxillary anterior sites including the first premolar. The mean age of the participants at implant-supported crown insertion was 48.4 years (range 23 to 79 years). Each implant was restored with a 1-piece screw-retained ceramic single crown. The vertical changes of 60 adjacent anterior maxillary teeth were evaluated from periapical radiographs and casts at baseline, 6, 12, and 36 months.

RESULTS

A global ANOVA test showed statistically significant differences for the outcomes of the distance-implant platform and cement-enamel junction (DPC) (P<.001), crown length distal (P=.021) and mesial (P=.035), implant crown length (P=.022), and incisal edge to edge (P<.001).

CONCLUSIONS

Continuous vertical tooth eruption next to a single dental implant was observed in adult participants.

Need for lateral bone augmentation at two narrow-diameter implants: A prospective, controlled, clinical study

OBJECTIVES

To detect the potential influence of implant diameter and anatomic factors on the need for bone augmentation procedures (BAPs) when replacing congenitally missing lateral incisors (MLIs).

MATERIALS AND METHODS

Patients with congenitally missing MLIs with a mesio-distal distance between the canine and the central incisor of 5.9-6.3 mm received a Ø2.9 mm implant while Ø3.3 mm implants were placed when the distance was 6.4-7.1 mm. The following linear measurements were recorded using a calliper: width of the alveolar process (WAP), width of the bony alveolar ridge (WAR) and thickness of the facial bone after implant osteotomy (TFB). Guided bone regeneration was performed in case of fenestration- or dehiscence-type defects or a thin TFB (<1.7 mm).

RESULTS

Fifty Ø2.9 mm and 50 Ø3.3 mm were included in 100 patients. WAP and WAR did not differ between the groups (p > .05). TFB was statistically significant larger in the Ø2.9 group (1.75 ± 0.59 mm) compared to the Ø3.3 group (1.5 ± 0.63 mm) (p = .041). Fenestration-type defects (p = .005) and a thin facial bone wall (p = .045) was observed more frequently in the Ø3.3 compared to the Ø2.9 group. Correspondingly, BAP was indicated more frequently in the Ø3.3 compared to the Ø2.9 group (p = .017). WAP, MD and WAR were statistically significant correlated to the need for BAP (p < .001). As independent variable, only WAR influenced the probability of BAP (p < .001).

CONCLUSION

The use of 2.9 diameter implants was correlated to a reduced frequency of BAP compared to 3.3 mm implants, without reaching a statistically significant difference. Measurement of the WAP provides the clinician useful information to predict BAP.

Resorption of retromolar bone grafts after alveolar ridge augmentation-volumetric changes after 12 months assessed by CBCT analysis

In this pilot study, a volumetric analysis of retromolar onlay bone grafts over a period of 12 months was conducted, using repeated CBCT imaging combined with automated image registration.

Eleven patients being treated with 16 bone grafts taken from the retromolar area were examined by CBCT scanning prior to bone augmentation (T0), immediately after bone augmentation (T1) and after a healing time of 12 months after augmentation (T2). Graft volumes were measured at each time point after automated image registration of consecutive CBCT scans.

The mean volume of the augmented site was 372.2 ± 179.4 mm³. Resorption relative to the original augmented volume was 43.7% ± 19.0% after 12 months.

Three-dimensional graft resorption could be precisely depicted by the use of automated image registration for CBCT data over a period of 12 months and demonstrated extensive volumetric changes of bone grafts taken from the ascending ramus of the mandible.

Graft resorption and continuous bony remodeling of the grafted site before and after implant insertion have to be carefully considered by the clinician.

Long-term crestal bone changes in implants placed in augmented sinuses with minimal or moderate remaining alveolar bone: A 10-year retrospective case-series study

OBJECTIVES

To evaluate long-term clinical and radiographic outcomes of dental implants placed after lateral window sinus augmentation utilizing the sagittal sandwich technique.

MATERIALS AND METHODS

Patients treated with sinus augmentation were included in this retrospective case-series study. The surgical procedure was performed with particulate autogenous bone- and anorganic bovine bone-derived mineral (3:7 ratio). Implants were grouped based on baseline residual alveolar ridge height: group S (residual alveolar ridge height of 0.1-3.5 mm), group M (height of 3.5-7mm), and group C (native bone). Radiographs were taken at baseline (abutment installation) and annually throughout the 10-year follow-up.

RESULTS

A total of 86 patients (92 sinus lifts) and 209 implants were included. Ten sinus membrane perforations were recorded (11% incidence), and graft infections occurred in 3 cases (3.2% incidence). During the 10-year follow-up, 3 implants (1.4%) failed. No significant differences in the mean implant marginal bone loss (MBL) between the three groups were found after 1-, 2-, and 5-year follow-up (p > .05). At 10 years, group C exhibited more MBL than group M with a mean difference of -0.53 mm (p = .01). After 10 years, MK III implants displayed significantly more bone loss in native bone than those in augmented bone with a mean difference of 0.48 mm (p = .02). Five patients and 7 implants developed peri-implantitis with no significant differences between the groups (p = .570).

CONCLUSION

Implant placement after two-stage sinus grafting utilizing the sagittal sandwich technique is a relatively safe and predictable procedure with minimal complications and MBL after 10-year follow-up.

Use of a Novel In Situ Hardening Biphasic Alloplastic Bone Grafting Material for Guided Bone Regeneration around Dental Implants - A Prospective Case Series

INTRODUCTION

The novel bioresorbable polymer poly (lactide-co-glycolic acid) (PLGA) coated biphasic calcium phosphate material (BCP) hardens into a stable and porous hard tissue scaffold when exposed to body fluids. The self-containable, stable bone graft material might be beneficial for facilitating guided bone regeneration (GBR) around dental implants, especially for a defect with an absence of bony wall(s). The aim of this prospective case series is to evaluate the post-surgical implant survival and success where the in situ hardening BCP was used for GBR around dental implants.

CASE SERIES

Ten patients received 13 implants with simultaneous bone augmentation. Dehiscence and/or fenestration type of bony defect was detected in nine surgical sites, and three surgical sites exhibited a suprabony defect. In nine out of the 13 implants, a membrane was used in conjunction with the bone grafting. Patients were evaluated at the day of the surgery as well as 2 weeks, and 1, 3, 6, and 12 months postoperatively. All post-surgical wounds were uneventfully healed. Radiographic bone levels showed stability over time with an average bone loss/remodeling of 0.19 ± 0.6 mm (range, -0.5-1.5 mm) from implant placement to the last follow-up at 12 months. All implants survived after 12 months.

CONCLUSIONS

Implant placement with simultaneous bone grafting using the in situ hardening BCP, was shown to be a viable and safe procedure with stable clinical and radiographic results over the follow-up period. Further long-term studies are warranted, however, the combination of the ease of handling and the favorable results are promising.

Volumetric soft tissue alterations in the early healing phase after peri- implant soft tissue contour augmentation with a porcine collagen matrix versus the autologous connective tissue graft: A controlled clinical trial

AIM

This study evaluates the early volumetric changes after buccal soft tissue contour augmentation around implants with a porcine collagen matrix (CM) vs. the subepithelial connective tissue graft (SCTG) from the palate.

MATERIALS AND METHODS

14 patients were enrolled after early implant placement with simultaneous contour augmentation and persistent buccal tissue deficits. At implant exposure, buccal soft tissues were thickened with the CM (n = 7) or the SCTG (n = 7). Impressions were taken before and after surgery, after ten days, one, three and six months. Impressions were digitized and augmented regions 3D evaluated (soft tissue volume (mm³ , %)/thickness (mm)).

RESULTS

Volume increase (mm³ ) after 6 months was 19.56 ± 8.95 mm³ (CM) and 61.75 ± 52.69 mm³ (SCTG) (insignificant, p = .058). In percentage, this was a volume loss of the initially augmented soft tissue volume (100%) of 81.76% in the CM group and 56.39% in the SCTG group (6 months). The mean soft tissue thickness increase (mm) in the buccal contour after 6 months was 0.30 ± 0.16 mm (CM) and 0.80 ± 0.61 mm (SCTG) (insignificant, p = .071).

CONCLUSION

The early healing phase is associated with a significant volume loss of the soft tissues. The SCTG shows insignificant superiority compared to the CM.

Vertical-guided bone regeneration with a titanium-reinforced d-PTFE membrane utilizing a novel split-thickness flap design: a prospective case series

Objectives

To evaluate the feasibility of a newly proposed minimally invasive split-thickness flap design without vertical-releasing incisions for vertical bone regeneration performed in either a simultaneous or staged approach and to analyze the prevalence of adverse events during postoperative healing.

Materials and methods

Following preparation of a split-thickness flap and bilaminar elevation of the mucosa and underlying periosteum, the alveolar bone was exposed over the defects, vertical GBR was performed by means of a titanium-reinforced high-density polytetrafluoroethylene membrane combined with particulated autogenous bone (AP) and bovine-derived xenograft (BDX) in 1:1 ratio. At 9 months after reconstructive surgery, vertical and horizontal hard tissue gain was evaluated based on clinical and radiographic examination.

Results

Twenty-four vertical alveolar ridge defects in 19 patients were treated with vertical GBR. In case of 6 surgical sites, implant placement was performed at the time of the GBR (simultaneous group); in the remaining 18 surgical, sites implant placement was performed 9 months after the ridge augmentation (staged group). After uneventful healing in 23 cases, hard tissue fill was detected in each site. Direct clinical measurements confirmed vertical and horizontal hard tissue gain averaging 3.2 ± 1.9 mm and 6.5 ± 0.5 mm respectively, in the simultaneous group and 4.5 ± 2.2 mm and 8.7 ± 2.3 mm respectively, in the staged group. Additional radiographic evaluation based on CBCT data sets in the staged group revealed mean vertical and horizontal hard tissue fill of 4.2 ± 2.0 mm and 8.5 ± 2.4 mm. Radiographic volume gain was 1.1 ± 0.4 cm³.

Conclusion

Vertical GBR consisting of a split-thickness flap and using titanium-reinforced non-resorbable membrane in conjunction with a 1:1 mixture of AP+BDX may lead to a predictable vertical and horizontal hard tissue reconstruction.

Clinical relevance

The used split-thickness flap design may represent a valuable approach to increase the success rate of vertical GBR, resulting in predicable hard tissue regeneration, and favorable wound healing with low rate of membrane exposure.

Electronic supplementary material

The online version of this article (10.1007/s00784-020-03617-6) contains supplementary material, which is available to authorized users.

Accuracy assessment of a novel semiautomatic method evaluating bone grafts around the dental implant: an in vitro and ex vivo study

The present study aimed to evaluate the accuracy and repeatability of morphological contour interpolation (MCI)-based semiautomatic segmentation method for volumetric measurements of bone grafts around dental implants. Three in vitro (one with a cylinder and two with a geometrically complex form) and four ex vivo models (peri-implant cylinder-shaped bone defect) were created for imitating implant placement with simultaneous guided bone regeneration (GBR) procedure. Cone beam computerized tomography (CBCT) scans of all models were obtained with the same parameters. For volumetric measurements, the actual volumes of bone grafts in models were assessed by computer-aided calculation and both manual and MCI-based methods were utilized as test methods. The accuracy of the methods was evaluated by comparing the measured value and the actual volume. The repeatability was assessed by calculating the coefficients of variation of repeated measurements. For the accuracy of three dimensional (3D) reconstructions, the computer-designed corresponding models were set as the reference and the morphological deviation of 3D surface renderings created by two methods were evaluated by comparing with reference. Besides, measurement time was recorded and a comparison between the two methods was performed. High accuracy of the MCI-based segmentation method was found with a discrepancy between the measured value and actual value never exceeding − 7.5%. The excellent repeatability was shown with coefficients of variation never exceeding 1.2%. The MCI-based method showed less measurement time than the manual method and its 3D surface rendering showed a lower deviation from the reference.

Cellular responses to deproteinized bovine bone mineral biofunctionalized with bone-conditioned medium

OBJECTIVES

The aim of the study was to investigate whether the osteoinductive properties of bone-conditioned medium (BCM) harvested from cortical bone chips within a clinically relevant short-term period can enhance the biologic characteristics of deproteinized bovine bone mineral (DBBM) in vitro.

MATERIALS AND METHODS

To assess the biofunctionalization of DBBM, the adhesive, proliferative, and differentiation properties of mesenchymal stromal ST2, pre-osteoblastic MC3T3-E1, and primary bone-derived cells grown on BCM-coated DBBM were examined by crystal violet staining of adherent cells, BrdU ELISA, and qRT-PCR, respectively.

RESULTS

BCM extracted within 20 min or 24 h in either Ringer's solution (BCM-RS) or RS mixed with autologous serum (BCM-RS + S) increased the adhesive properties of all three cell types seeded on DBBM. The 20-min BCM-RS preparation appeared more potent than the 24-h preparation. BCM-RS made within 20 min or 24 h had strong pro-proliferative effects on all cell types grown on DBBM. RS + S alone exhibited a considerable pro-proliferative effect, suggesting an impact of the serum on cellular growth. DBBM coated with BCM-RS or BCM-RS + S, made within 20 min or 24 h each, caused a significant induction of osteogenic differentiation marker expression with a higher potency of the BCM-RS + S. Finally, a strong additive effect of fresh bone chips combined with BCM-coated DBBM on the osteogenic differentiation of the three cell types was observed.

CONCLUSIONS

Altogether, the data strongly support the biofunctionalization of DBBM with BCM extracted within a clinically relevant time window of 20 min.

CLINICAL RELEVANCE

Pre-activation of non-osteoinductive biomaterials with BCM, prepared from autologous bone chips during a guided bone regeneration (GBR) procedure, bears the potential of an optimal treatment modality for bone defects in daily practice.

Evaluation of a Double Layer Technique to Enhance Bone Formation in Atrophic Alveolar Ridge: Histologic Results of a Pilot Study

The atrophic alveolar ridge has been a challenge in implant dentistry; various techniques using the principle of guided bone regeneration (GBR) have been applied in the past 2 decades.The aim of this study was to introduce and evaluate-clinically, histologically, and radiographically-a novel technique of regenerating a new bone in the atrophic alveolar ridge, which is based on the GBR principles, the double layer technique (DLT). Six patients with partially edentulous jaws with a residual bone width less than or equal to 4 mm in the maxilla were subjected to GBR. The sites were grafted using a DLT. At first, sites were grafted with allogenic bone and then a second layer of deproteinized bovine bone was placed. Next, grafted sites were covered with a resorbable membrane tucked with 2 titanium pins. Cone-beam computed tomography scans were obtained before and 5 months after DLT. In the latter case and during implant site preparation, trephine biopsies were obtained and processed for histologic and histomorphometric evaluation. In all cases, implants were successfully installed and primary stability was established. Implant diameter ranged from 3.8 to 4.1 mm. In all cases, radiographic findings showed increased alveolar ridge width before and after surgery. The new tissues consisted mostly of a variable amount of new trabecular bone, some loose connective tissue, blood vessels, and occasional inflammatory cells. All 15 implants placed had 100% survival rate after a 5-year follow-up. On the basis of these preliminary results, it seems that the double layer GBR technique may achieve satisfactory results from a clinical, radiographic, and histologic perspective favoring placement of dental implants in the atrophic maxillary alveolar ridge.

Selection of Collagen Membranes for Bone Regeneration: A Literature Review

Several treatment modalities have been proposed to regenerate bone, including guided bone regeneration (GBR) where barrier membranes play an important role by isolating soft tissue and allowing bone to grow. Not all membranes biologically behave the same way, as they differ from their origin and structure, with reflections on their mechanical properties and on their clinical performance. Collagen membranes have been widely used in medicine and dentistry, because of their high biocompatibility and capability of promoting wound healing. Recently, collagen membranes have been applied in guided bone regeneration with comparable outcomes to non-resorbable membranes. Aim of this work is to provide a review on the main features, application, outcomes, and clinical employment of the different types of collagen membranes. Comparisons with non-resorbable membranes are clarified, characteristics of cross-linked collagen versus native collagen, use of different grafting materials and need for membrane fixation are explored in order to gain awareness of the indications and limits and to be able to choose the right membrane required by the clinical condition.

A randomized controlled study comparing guided bone regeneration with connective tissue graft to re-establish buccal convexity: One-year aesthetic and patient-reported outcomes

OBJECTIVES

To compare guided bone regeneration (GBR) with connective tissue graft (CTG) in terms of aesthetic and patient-reported outcomes (PROMs).

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind RCT. All sites had a buccopalatal bone dimension of at least 6 mm, received a single implant and were randomly allocated to the control (GBR) or test group (CTG) to re-establish buccal soft tissue convexity. Primary outcomes were Pink Esthetic Score (PES) and Mucosal Scarring Index (MSI) assessed after 1 year. Secondary outcomes included PROMs registered during the early stages of healing and after 1 year.

RESULTS

Twenty-one patients were included per group (control: 11 females, mean age 51; test: nine females, mean age 48). Although there was no significant difference in the PES between the groups (control: 10.11; test: 10.48; p = .577), the MSI was significantly lower in the test (1.10) than in the control group (2.53) (p = .017). Based on descriptive statistics, the latter demonstrated wider scars, more colour mismatch and slightly more suture marks. However, these were not considered disturbing by the patients given similar VAS on soft tissue aesthetics (control: 84; test: 87). Oedema and haematoma were rated twice as high in the control group on at least two postoperative time points, and patients took more painkillers (7.10 vs. 4.86). OHIP-14 decreased in both groups between baseline and 1-year follow-up, indicative of less discomfort in daily life. Differences in MSI and PROMs between the groups may be explained by the need of a vertical releasing incision in order to achieve sufficient access for GBR, periosteal incisions and the use of biomaterials that may induce inflammation.

CONCLUSION

GBR and CTG resulted in favourable aesthetic outcomes as assessed by professionals and patients. However, given additional vertical and periosteal incisions, GBR resulted in more scarring, postoperative discomfort and a higher need for painkillers.

The two-dimensional size of peri-implant soft tissue in the anterior maxilla and some relevance: A 1- to 7-year cross-sectional study

AIM

This study measured the two-dimensional size of soft and hard tissues and analysed some relevance between them.

MATERIAL AND METHODS

Ninety-six maxillary anterior implants with a follow-up time 1-7 years postoperatively were evaluated. We superimposed the CBCT data of 72 patients with the optical scan data, followed by the measurements of the thickness and the height of soft and bone tissues. The shoulder of the implant was the reference point for all vertical measurements.

RESULTS

At the level of implant shoulder, the mid-buccal mean thickness of soft tissue was 1.83 ± 0.76 mm, and on the palatal side, it was 4.00 ± 1.22 mm. The mean height of mid-buccal and mid-palatal gingiva was 4.16 ± 1.07 mm and 4.27 ± 1.07 mm. The buccal and palatal vertical bone wall peak was 0.41 ± 0.73 mm and 0.22 ± 0.57 mm coronal to the implant shoulder, and the marginal bone loss was -0.28 ± 0.76 mm and -0.84 ± 1.41 mm. Correlation analysis showed that the soft tissue thickness was negatively correlated with the bone thickness at 0 mm on the buccal side and at 0/2/4 mm on the palatal side apical towards from implant shoulder. The gingival height was significantly positively correlated with bone peak height and marginal bone height.

CONCLUSION

Soft and hard tissues were basically negatively correlated in the horizontal direction. Sites with little marginal bone loss or high bone peak positively correlated with higher soft tissue levels.