UNASSIGNED: The aim of this study was to investigate the influence of abutment material, alveolar bone density, and occlusal forces on stress distribution around maxillary anterior implants.
UNASSIGNED: An in-vitro study was conducted. The maxillary anterior implant was modeled using a three-dimensional finite element model in D2 and D3 bones with three different abutment materials: titanium, zirconia, and poly-ether-ether ketone (PEEK). Von Mises stress was evaluated after the application of vertical and oblique loads of 100 N, 175 N, and 250 N. Statistical analysis was done by Friedman-Wilcoxon signed-rank test, Mann-Whitney U test, and Kruskal-Wallis test. The probability value <0.05 is considered a significant level.
UNASSIGNED: Stress distribution around D3 bone was higher than D2 bone in all the abutment materials with greater values seen in oblique load than vertical load with insignificant difference (P > 0.05). Statistically insignificant stress values were seen greater in PEEK than titanium or zirconia abutment (P > 0.05). A statistically significant difference was observed between 100 N and 175 N of load (P < 0.05).
UNASSIGNED: PEEK, zirconia, and titanium as abutment material in the anterior region showed similar properties. The stress on the bone was proportionately increased during the vertical and oblique loads suggesting the influence of mechanical load in crestal bone loss rather than the type of abutment material.

OBJECTIVE: This study aimed to histologically evaluate the healing at 8 weeks after coronally advanced flap (CAF) with either a superficial (SCTG) or deep palatal connective tissue graft (DCTG), or a collagen matrix (CM) to cover recession defects at teeth and implants.
METHODS: One mandibular side of 6 miniature pigs received each 3 titanium implants 12 weeks after extraction. Eight weeks later, recession defects were created around implants and contralateral premolars and 4 weeks later randomly subjected to CAF + SCTG, CAF + DCTG, or CAF + CM. After 8 weeks, block biopsies were histologically analyzed.
RESULTS: For the primary outcome, i.e., keratinization of the epithelium, all teeth and implants exhibited a keratinized epithelium with no histological differences among them also not in terms of statistically significant differences in length (SCTG 0.86 ± 0.92 mm, DCTG 1.13 ± 0.62 mm, and Cm, 1.44 ± 0.76 mm). Pocket formation was histologically seen at all teeth, around most implants with SCTG and DCTG, however not in the CM implant group. The connective tissue grafts showed hardly signs of degradation, whereas the CM was partly degraded and integrated in connective tissue. The mean gain in gingival height was similar in all experimental groups (SCTG 3.89 ± 0.80 mm, DCTG 4.01 ± 1.40 mm, CM 4.21 ± 0.64 mm). Statistically significant differences were found in the height of the junctional epithelium between the control teeth and the connective tissue groups (p = 0.009 and 0.044).
CONCLUSIONS: In this animal model, the use of either a superficial or deep connective tissue graft or a collagen membrane did not seem to have any impact on the epithelial keratinization around both teeth and implants. All procedures (CAF + SCTG/DCTG/CM) resulted in a long JE that was even longer at implants.
CONCLUSIONS: Deep/superficial palatal connective tissue graft yielded similar keratinization around teeth/implants. Given the absence of pocket formation and inflammatory processes at implants when using a CM, CAF + CM might bear potential clinical benefits.

(1) Aim: a cross-linked porcine-derived collagen matrix (CMX) has been developed for soft tissue augmentation. Although this grafting material does not require a second surgical site, recent findings have indicated deeper pockets, more marginal bone loss and more midfacial recession in the short term when compared to connective tissue graft (CTG). Hence, the aim of the present study was to evaluate the safety of CMX based on buccal bone loss over a one-year period. (2) Methods: Patients who were missing a single tooth in the anterior maxilla were included, in whom the failing tooth had been removed at least 3 months prior and who presented a horizontal mucosa defect. All sites had a bucco-palatal bone dimension of at least 6 mm as assessed on Cone-Beam Computed Tomography (CBCT) to ensure complete embedding of an implant by bone. All patients received a single implant and an immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX) to increase buccal soft tissue thickness. All surgeries were performed by means of full thickness mucoperiosteal flap elevation, placing CTG and CMX in contact with the buccal bone wall. Safety was assessed by evaluating the impact of CTG and CMX on buccal bone loss over a one-year period using superimposed CBCT scans. (3) Results: thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48) and 51 (control: 25; test: 26) could be analyzed for buccal bone loss. At 1 mm apical to the implant-abutment interface (IAI), most horizontal resorption was found pointing to 0.44 mm in the control group and 0.59 mm in the test group. The difference of 0.14 mm (95% CI: -0.17-0.46) was not statistically significant (p = 0.366). At 3 mm and 5 mm apical to the IAI, the difference between the groups was 0.18 mm (95% CI: -0.05-0.40; p = 0.128) and 0.02 mm (95% CI: -0.24-0.28; p = 0.899), respectively. Vertical buccal bone loss amounted to 1.12 mm in the control group and 1.14 mm in the test group. The difference of 0.02 mm (95% CI: -0.53-0.49) was not statistically significant (p = 0.926). (4) Conclusions: In the short term, soft tissue augmentation with CTG or CMX results in limited buccal bone loss. CMX is a safe alternative to CTG. Longer follow-up is needed to assess the impact of soft tissue augmentation on buccal bone.

Immediate implant placement has some advantages, such as time-saving, optimal soft tissue architecture preservation, and patient acceptance. In this case, prior to implant placement, minimally guided bone regeneration was performed to augment the concavity on the apico-labial aspect of a fractured maxillary right lateral incisor. After eight months, the tooth was extracted, and an implant was immediately inserted, and a provisional composite-based crown was delivered in the same appointment. After four months, well molded mid-facial gingiva and interproximal papilla were obtained, and a final metal-ceramic crown was fabricated.

Oral implants have helped clinicians to improve the quality of life for many patients. The material of choice for dental implants currently remains titanium type IV, whose mechanical and biological properties have been proven throughout the history of implantology. Yet, this material is not exempt from complications. For these reasons, ceramic alternatives to titanium have emerged. Thus, the purpose of this study is to evaluate peri-implant hard and soft tissue stability with the use of a one-piece ceramic implant (Straumann® PURE Ceramic Implant) during 1 year of follow-up.
One-piece all-ceramic zirconia (ZrO2) implants were placed to replace single missing teeth in the esthetic zone. Six to 8 weeks after the procedure, the definitive prosthesis was fabricated. At the time of prosthesis, placement (T0) photographs and periapical radiographs were taken, and the following clinical parameters were recorded: probing depth (PD), plaque index (PI), bleeding on probing (BOP), suppuration on probing (SOP), distance from gingival margin to incisal edge (GM-IE), and Jemt papilla index (JPI). Follow-up appointments were scheduled at 4 (T4), 8 (T8), and 12 (T12) months, when the same parameters were recorded. In addition, plaque control was reinforced and prophylaxis was carried out. In this last appointment, a final periapical radiograph was taken to assess marginal bone loss.
A total of 32 zirconia implants were placed in 28 patients (16 women and 12 men, aged between 34 and 67 years). The survival and success rate were 96.9%. The increase in probing depth from baseline to 12 months was 0.78 mm. Assessments of plaque index and bleeding on probing showed a slight increase throughout the study.
The results obtained with the Straumann® PURE Ceramic implants show them to exhibit very good clinical behavior. The survival rate of the implants of our pilot study was 96.9%. For these reasons, we can say that zirconia implants could be an alternative to titanium implants in the esthetic zone.

To assess the effect of connective tissue graft (CTG) in terms of vertical mid-facial soft tissue change when applied at the buccal aspect following single immediate implant placement (IIP).
Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, EMBASE and Cochrane databases as well as a manual search to identify eligible clinical studies up to January 2020. Randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP with CTG and without CTG over a mean follow-up of at least 12 months were included for a qualitative analysis. Meta-analyses were performed on data provided by RCTs.
Out of 1814 records, 5 RCTs and 3 NRSs reported on 409 (IIP + CTG: 246, IIP: 163) immediately installed implants with a mean follow-up ranging from 12 to 108 months. Only 1 RCT showed low risk of bias. Meta-analysis revealed a significant difference in terms of vertical mid-facial soft tissue change between IIP + CTG and IIP pointing to 0.41 mm (95% CI [0.21; 0.61], p < .001) in favour of soft tissue grafting. This outcome was clinically relevant since the risk for ≥1 mm asymmetry in mid-facial vertical soft tissue level was 12 times (RR 12.10, 95% CI [2.57; 56.91], p = .002) lower following IIP + CTG. Soft tissue grafting also resulted in a trend towards less bleeding on probing (MD 17%, 95% CI [-35%; 1%], p = .06). Meta-analyses did not reveal significant differences in terms of pink aesthetic score, marginal bone level change and probing depth. Results were inconclusive for horizontal mid-facial soft tissue change and papilla height change. Based on GRADE guidelines, a moderate recommendation for the use of a CTG following IIP can be made.
CTG contributes to mid-facial soft tissue stability following IIP. Therefore, CTG should be considered when elevated risk for mid-facial recession is expected in the aesthetic zone (thin gingival biotype, <0.5 mm buccal bone thickness).

OBJECTIVE: To assess on the one hand the 5-year outcome of early implant placement with guided bone regeneration (EIP/GBR) and on the other hand of alveolar ridge preservation with late implant placement and connective tissue graft (ARP/CTG).
METHODS: Patients who had been treated with a single implant in the anterior maxilla in 2014 were selected for reevaluation in 2019. In the EIP/GBR cohort, implants were installed 4 to 8 weeks following extraction and the buccal contour was overbuilt by means of GBR. In the ARP/CTG cohort, collagen-enriched deproteinized bovine bone mineral was applied at the time of extraction and implants were installed 5 months later. All ARP/CTG cases received a buccal CTG 3 months after implant installation to reestablish buccal convexity. Primary outcomes were the pink esthetic score (PES) (Belser et al 2009) and the mucosal scarring index (MSI) (Wessels et al 2019). Clinical and radiographical parameters were secondary outcomes.
RESULTS: Eighteen patients (9 females; mean age 52) in the EIP/GBR cohort, and 20 patients (9 females; mean age 38) in the ARP/CTG cohort were evaluated. PES was 6.28 following EIP/GBR. A (nearly) perfect aesthetic outcome defined as PES ≥8 was found in 3/18 cases. Perfect root convexity / soft tissue color and texture seemed most difficult to achieve. PES was 7.80 following ARP/CTG. A (nearly) perfect aesthetic outcome was found in 11/20 cases. MSI was 2.94 following EIP/GBR with 14/18 cases showing scarring. MSI yielded 0.50 following ARP/CTG with 6/20 cases showing scarring. In both cohorts, all implants survived, and none had developed periimplantitis. However, implants in the ARP/CTG cohort demonstrated a 5.4 times higher risk for periimplant mucositis than implants in the EIP/GBR cohort at 5 years follow-up.
CONCLUSIONS: EIP/GBR and ARP/CTG showed acceptable long-term outcomes. The aesthetic outcome was particularly favorable following ARP/CTG, yet this should be interpreted with caution due to selection bias and because soft tissue grafting was not performed in the EIP/GBR cohort. Randomized controlled trial (RCTs) comparing EIP with ARP are required to assess the need for soft tissue grafting and to evaluate clinical, aesthetic, volumetric, and patient-reported outcomes. Only on the basis of such studies clinical recommendations can be made.

OBJECTIVE: To volumetrically compare guided bone regeneration (GBR) with connective tissue graft (CTG) to reestablish convexity at the buccal aspect of single implants.
METHODS: Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind randomized clinical trial (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 reestablish buccal soft tissue convexity. Patients received a provisional crown at 3 months and a permanent crown at 6 months. Primary outcomes were volumetric increase (mm3 ) and linear increase (mm) in buccal soft tissue profile (BSP) within a well-defined area of interest at fixed time points. Alveolar process deficiency was a secondary outcome.
RESULTS: Twenty-one patients were included per group (control: 11 females, mean age 51; test: 9 females, mean age 48). After 1 year, GBR resulted in a significant volumetric increase of 20.74 mm3 (P < .001) corresponding to linear increase in BSP of 1.30 mm (P < .001). For CTG, this was 15.86 (P < .001) and 1.19 mm (P < .001), respectively. The changes over time in volume (P = .173) and BSP (P = .241) were not significantly different between the groups. Twenty-nine percentage and 26% of the final volumetric increase was the result of installing and altering prosthetic components in the control and test groups, respectively. Alveolar process deficiency significantly reduced from pre-op to 1 year following GBR (P < .001) and CTG (P < .001). The difference between the groups was not significant (P = .342). However, 58% of the patients treated with GBR and 38% treated with CTG failed to show perfect soft tissue convexity at the buccal aspect.
CONCLUSIONS: GBR as well as CTG are effective in reducing horizontal alveolar defects for aesthetic purposes. However, in about half of the cases, either strategy failed to optimally reestablish buccal convexity.

BACKGROUND: Xenogeneic soft tissue substitutes are currently being investigated as an alternative to subepithelial connective tissue grafts (CTG) with the intention to avoid postoperative morbidity associated with autologous grafting. The aim of the present study was to volumetrically evaluate the effectiveness and mid-long-term stability of a porcine-derived collagen matrix (PDCM) (Mucoderm®, Botiss gmbh, Berlin, Germany) in increasing soft tissue volume at the buccal aspect of molar implant sites.
METHODS: Periodontally healthy non-smoking patients with a single tooth gap in the molar area were selected for a prospective case series. All sites had a bucco-oral bone dimension of at least 8 mm and demonstrated a horizontal alveolar defect. A wide diameter implant was placed under the elevated buccal flap and a PDCM was applied. The primary outcome was the linear increase in buccal soft tissue profile (BSP) within a well-defined area of interest. This was performed with designated software (SMOP; Swissmeda AG, Zurich, Switzerland) on the basis of superimposed digitalized study casts taken before surgery (T0), immediately after surgery (T1), at three months (T2), one year (T3) and three years (T4). Secondary outcomes were alveolar process deficiency and clinical parameters.
RESULTS: Fourteen out of 15 treated patients attended the three-year re-assessment (four females; mean age 51.4 years). Mean linear increase in BSP at T1 was 1.53 mm (p = 0.001). The PDCM showed substantial resorption at T2 (1.02 mm or 66.7%) (p = 0.001). Thereafter, a 0.66 mm volume gain was observed (p = 0.030), possibly due to the installation of a permanent crown displacing the soft tissues to the buccal aspect. This resulted in a linear increase in BSP of 1.17 mm (76.5%) at T4. Alveolar process deficiency significantly reduced over time (p = 0.004). However, 50% of patients still demonstrated a slight (6/14) or obvious (1/14) alveolar process deficiency at study termination. Implants demonstrated healthy clinical conditions.
CONCLUSIONS: The PDCM demonstrated marked resorption during the early stages of healing. Due to the matrix thickening the tissues, and the permanent crown displacing the tissues, 76.5% of the initial increase in BSP could be maintained over a three-year period. Half of the patients failed to show perfect soft tissue convexity at the buccal aspect.

The aim of this retrospective study was to assess the clinical and aesthetic outcomes, and patient satisfaction, following dental implant therapy in cleft patients. Implant survival, changes in marginal bone level, pocket probing depths, plaque and bleeding indices, aesthetics, and patient satisfaction were assessed in 17 alveolar cleft patients and 17 matched controls. At follow-up (mean 72.4±46.4 months), one implant had been lost in the cleft group. Mean marginal bone loss at follow-up was -0.4±0.4mm in cleft patients and -0.2±0.4mm in controls. Aesthetics of the peri-implant soft tissues (pink aesthetic score) were less favourable (P=0.025) in cleft patients (5.0±1.9) than in controls (6.5±1.7), while peri-implant parameters were comparable in the two groups. Overall patient satisfaction was 8.6±0.9 in cleft patients and 8.9±1.1 in controls (P=0.331). In cleft patients, no difference in aesthetics was observed between patients who received additional bone augmentation at 3 months prior to implant placement and those who did not (P=0.092). Dental implant therapy in cleft patients is associated with high implant survival, minor marginal bone loss, healthy peri-implant soft tissues, and high patient satisfaction. Only the aesthetics of the soft tissues was worse in cleft patients compared to augmented non-cleft patients.