3D printing technology using calcium phosphate materials such as octacalcium phosphate (OCP, Ca 8 H 2 [PO 4 ] 6 ·5H 2 O) has emerged as a precise approach for fabricating personalized patient-specific constructs. However, the properties of materials and binder solutions for 3D printing may affect the optimal level of biocompatibility. Therefore, in this study, the OCP material was combined with a sodium alginate solution in a 3D printing paste to improve its biocompatibility. Moreover, Alg-OCP and 3D printing scaffolds increased the ALP activity and induced osteogenic differentiation without cytotoxicity in MG-63 cells. This study indicates the potential of Alg-OCP and 3D printing scaffold for novel bone graft materials. Graphical abstract

Other SectionsAbstractIntroductionMaterials and MethodsResultsDiscussionAcknowledgementsConflicts of InterestFiguresTablesReferences

This prospective single-arm clinical study aimed to radiographically and histomorphometrically evaluate the efficacy of the lateral approach for sinus floor elevation (LSFE) using biomimetic octacalcium phosphate (OCP) synthetic bone graft (Bontree®). LSFE using Bontree® was performed on 10 patients (15 implant placement sites) willing to undergo implant surgery, followed by implant placements after 6 months of the healing period. The vertical bone height (VBH) and Hounsfield unit (HU) values at each implant placement site were evaluated radiographically using cone-beam computed tomography at baseline immediately after surgery (T1) and 6 months after surgery (T2). A histomorphometric evaluation of the bone core biopsy specimen was also performed. The mean VBH and HU changes at all sites included a decrease by 0.91 mm and a statistically significant increase by 431.86, respectively, from T1 to T2. The mean ratio of the newly formed bone (23.34% ± 10.63%) was greater than that of the residual bone graft (19.09% ± 8.74%), indicating that Bontree® is effective for new bone formation. This pilot study suggests that Bontree® is a promising bone substitute for LSFE.

Purpose This study aimed to clinically evaluate the efficacy of vestibuloplasty around lower molar implants using 3 different modalities: apically positioned flap alone (APF), APF with a free gingival graft (FGG), and APF with modified periosteal fenestration (mPF). Methods Three different vestibuloplasty procedures during second-stage implant surgery were performed at the mandibular molar area in 61 patients with a shallow vestibule and insufficient keratinized tissue (KT). The clinical measurements of KT width were recorded at baseline, immediately after surgery (T0), 6 months after surgery (T6), and 12 months after surgery (T12). Soft tissue esthetic scores were measured. Results An additional KT width gain from baseline to T12 of approximately 2 mm was obtained with FGG and mPF compared to that with APF. Shrinkage of the re-established tissue was lower with mPF and FGG than with APF, whereas the esthetic profile was better with APF and mPF than with FGG. Conclusions Within the limitations of this study, mPF showed potential as a promising approach for vestibuloplasty around the lower molar implants compared to the traditional APF and FGG.

During the COVID-19 pandemic, e-learning has become more prevalent in dental education. In this study, we investigated the effectiveness of video lectures with embedded quiz questions. A questionnaire survey was conducted on the preferences of each educational method for dental students (n=70) who took all three lecture types (offline lecture, Group 1; video lecture without embedded quiz, Group 2; and video lecture with embedded quiz, Group 3). In terms of other behaviors that imply the nonacademic-related activities, Group 2 was significantly the highest, whereas in terms of lecture flow, it was the lowest. In terms of learning motivation and learning confidence, Group 3 lecture type was significantly preferred. In terms of communication with professor and communication with students, Group 1 was the most preferred, but there was no significant difference compared with Group 3. In terms of overall lecture satisfaction, Group 3 lecture type was significantly the highest. The e-learning method using video lectures with embedded quiz questions could be an effective alternative to traditional offline lectures in dental education.

BACKGROUND/PURPOSE:Due to the pneumatization of the maxillary sinus, the sinus floor augmentation is often performed to implant placement in the maxillary posterior region. The aim was to perform radiographic and histomorphometric evaluation after placement of mixed allografts (cortical freeze-dried bone allograft [FDBA] 50%:cancellous FDBA 50%) during sinus floor augmentation. MATERIALS AND METHODS:In 37 patients, anorganic bovine bone (ABB, sites = 16), mineralized cancellous bone allograft (MCBA, sites = 15), and mixed allografts (Mixed AG, sites = 20) were placed during sinus floor elevation via the lateral approach (LSFE), at total 51 sites with residual alveolar bone height (RBH) < 5 mm. Cone-beam computed tomography images were obtained before LSFE (T0), after surgery (T1), and 6 months after surgery (T2) for radiographic analysis. After a 6-month healing period, core biopsies were harvested and histomorphometric analysis was performed. RESULTS:The mean augmented bone height (ABH) of ABB, MCBA, and mixed AG groups after surgery was similar (13.86 ± 4.19 mm, 13.99 ± 4.07 mm, and 14.20 ± 3.12 mm, respectively; P > 0.05). The mean ABH of ABB, MCBA, and mixed AG groups after 6 months was similar (13.72 ± 4.55 mm, 11.83 ± 3.31 mm, and 12.53 ± 2.97 mm, respectively; P > 0.05). In the ABB, MCBA, and mixed AG groups, the proportion of newly formed bone (NB) was similar (36.13 ± 10.01%, 39.26 ± 10.72%, and 31.27 ± 18.31%, respectively; P > 0.05). CONCLUSION:This result demonstrated that mixed AG led to sufficient bone augmentation and histologically comparable NB formation as compared to ABB and MCBA for sinus floor augmentation.

Other SectionsAbstractIntroductionCaseDiscussionAcknowledgementsConflicts of InterestFiguresReferences

This study aimed to investigate the effect of pomegranate extract (PE) on the progression of periodontal disease in an experimental rat model of periodontitis. Periodontitis was induced in rats by placing a 5-0 black silk ligature and injecting a lipopolysaccharide of Porphyromonas gingivalis into the gingiva. Distilled water (DW) or PE solution was orally administered daily, and the animals were sacrificed after 3 weeks. Tissue specimens of the periodontitis model were analyzed using an enzyme-linked immunosorbent assay kit and by micro-computed tomography (CT) imaging. The expression levels of cyclo-oxygenase (COX)-1 and COX-2 were significantly reduced in ligation (Lig)+PE 22 µ g/mL and Lig+PE 44 µ g/mL groups, but there was no statistically significant difference in matrix metalloproteinase (MMP)-8 levels. Furthermore, micro-CT imaging demonstrated that alveolar bone resorption was inhibited in Lig+PE 22 µ g/mL and Lig+PE 44 µ g/mL groups compared with that in the Lig+DW group. These results demonstrate that PE has an inhibitory effect on the progression of alveolar bone loss caused by periodontal inflammation by reducing the expression levels of COX-1 and COX-2 in the process of periodontal disease.

Severe plaque accumulation might occur in the shallow vestibule around dental implants, resulting in a higher occurrence of peri-implant mucositis or peri-implantitis.This case series aimed to evaluate the efficiency of modified periosteal fenestration (mPF) for treating a patient with a shallow vestibule and reduced width of attached mucosa around dental implants.The mPF technique was performed by modifying the traditional periosteal fenestration method.Initially, the partial-thickness apically positioned flap (APF) was performed.After that, horizontal parallel periosteal fenestration incision was done from the coronal border of the APF toward the crown of the implant at 2 mm.A full thickness flap elevation in the apical direction was performed to create an osseous exposure of 2 mm or more from the incision site.A linear island of denuded bone was thus produced.The wound so created was covered with resorbable periodontal pack.In all three patients, sufficient dimension of attached mucosa and deepened vestibule around dental implants were gained and maintained during the follow-up period ranging from 12 to 18 months.Thus, the mPF procedure, which we first suggested, might be a powerful alternate treatment modality for vestibuloplasty around dental implants, to traditional APF only or free gingival graft procedures.

Stage-two implant surgery, which exposes the implant platform to connect the healing abutment, affects the width of the peri-implant keratinized mucosa thereby affecting the long-term prognosis of the implant. The purpose of this study was to compare the changes in the width of the peri-implant buccal keratinized mucosa between the minimally-invasive crestal incision (MCI) procedure and the apically-positioned full-thickness flap (APFTF) method during stage-two implant surgery. A total of 74 implants were placed in 41 patients. The MCI group included 27 implant cases wherein, healing abutments were connected after stage-two implant surgery using the MCI in 18 patients. The APFTF group comprised 47 implant cases wherein, healing abutments were connected after stage-two implant surgery using the APFTF method in 23 patients. The buccal keratinized mucosa widths (BKMW) of the healing abutment and prosthesis were measured at the mesial, central, and distal aspects after the stage-two surgery and the final restoration. A decrease in the BKMW in both groups after stage-two implant surgery was observed when compared with those after the final restoration; furthermore, the BKMW was significantly lower after stage-two implant surgery in the MCI group (p<0.001). No statistically significant difference in BKMW was noted between the MCI and APFTF groups at any point. These results reveal that the APFTF method was more effective than MCI in terms of preserving the buccal peri-implant keratinized mucosa during stage-two implant surgery.

A novel Gram-stain-negative, motile, and facultative anaerobic coccus, strain ChDC F240T was isolated from human subgingival dental plaque of a gingivitis lesion. The phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) sequence showed that the strain belonged to the genus Lautropia. 16S rDNA of strain ChDC F240T had the highest similarity to that of Lautropia mirabilis ATCC 51599T (98.8%). Major cellular fatty acids of strain ChDC F240T were C16:0 (43.9%) and C16:1ω6C/C16:1ω7C (38.1%). Draft genome of the strain was 3,834,139 bp in length and the G+C content was 65.0 mol%. Average nucleotide identity and genome-to-genome distance values between strain ChDC F240T and L. mirabilis ATCC 51599 T were 81.99% and 28.50% (26.1–30.9%), respectively. These results reveal that strain ChDC F240T is a novel species within the genus Lautropia, for which the name Lautropia dentalis sp. nov. is proposed; type strain is ChDC F240T (= KCOM 2505T = JCM 33297T).

In the recent years, the immediate placement of dental implants into fresh extraction sites has become an acceptable treatment approach. However, immediate molar implant placement presents specific challenges because of the anatomical and physiologic limitations. Such implant surgeries commonly require procedures that use a barrier membrane to generate bone and soft tissue or one that seals the molar extraction socket through a coronally advanced flap. Here, as an alternative, we report a method for treating molar extraction socket wounds in the hard and soft tissues after immediate placement of an implant using a silicone sheet.

Depulpin, is mainly composed of paraformaldehyde, and was widely been used in the past for root canal treatment due to its ease of use. However, its use was prohibited in Korea after several side effects of paraformaldehyde on periodontal tissue were reported. This case report demonstrates a successful dental implant restoration using platelet rich fibrin and recombinant human bone morphogenetic protein-2 for an acute mandibular bone necrosis caused by use of paraformaldehyde-containing paste.

In the present study, three strains (ChDC F213T, ChDC F251, and ChDC F267) were classified as novel species of genus Fusobacterium based on average nucleotide identity (ANI) and genome-to-genome distance (GGD) analysis and chemotaxonomic characterization. 16S rDNA sequences of strains ChDC F213T, ChDC F251, and ChDC F267 were highly similar to that of F. periodonticum ATCC 33693T (99.6, 99.4, and 99.4%, respectively). ANI and GGD values of the three isolates with F. periodonticum ATCC 33693T ranged from 92.5 to 92.6% and 47.7 to 48.2%, respectively. Considering that threshold of ANI and GGD values for bacterial species discrimination are 95–96% and 70%, respectively, these results indicate that the three isolates represent a novel Fusobacterium species. DNA G + C contents of the three isolates were 28.0 mol% each. Cellular fatty acid analysis of these strains revealed that C14:0, C16:0, and C16:1 ω6c/C16:1 ω7c were major fatty acids. Therefore, these three strains are novel species belonging to genus Fusobacterium. Strain ChDC F213T (= KCOM 1259T = KCTC 5677T = JCM 33009T) is the type strain of a novel species of genus Fusobacterium, for which a name of Fusobacterium pseudoperiodonticum sp. nov. is proposed.

Porous nickel–titanium (Ni-Ti) alloy implants have been previously introduced, and many studies have been performed. Porous Ni-Ti alloys have excellent properties for use in the dental field. Thus, the use of a porous Ni-Ti coating to combine the advantages of Ni-Ti with titanium implants should be considered. The aim of this study was to investigate the tissue response to porous Ni-Ti alloy in vivo. Three 8-mm diameter calvaria bone defects were established in New Zealand rabbits. In the control group, only a collagen membrane was applied to the defect. In experimental group I, the alloy disk was applied to the defect with a bone graft and resorbable membrane. In experimental group II, the alloy disk was placed in the defect covered by a resorbable membrane. After 4 and 8 weeks of healing, the experimental animals were euthanized for specimen preparation. Histomorphometric analysis was performed to quantify new bone formation and connective tissue. The data were analyzed by Kruskal–Wallis and Mann–Whitney U-tests. At 4 and 8 weeks, new bone formation was seen in all groups. The new bone formation was insufficient in the groups with the titanium implants. There was minor inflammation in the experimental groups compared with the control group. In this study, new bone formation and tissue reactions were seen around the porous Ni-Ti alloy. Minor inflammation and insufficient new bone formation were noted in the experimental groups. This meant that the porous Ni-Ti alloy affected the adjacent tissue.

Background Traumatic, inflammatory, congenital reasons, and physiological ridge resorption after tooth loss often lead to unfavorable hard and soft tissue conditions in edentulous regions. Therefore, horizontal or vertical alveolar bone augmentation procedures usually cannot be avoided. the GBR performed on extrabony defects still lacked predictability. The use of three-dimensional, preformed titanium membranes can achieve GBR by ensuring graft stability and space maintenance. Aim/Hypothesis This study aims to clinically and radiographically evaluate the results of bone gain in extrabony defects after GBR using three-dimensional, preformed Ti-membranes. Material and Methods This study was conducted clinically on 74 patients (114 implants) with extrabony defects which existed around dental implants at the time of implantation. Patients were evaluated clinically and radiographically by using cone beam computed tomography (CBCT) at baseline, Implant 1st surgery, after 5 months each. At first, the exposure of three-dimensional, preformed Ti-membrane is evaluated between first surgery and second surgery. Secondly, Horizontal bone gain was evaluated at implant's platform level on 114 implants (95 only horizontal GBR cases, 19 vertical GBR cases) at 3 times as described above. Results In this study, no severe pain was recorded postoperatively and no signs of inflammation or swelling were observed in almost all of the patients. Membrane exposure occurred in 3 (4%) of 74 patients and occurred in 3 (3%) of the total 114 implants. At the platform level, the mean horizontal bone gain in only horizontal GBR cases was 3.3 (±1.2) mm at 5 months postoperatively. The mean horizontal bone gain in vertical GBR cases was 3.3 (±1.3) mm at 5 months postoperatively. In almost all cases, it was possible to assure more than 2 mm of buccal bone width which is important for the long-term prognosis of the implant. Conclusion and Clinical Implications Three-dimensional, preformed Ti-membrane should be considered as a valuable option for GBR on extrabony defects.

Guided tissue regeneration (GBR) has been used to promote new bone formation in alveolar bone reconstruction at defective bone sites following tooth loss. Bone grafts used in GBR can be categorized into autogenous, xenogenous, and synthetic bones, and human allografts depending on the origin. The purpose of this study was to compare the rates of bone regeneration using two different bone grafts in the cranial defects of rabbits. Ten New Zealand rabbits were used in this study. Four defects were created in each surgical site. Each defect was filled as follows: with nothing, using a 50% xenograft and 50% human freeze-dried bone allograft (FDBA) depending on the volume rate, human FDBA alone, and xenograft alone. After 4 to 8 weeks of healing, histological and histomorphometric analyses were carried out. At 4 weeks, new bone formation occurred as follows: 18.3% in the control group, 6.5% in group I, 8.8% in group II, and 4.2% in group III. At 8 weeks, the new bone formation was 14.9% in the control group, 36.7% in group I, 39.2% in group II, and 16.8% in group III. The results of this study suggest that the higher the proportion of human FDBA in GBR, the greater was the amount of clinically useful new bone generated. The results confirm the need for adequate healing period to ensure successful GBR with bone grafting.

Purpose: The purpose of this study was to evaluate the clinical efficacy of enhancing deficient interdental papilla with hyaluronic acid gel injection by assessing the radiographic anatomical factors affecting the reconstruction of the interdental papilla.Methods: Fifty-seven treated sites from 13 patients (6 males and 7 females) were included. Patients had papillary deficiency in the upper anterior area. Prior to treatment, photographic and periapical radiographic standardization devices were designed for each patient. A 30-gauge needle was used with an injection-assistance device to inject a hyaluronic acid gel to the involved papilla. This treatment was repeated up to 5 times every 3 weeks. Patients were followed up for 6 months after the initial gel application. Clinical photographic measurements of the black triangle area (BTA), height (BTH), and width (BTW) and periapical radiographic measurements of the contact point and the bone crest (CP-BC) and the interproximal distance between roots (IDR) were undertaken using computer software. The interdental papilla reconstruction rate (IPRR) was calculated to determine the percentage change of BTA between the initial and final examination and the association between radiographic factors and the reconstruction of the interdental papilla by means of injectable hyaluronic acid gel were evaluated.Results: All sites showed improvement between treatment examinations. Thirty-six sites had complete interdental papilla reconstruction and 21 sites showed improvement ranging from 19% to 96%. The CP-BC correlated with the IPRR. More specifically, when the CP-BC reached 6 mm, virtually complete interdental papilla reconstruction via injectable hyaluronic acid gel was achieved.Conclusions: These results suggest that the CP-BC is closely related to the efficacy of hyaluronic acid gel injection for interdental papilla reconstruction.

PURPOSE:Obtaining predictable and aesthetically pleasing interdental papilla is challenging in dental reconstruction. Hyaluronic acid gel has been successfully used to reduce facial creases and similar abnormalities. The purpose of this study was to clinically assess the efficiency of interdental papilla reconstruction with injectable hyaluronic acid gel.MATERIALS AND METHODS:Ten patients with 43 treated sites in the maxillary anterior region were studied. Photographic standardization devices were designed for image analysis before treatment. This treatment was repeated up to five times during 3-week intervals. Patients were followed 6 months after initial gel application.RESULTS:Twenty-nine sites had complete papilla reconstruction and 14 sites improved from 39 to 96% of interdental papilla reconstruction rate. Complete interdental papilla reconstruction was performed when black triangle at initial examination had area of ≤0.25 mm(2) , height of ≤1mm, or width of ≤0.5mm.CONCLUSION:Injectable hyaluronic acid gel may be a promising treatment for enhancing papillary esthetics.CLINICAL SIGNIFICANCE:Interdental papilla reconstruction with injectable hyaluronic acid gel can be suggested as a minimally invasive treatment option for interdental papilla deficiencies in small areas. However, long-term results of this treatment beyond 6 months are not yet known. (J Esthet Restor Dent 28:221-230, 2016).