Relationship Between Third Mandibular Molar Angulation and Distal Cervical Caries in the Second Molar.

Third lower molar partially erupted is commonly encountered in dental practice. This situation challenges clinicians with the dilemma whether to remove or to monitor it, because this molar can cause pathology of the adjacent second molar. The aim of this retrospective study is to evaluate the relationship between third mandibular molar and distal cervical caries in second molar. This retrospective study analyzed 55 digital orthopantograms of adult patients and a total number of 95 mandibular third molars were assessed for eruption status, angulation, radiographic evidence of caries or restoration in the mandibular third molar, and radiographic evidence of caries or restoration in the distal surface of the mandibular second molar. The distal cervical caries in second molar is associated with fully erupted and partially erupted wisdom molar in horizontal, mesioangular and vertical position and less with presence of caries in third molar. There are caries lesions in distal second molars in mesioangular position when adjacent third molar is caries free.

Comparison of Two Techniques for Lateral Ridge Augmentation in Mandible With Ramus Block Graft.

UNLABELLED: The purpose of this manuscript was to assess mandibular ramus block grafts used for augmentation of mandibular posterior segments, followed by subsequent implant placement. Twenty-four human subjects in need of lateral ridge mandibular augmentation were included in the current patient series. INCLUSION CRITERIA: recipient site had at least 10-mm residual height, but less than 4.3-mm bucco-lingual dimension. Autogenous bone blocks were harvested from the mandibular ramus. In the first group ramus block was used in association with platelet-rich fibrin and in the second in association with pericardium membrane. Implant surgery was performed 4 months after bone graft surgery when a total number of 44 implants were placed. Abutments were placed 4 months after implant surgery followed by final restoration. Ramus bone graft was successful in 100% patients for the first group and in 91.67% patients for the second group. Measurement on cone beam computed tomography revealed an average of 5.35 mm of lateral ridge augmentation for group 1 and 5.099 mm for group 2, achieved 4 months after surgery. All implants placed received fixed prosthetic restorations and are in use. Ramus block grafts can be used to allow optimal implant placement, with favor long-term success. Lateral ridge augmentation using mandibular ramus bone graft in association with platelet-rich fibrin is a more predictable and successful technique.

Incidence, Size and Orientation of Maxillary Sinus Septa-A Retrospective Clinical Study.

BACKGROUND: The purpose of this study is to analyze if there is any statistical correlation between the surgery's complexity (easy to difficult-depending on the anatomical conditions) and the patient's sex, type of edentulism, and left or right side of the maxilla. METHODS: Cone beam computed tomography records of 1192 maxillary sinuses were evaluated, measured, and statistically analyzed with respect to patient sex, type of edentulism, and left or right side, taking into consideration Wen's proposed sinus septum classification. RESULTS: Our research suggests that most sinus augmentation procedures in patients presenting antral septum fall into the Moderate A category (31.94%) and that there is not a correlation between the surgery's complexity (easy to difficult) and the patient's sex, type of edentulism and left or right side of the maxilla. CONCLUSION: We suggest a minor modification to Wen's classification in view of the fact that our findings revealed a combination of medio-lateral and antero-posterior septa that we could not classify in one of the existing categories.

Immediate postoperative complications after lateral ridge augmentation - a clinical comparison between bone shell technique and sticky bone.

Nowadays, implant dentistry is strongly interconnected to bone augmentation procedures. Lateral ridge augmentation is often an imperative treatment stage for successful, prosthetic-driven implant placement. This study aimed to comparatively analyze the immediate postoperative complications of two horizontal bone grafting procedures: sticky bone and bone shell technique. Records of patients with lateral ridge augmentation were analyzed to identify immediate postoperative complications. The study group included 80 patients divided into 40 control (bone-shell technique - BS) and 40 tests (sticky bone -SB). More patients reported moderate and severe pain in the BS - group (11 patients - 27.5%) than in the SB group (6 patients - 15%). In the BS group, the incidence of severe and moderate trismus, neurosensory disturbances, and important hematoma was higher. There was an increased inflammatory response following the bone shell technique, while the sticky bone technique proved reduced surgical morbidity. There was no difference between the two groups in the risk of dehiscence or infection.

Guided Bone Regeneration with Concentrated Growth Factor Enriched Bone Graft Matrix (Sticky Bone) vs. Bone-Shell Technique in Horizontal Ridge Augmentation: A Retrospective Study.

BACKGROUND: The purpose of this study was to compare clinical results of two different horizontal ridge augmentation techniques: guided bone regeneration with sticky bone (SB) and the bone-shell technique (BS). METHODS: Records of patients who underwent horizontal ridge augmentation with SB (test) and BS (control) were screened for inclusion. Pre-operative and 6-month post-operative ridge widths were measured on cone beam computer tomography (CBCT) and compared. Post-operative complications and implant survival rate were recorded. RESULTS: Eighty consecutive patients were included in the present study. Post-operative complications (flap dehiscence, and graft infection) occurred in ten patients, who dropped out from the study (12.5% complication rate). Stepwise multivariate logistic regression analysis showed a significant inverse correlation between the occurrence of post-operative complications and ridge width (p = 0.025). Seventy patients (35 test; 35 control) with a total of 127 implants were included in the final analysis. Mean ridge width gain was 3.7 ± 1.2 mm in the test and 3.7 ± 1.1 mm in the control group, with no significant difference between the two groups. No implant failure was recorded, with a mean follow-up of 42.7 ± 16.0 months after functional loading. CONCLUSIONS: SB and BS showed comparable clinical outcomes in horizontal ridge augmentation, resulting in sufficient crestal width increase to allow implant placement in an adequate bone envelope.

PRF-Solution in Large Sinus Membrane Perforation with Simultaneous Implant Placement-Micro CT and Histological Analysis.

BACKGROUND: The purpose of the study was to analyze the efficacy of platelet-rich fibrin (PRF) as a single augmentation material for complicated cases of maxillary sinus floor elevation, resulting from membrane perforation or previous infections. METHODS: Implant insertion in the posterior region of the maxilla was simultaneously performed with maxillary sinus floor augmentation. Schneiderian membrane elevation can be accompanied by extremely serious sinus membrane perforation, due to accidental tearing or intended incision for mucocele removal. PRFs were placed in the sinus cavity both for membrane sealing and sinus floor grafting. Radiological, histological and micro-CT analyses were performed. Implant survival was assessed every 6 months for 1 to 4 years, with a mean follow up of 1.8 years, after prosthetic loading. Radiological examinations were performed on CBCT at 9 and 12 and 36 months postoperatively and revealed improved degrees of radiopacity. RESULTS: 19 implants were simultaneously placed in the course of nine maxillary sinus floor augmentation surgeries, with successful outcomes in terms of bone grafting and implant integration. New bone formation was evidenced 12 months postoperatively on radiological examination, micro-CT analysis, and histological analysis of a harvested bone segment from the augmented maxillary sinus. The mean gain in bone height of the sinus floor augmentation was 6.43 mm, with a maximum of 9 mm. The mean amount of vital bone obtained from histologic assessment was 52.30%, while bone volume/tissue volume ratio in micro-CT 3D had a mean of 50.32%. CONCLUSIONS: PRF may be considered as an alternative treatment for a single surgery of sinus augmentation with simultaneous implant placement, even in complicated cases with significant sinus membrane tearing.

Bending Fracture of Different Zirconia-Based Bioceramics for Dental Applications: A Comparative Study.

The fabrication of fixed dental prostheses using aesthetic materials has become routine in today's dentistry. In the present study, three-unit full zirconia fixed prosthetic restorations obtained by computer-aided design/computer-aided manufacturing (CAD/CAM) technology were tested by bending trials. The prostheses were intended to replace the first mandibular left molar and were manufactured from four different types of zirconia bioceramics (KatanaTM Zirconia HTML and KatanaTM Zirconia STML/Kuraray Noritake Dental Inc.; NOVAZir® Fusion float® ml/NOVADENT/Dentaltechnik; and 3D PRO Zirconia/Bloomden Bioceramics). In total, sixteen samples were manufactured-four samples per zirconia material. Additionally, the morphology, grain size area distribution, and elemental composition were analyzed in parallelepiped samples made from the selected types of zirconia in three different areas, noted as the upper, middle, and lower areas. The scanning electron microscope (SEM) analysis highlighted that the grain size area varies with respect to the researched area and the type of material. Defects such as microcracks and pores were also noted to a smaller extent. In terms of grain size area, it was observed that most of the particles in all samples were under 0.5 µm2, while the chemical composition of the investigated materials did not vary significantly. The results obtained after performing the bending tests showed that a zirconia material with fewer structural defects and an increased percentage of grain size area under 0.5 µm2, ranging from ~44% in the upper area to ~74% in the lower area, exhibited enhanced mechanical behavior. Overall, the resulting values of all investigated parameters confirm that the tested materials are suitable for clinical use.

Management of Schneiderian Membrane Perforations during Sinus Augmentation Procedures: A Preliminary Comparison of Two Different Approaches.

BACKGROUND: The aim of this study was to retrospectively analyze two different sealing techniques for sinus membrane perforations produced during sinus floor augmentation by a lateral approach. METHODS: A total of 172 lateral-approach sinus floor augmentation surgeries were performed on 130 patients. Sixty-one membrane perforations (35%) were reported. Most of the perforations were caused by accidental membrane tearing and 16 (26%) were caused by deliberate incision for mucocele removal. In 31 perforation cases (51%), the Schneiderian membrane was sealed by suturing, while the remaining 30 cases (49%) were sealed using a low-resorption collagen membrane coverage. RESULTS: Out of the 31 cases treated with a suture-sealing techniques, 26 (84%) were successful, presenting graft integration. Failure occurred in the other five (16%) cases. Out of the 30 perforations sealed with low-resorption collagen membranes, 28 (93%) presented successful graft integration, while two (7%) failed. CONCLUSIONS: Both surgical techniques yielded therapeutic success.

Can the Macrogeometry of Dental Implants Influence Guided Bone Regeneration in Buccal Bone Defects? Histomorphometric and Biomechanical Analysis in Beagle Dogs.

The aim of this experimental animal study was to assess guided bone regeneration (GBR) and implant stability (ISQ) around two dental implants with different macrogeometries. Forty eight dental implants were placed within six Beagle dogs. The implants were divided into two groups (n = 24 per group): G1 group implants presented semi-conical macrogeometry, a low apical self-tapping portion, and an external hexagonal connection (whereby the cervical portion was bigger than the implant body). G2 group implants presented parallel walls macrogeometry, a strong apical self-tapping portion, and an external hexagonal connection (with the cervical portion parallel to the implant body). Buccal (mouth-related) defects of 2 mm (c2 condition) and 5 mm (c3 condition) were created. For the control condition with no defect (c1), implants were installed at crestal bone level. Eight implants in each group were installed under each condition. The implant stability quotient (ISQ) was measured immediately after implant placement, and on the day of sacrifice (3 months after the implant placement). Histological and histomorphometric procedures and analysis were performed to assess all samples, measuring crestal bone loss (CBL) and bone-to-implant contact (BIC). The data obtained were compared with statistical significance set at p < 0.05. The ISQ results showed a similar evolution between the groups at the two evaluation times, although higher values were found in the G1 group under all conditions. Within the limitations of this animal study, it may be concluded that implant macrogeometry is an important factor influencing guided bone regeneration in buccal defects. Group G1 showed better buccal bone regeneration (CBL) and BIC % at 3 months follow up, also parallel collar design can stimulate bone regeneration more than divergent collar design implants. The apical portion of the implant, with a stronger self-tapping feature, may provide better initial stability, even in the presence of a bone defect in the buccal area.

Maxillary Sinus Floor Augmentation to Enable One-Stage Implant Placement by Using Bovine Bone Substitute and Platelet-Rich Fibrin.

Nowadays it is possible to perform an optimal implant placement and to achieve a good long-term prognosis for an implant-borne prosthesis in the grafted posterior maxilla. This study evaluates the efficiency of one-stage piezosurgery by using as graft material a combination of particulate bovine bone substitutes with platelet-rich fibrin to achieve sinus lift. We included in this study 14 cases of one-stage sinus lift surgeries during which we placed 30 standard implants. The mean vertical bone height gain was 10.12 mm six months after surgery, and the mean postoperative follow-up time was 43.79 months. There were no major complications during or after surgery, and all implants are in use. Therefore, it can be concluded that one-stage sinus piezosurgery using particulate bovine bone substitutes and platelet-rich fibrin can be applied as a predictable and effective technique in the treatment of the posterior edentulous maxilla ensuring 4-5 mm vertical bone height.

Correlations between cyto-histopathological tissue changes at the dental implant interface and the degree of surface processing.

The bone tissue is a specialized connective tissue adapted for support and protection. The bone physiology is balanced by the interaction between mechanical and metabolic factors. Current research focuses on the bone remodeling process after the insertion of dental implants, because, after the primary healing of the wound caused by the creation of the new alveolus, the proliferation and differentiation of the osteoblasts and fibroblasts will tip the balance of the healing pattern toward bone regeneration or fibrous encapsulation. Knowing and identifying the components of the connective and bone tissue prior to implant placement, researchers are investigating the quality and quantity of the bone matrix and the physiological stages of bone generation and resorption to improve the bone-implant interface. Our research included nine dental implant failures, without prosthetic supra-structures, immediately loaded or loaded after osseointegration. The analyzed samples were from the BIOMAT Research Center, Politehnica University of Bucharest, Romania, and experienced different modalities of surface preparation. Comparative analysis of the tissue at the bone-implant interface was investigated by scanning electron microscopy.