A Systematic Review on Organ-on-a-Chip in PDMS or Hydrogel in Dentistry: An Update of the Literature.

Organs-on-a-chip (OoCs) are microfluidic devices constituted by PDMS or hydrogel in which different layers of cells are separated by a semipermeable membrane. This technology can set many parameters, like fluid shear stress, chemical concentration gradient, tissue-organ interface, and cell interaction. The use of these devices in medical research permits the investigation of cell patterning, tissue-material interface, and organ-organ interaction, mimicking the complex structures and microenvironment of human and animal bodies. This technology allows us to reconstitute in vitro complex conditions that recapitulate in vivo environments. One of the main advantages of these systems is that they represent a very realistic model that, in many cases, can replace animal experimentation, eliminating costs and related ethical issues. Organ-on-a-chip can also contain bacteria or cancer cells. This technology could be beneficial in dentistry for testing novel antibacterial substances and biomaterials, performing studies on inflammatory disease, or planning preclinical studies. A significant number of publications and reviews have been published on this topic. Still, to our knowledge, they mainly focus on the materials used for fabrication and the different patterns of the chip applied to the experimentations. This review presents the most recent applications of organ-on-a-chip models in dentistry, starting from the reconstituted dental tissues to their clinical applications and future perspectives.

Stress-strain and fatigue life numerical evaluation of two different dental implants considering isotropic and anisotropic human jaw.

Dental prostheses are currently a valid solution for replacing potential missing tooth or edentulism clinical condition. Nevertheless, the oral cavity is a dynamic and complex system: occlusal loads, external agents, or other unpleasant events can impact on implants functionality and stability causing a future revision surgery. One of the failure origins is certainly the dynamic loading originated from daily oral activities like eating, chewing, and so on. The aim of this paper was to evaluate, by a numerical analysis based on Finite Elements Method (FEM), and to discuss in a comparative way, firstly, the stress-strain of two different adopted dental implants and, subsequently, their fatigue life according to common standard of calculations. For this investigation, the jawbone was modeled accounting for either isotropic or anisotropic behavior. It was composed of cortical and cancellous regions, considering it completely osseointegrated with the implants. The impact of implants' fixture design, loading conditions, and their effect on the mandible bone was finally investigated, on the basis of the achieved numerical results. Lastly, the life cycle of the investigated implants was estimated according to the well-established theories of Goodman, Soderberg, and Gerber by exploiting the outcomes obtained by the numerical simulations, providing interesting conclusions useful in the dental practice.

Adherence to Antibiotic Prescription of Dental Patients: The Other Side of the Antimicrobial Resistance.

Since non-adherence to antibiotic therapy can cause several problems, including antimicrobial resistance (AMR) and treatment failures, the present study evaluated adherence to oral antibiotic therapy and AMR awareness among consecutively enrolled dental patients. Data concerning age, gender, socioeconomic status, education level, cohabitation, and general health were retrieved from medical records. AMR awareness was investigated through direct questions and adherence to antibiotic treatment was assessed through a modified Italian version of the Morisky medical scale-8 items. Participants' characteristics were analyzed in relation to treatment adherence and AMR, using a Χ2 independence test (significance level of α <0.1). Dental patients generally showed a low (51.82%) adherence to oral antibiotic therapy, and medium and high adherence was reported only by 29.37% and 18.81% of participants. Treatment adherence was similar in relation to participants' gender and age but significantly lower in subjects with only secondary school graduation and higher in participants with higher education levels. Non-cohabitants were significantly more adherent than cohabitants. AMR awareness was declared by 42.15% of males and 38.70% of females: 56.52% of dental patients aware of AMR were 18−38 years old, 35.20% were 39−59 years old, and 26.95% were aged between 60 and 80. Further studies are needed to develop adequate strategies, expanding dental patients' knowledge of AMR, thus optimizing the benefits and reducing the risks of antibiotic administration in dental patients.

Periodontal and Peri-Implant Diseases and Systemically Administered Statins: A Systematic Review.

Hyperlipidemia is a well-recognized risk factor for cardiovascular disease, which, in turn, acts as a contributory factor in periodontitis development. Periodontitis has been associated with benign tumors and cancers and withseveral disorders, including hyperlipidemia. Correspondingly, periodontal treatment may exert a positive effect on lipid metabolism, although opposite evidence has also been reported. As a counterpart, the therapy for hyperlipidemia, conventionally based on statins, has been proposed to positively affect periodontal conditions, mainly due to statin pleiotropic effects, reducing periodontal inflammation and promoting osseointegration. Therefore, the present systematic review aimed to evaluate, in subjects with untreated periodontitis and peri-implant disease (Population), the effect of routine systemically administered statins (Intervention), compared to non-statin use (Comparison), on periodontal parameters around natural teeth and implants (Outcome). Discordant results were found in periodontal parameters, and the current lack of such data related to peri-implant tissues and to alveolar bone loss highlights the need for further studies on the topic, potentially paving the way for a more comprehensive approach to periodontitis and peri-implantitis management. Indeed, the validation of the beneficial effect provided by systemically delivered statins on periodontal and peri-implant tissues may direct recall scheduling, predict response to therapy and, therefore, guide treatment strategies of periodontal and peri-implant treatments in statin users.

Oral Healthcare and Idiopathic Thrombocytopenic Purpura: Early Recognition, Dental Management and Case Report.

A 47-year-old Caucasian man, in good general, oral and periodontal health, presented with a non-bleeding bluish lesion on the back of his tongue, presumably due to an ecchymotic area of traumatic origin which was left untreated. The day after, other ecchymotic-type lesions on the mucous membranes of the cheeks and the upper lip, a bleeding lesion at the apex of the tongue and gingivorrhagia, along with petechiae on the back, scalp, lower limbs and feet, occurred, with rapid clinical deterioration, requiring immediate hospitalization. Oral, dermatological, and hematological evaluations lead to idiopathic thrombocytopenic purpura (ITP) diagnosis and hydrocortisone prescription, with a complete recovery in the next few days.The presented case of ITP, with early intra-oral manifestations, aimed both to emphasize the role of oral healthcare workers in theearly recognition of ITP, which may be especially relevant for those cases with extremely fast platelet depletion, high risk of internal bleeding and consequent potentially fatal complications, and in the differential diagnosis of the diseasethat may be aided by the diagnostic protocol described, and to provide dentists with recommendations on oral care management of cases of ITP, both in dental and multi-disciplinary settings.

Vitamin C Acutely Affects Brain Perfusion and Mastication-Induced Perfusion Asymmetry in the Principal Trigeminal Nucleus.

Prolonged mastication may induce an asymmetric modification of the local perfusion of the trigeminal principal nucleus. The aim of the present study was to evaluate the possible influence of vitamin C (vit. C) on such effect. Four groups of healthy volunteers underwent arterial spin labeling magnetic resonance imaging (ASL-MRI) to evaluate the local perfusion of the trigeminal nuclei after a vit. C-enriched lunch or a control lunch. Two ASL-MRI scans were acquired, respectively, before and after a 1 h-long masticating exercise or a 1 h long resting period. The results showed (i) an increased global perfusion of the brain in the vit. C-enriched lunch groups, (ii) an increased local perfusion of the right principal trigeminal nucleus (Vp) due to mastication, and (iii) a reduction of the rightward asymmetry of the Vp perfusion, due to mastication, after the vit C-enriched meal compared to the control meal. These results confirmed a long-lasting effect of prolonged mastication on Vp perfusion and also suggest a possible effect of vit. C on cerebral vascular tone regulation. Moreover, the data strongly draw attention on the side-to-side relation in Vp perfusion as a possible physiological parameter to be considered to understand the origin of pathological conditions like migraine.

Possible Association of Periodontal Disease and Macular Degeneration: A Case-Control Study.

Oral pathogens have been identified in bioptic specimens from Age-Related Macular Degeneration (ARMD) patients, and alveolar bone loss has been related to ARMD. Therefore, the possible association between ARMD and periodontal disease was investigated in the present case-control study, evaluating clinical and radiographic periodontal parameters, primarily, in cases vs. controls and, secondarily, in relation to ARMD risk factors, in cases, to highlight a possible pathogenic link between the disorders. Forty ARMD cases and 40 non-ARMD controls, matched for age (±3 years) and gender and homogeneous for ARMD risk factors, therefore comparable, underwent full-mouth periodontal charting, panoramic radiograph, and medical data, including ARMD risk factors, collection. Statistical analysis was conducted using the language R. Comparisons between groups were made using both traditional t-tests and Yuen's test with bootstrap calibration. Enrolled subjects were ≥55 years old, and 50 females and 30 males were equally distributed among the two groups. No statistically significant difference was found in clinical and radiographic periodontal parameters in cases vs. controls. In the case group, no differences were found when relating the periodontal parameters to ARMD risk factors, except for Clinical Attachment Level values that were statistically significantly higher in hypertensive ARMD subjects. A possible association between periodontal disease and ARMD may be hypothesized in hypertensive ARMD subjects, with hypertension as a possible pathogenic link between the disorders.

The Association between Periodontitis and Human Colorectal Cancer: Genetic and Pathogenic Linkage.

Periodontitis has been associated with an increased risk of and mortality associated with human colorectal cancer (CRC). Current evidence attributes such an association to the direct and indirect effects of virulence factors belonging to periodontal pathogens, to inflammatory mediators and to genetic factors. The aims of the study were to assess the existence of a genetic linkage between periodontitis and human CRC, to identify genes considered predominant in such a linkage, thus named leader genes, and to determine pathogenic mechanisms related to the products of leader genes. Genes linking periodontitis and CRC were identified and classified in order of predominance, through an experimental investigation, performed via computer simulation, employing the leader gene approach. Pathogenic mechanisms relating to leader genes were determined through cross-search databases. Of the 83 genes linking periodontitis and CRC, 12 were classified as leader genes and were pathogenically implicated in cell cycle regulation and in the immune-inflammatory response. The current results, obtained via computer simulation and requiring further validation, support the existence of a genetic linkage between periodontitis and CRC. Cell cycle dysregulation and the alteration of the immuno-inflammatory response constitute the pathogenic mechanisms related to the products of leader genes.

Relation of Gastric Volume With Weight Loss After Sleeve Gastrectomy: Results of a Prospective Analysis.

BACKGROUND: Postoperative sleeve volume (SV) is a key factor in evaluating the results of laparoscopic sleeve gastrectomy (LSG). An objective measurement of SV was obtained with 3-dimensional computed tomographic (3DCT) reconstruction. Several studies have compared SV with percent excess weight loss (%EWL), identifying an inverse relationship. We hypothesized that gastric capacity is one of the factors responsible for weight loss after LSG. OBJECTIVES: Outcomes of the study were the analysis of the inverse correlation between SV and weight loss (%EWL and body mass index) at the 12-month follow-up, and evaluation of SV in the group with %EWL >50%. In addition, the failure rate was quantified in the SV >180 mL group. MATERIALS AND METHODS: This is a prospective study with the collection of data. All patients who received LSG from January to December 2017 were evaluated. Computed tomography was performed on the upper abdomen at 12 months postoperatively to measure the SV using a standardized technique involving gastric distension. RESULTS: A total of 42 patients were considered for 3DCT evaluation at the 12-month follow-up. A significant linear inverse relation was reported between SV and %EWL (P<0.05); a similar trend, without significant results, was reported for body mass index loss. The entire cohort was subdivided according to %EWL. A %EWL<50% presented a significantly higher mean SV (P<0.01) than %EWL >50%. SV >180 mL was powerful in predicting abnormal gastric distension. Over this value, %EWL was lower than that in the remaining group (P<0.05, 31.9% vs. 51.8%). CONCLUSIONS: Our results confirmed a direct relation between SV and %EWL. Objective evaluation of gastric compliance obtained with 3DCT should be used intensively for LSG.

Antibiotic's effectiveness after erupted tooth extractions: A retrospective study.

OBJECTIVE: The purpose of this retrospective study was to assess the influence of antibiotics on the development of alveolitis after tooth extractions. MATERIALS AND METHODS: The study population consisted of patients who had erupted tooth extractions in 3 centers. The patients' medical records were collected for several parameters. Moreover, use of antibiotics was evaluated. The primary outcome was the development of alveolitis during the postoperative period. The secondary outcome measure was the possible associations between alveolitis and other patients' characteristics. RESULTS: A total of 1579 patient charts were screened. The patients enrolled in the study were 418 (159 males and 259 females). Alveolitis was reported for 12 extraction sites (2.87%). Six were in the group of patients that received antibiotics (2.14% out of 280 patients treated with antibiotics), and six were in the group of patients that did not receive antibiotics (4.35% out of 138 patients not receiving antibiotics). None of patient-level parameters showed any significant association with the development of alveolitis. CONCLUSION: In conclusion, this study showed that the use of antibiotics after erupted tooth extractions is not useful in preventing alveolitis. Larger, prospective, and randomized studies are needed before incorporating these findings into the daily clinical practice.

Experimental Comparison on Dental BioTribological Pairs Zirconia/Zirconia and Zirconia/Natural Tooth by Using a Reciprocating Tribometer.

The application of tribology in dentistry is growing rapidly, intense research has been conducted to develop an understanding of dental tribology for better selection of artificial materials and dental implant design. Dental biotribology, has been one of the most important branches in biotribology in recent years. The aim of this research is to investigate the tribological performances in the tooth-to-tooth contact and material-to-natural tooth contact (zirconia vs. zirconia and natural tooth vs. zirconia). The presented research was carried out by testing the above mentioned tribological pairs with the use of a reciprocating tribometer under lubricated conditions (artificial saliva). The normal force used in the tests was 20 N the time for each test was of 60 min. The stroke length was 2 mm, according to the range of displacement used in scientific literature. The wear mass loss evaluation was evaluated by using a gravimetric method. In order to characterize the wear mechanisms, present in the worn surfaces after each of tribo-tests, a topographic analysis was carried with a 3D non-contact optical profiler. The results show that the minimum value of the COF is obtained in the case of Zirconia vs. Zirconia tribo-couple. The results on the wear mass loss show a very low wear rate when coupling in tribological condition natural tooth with a ceramic restoration (a mean value of 0.5 mg was found). This rate is even lower when the contact is between two artificial zirconia teeth.

A 5-year longitudinal cohort study on crown to implant ratio effect on marginal bone level in single implants.

BACKGROUND: A 5-year longitudinal cohort study was carried out to evaluate the influence of anatomical crown to implant ratio (CIR) on peri-implant marginal bone level (MBL) in single implants. MATERIALS AND METHODS: The longest possible implants, according to the availability of pristine bone, were inserted, one per patient, among periodontally healthy teeth in consecutively recruited subjects. CIR and MBL changes were measured on standardized radiographs. The relationship between MBL and multiple predictors was investigated. A statistical analysis suitable for mixed type distributions was conducted: for the discrete component a logistic regression model was used and for the continuous component the impact of the variables on MBL was examined by using robust nonparametric comparison tests. RESULTS: Seventy-eight dental implants were inserted in 34 mandibles and 44 maxillae, with one stage procedure in 40 cases and two stage in 38 cases. Thirty-five implants were <10 mm, while 43 were ≥ 10 mm long; 28 implants had a CIR ≤1 and 50 had a CIR >1. No drop-outs or implant loss were observed. Bone loss occurred only in a few cases, measuring less than 0.5 mm and being significantly more pronounced for implant length ≥10 mm, for lower CIR values and for the two stage procedure. CONCLUSION: Higher CIR values were not related to increased peri-implant bone loss; a <10 mm long implant insertion may be safely considered for reduced bone heights.

Computed tomography-aided descriptive analysis of maxillary and mandibular atrophies.

INTRODUCTION: The aim of the present retrospective chart review was to analyze by Computed Tomography (CT) scan technique the degree of maxillomandibular atrophies, searching for differences between totally- and partially-edentulous subjects, and possibly identify and classify maxillomandibular atrophy staged patterns for implant planning in both totally- and partially- edentulous jaws. MATERIAL AND METHODS: CT scans of 89 mandibles and 77 maxillae from 111 patients were classified according to six different patterns of residual ridge resorption and to two different groups of edentulism (totally- and partially-edentulous). Maxillomandibular absolute linear dimensions were calculated and results compared for statistically significant differences by Wilcoxon tests. RESULTS: Maxillomandibular CT cross-section interpretation showed different patterns of linear bone remodelling (height values) between the two groups of edentulism joined with specific positions in the maxilla or mandible. The judgment of the investigator was uncertain in the analysis of the mandibular posterior areas with similar percentages for both totally- and partially-edentulous groups (12.5% and 11.5%, respectively). DISCUSSION: The 3D analysis is self-explanatory and easy to apply, aided by CT scans. The measurements between the referring planes and inviolable anatomical structures (nasal floor NFD, lower border of mandible LBD, inferior alveolar nerve AND, and sinus floor SFD), showed that class III may not guarantee an optimal implant placement, especially in the totally-edentulous group, due to a major degree of pneumatisation.

Evaluation of volumetric dimensional changes in posterior extraction sites with and without ARP using a novel imaging device.

BACKGROUND: Alveolar ridge volume loss may be minimized when postextraction sockets are filled by bone substitutes. PURPOSE: The aim of the study was to measure the effect of alveolar ridge preservation (ARP) in maintaining the external contour of the ridge after fresh socket grafting with or without particulate anorganic bovine bone mineral (BBM) and resorbable barrier covering. MATERIALS AND METHODS: In the present controlled study, patients subjected to single-tooth extraction were allocated to 2 groups: postextraction sockets grafted with bovine bone mineral (bbm), and naturally healing sockets (nat). Before and at 5 months following tooth extraction, plaster cast contours of the sockets were acquired by means of an optical scanner; the 2 contours of each patient underwent voxelization and fusion using a matrix elaborator. Outcome variables at 5 months (volumetric, surface, and linear changes) were measured in digital fused plaster casts with a dental scan software analyzing a volume of interest ranging from residual papilla to 10 mm toward the apical point. Intra- and inter-group pair-wise variables' comparisons were conducted. Level of significance was set at 0.05. RESULTS: Twenty-four sites were enrolled: 12 ARP and 12 naturally healed. Five-month percentage of volume loss of the bbm-group (21.7% ± 7.4%) was significantly lower (Ps < .0003) than that of the naturally healing group (38.8% ± 7.9%). When tooth position was investigated, volume loss in percentage registered a significantly better (P values ≤ .0485) behavior in molars (ΔV% = -19.1% ± 6.5% and ΔV% = -35.6% ± 7.6%, respectively, for bbm and nat) than that in premolars (ΔV% = -26.9% ± 7.2% and ΔV% = -45.1% ± 4.2%, respectively, for bbm and nat), in both the preserved and naturally healing groups. CONCLUSION: The dimensional loss in postextraction sockets grafted with anorganic bovine bone substitute and covered by a resorbable collagen barrier was lower than that of the naturally healing sites. However, ridge preservation was able to maintain almost 80% of the pristine bone.

Retrospective volume analysis of bone remodeling after tooth extraction with and without deproteinized bovine bone mineral insertion.

OBJECTIVES: The aim of the study was to analyze volume changes of post-extractive sockets grafted with or without deproteinized bovine bone mineral (DBBM) and a resorbable barrier. MATERIALS AND METHODS: This retrospective analysis utilized patients who had undergone tooth extraction. Sites, one per patient, were allocated to two groups: post-extractive non-grafted sockets (NG) and post-extractive grafted sockets with DBBM and resorbable barrier insertion (G). Maximal primary soft tissue closure was sought for both procedures. Before extraction and 6 months later, three-dimensional features of the sockets (linear indexes, areas, and volumes) and outcome variables at 6 months (volume- and surface changes) were acquired through computer tomography scans. Intra- and inter-group comparisons of the outcome variables were performed. Nonparametric tests were applied with a level of significance set at P < 0.01. RESULTS: Twenty-four sites, 9 grafted and 15 ungrafted, were enrolled. Between baseline and the 6-month evaluation, significant bone volume loss, superior surface shrinkage, and height reduction were registered for the G (72 mm(3) , 76 mm(2) , and 0.5 mm, respectively) and the NG group (274 mm(3) , 87 mm(2) , and 1.8 mm, respectively) with all P-values ≤ 0.0039. A significant difference, regarding the percentage of the volume change, was registered between the two procedures with a volume loss of 9.9% for the grafted sockets and 34.8% for the ungrafted ones (P-value = 0.0073). CONCLUSION: Grafting of the sockets with DBBM and a resorbable barrier insertion seemed to reduce negative osseous remodeling in the short term when compared to that of the ungrafted sockets.

A 5-Year Implant Follow-Up in Maxillary and Mandibular Horizontal Osseous Onlay Grafts and Native Bone.

The purpose of this study is to analyze marginal bone levels (MBLs) around dental implants positioned in the upper and lower jaw with or without horizontal onlay grafting procedures, and to survey implant survival with a follow-up of 5 years. Seventeen patients were surveyed in the present retrospective chart review. A total of 27 dental implants positioned in pristine bone and 21 in horizontally grafted bone were enrolled. MBLs were recorded for 4 aspects during a radiologic survey of 5 years. Significant differences were searched for among times and surgical procedures with paired and unpaired comparison tests, respectively, and survival rates were calculated for the 2 groups. In the maxilla, no statistically-significant differences between pristine and augmented groups were obtained; the time comparisons for pristine implants showed an affection of palatal, mesial, and distal sides, whereas the resorption around implants placed into horizontally grafted bone of anterior maxilla seemed to be limited just to buccal and distal aspects. Comparisons with the pristine horizontal procedure revealed that just the buccal sides were involved. The analysis of time comparisons attested to a continuous alveolar bone remodeling during the entire time of the survey for the pristine group. Given the extremely unfavorable resorption at the buccal aspect of the augmented areas, clinicians should reserve dental implant positioning into horizontal bone graft to selected patients, in whom it may represent one of the last opportunities of rehabilitation with a fixed prosthesis.

Implant angulation: 2-year retrospective analysis on the influence of dental implant angle insertion on marginal bone resorption in maxillary and mandibular osseous onlay grafts.

OBJECTIVES: The purpose of this study was to determine the existence of correlations between marginal peri-implant linear bone loss and the angulation of implants in maxillary and mandibular augmented areas over the course of a 2-year survey. MATERIALS AND METHODS: Dependent variables described the sample of the present retrospective chart review. By using three-dimensional radiographs, input variables, describing the implant angulation (buccal-lingual angle [φ] and mesial-distal angle [θ]) were measured; outcome variables described survival rate and marginal bone resorption (MBR) around dental implants in autogenous grafts (10 maxillae and 14 mandibles). Pairwise comparisons and linear correlation coefficient were computed. RESULTS: The peri-implant MBR in maxillary buccal and palatal areas appeared less intensive in the presence of an increased angulation of an implant towards the palatal side. Minor MBR was recorded around mandibular dental implants positioned at a right angle and slightly angulated towards the mesial. CONCLUSIONS: Resorption in buccal areas may be less intensive as the angulation of placed implants increases towards the palatal area in the maxilla, whereas for the mandible, a greater inclination towards the lingual area could be negative. In the mandibular group, when the implant was slightly angulated in the direction of the distal area, bone resorption seemed to be more marked in the buccal area. CLINICAL RELEVANCE: In the planning of dental implant placement in reconstructed alveolar bone with autograft, the extremely unfavourable resorption at the buccal aspect should be considered; this marginal bone loss seemed to be very sensitive to the angulation of the dental implant.

Marginal masticatory mucosa dimensional changes in immediate post-extractive implants: a 2 year prospective cohort study.

OBJECTIVES: The present two-year prospective cohort study was undertaken to evaluate marginal masticatory mucosa dimensional changes around immediate post-extractive implants positioned transgingivally with a non-submerged healing screw. MATERIAL AND METHODS: Twenty-one immediate post-extractive implants from 21 patients were enrolled, peri-implant gap was filled with bovine bone mineral, and soft tissue was allowed to heal around a non-submerged healing screw. Post-extractive socket dimension was recorded. Intraoperative (T0) vertical distances: bone margin level (BML) from the bone margin to the implant platform and mucosal margin height (MMH) from marginal mucosa to implant platform were taken; MMH measurement was repeated 4 months later (T4). Horizontal mucosal level (HML): from customized stent to marginal mucosa at 0, 4, 12, and 24 months postoperatively (T0, T4, T12, T24) and vertical mucosal level (VML): from the stent to marginal mucosa at T4, T12, T24 were registered. RESULTS: One implant failed at 3 weeks; in the remaining 20 cases the MMH, coronally positioned with respect to the BML ≅2 mm at T0, showed a statistically significant vertical contraction of the mucosa at T4. Other vertical mucosal measurements (VML) did not show further changes over time. HML measures showed a, statistically significant, shrinkage of the mucosa on the transverse plane between T0/T12 and T0/T24 and between T4/T12 and T4/T24. CONCLUSIONS: Immediate post-extractive implant inserted transgingivally with a non-submerged healing screw and internal peri-implant gap filled with bovine bone mineral may favor an early and stable peri-implant soft tissue healing over 2 years.

Volumetric changes after sinus augmentation using blocks of autogenous iliac bone or freeze-dried allogeneic bone. A non-randomized study.

OBJECTIVES: To compare volumetric bone changes after sinus augmentation for implant positioning using blocks of autogenous iliac bone or freeze-dried allogeneic bone (FDBA) from the hip. Variables were compared between the two sources and for each surgical procedure at set times (pre- and post-augmentation procedure). PATIENTS AND METHODS: A non-randomized retrospective chart review of 7 patients who had autogenous and 7 allogeneic block grafts was carried out (1 procedure per patient). Analysis of Computer Tomographic (CT) data of maxillary sinuses, acquired with high-speed, double-detector CT scanner, was performed using dentascan software. The change between the preoperative (T0) and postoperative volume was measured at 4-6 months (T2) and 1.5 year after transplantation (T3). Annual- and overall-rates of bone change were calculated for the two sources. RESULTS: All patients were partially edentulous with a residual maxillary floor thickness in the planned implant insertion sites of 2.7 (0.5) mm and 2.8 (0.5) mm for allogeneic and autogenous procedures respectively. From identical intraoperative volume of grafts (2.25 cc at T1), volumetric changes were recorded at T2 and T3. The final volume of the grafts was 1.44 cc for allogeneic group and 1.78 cc for the autogenous group. Significant volumetric changes over time of transplanted grafts for both sources (23% for autograft and 18% for allograft) were found at T2. At 1.5-years post-operatively comparisons of volumes and rates of bone loss between sources were not statistically significant. No failure was recorded for either bone grafts or dental implants. CONCLUSIONS: Short-term sinus grafting procedure for dental implant placement performed with FDBA showed an outcome close to that reported for autogenous bone. Volumetric changes were comparable between the sources. These data suggest that performing maxillary sinus augmentation with dry-preserved bone allogeneic materials in block form could be considered even when the residual floor thickness is less than 3 mm.