Computer-assisted prosthetic planning and implant design with integrated digital bite registration: a treatment protocol.

The aim of this clinical study is to present an integrated digital project through the description of a clinical case, made entirely in digitized form, taking advantage of the opportunity offered by instrumental diagnostic software. A case report participant is a 65-year-old female patient presents with loss of diffuse bone support, caused by periodontal disease. After a sign of an informed consent and an explication of a plan of treatment, technical intraoral and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Smile Lynx Software and the scanner stereolithographic (STL) file was matched into the CAD Lynx to obtain a virtual previsualization of teeth and smile design, and to mill the provisional and the definitive crowns. The digital prosthetic design allows the evaluation of the dental parameters in relation to the parameters of the patient's face for the new prosthetic project and the radiological examination using CBCT guides the insertion of the fixtures for the rehabilitation phase. The surgical and prosthetic design are subsequently integrated. The evaluation of the bone bases is carried out with a radiological diagnostic software for CT (Real Guide 5.0-3Diemme, Cantù-Italy) which can virtually design the implant insertion. The functional examination of the patient is carried out through an occlusion-postural examination that uses digital electromyographic assessments. The integrated digital protocol proposal inserts in the rehabilitation path the digital recording of the free mandibular movement, as well as the scan of the patient's face, data that will be integrated into the CAD software for the design of temporary and definitive prosthetic artifacts, made using the CAM method. This study showed guided implant placement and the application of fixed implant-supported prosthetic restorations carried out with a fully digital workflow, dependent on the functional digital evaluation of the patient's occlusion. The proposed protocol described the correct use of digitalization of clinical, surgical, and prosthetic procedures, and the matching of the data into a computerized environment, to improve team communication and to take advantage of the combination of collected data to not lose information using classic manual steps.

ADULT syndrome: dental features of a very rare condition.

The Acro-Dermato-Ungual-Lacrimal-Tooth syndrome (ADULT syndrome) is one of the rarest ectodermal dysplasias and it is associated with several malformations involving especially the limbs. The most clinical features are the presence of ectrodactyly, syndactyly, hypermelanosis or multiple lentigines, onhycodysplasia, abnormalities in the lacrimal duct, recurrent conjuntivitis, photophobia, mammarian hypoplasia, hypotrichosis and frontal alopecia, hypohydrosis, cutaneous photosensitivity, nasal bridge prominence, exfoliative dermatitis and xerosis. The ectodermal dysfunction expresses itself with conoid teeth, enamel hypoplasia, dentinal dysplasia and especially hypodontia, with following functional and aesthetic defects. We report the case of an 11-year-old Caucasian girl affected by ADULT syndrome.

Human ß2-defensin in oral lichen planus expresses the degree of inflammation.

Syndrome (BMS). Seventeen OLP patients, with a positive histopathologic diagnosis of the disease, were recruited into this study in order to measure the relative quantity of HBD-2 in their saliva and crevicular fluid. The values were compared with those collected from a group of 9 patients affected by the Burning Mouth Syndrome (BMS) and with a control group (CTRL) of 9 patients. There was no statistically significant difference between the groups (p=0.523; p=0.897). However, patients affected by OLP showed a dycotomic distribution of values: while 10 of them showed similar values to those found out in the other two groups, 7 patients expressed high levels of HBD-2 and 3500 pg/ml was the threshold to distinguish the subgroups. During the dental visit the clinician classified OLP patients into two groups according to the clinical presentation of the disease: reticular and hyperplastic (white OLP), atrophic and erosive forms (red OLP). There was a statistical significant correlation between the clinical and numeric classification of the patients (p=0.004; p=0.001), and the expression of HBD-2 was higher in the red OLP group than in the white OLP group (p=0.000; p=0.000). In conclusion, this study shows that HBD-2 represents an index to assess active inflammation and it is probably linked to the presence of the typical band-like CD8+ infiltrate in Oral Lichen Planus.

The “elfin face”: craniofacial and dental aspects of the Williams-Beuren syndrome.

Williams Syndrome is a rare congenital disorder characterized by supravalvular aortic stenosis, peripheral pulmonary artery stenosis, mental retard and dysmorfic facial features. As regards the dental aspects of the syndrome, the deletion of the elastin gene induced clinicians to suspect periodontal alterations with a greater frequency of gingivo-periodontitis, but on the contrary no association between the syndrome and periodontal diseases have been found. Furthermore, patients show a higher frequency of teeth hypoplasia, an abnormal tooth morphology during primary dentition (12.5%) and during permanent dentition. We present a case report of a 12-year-old Caucasian boy affected by Williams-Beuren Syndrome who visited our hospital for a dental and orthodontic evaluation.

Genetic correlation between rheumatoid arthritis and periodontal disease: the role of sex and IL-10.

The chronic stimulation of the immune system due to the presence of bacterial antigens within periodontal tissues has been associated with several autoimmune diseases, like diabetes mellitus, infective endocarditis or cardiovascular atherosclerosis. The current study aims at evaluating the correlation between Rheumatoid Arthritis (RA) and Periodontal Disease (PD) with special attention to genetic polymorphisms in cytokine expression. A total number of 34 patients affected by RA were recruited. Each of them underwent haematochemical analysis and data were collected for Rheumatoid Factor (RF), Anti-Citrullinated Protein’s Antibody (CCP) and HLA-BDR1. DAS-28 questionnaire for disease activity was fulfilled by the rheumatologist, while a periodontal examination was carried out by the dental clinician and crevicular fluid samples were collected to evaluate the IL-6, IL-10 and VDR polymorphysms. A connection between CCP and IL-10 polymorphisms was found, with IL-10 expressing protecting tendency against periodontal disease when CCP are found in the bloodstream (p=0.0017). Finally, males mainly expressed IL-10 predisposing genes (p=0.046), while females showed a greater tendency to express RF (p=0.014) and CCP (p=0.050). This paper corroborates the idea of a correlation between sex, IL-10 polymorphisms and RA, which should be studied in depth, since recent papers have shown that IL-10 injected into joints seems to decrease inflammation.

A “burning” therapy for burning mouth syndrome: preliminary results with the administration of topical capsaicin.

Burning mouth syndrome is defined as an intraoral burning sensation for which no medical or dental cause can be found. Recently, researchers have demonstrated an altered trophism of the small nerve fibres and alterations in the numbers of TRPV-1 vanilloid receptors. Capsaicin is a molecule that is contained in hot peppers and is specifically detected by TRPV-1 vanilloid receptors that are distributed in the oral mucosae. We aimed at verifying if topical capsaicin could prove to be an effective treatment of Burning Mouth Syndrome. A group of 99 BMS patients were recruited. We subdivided the BMS patients into two groups: the collaborative patients, who expressed a predominantly neuropathic pattern of symptoms, and the non-collaborative patients, who were characterised by stronger psychogenic patterns of the syndrome. Both groups underwent topical therapy with capsaicin in the form of a mouth rinse 3 times a day for a long period. After 1 year of treatment, the final overall success rate was approximately 78%, but with a significant difference in the success rates of the two groups of patients (87% and 20% among the collaborative and non-collaborative patients, respectively; p=0.000). The use of topical capsaicin can improve the oral discomfort of BMS patients, especially during the first month of therapy, but it is more effective for those patients in which the neuropathic component of the syndrome is predominant. Our hypothesis is that chronic stimulation with capsaicin leads to decreases in burning symptoms. This phenomenon is called desensitisation and is accompanied by substantial improvements in oral symptoms.

Periodontal microbioma and rheumatoid arthritis: The role of Porhyromonas gingivalis.

Rheumatoid Arthritis is a disease, which can be described as an autoimmune response after molecular mimicry caused by infective agents. The current study aims at evaluating the correlation between Rhematoid Arthritis (RA) and Periodontal Disease (PD), with special attention to the microbioma detected in the gums. Thirty-four patients with RD were recruited into the current study. Among rheumatic parameters, Rheumatoid Factor (RF), anti-citrullinated protein antibody (CCP), HLA-BDR1 and DAS28 were collected. A dental clinician evaluated the periodontal screening record (PSR). Afterwards, 1 paper cone was inserted for 30 seconds into the gingival sulcus then sent to the laboratory for evaluation. Quantitative PCR of 16S rRNA genes was performed with the hydrolysis probes method to identify and evaluate the amount Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Fusobacterium nucleatum and Campylobacter rectus. There were no statistical differences in the composition of oral microbioma between PSR groups. There were no statistical significant differences between bacterial loads and serum values. On the contrary, a positive correlation was found between the presence of Porphyromonas gingivalis in periodontal pockets on one side and RF and CCP on the other. Therefore, the presence of Porhyromonas gingivalis in periodontal pockets is associated to RA inflammatory indices.

Oral manifestations of selective IgA-deficiency: review and case-report.

Immunoglobulin A deficiency is the most common primary immunodeficiency defined as decreased serum level of IgA (less than 7 mg/dl) in the presence of normal levels of other immunoglobulin isotypes. Most individuals with IgA deficiency are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections, allergic disorders and autoimmune manifestations, such as diabetes mellitus, Graves disease and celiac disease. The international literature has not produced any kind of review yet about intra-oral manifestations of selective IgA-deficiency. L.S., a 7-year-old Caucasian girl, was examined at our hospital. After she had undergone a professional dental cleaning, a symmetric, bilateral ulcerative gingivitis developed nearby the upper second primary molars. The gingival ulcers were persistent and did not disappear in the following 3 weeks. In the meantime, the young patient reported the presence of gastrointestinal symptoms. IgA serum level was 4.5 mg/dl, while the other isotypes levels were in the common range. The diagnosis of selective IgA-deficiency was formulated and the girl underwent further examination for the specific IgG autoantibodies in celiac disease, which were not present. Consequently, a full prevention program was planned. This case report emphasizes the role of the paediatric dentist in the early detection of systemic disorder, such as the immunological diseases. The oral cavity often reveals to be the first site of manifestation of important systemic diseases. Immunoglobulin A (IgA) deficiency is the most common primary immunodeficiency and is defined as a decrease in serum IgA levels in the presence of normal levels of other immunoglobulin isotypes (1). Serum IgA deficiency was first described in children with ataxia-telangiectasia (2) and has since been identified in other patients, including normal patients. The prevalence of IgA deficiency ranges from 1:223 to 1:1000 in community studies and from 1:400 to 1:3000 in healthy blood donors (3).

Nitric oxide synthase evaluation in oral precancerous and cancerous lesions.

Nitric Oxide (NO) has been linked to several cardiovascular, neurological and immunological physiological and pathological functions. Several studies have shown that the eNOS, nNOS and iNOS effects on cancer cell growth and proliferation are related to the upregulation of the Wnt pathway and have a central role during metastasis development. Recent studies suggest that cancer cells undergo metabolic reprogramming, which drives cancer cell growth and progression. The aim of this study was to observe the NOS activity in the pathogenesis of oral precancerous and cancerous lesions. The results showed changes in eNOS activity levels, which increased from healthy oral mucosa to oral squamous cell carcinoma SCC, through different dysplasia levels. The iNOS activity levels increased in precancerous lesions compared to healthy mucosa, where iNOS was absent, while it decreased in SCC lesions. Moreover, a gradual increase of nNOS activity together with the progression of the lesions was also found. These results may suggest how NO could play a critical role during pathogenesis, growth and development of precancerous lesions to cancer degeneration.

Adipose derived stem cells: basic science fundaments and clinical application. An update.

Soft tissues regeneration can be used to treat several kinds of diseases including congenital and post traumatic deformities, and to fill out tissue depression due to orbital and periorbital surgery, scars or cancer resections. Generally it is performed by the use of autologous tissue flaps, alloplastic implants and autologous fat grafting. All of these methods have several disadvantages, which include resorption of the autologous material, foreign body reaction and implant migration. Stem cell application has been suggested as a possible novel therapy for regenerative medicine thanks to their unlimited capacity of self-renewal, as well as the property to differentiate into multiple cell types under appropriate stimuli. This short review describe the recent development in stem cells isolation, expansion and characterization and their employment in tissue regeneration and tissue engineering.

Nitric oxide synthase isoenzyme expression in human oral lichen planus.

The roles of nitric oxide (NO) synthase (NOS) enzyme in pathological mechanisms of the oral cavity are still incompletely understood. The aim of this study was to investigate the expression of the endothelial, neuronal and inducible isoforms of NOS (eNOS, nNOS and iNOS) in oral lichen planus (OLP) development in humans. OLP and healthy oral mucosa biopsies were taken for mRNA and protein analysis of NOS isoenzymes by RT-PCR, western blot and immunohistochemistry. The mRNA and protein levels of eNOS and nNOS were present in all samples, with a significant increase only for eNOS in OLP. The normal oral mucosa exhibited only small amounts of iNOS mRNA and protein, while it showed a significant rise in OLP samples. These results were confirmed by immunohistochemical analysis. Our findings suggest that NO produced by increased eNOS and iNOS expression may have circulatory and immune functions in the development of OLP.

Assessment of activity of Crohn's disease of the ileum and large bowel: proposal for a new multiparameter MR enterography score.

PURPOSE: We evaluated the diagnostic accuracy of magnetic resonance enterography (MR-E) in assessing Crohn's disease (CD) activity by differentiating acute, chronic and remission stages of disease through a quantitative MR-E assessment. MATERIALS AND METHODS: One hundred patients with a histological diagnosis of CD were studied with MR-E. Intestinal distension was obtained by oral administration of approximately 2 L of a polyethylene glycol solution (PEG). In all cases, the ileum and large bowel were imaged with morphological sequences (heavily T2-weighted single-shot, dual fast-field echo, balanced fast-field echo) and a postcontrast dynamic sequence (T1-weighted high-resolution isotropic volume excitation). Disease activity was assessed according to a multiparameter score (0-8) based on lesion morphology, signal intensity and contrast enhancement. MR-E findings were compared with clinical-laboratory data and disease activity indices [Crohn's Disease Activity Index (CDAI); Inflammatory Bowel Disease Questionnaire (IBDQ)]. Multiple regression analysis was performed by correlating MR-E score, CDAI and IBDQ. Frequencies were then compared using the χ (2) test. RESULTS: MR-E identified inactive disease in 9% of cases, chronic disease in 57% and active disease in the remaining 34%. The most frequently involved bowel segment was the terminal ileum (52%). A statistically significant correlation was found between MR-E score and CDAI (R=0.86; p<0.001) and between MR-E score and IBDQ (R=-0.83; p<0.001). The most suggestive parameter for disease activity was layered bowel-wall enhancement, a finding predominantly present in patients with increased CDAI (≥ 150) and/or local complications (χ (2)=7.13; p<0.01). CONCLUSIONS: MR-E is a noninvasive and diagnostic imaging modality for CD study and follow-up. The MR-E score proposed in this study proved to be useful in assessing disease severity and monitoring response to treatment.

Rotator cable at MR imaging: considerations on morphological aspects and biomechanical role.

PURPOSE: The rotator cable (RC) is a thickening of the coracohumeral ligament. It extends from the coracohumeral ligament to the inferior border of the infraspinatus tendon, with fibres running perpendicularly to the rotator cuff fibres. According to some authors, the RC tends to thicken with age, thus allowing some individuals with a cuff lesion to preserve normal shoulder function. We evaluated the RC with magnetic resonance (MR) imaging and investigated its possible role in the biomechanics of the shoulder affected by cuff lesions. MATERIALS AND METHODS: Between November 2007 and May 2008, we performed shoulder MR examinations for shoulder pain or disability on 94 patients (46 males, 48 females; age range 16-79 years; mean age 54.09 ± 15.09 years) for a total of 104 shoulders (62 right, 42 left). RESULTS: RC was more easily detectable in oblique coronal scans where it appeared as a crescent-shaped, regularly marginated structure adjacent to the articular surface of the supraspinatus tendon and medial to the insertion point of this tendon on the greater tuberosity. Its thickness was 2.8 ± 0.3 mm. The structure was identified in 62% of cases (mean patient age 55.3 ± 14.9 years). No statistically significant difference in age was found between patients with and without evidence of RC (Student's t test=0.05; p=0.82). Among patients with partial- or full-thickness supraspinatus tendon lesions at MR imaging, no statistically significant difference was found between the presence or absence of RC and disability on Jobe's test (χ(2)=1.17; p>0.05). CONCLUSIONS: RC can be observed at MR imaging in >60% cases. In our sample it did not seem to influence shoulder function in patients with cuff lesions.

From angiotensin-converting enzyme 2 disruption to thromboinflammatory microvascular disease: A paradigm drawn from COVID-19.

We concisely review clinical, autopsy, experimental and molecular data of 2019 coronavirus disease (COVID-19). Angiotensin-converting enzyme 2 disruption and thromboinflammatory microangiopathy emerge as distinctive features. Briefly, entry of the virus into microvessels can profoundly disrupt the local renin-angiotensin system, cause endothelial injury, activate the complement cascade and induce powerful thromboinflammatory reactions, involving, in particular, von Willebrand factor, that, if widespread, may lead to microvascular plugging, ischemia and, ultimately, organ failure. We believe the current COVID-19 data consolidate a widely unrecognised paradigm of potentially fatal thromboinflammatory microvascular disease.

Accuracy of Edentulous Computer-Aided Implant Surgery as Compared to Virtual Planning: A Retrospective Multicenter Study.

PURPOSE: To evaluate the accuracy of computer-aided dental implant positions obtained with mucosal-supported templates as compared to Three-Dimensional (3D) planning. MATERIALS AND METHODS: One-hundred implants were inserted into 14 edentulous patients using the All-on-4/6 protocol after surgical virtual planning with RealGUIDE, 3DIEMME, and Geomagic software. After 6 months, three-dimensional neck (V) and apex (S) spatial coordinates of implants and angle inclination displacements as compared to virtual plans were evaluated. RESULTS: The S maxilla coordinates revealed a significant discrepancy between clinical and virtual implant positions (p-value = 0.091). The V coordinates showed no significant differences (p-value = 0.71). The S (p-value = 0.017) and V (p-value = 0.038) mandible coordinates showed significant discrepancies between the clinical and virtual positions of the screws. Implant evaluation showed a 1-mm of the horizontal deviation in the V point and a 1.6-mm deviation in the S point. A mean 5° angular global deviation was detected. The multivariate permutation test of the S (p-value = 0.02) confirmed the difference. Greater errors in the mandible were detected as compared to the maxilla, and a higher S discrepancy was found in the posterior jaw compared to the anterior section of both the mandible and maxilla. CONCLUSIONS: Computer-aided surgery with mucosal-supported templates is a predictable procedure for implant placement. Data showed a discrepancy between the actual dental implant position as compared to the virtual plan, but this was not statistically significant. However, the horizontal and angle deviations detected indicated that flap surgery should be used to prevent implant positioning errors due to poor sensitivity and accuracy in cases of severe jaw atrophy.

Vascular endothelial growth factor and e-nitric oxide synthase-mediated regenerative response occurring upon autologous and heterologous bone grafts.

Bone regeneration procedures allow oral rehabilitation with dental implants also in edentulous ridges with severe bone atrophy. The integration of grafted materials with the host tissue can initiate regenerative, inflammatory and apoptotic response. Since molecular mechanisms exist at the basis of such response, the aim of this work is to investigate, by immunohistochemical analyses, the expression of proteins involved in the graft integration process, in parallel to clinical and histological modifications, occurring on sites treated with extraoral autologous bone graft deriving from the parietal region of the calvaria (eAB), intraoral autologous bone graft deriving from mandibular ramus (iAB) and heterologous bone graft from swine (hB) in human patients. In our study, the immunohistochemical expression of BSP, VEGF, eNOS in eAB samples was significantly higher (p < 0.05) compared to values recorded in iAB and hB samples. The inflammatory response, investigated by iNOS expression, was found lower in all autologous samples (eAB and iAB) compared to hB, at statistically significant values. Moreover, the expression of the pro-apoptotic molecule, Bax, resulted significantly lower (p < 0.05) in eAB than in iAB and hB samples. These values, together with the low number of apoptotic cells detected in autologous samples, suggest a good regenerative response when extraoral autologous bone graft is used in comparison to the response from the other grafts, and also suggest the use of calvaria graft as a predictable therapeutic procedure for repairing severe bone defects in oral and maxillofacial surgery, not only by clinical and biomechanical criteria, but also from a biomolecular aspect.

MR characterisation of dysplastic nodules and hepatocarcinoma in the cirrhotic liver with hepatospecific superparamagnetic contrast agents: pathological correlation in explanted livers.

PURPOSE: The authors sought to evaluate the potential of magnetic resonance (MR) imaging with superparamagnetic iron oxide (SPIO) contrast material for identifying, characterising and differentiating dysplastic nodules (DN) and hepatocellular carcinoma (HCC) in the cirrhotic liver by correlating the results with pathological findings on the explanted liver. MATERIAL AND METHODS: MR imaging was used to study the liver of 400 cirrhotic patients awaiting liver transplantation, 31 of whom were selected to receive a liver. Of these 31 patients, we included in the study 22 patients (mean age 53 years; range 46-57 years) who underwent liver transplantation within 12-24 h after MR examination. Patients were studied with a 1.5-T device, and scans were acquired before and after the administration of paramagnetic contrast material. For every lesion, we recorded signal intensity on unenhanced baseline T1- and T2-weighted images and enhancement pattern after SPIO administration. Histological examination of the entire liver provided the definitive diagnosis of the lesions. RESULTS: Histological examination identified 59 lesions: 14 HCC, 4 HCC-DN, 39 DN, and 2 cystoadenomas. Among the 14 HCC, three were well differentiated, eight were moderately differentiated and three were poorly differentiated. Of the 39 DN, 28 were low-grade and 11 high-grade lesions. Unenhanced baseline MR imaging correctly identified and characterised 20 lesions, equal to 33.90% of all lesions: 6 HCC, 12 DN and 2 DN with a subfocus of HCC. SPIO-enhanced MR imaging showed greater sensitivity detecting and characterising 45 lesions, equal to 76.27% of all lesions identified at histology: 14 HCC, 27 DN and 4 DN with subfocus of HCC. SPIO administration improved the sensitivity of MR imaging in lesion detection and characterisation by 42.37%. False negative results with SPIO-enhanced MR imaging occurred in 12 DN (31%), which histological examination revealed to be low-grade DN with a diameter <1 cm. CONCLUSIONS: SPIO-enhanced MR imaging proved to be of value in detecting and characterising lesions in the cirrhotic liver, allowing differentiation of DN from HCC and providing an early diagnosis of neoplastic degeneration of DN.

Morphostructural analysis of human follicular stem cells on highly porous bone hydroxyapatite scaffold.

In this study we investigated the in vitro behaviour, morphostructure and extracellular matrix synthesis of human dental follicular stem cells (hDFSCs) isolated from human dental bud, which resulted to be positive for mesenchymal markers (CD29, CD90, CD146 and CD166) by FACS analysis. Cells were analysed by light and electronic microscopy to evaluate their biological response either at week 1, that is before differentiation, or at weeks 3-6, when they had been cultured in osteogenic medium onto a highly porous natural scaffold material (Bio-Oss). Microscopy analysis of primary culture cells showed they had a mesenchymal stem cell-like morphostructure, spindle shaped, similar to the culture of mesenchymal stem cells derived from adult bone marrow. Also, after osteogenic differentiation, these analyses indicate typical osteoblast morphostructure and reveale a tri-dimensional organization of the cells and deposition of extracellular matrix (ECM) in close contact with biomaterial. This approach would allow to personalize the scaffold for bone tissue engineering in order to accelerate the process of osteogenesis.

Dentin sialophosphoprotein expression during human matrix development.

Dentin sialophosphoprotein (DSPP) is a phosphorylated parent protein that is cleaved post-translationally into three dentin components: dentin sialoprotein, dentin glycoprotein, and dentin phosphoprotein. In this study we evaluated the dentin sialophosphoprotein expression in human tooth germs to determine its role in tooth development and matrix deposition. DSPP gene expression was investigated performing reverse-transcription polymerase chain-reaction (RT-PCR) and a microarray analysis carried out using high density array containing 21.329 transcripts in replicates. To test for the expression of the DSPP protein, were performed western immunoblot and immunohistochemical analysis during different phases of tissues and matrix formation. All the analysis performed showed high expression level of DSPP in human tooth germs indicating that it may play an essential role for physiological and pathological events in tooth development.

Post extractive implant: evaluation of the critical aspects.

PURPOSE: Nowadays, implant supported prosthetic rehabilitation is a reliable procedure to replace compromised or untreatable teeth. The purpose of this review is to explore the concept of post extractive implant and the indications for clinical practice through an analysis of recent studies in the literature. All the main factors that could influence the outcome of this treatment will also be considered. MATERIALS AND METHODS: Focusing on the extraction-socket healing time, three different implant insertion protocols have been defined: Immediate implant placement (IIP), Early implant placement (EIP), Delayed implant placement (DIP). The entity of bone remodeling can be associated with different factors: three dimensional implant position, presence/absence of platform switching, absence of facial bony wall, inter implant/tooth distance. RESULTS: All the studies in literature agreed that implant primary stability is the main condition for a successful osseointegration of dental implants. Primary implant stability is influenced by many factors including local bone quality and quantity, implant macro-design, soft tissue conditions and rehabilitation, surgical technique, prosthetic load timing, oral hygiene. CONCLUSIONS: There is insufficient evidence in literature to determine possible advantages or disadvantages of IIP, EIP or DIP. Studies suggest that IIP and EIP may be at higher risks of implant failures and complications than delayed implants; on the other hand the aesthetic outcome might be better when placing implants just after teeth extraction.