Implant treatment choice after extraction of a vertically fractured tooth. A proposal for a clinical classification of bony defects based on a systematic review of literature

Three-dimensional (3D) facially driven workflow for anterior ridge defect evaluation: a treatment concept

The esthetic rehabilitation of anterior ridge defects and the achievement of patient satisfaction has become major clinical challenges for dentists and technicians. Poor diagnosis and treatment planning are frequently associated with multiple surgical procedures which fail to meet patient expectations. The loss of hard and soft tissues in esthetic compromised zone is commonly associated with anterior ridges and affects the rehabilitation prognosis. The presence of interdental papilla and papillary configuration play a decisive role in patient satisfaction. A treatment planning considering esthetic parameters, prosthetic needs, and morphological defects must be conducted to improve treatment outcomes. Therefore, this study aims to propose a treatment concept for anterior ridge defects focusing on digital evaluation systems and guided by an ideal facially driven smile design project. In addition, the relevance of the papilla for the esthetic outcomes and the treatment alternatives for anterior ridge defects are also addressed.

The Anatomical Conditions of the Alveolar Process of the Anterior Maxilla in Terms of Immediate Implantation-Radiological Retrospective Case Series Study

The feasibility and the level of difficulty of immediate flapless implantation depend largely on the residual alveolar bone. The purpose of the study was to determine how often immediate flapless implantation in the anterior maxilla is feasible and assess the difficulty level using cone-beam computed tomography (CBCT) scans. A radiological retrospective case series study was conducted. In total, 1200 CBCT scans from 300 consecutive patients were analyzed with dedicated planning software. Immediate flapless implants were possible in 78.33% of cases. Drilling direction was either through the apex or the palatal slope. Bimodal was conducted in 9% of the cases; only through the apex in 13.08% of the cases and in 56.25% only in the slope. In 21.67%, immediate flapless implants were excluded. The feasibility and degree of difficulty differed statistically to the disadvantage of the lateral incisors compared to the central incisors. Drilling direction caused that BASE classification reflects the difficulty level of immediate implantation. CBCT is a helpful diagnostic tool for assessing the feasibility of immediate flapless implants due to the residual bone shape and volume. BASE classification helps to determine a challenge level that may also facilitate communication and result in comparison. The alveolar bone condition allows for immediate flapless implants in most cases in the aesthetic region of the maxilla, but they should be performed by an experienced specialist with regard to the bone and soft tissue quality.

Apoptosis repressor with caspase recruitment domain (ARC) promotes bone regeneration of bone marrow-derived mesenchymal stem cells by activating Fgf-2/PI3K/Akt signaling

Objectives

This study aims to investigate whether apoptosis repressor with caspase recruitment domain (ARC) could promote survival and enhance osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs).

Materials and methods

The lentivirus transfection method was used to establish ARC-overexpressing BMSCs. The CCK-8 method was used to detect cell proliferation. The BD Pharmingen™ APC Annexin V Apoptosis Detection kit was used to detect cell apoptosis. The osteogenic capacity was investigated by OCN immunofluorescence staining, ALP analysis, ARS assays, and RT-PCR analysis. Cells were seeded into calcium phosphate cement (CPC) scaffolds and then inserted subcutaneously into nude mice and the defect area of the rat calvarium. Histological analysis was conducted to evaluate the in vivo cell apoptosis and new bone formation of the ARC-overexpressing BMSCs. RNA-seq was used to detect the possible mechanism of the effect of ARC on BMSCs.

Results

ARC promoted BMSC proliferation and inhibited cell apoptosis. ARC enhanced BMSC osteogenic differentiation in vitro. An in vivo study revealed that ARC can inhibit BMSC apoptosis and increase new bone formation. ARC regulates BMSCs mainly by activating the Fgf-2/PI3K/Akt pathway.

Conclusions

The present study suggests that ARC is a powerful agent for promoting bone regeneration of BMSCs and provides a promising method for bone tissue engineering.

Microbiological findings in early and late implant loss: an observational clinical case-controlled study

Background

Implants are a predictable and well-established treatment method in dentistry. Nevertheless, looking at possible failures of dental implants, early and late loss have to be distinguished. The intent of the study was to report microbiological findings on the surface of implants with severe peri-implantitis, which had to be explanted.

Methods

53 specimens of implants from 48 patients without severe general illnesses have been examined. The groups investigated were implants that had to be removed in the period of osseointegration (early loss, 13 patients with 14 implants) or after the healing period (late loss, 14 patients with 17 implants). The implant losses were compared with two control groups (implants with no bone loss directly after completed osseointegration, two to four months after implant placement (17 patients with 17 implants) and implants with no bone loss and prosthetic restoration for more than three years (5 patients with 5 implants)). Data about the bacteria located in the peri-implant sulcus was collected using amplification and high throughput sequencing of the 16S rRNA gene.

Results

The biofilm composition differed substantially between individuals. Both in early and late implant loss, Fusobacterium nucleatum and Porphyromonas gingivalis were found to be abundant. Late lost implants showed higher bacterial diversity and in addition higher abundances of Treponema, Fretibacterium, Pseudoramibacter and Desulfobulbus, while microbial communities of early loss implants were very heterogeneous and showed no significantly more abundant bacterial taxa.

Conclusions

Specific peri-implant pathogens were found around implants that were lost after a primarily uneventful osseointegration. P. gingivalis and F. nucleatum frequently colonized the implant in early and late losses and could therefore be characteristic for implant loss in general. In general, early lost implants showed also lower microbial diversity than late losses. However, the microbial results were not indicative of the causes of early and late losses.

The etiology of hard- and soft-tissue deficiencies at dental implants: A narrative review

OBJECTIVE

The objective of the present paper was to review factors and conditions that are associated with hard and soft-tissue deficiencies at implant sites.

IMPORTANCE

Hard- and soft-tissue deficiencies at dental implants are common clinical findings. They can lead to complications and compromise implant survival and, hence, may require therapeutic interventions. It is, therefore, important to understand the etiology of hard and soft-tissue deficiencies. Based on this understanding, strategies should be developed to correct hard and soft-tissue deficiencies with the aim of improving clinical outcomes of implant therapy.

FINDINGS

A large number of etiological factors have been identified that may lead to hard and soft-tissue deficiencies. These factors include: 1) systemic diseases and conditions of the patients; 2) systemic medications; 3) processes of tissue healing; 4) tissue turnover and tissue response to clinical interventions; 5) trauma to orofacial structures; 6) local diseases affecting the teeth, the periodontium, the bone and the mucosa; 7) biomechanical factors; 8) tissue morphology and tissue phenotype; and 9) iatrogenic factors. These factors may appear as an isolated cause of hard and soft-tissue defects or may appear in conjunction with other factors.

CONCLUSIONS

Hard- and soft-tissue deficiencies at implant sites may result from a multitude of factors. They encompass natural resorption processes following tooth extraction, trauma, infectious diseases such as periodontitis, peri-implantitis, endodontic infections, growth and development, expansion of the sinus floor, anatomical preconditions, mechanical overload, thin soft tissues, lack of keratinized mucosa, malpositioning of implants, migration of teeth, lifelong growth, and systemic diseases. When more than one factor leading to hard and/or soft-tissue deficiencies appear together, the severity of the resulting condition may increase. Efforts should be made to better identify the relative importance of these etiological factors, and to develop strategies to counteract their negative effects on our patient's wellbeing.

The etiology of hard- and soft-tissue deficiencies at dental implants: A narrative review

OBJECTIVE

The objective of the present paper was to review factors and conditions that are associated with hard and soft-tissue deficiencies at implant sites.

IMPORTANCE

Hard- and soft-tissue deficiencies at dental implants are common clinical findings. They can lead to complications and compromise implant survival and, hence, may require therapeutic interventions. It is, therefore, important to understand the etiology of hard and soft-tissue deficiencies. Based on this understanding, strategies should be developed to correct hard and soft-tissue deficiencies with the aim of improving clinical outcomes of implant therapy.

FINDINGS

A large number of etiological factors have been identified that may lead to hard and soft-tissue deficiencies. These factors include: 1) systemic diseases and conditions of the patients; 2) systemic medications; 3) processes of tissue healing; 4) tissue turnover and tissue response to clinical interventions; 5) trauma to orofacial structures; 6) local diseases affecting the teeth, the periodontium, the bone and the mucosa; 7) biomechanical factors; 8) tissue morphology and tissue phenotype; and 9) iatrogenic factors. These factors may appear as an isolated cause of hard and soft-tissue defects or may appear in conjunction with other factors.

CONCLUSIONS

Hard- and soft-tissue deficiencies at implant sites may result from a multitude of factors. They encompass natural resorption processes following tooth extraction, trauma, infectious diseases such as periodontitis, peri-implantitis, endodontic infections, growth and development, expansion of the sinus floor, anatomical preconditions, mechanical overload, thin soft tissues, lack of keratinized mucosa, malpositioning of implants, migration of teeth, lifelong growth, and systemic diseases. When more than one factor leading to hard and/or soft-tissue deficiencies appear together, the severity of the resulting condition may increase. Efforts should be made to better identify the relative importance of these etiological factors, and to develop strategies to counteract their negative effects on our patient's wellbeing.

A rare case of bevacizumab-related osteonecrosis of the jaw associated with dental implants

Background

Medication-related osteonecrosis of the jaw (MRONJ) is characterized by the development of bone necrosis in the jaws of patients receiving antiresorptive and/or antiangiogenic medications. No scientific reports have been published yet on bevacizumab-related osteonecrosis of the jaw (BeRONJ) when associated with dental implant placement and adjuvant ozone therapy.

Case presentation

A 54-year-old female patient with a history of metastatic breast cancer and bevacizumab use presented with a dental infection. Dental extraction followed immediately by dental implant placement was planned after suspension of the bevacizumab treatment. The patient presented with pain, drainage of purulent secretion, and bone exposure 5 weeks post-surgery. Complete healing was achieved at postoperative 7 months.

Conclusions

The combination of adjuvant ozone therapy and surgical debridement was effective for the treatment of MRONJ; however, the risk of MRONJ may persist after the suspension of bevacizumab for 28 days.

Immediate Early and Delayed Implants: A 2-Year Prospective Cohort Study of 131 Transmucosal Flapless Implants Placed in Sites With Different Pre-extractive Endodontic Infections

INTRODUCTION

To evaluate clinical outcome of early, immediate, and delayed transmucosal implants placed in patients affected by acute/chronic endodontic lesions.

MATERIALS AND METHODS

Eighty-five consecutive patients received 131 titanium implants with zirconium-oxide blasted surface. Pre-extractive diagnosis represented the main criteria for implant placement timing, following "best treatment" criteria. Implants were placed with flapless transmucosal technique. Hopeless teeth with chronic periapical lesions received atraumatic extraction, and an implant was immediately placed (Immediate Group, n = 29). Teeth with acute periapical lesion/abscess were extracted and implants placed after 8 to 12 weeks (Early Group, n = 29). Implants placed 10- to 12-month after extraction constituted the control group (delayed group, n = 73). Implants were loaded 3 months after insertion with provisional resin crowns and after approximately 15 days with definitive ceramic crowns. Marginal bone loss (MBL) was measured in a single-blind manner on periapical radiographs at 1, 3, 6, 12, and 24 months.

RESULTS

Multilevel analysis described exploring factors associated with MBL. Survival rate was 100%. MBL after 24 months was 0.78 ± 0.70 (95% confidence interval [CI]: 0.20 to -1.37) at immediate, 0.48 ± 0.70 at early (95% CI: -0.006 to -0.961), and 1.02 ± 1.01 (95% CI: 0.61 to -1.43) at delayed groups. Implant groups (immediate/early/delayed) and location (maxillary/mandibular) showed statistically significant results. Early group showed the lowest MBL values. The immediate group demonstrated less MBL than the delayed group.

CONCLUSION

Early implant placement technique preserves periimplant marginal bone level more than immediate and delayed techniques.

Rho/Rho-associated protein kinase signaling pathway-mediated downregulation of runt-related transcription factor 2 expression promotes the differentiation of dental pulp stem cells into odontoblasts

The present study investigated the role of runt-related transcription factor 2 (Runx2) in regulating the differentiation of human dental pulp stem cells (hDPSCs) into odontoblasts under the mediation of the Rho/Rho-associated protein kinase (ROCK) signaling pathway. hDPSCs and human bone marrow mesenchymal stem cells (hBMSCs) were mineralized to induce differentiation. The expression levels of odontoblast- and osteoblast-specific proteins, dentin sialophosphoprotein (DSPP), osteocalcin (OCN) and Runx2, were measured using western blot analysis. The hDPSCs were treated with Rho/ROCK signaling pathway inhibitor, C3 exoenzyme, and mineralized prior to determining the protein expression levels of RhoA, ROCK, Runx2, OCN, DSPP, and mRNA expression levels of early mineralization genes, including alkaline phosphatase, collagen type I, Msh homeobox 2 and distal-less homeobox 2, and late mineralization genes, including DSPP, dentin matrix protein-1 (DMP-1), bone sialoprotein (BSP) and OCN. Flow cytometry data indicated that 95% of the isolated hDPSCs were positive for mesenchymal stem cell markers, including cluster of differentiation (CD)29, CD90 or CD105, and vascular endothelial cell marker, CD146, whereas <5% of the hDPSCs were positive for hematopoietic stem cell markers, CD34 and CD45. The expression levels of DSPP in hDPSCs and OCN in hBMSCs were significantly upregulated with increased time in mineralization medium (P<0.01), which suggested that hDPSCs and hBMSCs were differentiated into odontoblasts and osteoblasts, respectively. During the osteogenic process, Runx2 protein was highly expressed in mesenchymal stem cells following stimulation with mineralization medium compared with cells that received no stimulation. During odontoblast differentiation in hDPSCs, Runx2 protein was highly expressed in the early stage; however, the expression declined in the late stage. Furthermore, treatment with C3 exoenzyme significantly downregulated the expression of RhoA, ROCK and Runx2 compared with the control in hDPSCs (P<0.01). Additionally, in mineralization solution, C3 exoenzyme also significantly downregulated the expression of Runx2 (P<0.01); however, the Rho/ROCK signaling pathway inhibitor did not significantly impact the expression of early mineralization genes. By contrast, C3 exoenzyme significantly upregulated the expression of DSPP and DMP-1, and downregulated the expression of BSP and OCN (P<0.01). The present findings suggested that odontoblast differentiation in hDPSCs may be regulated by Rho/ROCK signaling pathway-mediated downregulation of Runx2.

Horizontal bone augmentation in full-arch maxillary implant-supported restorations: a preliminary clinical report

PURPOSE

The purpose of this study was to describe a technique for horizontal maxillary bone grafting in combination with implant placement for full arch.

MATERIALS AND METHODS

Patients requiring complete rehabilitation of the edentulous maxillae were included. Two axial mesial implants and 2 tilted distal ones were placed approximately 2 mm buccally about the centre of the bone crest. A graft made of a mixture of deproteinized bovine bone and platelet-rich plasma was placed buccally covering bony dehiscence. Horizontal bone gain and differences in bone volume were evaluated 6 months after surgical intervention, at the time of prosthetic loading, through comparison of standardized cone beam computed tomographic scans.

RESULTS

A total of 10 patients were consecutively treated after the proposed protocol. After 6 months, the mean horizontal bone gain was 1.87 ± 0.54 mm for the left side and 1.79 ± 0.78 mm for the right side without any significant difference between them. The bone volume increased by 610.5 ± 27.57 mm after 6 months.

CONCLUSIONS

It can be postulated that the proposed protocol may provide a significant horizontal bone gain for minimizing the anterior cantilever in full-arch prosthesis.

Microsurgical re-treatment of an endodontically treated tooth with an apically located incomplete vertical root fracture: a clinical case report

Although it is challenging, the early diagnosis of a vertical root fracture (VRF) is crucial in order to ensure tooth preservation. The purpose of this clinical case report was to describe reparative surgery performed to treat a tooth affected by an incomplete VRF. A 26 year old male patient was suspected to have a VRF in a maxillary left central incisor, and an exploratory flap was performed in order to confirm the diagnosis. After detecting the fracture, the lesion was surgically treated, the fracture and the infected root-end were removed, and a platelet-rich plasma membrane was used to cover the defect in order to prevent bacterial migration. A 24 month clinical and radiological follow-up examination showed that the tooth was asymptomatic and that the healing process was in progress. The surgical approach described here may be considered an effective treatment for a combined endodontic-periodontal lesion originating from an incomplete VRF and a recurrent periapical lesion.

Autogenous demineralized dentin matrix from extracted tooth for the augmentation of alveolar bone defect: a prospective randomized clinical trial in comparison with anorganic bovine bone

OBJECTIVES

The aim of this study was to prospectively evaluate the clinical efficacy and histological outcome of the autogenous tooth graft material (AutoBT) compared to that of anorganic bovine bone (Bio-Oss^® , Geistlich, Switzerland) in post-extraction alveolar bone augmentation.

PATIENTS AND METHODS

A total of 33 graft sites in 24 patients were included in this study. AutoBT was used in 21 sites of 15 patients and Bio-Oss^® was used in 12 sites of 9 patients for alveolar bone augmentation 2-4 weeks after dental extraction. Vertical dimension of grafted bone was measured both at the time of graft placement and at implant fixture placement after 6 months. Trephine cores were harvested for the histomorphometric evaluations during implant placement when feasible. The primary stability of implant fixture was also measured.

RESULTS

Infection of graft material or graft bed was not observed and graft sites healed without any notable complications in both groups. The vertical dimensions of alveolar bone increased by 5.38 ± 2.65 mm in AutoBT group and 6.56 ± 3.54 mm in Bio-Oss^® group at 6 months post-extraction. Histomorphometrically, new bone formation of AutoBT-grafted site was 31.24 ± 13.87% while that of Bio-Oss^® was 35.00 ± 19.33%. The implant stability quotient (ISQ) of implants placed in AutoBT-grafted sites measured 72.80 ± 10.81 while those placed in Bio-Oss^® -grafted sites measured 70.0 ± 12.86. There were no statistically significant differences between measurements of the two groups.

CONCLUSION

Autogenous demineralized dentin matrix from extracted tooth grafted to extraction sockets for the augmentation of vertical dimension was as effective as augmentation using anorganic bovine bone. Both groups showed favorable wound healing, similar amount of implant stability, and histologically confirmed new bone formation. Thus, the results of this study suggest that autogenous tooth graft material is a viable option for alveolar bone augmentation following dental extraction.