International Journal of Periodontics & Restorative Dentistry, 01/2022

The present study aimed to evaluate the osseoconduction ability of an airborne particle-abraded and etched (SAE) titanium alloy surface when placed in humans with poor bone quality. Four patients scheduled to receive an implant-supported full-arch prosthesis received two additional reduced-diameter implants to be harvested after 6 months of submerged healing. Undecalcified vestibulopalatal/vestibulolingual histologic sections were prepared after the micro-computerized tomography (μCT) examination. Six implant sides from four biopsied implants displayed a type IV bone environment and were included in the present study. Bone-to-implant contact (BIC) was first measured on each implant side. The estimated initial BIC (E-iBIC) was evaluated by superimposing the implant profile 0.25 mm away from its actual position. The μCT provided information about the local and adjacent bony architecture. The mean BIC was 62.5% ± 10.6%, while the mean E-iBIC was 33.1% ± 4.4%. The E-iBIC/BIC ratio was 1.81 ± 0.38. The 3D μCT sections showed the thin bone trabeculae covering the implant surface; although they seemed to be separated from the rest of the bony scaffold, they were much more interconnected than what appeared to be on the 2D histologic preparations. This limited number of human histologic samples document, for the first time, that the SAE titanium alloy implant surface is apparently osseoconductive when placed in poor human bone quality. The average BIC was 1.81 times higher than the E-iBIC. This high osseoconductivity may explain the predictable clinical behavior of implants with this type of SAE textured surface in type IV bone.

Tooth malposition negatively affects the outcome of root coverage procedures, limiting chances for complete root coverage (CRC). This case series introduces a combined orthodontic-mucogingival approach for the treatment of deep (> 4 mm) isolated gingival recession defects affecting mandibular incisors with a buccally displaced root. Twenty patients were treated with a novel orthodontic device (FZ Root Torque Controller) for selective correction of tooth malposition at the affected site, turning all isolated recessions into Miller Classes I and II. Subsequent surgical treatment of the gingival recession with a vertically-coronally advanced flap plus a connective tissue graft achieved 90% CRC at the 1-year follow-up, with a recession reduction of 5.6 ± 1.5 mm, a 1.24 ± 0.24 mm increase in gingival thickness, and improved esthetic outcomes.

Standard treatment for full rehabilitation of compromised maxillae with regular implants includes sinus elevation grafting, a minimum of two to three surgeries, and a minimum treatment time of 9 to 15 months. Zygomatic implants are a viable alternative. However, prosthetic restorations have been compromised due to abutments emerging on the palate. The purpose of this study was to find ways that abutments will emerge on the ridge (occlusal surface). The presented results show it can be done if zygomatic implants are placed in the sinus wall (extra-sinus) and use an internal, conical connection with platform-switching and 45-degree abutments. Thus, marginal tissue prognosis and primary stability may also be improved by adding coronal threads to an implant design. These improvements, if confirmed in longer follow-ups and further studies, may encourage more graftless rehabilitations of severely compromised maxillae, reducing the number of surgeries and overall treatment time.

This article presents a retrospective case series of implant site development using titanium mesh (Ti-mesh) in the maxilla. A total of 58 mesh procedures in combination with several different bone grafts (allograft, cellular allograft, and bovine xenograft) and biologics (including recombinant human platelet-derived growth factor, autogenous platelet-rich growth factor, and recombinant human bone morphogenetic protein-2) were performed in 48 patients. Ti-mesh guided bone regeneration procedures were performed 2 to 3 months after extraction of nonrestorable/hopeless teeth, and the implants were placed 6 to 8 months postaugmentation. The mean initial ridge width was 2.0 ± 1.0 mm, and the mean horizontal gain after Ti-mesh procedures was 4.7 ± 1.6 mm. The ridge width was first measured on the cross-sectional presurgical CBCT image and then confirmed clinically during surgical procedures. No statistical difference in the horizontal gain was found among different combinations of bone grafts and biomaterials. Ti-mesh exposure occurred 22% of the time. The middle-aged adults (odds ratio [OR] = 8.59; P = .046) and older adults (OR = 16.66; P = .02) had significantly higher chances of mesh exposure compared to young adults. While all implants were successfully placed, about 56% of the implants had < 2 mm of bone to the facial aspect of the osteotomy and received additional contour augmentation when placed in a prosthetically appropriate position for a screw-retained restoration. This study demonstrates that although Ti-mesh procedures result in significant bone regeneration in narrow alveolar ridges to predictably allow implant placement, the age-related mesh exposure rate and frequency of need for additional contour grafting should be discussed with patients.

This study compares the clinical outcomes of Er,Cr:YSGG (2,780 nm) laser-assisted open-flap (OF) and flapless (FL) esthetic crown lengthening (ECL) for the treatment of altered passive eruption. Thirty-six healthy patients requiring ECL were randomly divided into two groups: OF and FL. Gingivectomy and ostectomy were performed with an Er,Cr:YSGG laser in both groups. The periodontal condition and gingival margin level (GML) were assessed at baseline, immediately postsurgery, and at 1, 3, and 9 months postsurgery. The effect of periodontal phenotype and tooth location on GML and supracrestal gingival tissue dimension were evaluated. A significant difference was detected in the mean of GML at all time points, except between 3 and 9 months. The main tissue rebound after 9 months was 0.25 ± 0.3 mm in the OF group and 0.26 ± 0.3 mm in the FL group (no significant difference) and was significantly higher in thick periodontal phenotypes. Er,Cr:YSGG laser-assisted ECL is a predictable technique that achieved similar outcomes using flap and flapless approaches, providing esthetic and restorative opportunities for clinicians.

The present study clinically and radiographically compares the outcome of implants inserted in maxillary sinuses augmented with concentrated growth factors (CGFs) or demineralized bovine bone matrix (DBBM) in a one-stage lateral approach. In 20 patients with a residual bone height of 1 to 4 mm, lateral sinus floor elevation was performed, using CGFs or DBBM as the sole grafting material, with simultaneous implant placement. Outcome variables were implant and prosthesis failures, complications, subjective satisfaction, and radiographic changes in marginal bone level (MBL) 12 months after surgery. The patients were consecutively recruited: 10 to the CGF group and 10 to the DBBM group. No implant failed in either group at 12 months postsurgery, and there were no complications. There was no statistically significant difference in MBL change between the CGF and DBBM groups (difference of -0.3 mm, favoring the CGF group; 95% confidence interval [CI]: -0.8 to 0.2; P = .18). There was no statistically significant difference in satisfaction (difference of 0.2, favoring the CGF group; 95% CI: -0.2 to 0.6; P = .29). Within the limitations of the present study, the lateral sinus floor elevation performed with the use of CGFs as the sole grafting material showed implant survival rates and marginal bone level changes comparable to DBBM grafting.

Bone blocks are proposed in oral bone regeneration for their biocompatibility and osteoconductivity. Human dental pulp stem cells (hDPSCs) have been used with bone substitutes as a biocomplex. Melatonin, produced by the pineal gland, has specific functions in the oral cavity in bone remodeling and enhancing the dual actions on osteoblasts and osteoclasts, the genic expression of bone markers. This study evaluated the osteogenic differentiation of hDPSCs, stimulated by melatonin on equine bone blocks. hDPSCs were cultured in growth medium (GM) or differentiation medium (DM) with or without the presence of equine bone blocks and 100 μm melatonin. After 7, 14, and 21 days of culture, expression of miRNAs (miR-133a, miR-133b, miR-135a, miR-29b, miR-206, and miR- let-7b) and genes (RUNX2, SMAD5, HDAC4, COL4a2, and COL5a3), osteocalcin levels and histolgic analyses were evaluated. Melatonin and equine blocks increased the osteogenic potential of hDPSCs even in GM, regulated miRNA and gene expression related to osteogenesis, and increased osteocalcin. hDPSCs cultured in DM showed a significantly higher osteogenic potential compared to GM. This study suggests that equine bone blocks and melatonin enhanced osteogenesis, stimulating early stages of cell differentiation. hDPSCs/equine bone block and melatonin represent a promising, useful biocomplex in bone regeneration with a potential for a possible clinical application.

Alveolar ridge preservation (ARP) is indicated to attenuate anatomic and physiologic changes following tooth extraction. A properly contoured ovate pontic placed immediately into an extraction socket may be adequate to maintain alveolar ridge architecture for improved esthetic results. This prospective clinical study evaluated the ability of immediately placed ovate pontics in conjunction with ARP to attenuate postextraction tissue dimensional changes in the esthetic zone and maintain alveolar ridge contour. Ten patients (11 sites) completed the study. All subjects received a combination of socket grafting with allogeneic particulate graft material and socket sealing with an ovate pontic provisional restoration. A set of clinical linear and volumetric outcomes were assessed after a 6-month healing period. At 6 months postoperative, the linear measurements for the mean ridge dimensional loss were 0.9 ± 0.6 mm (range: 0.2 to 1.8 mm) in height and 1.4 ± 0.6 mm (range: 0.1 to 2.4 mm) in width. The mean volumetric tissue loss observed was 24.4 ± 15.4 mm³ (range: 2.6 to 50.1 mm³) at 3 months postoperative and 32.2 ± 14.2 mm³ (range: 3.8 to 50.5 mm³) at 6 months postoperative. Resorption pattern assessment showed the overall cervical area to have less resorption than the apical areas at 6 months postoperative, with the least amount of resorption in the midbuccal cervical section. When compared to the data of a previous pilot study, no statistically significant difference was seen between the dimensional losses when using ovate pontics with and without ARP. This may be evidence that the use of an ovate pontic provisional restoration immediately after extraction effectively attenuates postextraction dimensional changes.

This study aimed to histologically and histomorphometrically evaluate osseointegration following simultaneous implant placement and maxillary sinus augmentation. Three retrospective human cases are described in which implants were placed at the maxillary sinus site augmented with deproteinized bovine bone mineral (DBBM) and later retrieved due to implant fracture after 5 to 8 years of occlusal loading. The removed implants with bone were processed for histologic evaluation, and bone-to-implant contact (BIC), bone area (BA), and mirror-image bone area (MIBA) were measured. Mature lamella bone was mainly observed, and some unabsorbed grafted bone particles remained in all cases. The measured values of BIC, BA, and MIBA in the three consecutive threads with the highest values were 86.0% to 91.2%, 65.8% to 91.9%, and 73.0% to 90.4%, respectively, and there were no signs of inflammation. Within the limits of this study, these cases demonstrate successful bone formation after maxillary sinus bone augmentation with DBBM and simultaneous implant placement.

This study aimed to simultaneously assess hard and soft tissues alterations and their proportions after alveolar ridge preservation (ARP). Participants (n = 65) who were previously enrolled in a clinical trial investigating ARP healing were selected. The CBCT DICOM (Digital Imaging and Communications in Medicine) and the cast STL (stereolithographic) files of each subject were imported, segmented, and superimposed. A cross-section view of the superimposed image presented the outlines from each DICOM and STL file. The center of preserved ridge was selected in the superimposed image and used to draw the reference lines to realize the measurements. Horizontal linear measurements determined ridge width (RW) and its respective hard/soft tissue proportion (H:S) at 1, 3, 5, and 7 mm below the buccal bone crest immediately after ARP and at the 4-month follow-up. At 1 mm, the baseline RW was 11.6 mm and reduced to 10 mm after 4 months. The baseline H:S was 65%:35% and was 43%:57% at the 4-month follow-up. Considering only the buccal half of the ridge, baseline H:S was 77%:23%, while after 4 months it shifted to 58%:42%. A similar pattern was observed at 3, 5, and 7 mm but with decreased resorption degree. The present study showed that hard tissue is mostly responsible for RW loss after healing, especially in the first 3 mm below the buccal bone crest. Soft tissue partially compensated for the hard tissue shrinkage, gaining thickness in the analyzed areas.

Restoring the proximal contacts is important for a restoration's long-term success. A frequently observed late complication of implant restoration is proximal contact loss. At present, there is a lack of sufficient research for determining the prevalence of proximal contact loss and for identifying the causative factors. The purpose of this clinical retrospective study was to evaluate the prevalence of proximal contact loss between implant restorations and adjacent teeth and to identify the causative factors. Partially edentulous patients who had received single crowns or fixed dental prostheses on implants were selected; the rehabilitations were metal-ceramic or all-ceramic, screw- or cement-retained. The primary study outcome was clinical evaluation of mesial and distal proximal contact tightness. The secondary outcome was evaluation of patient awareness of proximal contact loss, food impaction, and occurrence of biologic complications. In total, 237 single crowns and 83 fixed partial dentures were assessed. A multivariate logistic regression model was adopted. The overall prevalence of proximal contact loss was 51%. Among the patients with proximal contact loss, 107 (65%) were aware of its presence, while 58 (35%) reported food impaction. Within the limits of the present study, proximal contact loss between implant prostheses and adjacent teeth can be considered a frequent event, even at a 10-year follow-up, that should be carefully considered and monitored by patients and operators.

Various free connective tissue graft (CTG) harvesting techniques have been reported. The lining epithelium of the palatal graft may be retrieved either intra- or extraorally. This report presents a series of root coverage cases where deepithelialization was intraorally performed before harvesting the graft with a round diamond bur mounted on a low-speed handpiece. Ten single-tooth gingival recession defects in five patients were treated, applying a surgical procedure based on a coronally advanced flap combined with a free CTG that was deepithelialized in situ by the same method. Recession and probing depths and keratinized tissue and recession widths were recorded at baseline and the follow-up evaluations. Follow-up was between 7 and 21 months (mean: 12.1 ± 5.04 months). Clinical, esthetic, and histologic evaluations were performed. Mean root coverage was 89% ± 24.86% (range: 25% to 100%), and complete root coverage was observed in 80% of cases; the esthetic score range was 6 to 9 (mean: 7.44 ± 1.01). Epithelial remnants, although different in proportions, were evident in all samples (range of prevalence: 4.57% to 29.12%). Within the limitations of the small number of clinical cases, the presented in situ deepithelialization technique for CTG seems to be valuable and may accordingly be routinely applied.

Preserving a sufficient blood supply and maintaining wound stability during the healing phase are the most crucial factors for success in root coverage procedures. Selecting the surgical technique and suturing protocol used to achieve these goals is therefore indispensable for predictable treatment outcomes. Tunneling flap procedures have evolved as a technical advancement in periodontal plastic surgery, particularly focusing on improving the vascular supply at the surgical site. Along with the development of newer flap designs for recession coverage, several suturing protocols for flap stability have been described. This paper illustrates the use of a modified suturing method for soft tissue graft stabilization in a coronally advanced tunnel flap procedure for the treatment of isolated gingival recession. It allows precise three-dimensional positioning and tripod stabilization of the graft in the tunnel as an independent step, differing from previously described techniques. A modified tissue-supported vertical mattress suture is then placed for coronal advancement and improved wound adaptation. The present authors have found that the proposed suturing protocol achieves successful integration of graft, maximum root coverage, excellent esthetic results, and limited postoperative morbidity. The suturing technique is described in detail with schematic illustrations and clinical cases, and its advantages and potential limitations are discussed.

The number of complications related to dental implants has been increasing, as implant therapy has grown to become the most popular treatment choice for replacing missing teeth. Various cases of implant complications have been reported, particularly biologic complications caused by inadequate surgical techniques, including malpositioned implants, that are difficult to solve. In the present case, two malpositioned implants with peri-implantitis were placed in the maxillary right first molar area of a 64-year-old woman. To treat the peri-implant infection and facilitate self-plaque control, one malpositioned implant was removed, and the other was treated with open flap debridement using an erbium-doped yttrium aluminum garnet (Er:YAG) laser. The implant suprastructure was then changed adequately to recover oral function. This case report demonstrates the clinical steps, healing process, and 6-month follow-up of peri-implantitis caused by malpositioned implants.