Five-year outcomes of a randomized controlled clinical trial comparing single-tooth implant-supported restoration with either zirconia or titanium abutments.

AIM: To evaluate the influence of the abutment material (zirconia vs. titanium) on the long-term aesthetic and clinical outcomes of implant-supported restorations. MATERIALS AND METHODS: In 30 patients, a single implant-supported restoration with either a zirconia or a titanium abutment was placed in the anterior maxilla (incisors, canines, and bicuspids). Aesthetic (Implant Crown Aesthetic Index or ICAI), clinical, radiographic, and patient-centred outcomes were recorded at baseline (1 month after final restoration), 1 year, and 5 years of follow-up. This study was registered in ClinicalTrials.gov (NCT02315794). RESULTS: Twenty-five subjects completed the follow-up visits at 1 and 5 years. ICAI values showed statistically significant better aesthetic outcomes when zirconia abutments were used compared to titanium abutments. Between 1 and 5 years, the aesthetic sub-analysis of the crown component worsened but the mucosal sub-analysis improved. There were no significant changes in bone levels, but the plaque index, bleeding on probing, and probing depths worsened in both groups. CONCLUSIONS: At 5 years, standard zirconia abutments achieved better aesthetic outcomes, although with similar clinical behaviour.

Rough Implants in Vertically Augmented Bone: A Retrospective Study with 4 to 15 Years of Follow-up

Although vertical guided bone regeneration (v-GBR) is a popular technique for treating alveolar bone deficiency, there are no long-term studies analyzing the longevity and success of the results. This retrospective study analyzes the clinical and radiographic outcomes of oxidized implants placed after v-GBR, with a follow-up period of 4 to 15 years. The study considers 41 v-GBR patients receiving one or more dental implants between 2001 and 2013 (115 implants total). Clinical and radiographic outcomes were recorded during follow-up visits. A multiple logistic regression model was used to analyze the correlation between peri-implantitis and demographic, surgical, and clinical variables, as well as the length of the follow-up period. The cumulative survival rate of the implants over the mean follow-up period of 9.6 ± 3.4 years was 95.7%, with peri-implantitis observed in 26.1% of the implants. The variables that correlated with the occurrence of peri-implantitis were smoking (OR = 8.5, 95% CI = 1.6 to 44.5, P < .01), posterior mandible implant position (OR = 2.1, 95% CI = 1.2 to 3.9, P < .01), and the length of the follow-up period (OR = 1.5, 95% CI = 1.1 to 2.2, P < .01). In this study, smoking, time since the surgery, and the implant position were associated with peri-implantitis developing on rough surface implants. Along with with previous long-term follow-up studies, this suggests that oxidized surface implants have a higher risk of peri-implantitis than machined ones.

Clinical Performance Evaluation of a Hyaluronic Acid Dental Gel for the Treatment of Traumatic Ulcers in Patients with Fixed Orthodontic Appliances: A Randomized Controlled Trial.

BACKGROUND: A newly available gel containing hyaluronic acid (HA) and polyvinylpyrrolidone was tested for efficacy on traumatic oral ulcers (TOU) caused by fixed orthodontic appliances. METHODS: A double-blind RCT was conducted to test the new gel versus a placebo. According to the sample size calculation, a total of 60 patients were considered sufficient and randomly allocated to one of the two groups out of a pool of 100 total patients who initially agreed to participate in the study. A VAS scale test and lesion measurements at T0, T1, and T2 were performed on the patients. RESULTS: A total of 70 patients developed TOU, with 8 drop-outs; the intergroup comparison showed a statistically significant greater dimension of the lesion in the control group at T2 when compared to the test group. The pain experienced by the patients belonging to the test group was significantly lower than the pain in the patients in the control group Conclusions: Under the limitations of the study, the new formula might provide faster healing with less pain experienced by the patient when compared to a placebo.

Global DNA Methylation in Dental Implant Failure Due to Peri-Implantitis: An Exploratory Clinical Pilot Study.

BACKGROUND: Peri-implantitis (PIT) is highly prevalent in patients with dental implants and is a challenging condition to treat due to the limited outcomes reported for non-surgical and surgical therapies. Therefore, epigenetic therapeutics might be of key importance to treat PIT. However, developing epigenetic therapeutics is based on understanding the relationship between epigenetics and disease. To date, there is still scarce knowledge about the relationship between epigenetic modifications and PIT, which warrants further investigations. AIM: The purpose of this study was to evaluate the level of global DNA methylation associated with implant failure (IF) due to PIT compared to periodontally healthy (PH) patients. MATERIAL AND METHODS: A total of 20 participants were initially enrolled in this pilot, exploratory, single-blinded, cross-sectional clinical human study in two groups: 10 in the PH group and 10 in the IF group. In the participants who have completed the study, gingival tissue and bone samples were harvested from each participant and were used to perform global DNA methylation analysis. The percentage of global DNA methylation (5-mC%) was compared (1) between groups (PH and IF); (2) between the subgroups of gingival tissue and bone separately; (3) in the whole sample, comparing gingival tissue and bone; (4) within groups, comparing gingival tissue and bone. Demographic, periodontal, and peri-implant measurements as well as periodontal staging, were also recorded. All statistical comparisons were made at the 0.05 significance level. RESULTS: Out of the initially enrolled 20 patients, only 19 completed the study and, thus, were included in the final analysis; 10 patients in the PH group and 9 patients in the IF group, contributing to a total of 38 samples. One patient from the IF group was excluded from the study due to systemic disease. The mean implant survival time was 10.8 years (2.17-15.25 years). Intergroup comparison, stratified by group, indicated a similar 5-mC% between the PH and IF groups in both gingival tissue and bone (p = 0.599), only in bone (p = 0.414), and only in gingival tissue (p = 0.744). Intragroup comparison, stratified by the type of sample, indicated a significantly higher 5-mC% in gingival tissue samples compared to bone in both the PH and IF groups (p = 0.001), in the PH group (p = 0.019), and in the IF group (p = 0.009). CONCLUSIONS: Within the limitations of this study, higher global DNA methylation levels were found in gingival tissue samples compared to bone, regardless of the study groups. However, similar global DNA methylation levels were observed overall between the IF and PH groups. Yet, differences in the global DNA methylation levels between gingival tissues and bone, regardless of the study group, could reflect a different epigenetic response between various tissues within the same microenvironment. Further studies are necessary to elucidate the present findings and to evaluate the role of epigenetic modifications in IF due to PIT.

Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study.

AIM AND OBJECTIVE: The aim of the present split-mouth prospective study was to evaluate clinically and histologically the bone regeneration obtained following preprosthetic vertical bone augmentation performed with titanium-reinforced dense polytetrafluoroethylene membrane (d-PM) compared to titanium mesh (TM). MATERIALS AND METHODS: Healthy adult patients presenting with bilateral partial edentulism in the posterior mandible requiring vertical ridge augmentation for implant placement purposes were consecutively included. One side of the mandible was randomly assigned to the use of d-PM, the other to TM. The graft consisted in a mixture of autogenous bone harvested nearby the surgical site and deproteinized bovine bone mineral particles in a 1:1 ratio. On each side during bone augmentation surgery, a 2-mm diameter mini-implant was inserted for clinical and histological analyses. After a healing period of 8 months, the second surgical phase was carried out to remove the nonresorbable barriers, to evaluate clinically the vertical bone gain, and to collect a bone biopsy that included the mini-implant. During the same surgical session, dental implants were inserted in a prosthetically guided position. RESULTS: A total of five patients were enrolled. Eight out of 10 sites healed uneventfully. In the remaining two sites, premature exposure of the TM was observed. Mean vertical bone gain of 4.2 and 1.5 mm was achieved in d-PM and TM groups, respectively (p = 0.06). A mean mineralized tissue of 48.28 and 35.54% was observed in d-PM and TM groups, respectively (p = 0.51). CONCLUSION: The vertical bone gain, although not significantly, was higher in the d-PM group. Similar histological outcomes were noticed if exposure did not occur. In case of wound dehiscence, major resorption was observed. CLINICAL SIGNIFICANCE: Both d-PM and TM can be used to augment atrophic localized ridges vertically. The outcome of bone regeneration seems to be impaired by exposure of the device. How to cite this article: Maiorana C, Fontana F, Rasia dal Polo M, et al. Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study. J Contemp Dent Pract 2021;22(5):465-472.

Aesthetic outcomes of non-functional immediately restored single post-extraction implants with and without connective tissue graft: A multicentre randomized controlled trial.

OBJECTIVES: To compare the 1-year aesthetic results of flapless single implants, placed in fresh extraction sockets with bone replacement and immediate provisional restoration with or without a connective tissue graft (CTG). MATERIAL AND METHODS: The present study proposes a partially blinded multicentre parallel randomized controlled trial, where computer-generated tables were used for central randomization to allocate treatments. A total of 59 of the 60 patients screened by eight private practices in Northern Italy fulfilled the inclusion criteria. Immediate implants were placed in a fresh extraction socket with a non-functional immediate provisional restoration with (Test group) or without (Control group) a CTG. The primary outcome variable was the implant Crown Aesthetic Index (ICAI) at the 1-year follow-up. RESULTS: ICAI for the 59 randomized patients (Test group = 31, Control group = 28) at the 1-year follow-up was 4.69 (95% CI = 3.16-6.22) for the Test group and 3.45 (95% CI = 1.83-5.08) for the Control group, without statistically significant difference between the two groups (p = .086). One implant failure was recorded in each group, resulting in an implant survival rate of 96.8% [95% CI = 83.3-99.9] for the Test group and 96.4% [95% CI = 81.7-99.9] for the Control group. Other secondary outcome variables and complication rates were comparable across the two groups. CONCLUSIONS: Within the limitations of the present clinical trial, the results suggested that the adjunct use of CTG is not mandatory to achieve successful aesthetic outcomes for a well-planned immediate implant placement with immediate non-functional provisional restoration in a fresh extraction socket.

A Prospective Longitudinal Clinical Trial Evaluating the Preservation of the Peri-implant Hard and Soft Tissues.

This prospective longitudinal clinical trial aimed to evaluate the success of a bone-level implant with an integrated platform-switched connection by assessing peri-implant soft tissue and marginal bone level. Twenty-six patients were treated in two different centers with implants placed in healed partially edentulous ridges. Implant success rate and marginal bone level were evaluated with photographs, radiographs, and clinical measurements, with a 6-month postloading follow-up. The esthetic appearance of the photographed peri-implant soft tissue was evaluated at 6 months via the Pink Esthetic Score applied by two calibrated operators. All of the implants except for one placed in the mandible demonstrated successful osseointegration, resulting in a success rate of 97.8% at the 6-month follow-up. Compared to historical controls, no detectable differences in peri-implant marginal bone loss or esthetic outcome were seen.

Clinical Audit of Minimally Invasive Nonsurgical Techniques in Active Periodontal Therapy.

AIMS: Periodontitis is one of the most widespread diseases worldwide. Many efforts have been made to increase the efficacy of periodontitis therapy as much as possible. Recently, minimally invasive nonsurgical techniques (MINST) were introduced in the periodontal field as an alternative to minimally invasive surgical techniques (MIST). This clinical audit aims to evaluate the results of MINST in the initial phase of treatment for periodontitis. MATERIALS AND METHODS: One hundred seven patients with periodontitis who were treated with MINST between 2013 and 2017 and reevaluated after 2 months were included in this clinical audit. The primary outcome analyzed was the proportion of pocket closure. The secondary outcomes were tooth extraction before active periodontal therapy, full-mouth plaque score (FMPS) change, full-mouth bleeding score (FMBS) change, average probing pocket depth (PPD) reduction, and average clinical attachment level (CAL) gain between the baseline and reevaluation values. RESULTS: A total of 2,407 teeth were included in the analysis. At the patient level, the treatment resulted in a mean pocket closure rate of 71.6 ± 15.7% for sites with an initial PPD ≥5 mm. The treatment was statistically significantly (p < 0.001) more effective with respect to the primary outcome compared with expected values reported in a recent meta-analysis (57%). The subgroup analysis revealed statistically significant differences between single and multirooted teeth and between shallow (5-6 mm) and deep pockets (≥7 mm) at the baseline. CONCLUSION: Nonsurgical periodontal therapy with MINST achieved satisfactory results that were better than expected based on the scientific literature. Single-rooted and shallow pockets showed the best proportion of pocket closure at the reevaluation after treatment. CLINICAL SIGNIFICANCE: Minimally invasive nonsurgical techniques can be the treatment of choice when approaching periodontally diseased patients with nonsurgical periodontal therapy.

Tissue Response to a Porous Collagen Matrix Used for Soft Tissue Augmentation.

A short inflammatory phase and fast ingrowth of blood vessels and mesenchymal cells are essential for tissue integration of a biomaterial. Macrophages play a key role in this process. We investigated invasion of macrophages, blood vessels, and proliferating cells into a highly porous and volume-stable collagen matrix (VCMX) used for soft tissue augmentation around teeth and dental implants. The biomaterial was implanted in submucosal pouches in the canine maxilla, and the tissue response was analyzed at six different time points. Immunohistochemistry was done for proliferating cells (PCNA), macrophages (MAC387), multinucleated giant cells (CD86), and blood vessels (TGM2). Blood rapidly filled the VCMX pores. During the first week, MAC387+ cells populated the VCMX pores, blood vessels and PCNA+ cells invaded the VCMX, and CD86+ scattered cells were observed. At 15 days, MAC387+ cells were scanty, blood vessels had completely invaded the VCMX, the number of proliferating cells peaked, and fibroblasts appeared. At 30 days, MAC387+ were absent, the numbers of proliferating and CD86+ cells had declined, while blood vessel and fibroblast numbers were high. At 90 days, residual VCMX was well-integrated in soft connective tissue. In conclusion, the VCMX elicited a short inflammatory phase followed by rapid tissue integration.

A Clinical and Radiographic Retrospective Study on 223 Anodized Surface Implants with a 5- to 17-Year Follow-up.

The aim of this study is to evaluate the long-term performance of anodized surface implants placed in native bone and followed-up for up to 17 years. Success and survival rates, prevalence of peri-implantitis, and the correlation between the presence of peri-implantitis and other clinical and demographic variables were calculated. After a mean follow-up time of 10.4 years (range: 5 to 17 years), 91.7% of 223 analyzed implants were still in function. Peri-implantitis affected 63 implants (28.3%) in 26 patients (44%). Eleven implants with peri-implantitis (4.9%) failed. Within the limits of this retrospective analysis, anodized implants appear to be prone to peri-implantitis, mainly in the posterior mandible and in patients with unsatisfactory plaque control.

Cervical margin relocation: case series and new classification system.

PURPOSE: The present clinical study aimed to investigate the safety and feasibility of cervical marginal relocation (CMR) procedures in cases of deep caries involving supracrestal tissue attachment (STA). MATERIALS AND METHODS: Fifteen patients were selected from those attending the Studio Ghezzi Dental Clinic, Settimo Milanese, Milan, Italy. After following an oral hygiene program with specific counseling sessions, the selected patients were included in a periodic supportive periodontal therapy program. Depending on the treatment they received, the patients were divided into three groups according to a new classification system: a) Class 1: Nonsurgical CMR; b) Class 2a: Surgical CMR (gingival approach); c) Class 2b: Surgical CMR (osseous approach). The primary and secondary outcomes were pocket depth (PD) on probing and residual bleeding on probing (BOP) after 1 year. RESULTS: No differences were found among the three CMR approaches for PD (overall mean value after 1 year: 2.5 ± 0.64 mm; overall mean value after 5.7 years: 2.3 ± 0.49 mm) or residual BOP (40% of the cases after 1 year). CONCLUSION: Based on the study results, the authors can conclude that CMR procedures do not negatively affect the periodontal health status of patients when the connective compartment of the STA is not violated.

Ultrasonic Surgical Aspirator to Treat Deep Infrabony Defects: A New Flapless Minimally Invasive Approach.

The primary outcome of the present study was to assess the percentage of pocket closure, and the secondary aim was to evaluate the clinical performance in terms of clinical attachment level (CAL) gain, probing pocket depth (PPD) reduction, and gingival recession (REC) after the use of cavitron ultrasonic surgical aspirator (CUSA) in deep infrabony defects. Fourteen deep infrabony defects in 11 patients who were previously treated with active periodontal therapy followed by one year of supportive periodontal therapy (at least three sessions) were additionally treated by the aid of CUSA. Eighty-six percent of the initial defects (12 out of 14) resulted in a PD < 5 mm, showing complete resolution six months after CUSA treatment, without any adverse event and with negligible pain (VAS from 0 to 3). CUSA showed potential as a method to promote pocket healing, reduce PPD, and increase clinical attachment (P < 0.001) in deep infrabony defects. This trial is registered with ClinicalTrials.gov NCT03567161.

Preaugmentation Soft Tissue Expansion: A Report of Four Pilot Cases.

This pilot study aimed at investigating the safety and feasibility of pre-augmentation soft tissue expansion (STE). Tissue expanders of different sizes (from 240 to 1300 mm3) were implanted subperiosteally in four patients requiring vertical and/or horizontal bone augmentation, and left in situ for 20-60 days, according to the expander size. Guided bone regeneration was carried out after STE completion. Horizontal and vertical bone gains were analyzed through CBCT. Optical scanning and superimposition of cast models were used for volumetric analysis. The mean soft tissue volume increase was 483.8 ± 251.7 mm3. Horizontal bone gain averaged 3 mm in two successfully expanded sites while one case had a vertical bone gain of 8 mm. Despite promising outcomes in bone and soft tissue gain, the present technique needs improvement before being applied routinely in everyday dental practice.

Vertical ridge augmentation in the esthetic zone.

The reconstruction of deficient alveolar ridges using vertical and/or horizontal guided bone regeneration techniques allows for ideal implant placement, which is crucial for function and also for esthetically successful outcomes. Unlike in the past, when meeting a patient's functional demands was sufficient, many patients now have greater expectations from their implant restoration. Hence, it is no longer enough simply to restore the edentulous space with a functioning tooth or teeth. It has been suggested that patients now measure their final restoration using the contralateral natural tooth as the gold standard. Both subjective and objective levels of patient information on dental implants have increased significantly in the last decade. As a result of this demand, implant literature has inherited and developed specific esthetic parameters and patient-centered outcomes from studies in the restorative field. Unfortunately, studies reporting on guided bone regeneration in the esthetic zone entirely lack such parameters and outcomes. Currently, there is a strong need for a consensus on objective and well-defined parameters to assess the esthetics in bone regeneration and subsequently on implant dentistry.

Guided bone regeneration of non-contained mandibular buccal bone defects using deproteinized bovine bone mineral and a collagen membrane: an experimental in vivo investigation.

AIM: The aim of this pre-clinical in vivo study was to analyse different stages of wound healing after guided bone regeneration in non-contained mandibular buccal bone defects. MATERIALS AND METHODS: Eighteen female beagle dogs, between 1.5 and 2 years old, were used. Buccal bone defects were created in the mandible following extraction of the mesial roots of M1, P4, the distal root of P3 and booth roots of P2. Augmentation procedures of the healed defects were performed 3 months later using a bone replacement graft (T1), an absorbable collagen membrane (T2) or a combination of both procedures (T3). Using a randomized block study design, four stages of healing in two groups of dogs were examined (4 days, 2, 6 weeks and 3 months). The animals were euthanized, and biopsies obtained at the end of each of the study periods were prepared for histological examination. RESULTS: The different reconstructive procedures resulted in regenerated tissue compartments of varying size that contained newly formed bone, non-mineralized tissue and bone augmentation biomaterial when a bone replacement graft was used. While the proportions of mineralized tissue increased and non-mineralized tissue decreased over time in the three groups, the changes in proportions of the DBBM material were small. Initial defect depth, healing time and treatment group significantly influenced the percentage of mineralized tissue obtained. The multivariate multilevel analysis showed that significantly larger area proportions of mineralized tissue were obtained when the T2 sites were compared with T1 and T3 sites, what highlights the importance of the barrier membrane effect for attaining new bone formation. Only in the larger size defects (M1) total ROI at T3 and T1 sites was significantly larger than at T2, what highlights the importance of using a bone replacement graft as a space maintenance scaffold. CONCLUSION: It is suggested that healing following augmentation of non-contained buccal bone defects was characterized by a gradual shift in the relative proportions of non-mineralized and mineralized tissue components.

Tissue Integration of a Volume-Stable Collagen Matrix in an Experimental Soft Tissue Augmentation Model.

Reducing the need for a connective tissue graft by using an efficacious biomaterial is an important task for dental professionals and patients. This experimental study aimed to test the soft tissue response to a volume-stable new collagen matrix. The device demonstrated good stability during six different time points ranging from 0 to 90 days of healing with no alteration of the wound-healing processes. The 90-day histologic specimen demonstrates eventual replacement of most of the matrix with new connective tissue fibers.

Minimally Invasive Surgical Technique in Periodontal Regeneration: A Randomized Controlled Clinical Trial Pilot Study.

The purpose of this study was to compare two minimally invasive surgical techniques (MISTs) for the treatment of periodontal defects: (1) guided tissue regeneration (GTR) using resorbable minimembrane and particulate xenograft (DBBM); and (2) inductive periodontal regeneration (IPR) using enamel matrix derivatives and DBBM. A sample of 20 infrabony periodontal defects in 20 patients were randomly assigned to either the GTR or the IPR group. A follow-up was performed at 12 months postoperative. Significant improvement in clinical parameters was observed in both groups, although no intergroup differences were found. MIST with GTR or IPR demonstrated very good outcomes 1 year after surgery, with no differences between treatment groups.

Turned Implants in Vertical Augmented Bone: A Retrospective Study with 13 to 21 Years Follow-Up.

The aim of this retrospective clinical trial was to evaluate the performance of 91 turned implants placed in vertically augmented ridges in 33 patients by means of guided bone regeneration techniques after a mean follow-up of 15 years. A total of 88 implants were in function (97% survival rate), whereas 9 showed peri-implantitis (9.9%). A mean radiographic bone loss of 1.02 mm between the baseline evaluation (1 year after loading) and the final visit (13 to 21 years later) was recorded. In conclusion, turned implants placed in vertically augmented bone seem to remain stable after many years of function.

The Association of Guided Bone Regeneration and Enamel Matrix Derivative for Suprabony Reconstruction in the Esthetic Area: A Case Report.

This case report presents the correction of severe alveolar ridge atrophy due to congenital and iatrogenic factors. Implants that compromised the natural adjacent teeth and overall esthetics for this young patient were removed and replaced after significant vertical bone and soft tissue regenerative procedures. A treatment combination of bone graft particles, a nonresorbable membrane, and enamel matrix derivatives was used. Significant and stable improvement in esthetics was achieved 12 months after final prosthetic restoration, demonstrating the ability of such a combined treatment to correct the esthetic deformity, improve the health of the adjacent natural teeth, and allow for successful implant treatment.

A randomized trial on the aesthetic outcomes of implant-supported restorations with zirconia or titanium abutments.

AIM: To evaluate the aesthetic outcomes of zirconia versus titanium abutments for single tooth implant-supported crowns in the anterior maxilla. MATERIAL & METHODS: A parallel, double blind clinical trial was conducted at the Complutense University (Madrid), where 38 patients were recruited. After random allocation (via computer-generated permuted blocks), either zirconia (test) or titanium (control) abutments were placed. Intra- and inter-group differences in aesthetic (main outcome), clinical, radiographical, and patient-centred outcomes were evaluated at baseline (crown placement) and at 1-year follow-up. RESULTS: At 1 year, 25 of the 30 randomized patients were analysed (11 test and 14 control). Using the Implant Crown Aesthetic Index (ICAI), the scoring at baseline and 1-year were 7.9 and 7.6 for the test group and 10.6 and 11.3 for the control group, respectively. These differences were not statistically significant (sample size non-contrasted). Patient satisfaction was similarly high in both groups (visual analogue scale 8.5). Furthermore, no differences were observed in the clinical or radiographical outcomes. Two abutment fractures were registered in the test group. CONCLUSIONS: The use of zirconia abutments demonstrated a tendency towards better aesthetic outcomes although the differences were not statistically significant. However, more technical complications were noted with the use of zirconia abutments.