Periodontal Phenotype Modification of Peri-Implant Soft Tissue Deficiency Using Subepithelial Connective Tissue Grafts and Bone Grafts in the Esthetic Region.

Peri-implant soft tissue deficiency (PSTD) is a significant factor impacting aesthetics, particularly in the anterior zone, where labial bone resorption and thin peri-implant phenotypes are common. The occurrence of a gray color around the implant fixture due to PSTD can be aesthetically concerning in the esthetic zone. In cases involving natural teeth, autogenous soft tissue grafts such as subepithelial connective tissue grafts (SCTGs), free gingival grafts (FGGs), and coronally advanced flaps (CAFs) are commonly utilized. However, there are limited reports of using bone grafts in conjunction with these techniques for modifying the gingival phenotype around both teeth and implants. In the presented cases where PSTD resulted in visible gray coloration of the implant fixture in the esthetic zone, mechanical and chemical decontamination of the exposed implant surface was performed using a titanium brush and tetracycline (Tc) HCl. Subsequently, to enhance peri-implant mucosa thickness and mask the titanium color, simultaneous SCTG and bone grafting procedures were conducted. Within the limitations of these case reports, successful esthetic outcomes were achieved and maintained without recurrence for 3-6 years following the simultaneous subepithelial connective tissue graft and bone graft procedures. These findings suggest the potential efficacy of this combined approach in addressing PSTD and enhancing aesthetic results around dental implants, though further studies are needed to validate these outcomes.

Long-term Comparisons of Photoluminescence Affected by Organic Cations of Formamidinium and Methylammonium in Monophasic Lead Iodide Perovskite Quantum Dots.

This study compared the photoluminescence (PL) stabilities of formamidinium (FA) and methylammonium (MA) in lead iodide perovskite quantum dots (QDs). To exclude other factors, such as size and purity, that may affect stability, MAPbI3 and FAPbI3 QDs with nearly identical sizes (~10.0 nm) were synthesized by controlling the ligand concentration and synthesis temperature. Transmission electron microscopy images and X-ray diffraction patterns confirmed homogeneous single-phase perovskite structures. Additionally, the bandgaps and sizes of the synthesized QDs closely matched those of the infinite quantum well model, which guaranteed that the photostability was solely caused by the different organic molecules in the two QDs. We analyzed the PL peak centers and full-width at half maximum of the QDs for 32 days. The enhanced stability of FAPbI3 was found to be caused by the nearly zero redshift (1.615 eV) of its PL peak, in contrast to the redshift (1.685→1.670 eV) of that of MAPbI3.

A Novel Approach for the Treatment of Recurrent Oroantral Fistula Occurring at an Infected Sinus Augmentation Site.

Closing a recurrent oroantral fistula (OAF) that occurs at an infected sinus augmentation site is a challenge for clinicians. The recurrent OAF has a detrimental impact on bone regeneration and subsequent implant placement. This case report includes three cases in which sinus graft infection and OAF occurred after maxillary sinus augmentation (MSA). In these cases, treatments to control sinus infection were performed using an otolaryngologist; then, intraoral interventions comprising mucosal flap procedures, bone grafts, and barrier membrane applications were performed 2-5 times by oral surgeons. Nevertheless, OAF recurred persistently. The failure to stop OAF recurrence may be due to the inability to effectively block air pressure at the OAF site. Following a comprehensive debridement of the infected tissue at the previous sinus augmentation site, a pouch was created through sinus mucosal elevation. The perforated sinus mucosa at the OAF site was covered with a non-resorbable membrane in one case and with resorbable collagen membranes in the other two cases, followed by bone grafting within the pouch. Lastly, this procedure was completed by blocking the entrance of the pouch with a cortical bone shell graft and a resorbable collagen membrane. The cortical bone shell graft, obstructing the air pressure from the nasal cavity, facilitated bone formation, and, ultimately, allowed for implant placement. Within the limitations of the present case report, the application of a guided bone regeneration technique involving a cortical bone shell graft and a barrier membrane enabled the closure of the recurrent OAF and subsequent implant placement.

Submerged Technique of Partially De-Epithelialized Free Gingival Grafts for Gingival Phenotype Modification in the Maxillary Anterior Region: A Case Report of a 34-Year Follow-up.

A coronally advanced flap combined with a subepithelial connective tissue graft is considered the gold standard for achieving root coverage on exposed root surfaces. Nevertheless, challenges arise when this technique is applied to multiple teeth and when the palatal soft tissue is very thin. Several surgical modifications have been reported to simultaneously achieve both single or multiple root coverage and widening of the keratinized gingiva. In this context, there have been no reported cases utilizing the submerged technique with partially de-epithelialized free gingival grafts. We intend to introduce a submerged technique involving partially de-epithelialized free gingival grafts for the modification of soft tissue phenotypes in the maxillary anterior region.

The Bone Bridge Technique Utilizing Bone from the Lateral Wall of the Maxillary Sinus for Ridge Augmentation: Case Reports of a 1-7 Year Follow-Up.

The post-extraction socket of a periodontally compromised tooth/implant is oftentimes accompanied by a very wide-deep alveolar ridge defect. The commonly utilized treatment is ridge preservation followed by delayed implant placement 4 to 6 months after extraction. In the four cases presented in this study, a novel technique of utilizing a bone block obtained from the lateral wall of the maxillary sinus is introduced. Due to the severe localized vertical ridge deficiency, an intraoral autogenous bone block was obtained from the ipsilateral sinus bony window. After the obtained bone block was properly trimmed, it was fixed in the form of a bridge over the vertical defect by the press-fit method. In two cases, the gap between the autogenous bone and defect was filled with a particulate synthetic bone graft, and in another two cases, the gap was left without grafting. All cases were covered with a resorbable collagen membrane. At the time of re-entry after 5 to 6 months, the bone bridge was well incorporated beside the adjacent native bone and helped by the implant placement. Uncovering was performed after 3 to 6 months, and prostheses were delivered after 2 months. Oral function was maintained without any change in the marginal bone level even after the 1- to 7-year post-prosthesis delivery. This case series showed that the bone bridge technique performed using an ipsilateral sinus bony window for a localized vertical deficiency of a post-extraction socket can be used for successful vertical ridge augmentation (VRA).

Lateral Peri-Implantitis: Successful Management via Guided Bone Regeneration at Mandibular First Molar Implant.

Infections occurring around implants are divided into marginal peri-implantitis and retrograde peri-implantitis (RPI). Marginal peri-implantitis starts in the crestal bone and progresses to the apical portion, and RPI starts in the apical bone and progresses to the coronal portion. However, lateral peri-implantitis (LPI) occurring on the side of the implant body has not yet been reported, and the cause is unclear. This 63-year-old male patient is a case of unusual bone resorption that occurred in the lateral portion of the implant body 26 months after lateral bone augmentation. The origin of LPI was an infection at the site of laterally augmented bone. Rather than implant removal, this report demonstrates an alternative treatment option of guided bone regeneration after the enucleation and detoxification of the implant surface with successful clinical and radiographic results for 2 years.

Polarization or Mainstreaming? How COVID-19 News Exposure Affects Perceived Seriousness of the Pandemic and the Susceptibility to COVID-19 Misinformation?

Two surveys investigated whether the exposure to COVID-19 news widens (polarization) or narrows (mainstreaming) the partisan gap in perceived seriousness of the pandemic, and how the perception affects individuals' susceptibility to COVID-19 misinformation that either exaggerates or downplays its health risks. Overall exposure to COVID-19 news homogenized the partisans' otherwise divergent risk perceptions, but the partisan divide was wider among those selectively approaching like-minded news outlets. Perceived seriousness of COVID-19 subsequently altered participants' susceptibility to either fear-arousing or fear-suppressing COVID-19 misinformation in a belief-confirming manner. It is discussed how news media shape the public's reality perception amid the global crisis.

Periodontal Phenotype Modification Using Subepithelial Connective Tissue Graft and Bone Graft in the Mandibular Anterior Teeth with Mucogingival Problems Following Orthodontic Treatment.

Among the complications of orthodontic treatment, mucogingival problems with gingival recession in the mandibular anterior teeth are challenging for clinicians. Mucogingival problems can lead to esthetic deficits, thermal hypersensitivity, tooth brushing pain, and complicated plaque control. Herein, we present a case of a 16-year-old female with gingival recession in the left mandibular central incisor after orthodontic treatment. The preoperative clinical findings showed a thin soft tissue biotype with root prominence in the mandibular anterior area. The interdental area was relatively depressed. After reflection of the full-thickness flap, root coverage using a bone graft substitute and subepithelial connective tissue graft obtained from the palatal mucosa was performed. The 6-month and 5-year postoperative clinical findings showed improved soft tissue phenotype. The cross-sectional CBCT scans 5 years after surgery showed a well-maintained labial bone plate in the mandibular incisors. Within the limitations of this case report, for patients with gingival recession in the mandibular incisors after orthodontic treatment, a successful biotype modification can be achieved with a combined procedure using subepithelial connective tissue graft with bone graft substitutes.

Successful Implant Placement via Simultaneous Nasal Floor Augmentation in an Inferior Meatus Pneumatization Case.

Partially edentulous patients who present with inadequate bone height in the posterior maxillary can predictably be rehabilitated with lateral wall sinus augmentation and subsequent implant placement. However, the sinus augmentation is defined by variations observed in the anatomical presentation of the maxillary sinus. Herein, we describe a case study managing sinus augmentation when a rare anatomic variant termed inferior meatus pneumatization was observed. A 65-year-old female patient presented, wherein the inferior meatus of the nasal cavity was located directly above the maxillary posterior dentition as opposed to the maxillary sinus. The clinically atrophied maxilla was rehabilitated by employing nasal floor elevation, bone augmentation, and simultaneous implant placement. Post-operatively, no sino-nasal complications were recorded. Subsequently, 8 months after the initial procedure, osteointegration of the implants along with the presence of vital bone was observed. The patient posterior occlusion in the upper right quadrant was rehabilitated by engaging the stable implants with a cement-retained fixed final prosthesis. Follow-ups recorded for up to 2 years demonstrated no further complications. The case report demonstrates diagnosis, appropriate treatment, and management of inferior meatus pneumatization and a viable surgical approach for augmentation and implant treatment.

Bone Regenerative Potential of Cross-Linked Collagen Membrane in Peri-Implant Osseous Defect: Case Series with Histologic/Micro-Computed Tomographic Findings.

The role of a barrier membrane is crucial in guided bone regeneration (GBR) for space creation and cell occlusiveness. Those properties of the membrane should be sustained for a sufficient period. For such purpose, several cross-linked collagen membranes were introduced and demonstrated favorable clinical outcomes. However, histologic data were not sufficient to support the effect of cross-linked collagen membranes. In the present case series, healing after GBR using a cross-linked collagen membrane was investigated in-depth via histologic and micro-computed tomographic (micro-CT) analyses. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide cross-linked collagen membrane was used in GBR for treating various peri-implant bone defects in seven patients. After 4-7 months of healing, newly formed tissue of hard consistency was observed over the implant platform. This tissue was carefully harvested and assessed. In micro-CT and histological analyses, evident new bone formation was revealed, especially in the vicinity of the collagen membrane. Moreover, it was histologically found that some newly formed bone was in intimate contact with the membrane. Although the exact mechanism of bone regeneration in the present cases was not clearly elucidated, the cross-linked collagen membrane appeared to contribute to ossification in GBR. Further studies are needed to confirm the findings of the present case series.

Changes in sinus mucosal thickening in the course of tooth extraction and lateral sinus augmentation with surgical drainage: A cone-beam computed tomographic study.

OBJECTIVES: The objective of the study was to evaluate the radiographic changes in sinus mucosal thickness (SMT) in patients with mucosal thickening of odontogenic origin after maxillary molar extraction and lateral sinus augmentation with simultaneous surgical drainage and implant placement. MATERIALS AND METHODS: Forty-six patients were included in this study. The changes in SMT were evaluated using cone-beam computed tomography images produced at four time points: before extraction (T0), before surgery (T1), immediately after surgery (T2), and after prosthesis delivery (T3), and statistical differences between time points were analyzed. The changes in SMT and augmented bone height (ABH) regarding the reason of extraction, smoking, ostial patency, and the presence of postoperative sinusitis were also evaluated. RESULTS: Over time points, SMT gradually decreased (T0: 19.44 ± 9.22 mm, T1: 15.10 ± 8.89 mm, T2: 8.42 ± 6.01 mm, and T3: 4.16 ± 4.91 mm) (p < .05). Five out of 6 patients with ostial obstruction at T1 presented ostial patency at T3. Two patients developed postoperative sinusitis but recovered with medication. Ostial patency at T1, SMT at T1, and reason of extraction did not statistically significantly influence SMT at T3. SMT at T1 had no statistically significant impact on ABH change between T2 and T3. CONCLUSION: Sinus mucosal thickness was gradually reduced by extraction of compromised teeth and drainage during lateral sinus augmentation. The drainage contributed more to the reduction in SMT.

Endodontic sealer-induced maxillary sinusitis: intraoral surgical approach and implant placement at a site of failed nasal endoscopic surgeries.

A 28-year-old male patient was referred from an otorhinolaryngologist for managing unilateral chronic maxillary sinusitis (MS). The patient had undergone two functional endoscopic sinus surgeries (FESS), although the MS was not resolved. Based on his dental history, endodontic treatment had been done on the symptomatic area. A leak of endodontic sealer and peri-apical lesion on tooth #14 was found on cone-beam computed tomographic examination. Extraction of tooth #14 and the modified Caldwell-Luc operation were performed to remove the endodontic sealer material and relevant inflammatory tissue. The sinus membrane lining was maintained as much as possible during the surgery. Implant placement was performed on the tooth extraction site. All clinical symptoms disappeared after the surgery. Radiographic and endoscopic examination revealed successful osseointegration of the implant and complete resolution of the MS. FESS alone may not be sufficient to treat MS derived from dental origin. For unilateral MS, dental history should be carefully checked.

Use of a Lateral Sinus Bony Window as an Intraoral Donor Site for Guided Bone Regeneration in Wide Post-Extraction Defects.

Maxillary sinus augmentation (MSA) and guided bone regeneration (GBR) have shown successful clinical, radiological, and histological outcomes for implant-related bone reconstruction and have been used to augment bony defects of various shapes and sizes. This study demonstrated that the lateral sinus bony window obtained during MSA can be used as an autogenous block bone graft for the augmentation of wide post-extraction defects. During the uncovering procedure performed 6 months after surgery, the grafted lateral bony window was well integrated with the adjacent native bone, and complete bone filling was observed in all bony defects around the implants. All of the implants survived. Within the limitations of this study, autogenous block bone obtained from lateral window sites can be used as novel donors for the resolution of wide bony defects around implants.

Infra- and labio-position of two maxillary central incisor implants in an older adult at a 17-year follow-up.

OBJECTIVE: This report aims to present an infra- and labio-version of the implants relative to the surrounding teeth in an older patient. BACKGROUND: Infra-positioning of dental implants has been sometimes observed in young adults but not in older patients. MATERIALS AND METHODS: Two implants were placed in both central incisor areas in a 63-year-old female patient in 2002. A splinted implant prosthesis was inserted six months later. RESULTS: After 17 years, a deviation in the position of the implant crown on the #21 area was 9.94 mm labially and 4.69 mm apically with respect to the adjacent tooth (#22). The corresponding values of the implant crown on the #11 area were 5.96 and 2.34 mm (with respect to #12), respectively. CONCLUSION: Dental implants in older adults might develop horizontal and vertical discrepancies relative to the neighbouring teeth.

Flap Extension Technique Using Intrasocket Granulation Tissue in Peri-Implant Osseous Defect: Case Series.

A compromised extraction socket is characterized by severe bone resorption around neighboring teeth and is often occupied with thick intrasocket granulation tissue (IGT). Guided bone regeneration (GBR) is a procedure that can preserve the bone volume around extraction sockets, and it can also be combined with immediate implant placement. However, an early exposure of GBR sites is a possible complication because it increases the risk of infection and can inhibit successful bone regeneration. The purpose of these case series is to introduce a novel, surgical procedure that can prevent the exposure of GBR sites by using IGT for flap extension during immediate implant placement in compromised extraction sockets. The technique was successfully performed in six patients. For successful flap closure, the inner portion of the IGT was dissected so that the flap was properly extended with the base of IGT attached to the flap for blood supply. Periosteal releasing incisions were not performed. The IGT was first sutured to the palatal flap with resorbable sutures, and then the overlying flap was closed with additional sutures. There was no post-operative exposure of the surgical GBR site in any of the patients, and the location of the mucogingival junction remained unchanged. All grafted sites also achieved sufficient bone regeneration. Within the limitations, this case series demonstrates the potential use of IGT, a concept which was previously obsolete.

Large Grafting Void Resembling a Surgical Ciliated Cyst following Maxillary Sinus Augmentation. Four Case Reports with Histological Observation.

The cause and pathogenicity of grafting voids following lateral maxillary sinus augmentation (MSA) have not yet been elucidated. The first purpose of this case series is to introduce an unusually large grafting void that radiologically resembles a surgical ciliated cyst (SCC) at the sinus augmented site; the second is to observe the histological findings of these grafting voids. In four patients, MSA was performed using the lateral window technique. An unusually large grafting void appeared on cone-beam-computed tomography (CBCT) taken one week after surgery and except for one patient, there were no clinical symptoms. On CBCT taken six months after surgery, the grafting voids were slightly smaller in size but showed radiographic findings similar to those of SCC. During uncovering, grafting voids were removed through the lateral window site. Histologically, the grafting void was empty or filled with dense connective tissue, and no ciliated columnar epithelium or inflammatory cells were observed. Within the limitations of this case series, the large grafting voids generated after MSA was not converted to SCCs. Rather, they remained scar tissue, which could infringe the sinus bone graft and affect the apical bone support of the implant.

Successful Management of Apically Exposed Implants in the Maxillary Sinus and Associated Sinus Pathologies Via Maxillary Sinus Floor Augmentation.

One common complication with dental implants placed in the atrophic posterior maxilla, especially with simultaneous transcrestal sinus augmentation, is the implant protruding into the sinus without apical bone support. Frequently, apically exposed implants contribute to various sinus pathologies that may lead to implant failure. Treatment options include (1) managing asymptomatic sinus pathology; (2) regrafting the apically exposed portion of the implant(s); and (3) removing the implant and placing a new implant with simultaneous grafting. The purpose of this case report is to present 4 clinical cases of apically exposed implants in the maxillary sinus. The report will cover: (1) exposed implants with asymptomatic sinus pathologies and (2) show successful management of protruding implants and pathologies using maxillary sinus floor augmentation. Various methods of implant surface detoxification, mechanical and chemical, are described for predictable bone remodeling around existing implants as well as newly installed implants. After 6 months of healing, osseointegration was well achieved for all implants and sinonasal complications were not observed. Clinical photographs and 3-dimensional imaging of surgical sites were used to validate clinical assessments.

Increasing model vertical resolution may not necessarily lead to improved atmospheric predictability.

The widely accepted existence of an inherent limit of atmospheric predictability is usually attributed to weather's sensitive dependence on initial conditions. This signature feature of chaos was first discovered in the Lorenz system, initially derived as a simplified model of thermal convection. In a recent study of a high-dimensional generalization of the Lorenz system, it was reported that the predictability of its chaotic solutions exhibits a non-monotonic dimensional dependence. Since raising the dimension of the Lorenz system is analogous to refining the model vertical resolution when viewed as a thermal convection model, it is questioned whether this non-monotonicity is also found in numerical weather prediction models. Predictability in the sense of sensitive dependence on initial conditions can be measured based on deviation time, that is, the time of threshold-exceeding deviations between the solutions with minute differences in initial conditions. Through ensemble experiments involving both the high-dimensional generalizations of the Lorenz system and real-case simulations by a numerical weather prediction model, this study demonstrates that predictability can depend non-monotonically on model vertical resolution. Further analysis shows that the spatial distribution of deviation time strongly contributes to this non-monotonicity. It is suggested that chaos, or sensitive dependence on initial conditions, leads to non-monotonic dependence on model vertical resolution of deviation time and, by extension, atmospheric predictability.

Utilizing Previously Grafted Sinus as Intraoral Donor Site for Successful Augmentation in Peri-Implant Osseous Defect: A Case Report.

The purpose of this case report is to introduce a novel guided bone regeneration (GBR) technique that utilized bone harvested from previously grafted maxillary sinus with deproteinized bovine bone mineral (DBBM) 16 years ago. The patient is a 63-year-old male with hopeless maxillary right molars due to severe bone loss. Two months after the extraction, two bone blocks were harvested with a trephine drill from the lateral wall. One was used for histologic analysis and the other was crushed into particulate forms, which was used for a GBR procedure around an implant at the time of implant placement. The grafted site was then covered with a resorbable collagen membrane. The histological specimen showed newly-formed bone containing residual DBBM particles. The DBBM in the harvested bone was mostly resorbed; DBBM particles comprised only 3.6% of the total bone volume. The final prosthesis was delivered six months post-operatively. No change in crestal bone around the implant was observed throughout the 2 year follow-up period. Within the limitation of the present case report, previously grafted sinus can be a good donor site for further harvesting for a successful GBR procedure.

Bioaerosol exposure by farm type in Korea.

INTRODUCTION AND OBJECTIVE: Bioaerosols exist in almost every environment and are known to be risk factors for a variety of diseases. Agricultural work involves high exposure to bioaerosols and its workplace concentrations affect the surrounding areas. The study evaluates bioaerosol concentrations in agricultural workplaces and residential areas according to farm type. MATERIAL AND METHODS: In 2013-2015, a total of 381 samples were collected for endotoxin and microbial testing from three farm types: open field, greenhouse, and livestock facilities. Endotoxins were measured using a 37-mm glass fire filter connected to an air pump calibrated to 2 LPM. Microorganisms were measured using a gelatin filter and impaction (single-stage Andersen sampler). RESULTS: The concentration of endotoxins and microorganisms at the livestock facilities was significantly higher than in the open fields and greenhouses (p<0.05). Among the livestock farms, the concentrations of endotoxins and gram-negative bacteria were highest at hog farms, and the concentrations of total bacteria and fungi were the highest in poultry houses. In both greenhouses and livestock facilities, the concentrations of bioaerosols were higher in the workplace than in a nearby residential area, and the difference in concentration was significantly greater in the case of livestock facilities. CONCLUSIONS: The concentrations of bioaerosols in agricultural workplaces and nearby residential areas were higher than in the control and general areas. Therefore, measures should be taken to prevent exposure to bioaerosols at agricultural workplaces and their vicinities.