International Journal of Periodontics & Restorative Dentistry, 03/2023

Implant esthetic complications can negatively affect a patient's perception of implant therapy and their quality of life. This article discusses the etiology, prevalence, and strategies for the treatment of peri-implant soft tissue dehiscences/deficiencies (PSTDs). Three common scenarios of implant esthetic complications were identified and described, in which PSTDs could be managed without removing the crown (scenario I), with the surgical-prosthetic approach (crown removal; scenario II), and/or with the horizontal and vertical soft tissue augmentation and submerged healing (scenario III).

This pilot case series study reports the dimensional alveolar bone changes after reconstruction of severely resorbed postextraction sockets treated with a mixture of particulate bone allograft and xenograft in combination with titanium-reinforced dense polytetrafluoroethylene (Ti-d-PTFE) membranes. Ten subjects who required premolar or molar extraction were included. Bone grafts were protected with Ti-d-PTFE membranes, utilizing an open-healing environment; membranes were removed 4 to 6 weeks after extraction, and implants were placed 6.7 months (mean) after extraction (T1). One patient required additional augmentation to correct an apical undercut of the alveolar process that was present preextraction. All implants integrated well and showed an implant stability quotient (ISQ) value between 71 and 83. The mean horizontal ridge width reduction from baseline (extraction) to T1 was 0.8 mm. Throughout the study, the mean vertical bone gain increase ranged from 0.2 mm to 2.8 mm (mean keratinized tissue width increase: 5.8 mm). The ridge preservation/restoration technique showed good preservation and restoration of severely resorbed sockets as well as improved amounts of keratinized tissue. If implant therapy is required after tooth extraction and severely resorbed sockets are present, the use of a Ti-d-PTFE membrane is a realistic option.

Current evidence suggests that proper implant transmucosal contouring can significantly impact supracrestal soft tissue development and crestal bone response both in early and late stages of treatment. The macrodesign and composition of the anatomical healing abutment or temporary prosthesis used during transmucosal contouring are crucial elements for establishing biologic and prosthetic conditions that minimize early bone remodeling, improve esthetic outcomes, and reduce the possibility for future peri-implant inflammation. This article presents clinical directions on the design and fabrication processes of anatomical healing abutments or temporary prostheses for single implant sites under the interpretation of currently available scientific data.

This study investigated the diagnostic accuracy of CBCT for detection of accessory mental foramina (AMFs) in dry mandibles using two different devices and three different CBCT imaging modalities. A total of 40 dry mandibles (20 per group) were selected to generate corresponding CBCT images, each with three different CBCT imaging modalities (high, standard, and low doses), using ProMax 3D Mid (Planmeca) and Veraview X800 (J. Morita). The presence, count (n), location, and diameter of the AMFs were measured on both dry mandibles and CBCT scans. The Veraview X800 with different imaging modalities showed the highest accuracy (97.5%), while the ProMax 3D Mid in low-dose imaging modality exhibited the lowest accuracy (93.8%). The most common AMF sites on dry mandibles were anterior-cranial and posterior-cranial, while anterior-cranial was the most frequent on CBCT scans. As for AMF diameter, the mean mesiodistal and vertical diameters on dry mandibles were 1.89 mm and 1.47 mm, respectively, which were greater or equal to the values obtained from CBCT scans. The overall diagnostic accuracy for assessing AMFs exhibited good results, but some caution is warranted when using a low-dose imaging modality with a large voxel size (400 μm).

The purpose of this pilot randomized controlled trial was to analyze and compare the effects of advanced platelet-rich fibrin (A-PRF) and plasma rich in growth factors (PRGF) combined with deproteinized bovine bone mineral (DBBM) on bone regeneration outcomes in maxillary sinus augmentation (MSA) procedures. A total of 15 patients in need of MSA were consecutively recruited. Maxillary sinuses were grafted with DBBM alone (control group), DBBM mixed with A-PRF (PRF group), or DBBM mixed with PRGF (PRGF group). After a 6-month healing period, bone core biopsy samples were collected prior to implant placement for histologic and histomorphometric analyses. The mean percentage of mineralized tissue (MT) was 20.33 ± 11.50 in the control group, 32.20 ± 7.29 for the PRF group, and 34.80 ± 6.83 for the PRGF group, with no statistically significant differences across the three groups (P > .05). The mean percentage of remaining bone grafting material (RBGM) was 24.00 ± 7.94 for the control group, 26.00 ± 7.78 for the PRF group, and 15.80 ± 8.23 for the PRGF group, with no statistically significant differences across the three groups (P > .05). Finally, the mean percentage of nonmineralized tissue (NMT) was 55.66 ± 7.77 for the control group, 41.40 ± 8.32 for the PRF group, and 49.60 ± 5.68 for the PRGF group, with no statistically signifcant differences across the three groups (P > .05). These findings suggest that the addition of A-PRF and PRGF to DBBM does not enhance new bone formation outcomes in maxillary sinus augmentation procedures. Neither of the two platelet concentrates were superior to the other in any of the variables assessed.

A 12-month prospective consecutive case series study was conducted to evaluate the effectiveness of a novel porcine collagen matrix to correct moderate to severe buccogingival recession defects. A total of 10 healthy patients (8 women and 2 men; age range: 30 to 68 years) with 26 maxillary and mandibular recession gingival defects > 4 mm deep were included. Healthy maturation of gingival tissues with natural color and texture matching the adjacent soft tissue areas were observed at all reevaluation visits. Complete root coverage was not achieved in all cases, possibly due to severe buccal bone loss in most of the selected cases, which negatively impacted the results. Nevertheless, when a novel porcine collagen matrix was used, a mean root coverage of 63.15% was achieved, and gains in clinical attachment level and keratinized tissue height were seen. Future randomized clinical trials are needed to further explore the potential of porcine collagen matrix for treatment of localized gingival recession defects.

This study evaluated how implant design features influence osseointegration. Two implant macrogeometries and surface treatments were evaluated: (1) progressive buttress threads with an SLActive surface (SLActive/BL), and (2) inner and outer trapezoidal threads with a nanohydroxyapatite coating over a dual acid-etched surface (Nano/U). Implants were placed in the right ilium of 12 sheep, and histologic and -metric analyses were conducted after 12 weeks. Percentages of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within the threads were quantified. Histologically, the SLActive/BL group showed greater and more intimate BIC than the Nano/U group. In contrast, Nano/U group depicted woven bone formation within the healing chambers, between the osteotomy wall and implant threads, and bone remodeling was evident at the outer thread tip. Significantly higher BAFO was seen in the Nano/U group than the SLActive/BL group at 12 weeks (P < .042). Different implant design features influenced the osseointegration pathway, supporting further investigations to describe the differences and clinical performance.

One of the key factors in determining the esthetic success of implant-supported prostheses in the esthetic zone is the preservation of the natural architecture of the peri-implant tissues. A case replacing two maxillary lateral incisors with reduced buccal cortical bone by means of implant-supported crowns was illustrated. The socket shield technique was adopted to conserve the tissue volume, guided surgery was used to manage the optimal implant insertion, and anatomically shaped transmucosal implant components were selected to shape peri-implant soft tissues with the ideal emergence profiles and allow for direct digital impressions without scan bodies. The association of immediate implantation, guided surgery, socket shield technique, anatomically shaped transmucosal implant components, and digital impressions without scan bodies was used to achieve a successful rehabilitation with healthy, stable, and anatomically shaped peri-implant tissues.

Phenotype modification therapy has emerged as one of the main treatment objectives of periodontal plastic surgery. However, long-term data on the stability of gingival thickness gains are not available. This study examined the kinetics of mucosal thickness gain as a measure of phenotype modification therapy following treatment of multiple gingival recession defects with vestibular incision subperiosteal tunnel access (VISTA). Six patients with 14 recession type (RT) II teeth were treated using VISTA and subepithelial connective tissue grafts (SCTG). Scanned images of study casts at pre- and postoperative periods (6 to 66 months) were digitally superimposed for quantitative evaluation of soft tissue dimensional changes. Mucosal thickness gains ranged from 1.0 ± 0.7 mm (1 mm apical to cement-enamel junction [CEJ]) to 1.4 ± 0.4 mm (5 mm apical to CEJ). The gingival thickness gains remained relatively stable, with thickness gains at 66 months of 0.5 ± 0.8, 0.9 ± 0.6, 1.1 ± 0.6, 1.0 ± 0.4, and 1.2 ± 0.6 mm at 1, 2, 3, 4 and 5 mm apical to the CEJ, respectively. Treatment of multiple gingival recession defects with VISTA and SCTG led to stable gingival thickness gains and shows promise as a strategy for phenotype modification therapy.

Health care is entering a new era where data mining is applied to artificial intelligence. The number of dental implant systems has been increasing worldwide. Patient mobility from different dental offices can make identification of implants for clinicians extremely challenging if there are no past available records, and it would be advantageous to use a reliable tool to identify the various implant system designs in the same practice, as there is a great need for identifying the systems in the field of periodontology and restorative dentistry. However, there have not been any studies devoted to using artificial intelligence/convolutional neural networks to classify implant attributes. Thus, the present study used artificial intelligence to identify the attributes of radiographic images of implants. An average accuracy rate of over 95% was achieved with various machine learning networks to identify three implant manufacturers and their subtypes placed during the past 9 years.

The histological findings and histomorphometrical analyses of peri-implant tissues from nine functionally loaded dental implants from an adult cadaver were analyzed. Despite the presence of peri-implant bone loss, all implants were found to have a high degree of osseointegration, with the bone-implant contact (BIC) ranging from 69% to 88%. The mean value of the BIC was 83.2 ± 4.3% (range: 76.5 - 87.7%) for the maxillary implants and 74.4 ± 7.1% (range: 69.4 - 84.9%) for the mandibular implants. The BIC was comparable for maxillary and mandibular implants. Relatively prominent bone remodeling and resorption with soft tissue ingrowth were observed in the vertical bony defects compared to the areas without intrabony components, which might represent the sequence of bone loss around the dental implants.

This report describes the utilization of multiple subperiosteal sling (SPS) sutures to stabilize connective tissue grafts in the treatment of multiple recession defects using subperiosteal tunnels via vestibular and intrasulcular accesses. The SPS sutures engage only the graft and stabilize it against teeth inside the subperiosteal tunnel without engaging the overlying soft tissue, which is neither sutured nor coronally advanced. At sites with deep recessions, the graft is left exposed over the denuded root surfaces and allowed to epithelialize, which results in root coverage and increased attached keratinized tissue. Further controlled studies are required to investigate the predictability of this treatment approach.

The aim of this study was to evaluate the outcomes of a modified entire papilla preservation technique (EPPT) in the treatment of isolated intrabony defects in patients diagnosed with stage III periodontitis. A total of 18 intrabony defects were treated: 4 one-wall, 7 two-wall, and 7 three-wall. Mean probing pocket depth reductions of 4.33 mm (P < .0001), clinical attachment level gains of 4.87 mm (P < .0001), and radiographic defect depth reductions of 4.27 mm (P < .0001) were observed at 6 months. Changes in gingival recession and keratinized tissue were not statistically significant. It can be concluded that the proposed modification of the EPPT is useful in the treatment of isolated intrabony defects.

This study compares the fracture strength of teeth restored with conventional round fiber post (CP) and bundle post (BP) in two different lengths. A total of 48 mandibular premolars were selected. Endodontic treatment was performed, and the premolars were divided into four groups (n = 12 per group): Group C9 = 9-mm CP; Group C5 = 5-mm CP; Group B9 = 9-mm BP; Group B5 = 5-mm BP. Post spaces were prepared, and posts were disinfected with alcohol. Silane was applied, and posts were placed with self-etch dual-cure adhesive. The core structures were created using dual-cure adhesive and standardized core-matrix. Specimens were embedded in acrylic, and the periodontal ligament was simulated with polyvinyl-siloxane impression material. Thermocycling was performed, and specimens were then loaded at a 45-degree angle to the long axis. The failure mode was analyzed with ×5 magnification, and statistical analyses were performed. No statistical difference was found between post systems and post lengths (P > .05). Chi-square test revealed no statistical difference in the failure mode (P > .05). BP did not affect fracture resistance compared to CP. For the restoration of extremely irregular canals with a fiber post, BP can be used as an alternative system because it does not reduce the fracture strength. If necessary, longer posts can be used without decreasing the fracture resistance.

The aim of the present study was to develop a 3D digital image-analysis method to quantitatively assess gingival changes after clear-aligner orthodontic therapy. Using teeth as fixed reference points, 3D image analysis tools have been used to quantify mucosal level changes after specific therapies. This technology has not been applied to orthodontic therapy, primarily because orthodontic tooth movement precludes using teeth as fixed reference points. Rather than superimposing the pre- and posttherapy volumes for the entire dentition, the methodology presented herein superimposed the pre- and post-therapy volumes for individual teeth. The lingual tooth surfaces, which remained unaltered, were used as fixed references. Intraoral scans taken before and after clear-aligner orthodontic therapy were imported for comparison. Volumes were created for each 3D image and were superimposed in a 3D image-analysis software that allowed quantitative measurements. The results demonstrated this technique's ability to measure very small changes in the apicocoronal position of the gingival zenith, as well as alterations of gingival margin thickness, following clear-aligner orthodontic therapy. The present 3D image-analysis method offers a useful tool for investigating the periodontal dimensional and positional changes that accompany orthodontic therapy.

The aim of this study was to compare root trunk measurements taken parallel to the tooth axis (TA) to those taken parallel to the root surface (RS) in order to assess the decision-making implications of each method on crown-lengthening surgery. A total of 672 root trunks were measured via CBCT in two planes: TA and RS. The possibility of performing crown lengthening in each clinical situation based on the distance from the cementoenamel junction (CEJ) to the crestal bone (CB) after ostectomy (CEJ-CB) was judged and compared between groups. When RS was used as a reference point, the proportions of cases that judged crown lengthening to be possible were 83.63%, 59.08%, and 39.18% for CEJ-CB values of 4, 5, and 6 mm, respectively. When TA was used instead, those proportions decreased by 3.87% to 7.29%. The lingual root trunk of the lower first molar (LFL) with a CEJ-CB of 4 to 5 mm emerged as the most problematic area; here, the difference between reference planes occurred with one out of every six teeth. Within the limits of this study, utilizing TA for surgical crown-lengthening treatment planning is not ideal because it may lead to extraction of many savable teeth.

Acellular dermal matrix (ADM) is commonly used for soft tissue augmentation in root coverage, increasing the width of keratinized gingiva or vestibular depth, or filling the localized alveolar bone defects. This parallel-design randomized controlled clinical trial assessed the effect of ADM membrane placement simultaneous with implant placement on vertical soft tissue thickness. A total of 25 submerged implants were placed in 25 patients (8 men, 17 women) with vertical soft tissue thickness < 3 mm at the surgical site. Patients were randomized into two groups: The intervention group (n = 13) received ADM over the implant for soft tissue augmentation, while no augmentation was performed for the control group (n = 12). After 3 months, healing abutments were placed, and the soft tissue thickness at the surgical site was measured again with a periodontal probe in both groups. Data were analyzed using Mann-Whitney and Wilcoxon tests. All 25 patients were successfully treated. The presurgical vertical soft tissue thickness was 2 mm and 1.92 mm in the control and test groups, respectively (P > .05). These values changed to 1.83 mm and 2.69 mm, respectively, after the intervention. The mean gain in soft tissue thickness was 0.76 mm in the test group, and the difference between groups was statistically significant (P < .05). ADM membrane can be successfully used to augment vertical soft tissue thickness simultaneous with implant placement.