Dental Erosion in Competitive Swimmers and Preventive Treatments: An In Vitro Study.

The aim of this in vitro study was to evaluate the effectiveness of highly concentrated fluoride products and remineralizing products (F-APC) in preventing erosive dental lesions in competitive swimming patients. A total of 48 teeth were extracted, preserved in saline solution and divided into three groups. In G1 (control group), each tooth was half-immersed in chlorinated pool water; in G2 (fluoride-treated group), after being totally immersed in chlorinated water, each tooth had half of its surface treated with a highly concentrated fluoride product once a week; in G3 (remineralization product-treated group), each tooth was totally immersed in chlorinated water and half of its surface was treated with a remineralizing product after each immersion. The study was conducted over a 4-week period, immersing the teeth for 4 h per day. In G1, statistically significant differences were observed in submerged versus non-submerged tooth surfaces at week 3 (T3) (p = 0.019) and week 4 (T4) (p = 0.0007), with four and eight surfaces showing erosive tooth wear (ETW), respectively. In G2, a difference was observed between fluoride-treated and non-fluoride-treated surfaces at T4 (p = 0.039), with three surfaces with ETW among the non-treated ones. In G3, the difference was observed between portions treated with F-APC and those not treated at T4 (p = 0.019), with four surfaces with ETW among the untreated ones. Chlorinated pool water is a potential erosive agent for teeth if water pH values reach a critical value. Treating the teeth surface with highly concentrated fluoride products, once a week for 5 min, and F-APC are effective in protecting teeth against tooth erosion.

Maintaining Hygiene in Orthodontic Miniscrews: Patient Management and Protocols-A Literature Review.

BACKGROUND: Oral hygiene is crucial for the success of orthodontic therapy involving temporary anchoring devices like miniscrews. Plaque buildup, exacerbated by orthodontic appliances, causes inflammation that can undermine treatment outcomes. Individualized prevention plans based on patient risk factors are essential. This review emphasizes the importance of oral hygiene in orthodontic therapy with miniscrews, identifies optimal devices for ensuring long-term stability, and explores protocols for high-risk patients. MATERIALS AND METHODS: A comprehensive search was conducted on two primary databases, PubMed and Google Scholar, for relevant articles on oral hygiene and inflammation. Fourteen articles meeting the inclusion criteria were selected, covering topics such as "orthodontic miniscrew", "miniscrew and laser", "miniscrew and mouthwash", "electric toothbrush", and "GBT". RESULTS: Inflammation can compromise miniscrew stability by damaging surrounding bone. Miniscrews of 10 mm length have lower failure rates due to better bone contact and stability. Chlorhexidine reduces inflammation risk and inhibits epithelialization around the implant head. Laser therapy enhances miniscrew stability and reduces inflammation. Chitosan effectively suppresses inflammatory mediators and prevents microorganism adhesion. Both sonic and roto-oscillating electric toothbrushes remove plaque effectively, with roto-oscillating brushes showing superior results. The Guided Biofilm Therapy (GBT) protocol offers professional hygiene benefits similar to traditional methods, with improved patient engagement and motivation. CONCLUSIONS: Home oral hygiene maintenance is paramount for preventing inflammatory complications. Professional interventions such as diode laser usage, particularly in adult patients with a history of periodontitis or underlying systemic conditions, can mitigate orthodontic therapy failure risks. The GBT protocol fosters a more comfortable and participatory professional hygiene experience for patients, promoting better oral health awareness and compliance.

Cleft lip and palate outcomes: Multidisciplinary approach for comprehensive management.

In patients with cleft lip and palate the most common associated dental problem is lateral incisor agenesis, often associated with lack of support and definition of the nasal tip. In many cases, adhesions deriving from surgical procedures and skeletal discrepancy make orthognathic surgery and rhinoseptoplasty unavoidable. In the present case report a dental rehabilitation with canine substitution and prosthetic-implant treatment in a posterior area is described. The use, during rhinoseptoplasty, of a customized titanium prosthesis, which provides projection for the tip of the nose, is also introduced. The patient was administered two questionnaires in order to assess the psychological aspects related to the cleft outcomes and the influence that the treatment conveyed.

Edge level of aligners and periodontal health: a clinical perspective study in young patients.

INTRODUCTION: Although the superiority of clear aligners over multi-bracket appliances in keeping gingiva healthy has been suggested, the possible benefits of one aligner design over another have not yet been investigated, especially with regard to the vestibular edge. OBJECTIVE: The aim of this study was to measure several periodontal indexes in adolescents undergoing orthodontic treatment with aligners, comparing two different types of rim. METHODS: The study involved 43 patients aged between 14 and 18 years. The periodontal health was assessed using plaque index (PI), gingival index (GI), and gingival bleeding index (GBI), at the start of the treatment with aligners (T0), with a vestibular rim (VR) reaching up to 3 mm beyond the gingival margin. Three months later (T1), aligners were set to obtain a juxtagingival rim (JR) on the second quadrant and VR on the first quadrant. The periodontal indexes were measured again, both at T1 and then three months later (T2). RESULTS: Intra-quadrant comparisons revealed a statistically significant worsening of the periodontal indexes only for the second quadrant (p<0.05), at T1 (GI), and especially at T2 (PI, GI, GBI), while no statistically significant changes were found for the first quadrant. CONCLUSIONS: More severe mechanical irritation, especially during insertion and removal of the aligner, can explain the worsening inflammatory indexes with the JR. In addition, the pressure exerted by the JR on the gingival sulcus seemed to facilitate plaque deposition, whereas the VR had a protective effect, reducing the risk of mechanical trauma.

Ecological Momentary Assessment of Awake Bruxism Behaviors: A Scoping Review of Findings from Smartphone-Based Studies in Healthy Young Adults.

BACKGROUND: The recent introduction of ecological momentary assessment (EMA) smartphone-based strategies has allowed achieving some interesting data on the frequency of different awake bruxism (AB) behaviors reported by an individual in the natural environment. OBJECTIVE: The present paper aims to review the literature on the reported frequency of AB based on data gathered via smartphone EMA technology. METHODS: On September 2022, a systematic search in the Pubmed, Scopus and Google Scholar databases was performed to identify all peer-reviewed English-language studies assessing awake bruxism behaviors using a smartphone-based Ecological Momentary Assessment. The selected articles were assessed independently by two authors according to a structured reading of the articles' format (PICO). RESULTS: A literature search, for which the search terms "Awake Bruxism" and "Ecological Momentary Assessment" were used, identified 15 articles. Of them, eight fulfilled the inclusion criteria. The results of seven studies using the same smartphone-based app reported a frequency of AB behaviors in the range between 28.3 and 40% over one week, while another investigation adopted a different smartphone-based EMA approach via WhatsApp using a web-based survey program and reported an AB frequency of 58.6%. Most included studies were based on convenience samples with limited age range, highlighting the need for more studies on other population samples. CONCLUSIONS: Despite the methodological limits, the results of the reviewed studies provide a standpoint for comparison for future studies on the epidemiology of awake bruxism behaviors.

Edge level of aligners and periodontal health: a clinical perspective study in young patients

ABSTRACT Introduction: Although the superiority of clear aligners over multi-bracket appliances in keeping gingiva healthy has been suggested, the possible benefits of one aligner design over another have not yet been investigated, especially with regard to the vestibular edge. Objective: The aim of this study was to measure several periodontal indexes in adolescents undergoing orthodontic treatment with aligners, comparing two different types of rim. Methods: The study involved 43 patients aged between 14 and 18 years. The periodontal health was assessed using plaque index (PI), gingival index (GI), and gingival bleeding index (GBI), at the start of the treatment with aligners (T0), with a vestibular rim (VR) reaching up to 3 mm beyond the gingival margin. Three months later (T1), aligners were set to obtain a juxtagingival rim (JR) on the second quadrant and VR on the first quadrant. The periodontal indexes were measured again, both at T1 and then three months later (T2). Results: Intra-quadrant comparisons revealed a statistically significant worsening of the periodontal indexes only for the second quadrant (p<0.05), at T1 (GI), and especially at T2 (PI, GI, GBI), while no statistically significant changes were found for the first quadrant. Conclusions: More severe mechanical irritation, especially during insertion and removal of the aligner, can explain the worsening inflammatory indexes with the JR. In addition, the pressure exerted by the JR on the gingival sulcus seemed to facilitate plaque deposition, whereas the VR had a protective effect, reducing the risk of mechanical trauma.

RESUMO Introdução: Embora se alegue uma superioridade dos alinhadores transparentes sobre os aparelhos multibraquetes em manter a gengiva saudável, ainda não foram investigados os possíveis benefícios de um modelo de alinhador sobre outro, especialmente no que diz respeito à borda vestibular. Objetivo: O objetivo deste estudo foi medir vários índices periodontais em adolescentes submetidos a tratamento ortodôntico com alinhadores, comparando dois tipos diferentes de borda. Métodos: O estudo envolveu 43 pacientes com idade entre 14 e 18 anos. A saúde periodontal foi avaliada por meio do índice de placa (IP), índice gengival (IG) e índice de sangramento gengival (ISG), ao início do tratamento com alinhadores (T0), com borda vestibular (BV) estendendo-se até 3 mm além da margem gengival. Três meses depois (T1), os alinhadores foram ajustados para se obter uma borda justagengival (BJ) no segundo quadrante e BV no primeiro quadrante. Os índices periodontais foram medidos novamente tanto em T1 quanto três meses depois (T2). Resultados: As comparações intraquadrantes revelaram uma piora estatisticamente significativa nos índices periodontais apenas para o segundo quadrante (p<0,05), em T1 (IG) e especialmente em T2 (IP, IG, ISG), enquanto nenhuma mudança estatisticamente significativa foi encontrada para o primeiro quadrante. Conclusões: Irritações mecânicas mais intensas, principalmente durante a inserção e remoção do alinhador, podem explicar a piora dos índices inflamatórios com a BJ. Além disso, a pressão exercida pela BJ no sulco gengival pareceu facilitar a deposição de placa, enquanto a BV teve um efeito protetor, reduzindo o risco de trauma mecânico.

Mandibular Molar Uprighting Using Skeletal Anchorage: A Novel Approach.

BACKGROUND: The management of eruption anomalies affecting second molars, although quite uncommon, may represent a real challenge for the clinician. The aim of this study is to present a novel technique that combines the surgical and orthodontic approach in order to obtain the retrieval of impacted second molars through a complex distalizing movement and skeletal anchorage. METHODS: Nineteen consecutive patients with impacted second molars were treated according to this technique, which involved extraction of the third molar followed by the placement of a distally positioned screw, and the subsequent use of a coil spring to connect the screw to an eyelet directly bonded on the second molar. In selected cases, it proved to be necessary to reposition the second molar through traditional orthodontics. All of the parameters were recorded: the time required for completing the treatment, the initial angle between the second molar and the adjacent tooth, and treatment related-complications. RESULTS: Twenty impacted second molars were correctly repositioned. The mean initial angle of the second molar was 55.7° (SD 22.6°, min 13.3°, max 104.8°). The mean treatment time was 10 months. There were no major complications. CONCLUSIONS: Given that periodontal tissues were minimally affected, the temporary anchorage device was fully controlled, and there was no unwanted movement of adjacent teeth, the presented technique not only proved effective but also minimally invasive.

Exosomes Derived from Dental Pulp Stem Cells Show Different Angiogenic and Osteogenic Properties in Relation to the Age of the Donor.

Craniofacial tissue reconstruction still represents a challenge in regenerative medicine. Mesenchymal stem cell (MSC)-based tissue engineering strategies have been introduced to enhance bone tissue repair. However, the risk of related complications is limiting their usage. To overcome these drawbacks, exosomes (EXOs) derived from MSCs have been recently proposed as a cell-free alternative to MSCs to direct tissue regeneration. It was hypothesized that there is a correlation between the biological properties of exosomes derived from the dental pulp and the age of the donor. The aim of the study was to investigate the effect of EXOs derived from dental pulp stem cells of permanent teeth (old donor group) or exfoliated deciduous teeth (young donor group) on MSCs cultured in vitro. Proliferation potential was evaluated by doubling time, and commitment ability by gene expression and biochemical quantification for tissue-specific factors. Results showed a well-defined proliferative influence for the younger donor aged group. Similarly, a higher commitment ability was detected in the young group. In conclusion, EXOs could be employed to promote bone regeneration, likely playing an important role in neo-angiogenesis in early healing phases.

Olfactory Dysfunction in COVID-19 Patients Who Do Not Report Olfactory Symptoms: A Pilot Study with Some Suggestions for Dentists.

BACKGROUND: Smell and taste dysfunction are frequently reported by SARS-CoV-2 positive patients. The degree of olfactory and gustatory dysfunction varies from a very mild reduction to their complete loss. Several studies have been performed to determine their prevalence in COVID-19 patients, mostly using subjective measurement methods. The literature lacks long-term studies regarding duration and recovery. METHODS: We assessed olfactory performance, using the Sniffin' Sticks olfactory test, in a group of patients who had not reported olfactory dysfunction, around 131 days after their COVID-19 diagnosis. RESULTS: 11 out of 20 subjects showed no olfactory reduction (65%), while 9 subjects showed reduced TDI score (45%). A total of 13 subjects (65%) scored above the cutoff point for Threshold, 16 subjects (80%) scored above the cutoff point for discrimination and 13 subjects (65%) scored above the cutoff point for identification. CONCLUSION: Objective measurement methods of olfactory performance show a higher prevalence of olfactory reduction compared to patients' self-reported questionnaires. Olfactory dysfunction can last even months after its onset and because of its high prevalence, it could be a screening symptom for suspect COVID-19 cases.

Effect of Water-Based Disinfectants or Air-Drying on Dimensional Changes in a Thermoplastic Orthodontic Aligner.

The polymer structure of thermoplastic materials currently used to make aligners is altered by the oral conditions and this negatively affects their capacity to move teeth. This study aimed to compare different options for storing aligners when not in use by superimposing successive 3D images to identify which storage method least affects material shape and weight. Fifty PET-G aligners, produced using the CA Digital method, were divided into four groups (1A, 1B, 1C, and 2D) and were stored for 18 h a day in artificial saliva at 37 °C. Then, to mimic their storage conditions when not in use, aligners in group 1A were immersed for the remaining 8 hours a day in bicarbonate solution, those in group 1B in chlorhexidine solution, those in group 1C in distilled water, and those in group 2D were stored dry. The samples were scanned at the baseline (before the immersion cycles began) and again two weeks later. The digital scans were superimposed and the median deformation, its variability, and weight differences were recorded for each group. Statistical analysis showed aligner deformation (expansion) in all three groups stored in wet conditions, with a statistically significant difference between groups 1A and 1C. Aligners in group 2D shrank slightly, and to a significantly greater degree with respect to group 1C. Variability in the degree of deformation was similar among the three groups stored in wet conditions, but significantly greater in group 2D. Weight gains were recorded in all four groups, the smallest in group 2D and the largest in group 1A. Storing aligners in dry conditions promoted lower deformation in the material, involving a slight shrinkage, whereas wet storage conditions caused an expansion of the aligner, especially when distilled water is used.

Smartphone-based evaluation of awake bruxism behaviours in a sample of healthy young adults: findings from two University centres.

A smartphone-based ecological momentary assessment (EMA) strategy was used to assess the frequency of awake bruxism behaviours, based on the report of five oral conditions (ie relaxed jaw muscles, teeth contact, mandible bracing, teeth clenching and teeth grinding). One hundred and fifty-three (N = 153) healthy young adults (mean ± SD age = 22.9 ± 3.2 years), recruited in two different Italian Universities, used a dedicated smartphone application that sent 20 alerts/day at random times for seven days. Upon alert receipt, the subjects had to report in real-time one of the above five possible oral conditions. Individual data were used to calculate an average frequency of the study population for each day. For each condition, a coefficient of variation (CV) of frequency data was calculated as the ratio between SD and mean values over the seven recording days. Average frequency of the different behaviours over the seven days was as follows: relaxed jaw muscle, 76.4%; teeth contact, 13.6%; mandible bracing, 7.0%; teeth clenching, 2.5%; and teeth grinding, 0.5%. No significant differences were found in frequency data between the two University samples. The relaxed jaw muscles condition was more frequent in males (80.7 ± 17.7) than in females (73.4 ± 22.2). The frequency of relaxed jaw muscles condition over the period of observation had a very low coefficient of variation (0.27), while for the different awake bruxism behaviours, CV was in a range between 1.5 (teeth contact) and 4.3 (teeth grinding). Teeth contact was the most prevalent behaviour (57.5-69.7). Findings from this investigation suggest that the average frequency of AB behaviours over one week, investigated using EMA-approach, is around 23.6%.

Sinus Mucosa Thinning and Perforations after Sinus Lifting Performed with Different Xenografts: A Histological Analysis in Rabbits.

BACKGROUND: Experimental studies have shown a progressive thinning and perforations of the sinus mucosa associated with sharpened edges and the cutting projections of graft particles used simultaneously for maxillary sinus augmentation. Hence, the aim of the present study was to evaluate the damaging effects of two different bovine grafts on the sinus mucosa after sinus augmentation. METHODS: Twenty New Zealand rabbits received a bilateral sinus lifting using, as fillers, two different types of deproteinized bovine bone in granules, one processed at low temperature (low-T group), and the other at high temperature (high-T group). Thinned mucosa sites (<40 µm) and perforations were evaluated in the sinus mucosa that were in contact with graft granules after 2 and 10 weeks, in ten animals per period. RESULTS: After 2 weeks of healing, the number of thinned mucosa sites was 118 in the low-T group, and 149 in the high-T group (p = 0.191). At the 10-week assessment, the thinned sites increased to 237 and 195 sites, respectively. The numbers of sinus mucosa perforations after 2 weeks were eight and three in the low-T and high-T group, respectively. At the 10-week evaluation, the perforations increased to 19 in the low-T group, and to 14 in the high-T group. CONCLUSIONS: The contact with bovine xenografts yielded thinning and perforations of the sinus mucosa. Despite the differences in characteristics and dimensions, no differences were found between the two xenografts in the numbers of thinning mucosa sites and perforations. However, a trend of more events was found in the low-T compared to the high-T group.

Bone healing at collagenated bicortically installed implants: an experimental study in rabbits.

PURPOSE: To study the healing at collagenated bicortically installed implants. METHODS: Twenty albino New Zealand rabbits were used for implant installation. Two implants with a double acid etched surface, coated with a collagen type I or left uncoated, were installed bicortically in the metaphysis and in the diaphysis of each tibia. Ten rabbits were euthanized after 2 weeks and ten after 6 weeks after installation. Ground sections were prepared for histological analyses that were performed both in the cortical layers and in the marrow regions. RESULTS: After 2 weeks of healing, highest amounts of new bone were found at the collagenated implants (43.2 ± 6.0%) compared to the standard implants (33.9 ± 6.1%; p = 0.022). After 6 weeks of healing, similar percentages of new bone were observed, being 51.8 ± 7.3% and 50.9 ± 9.6% (p = 0.678) for the standard and collagenated surfaces, respectively. CONCLUSIONS: A coated surface with collagen type I promoted bone apposition in the earliest periods of healing. However, the effect vanished over time so that similar results were obtained after 6 weeks of healing.

Accuracy of 3D digital modeling of dental arches.

OBJECTIVE: The aim of the study was to verify and compare the accuracy of full-arch digital impressions obtained using two intraoral scanners and three scanning methodologies. METHODS: A resin model created with dental 3-D printing was scanned by a reference scanner (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) in order to obtain a 3D reference; the same resin model was then scanned with two different intraoral scanners (Zfx IntraScan and Carestream 3600 - CS 3600®, Carestream, Rochester, NY, USA) using: Technique A (from tooth #27 up to tooth #17); Technique B (from tooth #11 up to tooth #17 and then from tooth #21 up to tooth #27) and Technique C (from tooth #22 up to tooth #17, and then from tooth #12 up to tooth #27 - the MeshLab software v. 1.3.3 was then used to match the two scans). The scans obtained were superimposed over the reference scan by means of a software, and the volumetric discrepancies were calculated. RESULTS: The mean results for the Zfx Intrascan scanner were: Technique A = 302.47 ± 37.42 µm; Technique B = 180.45 ± 29.86 µm; Technique C = 147.34 ± 28.23 µm. The mean results for the Carestream 3600 scanner were: Technique A = 303.59 ± 40.20 µm; Technique B = 181.53 ± 29.61 µm; Technique C = 142.28 ± 35.33 µm. Technique C, used by both scanners, produced less volumetric discrepancies compared to the other techniques. CONCLUSIONS: The scanning technique had a statistically significant effect on the quality of the scan (p< 0.0001), whereas the scanner did not present any significant influence (p= 0.91).

Accuracy of 3D digital modeling of dental arches

ABSTRACT Objective: The aim of the study was to verify and compare the accuracy of full-arch digital impressions obtained using two intraoral scanners and three scanning methodologies. Methods: A resin model created with dental 3-D printing was scanned by a reference scanner (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) in order to obtain a 3D reference; the same resin model was then scanned with two different intraoral scanners (Zfx IntraScan and Carestream 3600 - CS 3600®, Carestream, Rochester, NY, USA) using: Technique A (from tooth #27 up to tooth #17); Technique B (from tooth #11 up to tooth #17 and then from tooth #21 up to tooth #27) and Technique C (from tooth #22 up to tooth #17, and then from tooth #12 up to tooth #27 - the MeshLab software v. 1.3.3 was then used to match the two scans). The scans obtained were superimposed over the reference scan by means of a software, and the volumetric discrepancies were calculated. Results: The mean results for the Zfx Intrascan scanner were: Technique A = 302.47 ± 37.42 µm; Technique B = 180.45 ± 29.86 µm; Technique C = 147.34 ± 28.23 µm. The mean results for the Carestream 3600 scanner were: Technique A = 303.59 ± 40.20 µm; Technique B = 181.53 ± 29.61 µm; Technique C = 142.28 ± 35.33 µm. Technique C, used by both scanners, produced less volumetric discrepancies compared to the other techniques. Conclusions: The scanning technique had a statistically significant effect on the quality of the scan (p< 0.0001), whereas the scanner did not present any significant influence (p= 0.91).

RESUMO Objetivo: o objetivo do presente estudo foi verificar e comparar a precisão de modelos digitais de uma arcada dentária completa obtidos utilizando-se dois tipos de scanners e três metodologias de digitalização. Métodos: um modelo de resina feito com impressão 3D foi digitalizado em um scanner de referência (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) para se obter uma referência em 3D; o mesmo modelo de resina foi, então, digitalizado com dois scanners intrabucais diferentes (Zfx IntraScan e Carestream 3600 - CS 3600®, Carestream, Rochester, NY, EUA) utilizando: Técnica A (do dente #27 ao dente #17); Técnica B (do dente #11 ao dente #17 e, em seguida, do dente #21 ao dente #27); e Técnica C (do dente #22 ao dente #17 e, em seguida, do dente #12 ao dente #27 - osoftware MeshLab v. 1.3.3 foi, então, usado para mesclar as duas leituras). Em seguida, as imagens digitalizadas foram sobrepostas à imagem de referência, utilizando-se um software, e as discrepâncias volumétricas foram calculadas. Resultados: a média dos resultados para o scanner Zfx Intrascan foram: Técnica A = 302,47 ± 37,42 µm; Técnica B = 180,45 ± 29,86 µm; Técnica C = 147,34 ± 28,23 µm. A média dos resultados para o scanner Carestream 3600 foram: Técnica A= 303,59 ± 40,20 µm; Técnica B = 181,53 ± 29,61 µm; Técnica C = 142,28 ± 35,33 µm. A Técnica C, utilizada em ambos os scanners, produziu as menores discrepâncias volumétricas, quando comparada às outras técnicas. Conclusões: a técnica de digitalização teve um efeito estatisticamente significativo sobre a qualidade do modelo digital (p< 0,0001), enquanto o tipo de scanner usado não apresentou qualquer influência significativa (p= 0,91).

Bone Healing at Functionally Loaded and Unloaded Screw-Shaped Implants Supporting Single Crowns: A Histomorphometric Study in Humans.

PURPOSE: To evaluate histologically and histomorphometrically the effect of a delayed load on healing at implants with a moderately rough surface. MATERIALS AND METHODS: Two solid titanium screw-shaped devices, 5 mm long and 3.5 mm in diameter, were inserted in the distal segments of the alveolar ridge of 16 volunteer patients in a nonsubmerged fashion. After 2 months, one implant was loaded, while the other was left unloaded. After 2 months, the two implants were collected from 10 patients using a sonic instrument, and ground sections were prepared from the biopsy specimens. Histomorphometric analyses were performed. RESULTS: After 4 months of healing, biopsy specimens from 10 patients were available for analyses (n = 10). The total bone-to-implant contact percentage was 86.8% ± 6.5% and 84.6% ± 3.7% for loaded and unloaded implants, respectively. New bone was represented by 85.5% ± 6.7% and 83.4% ± 3.9% at the loaded and unloaded sites, respectively. A very small amount of old parent bone was found. The density of the mineralized bone was 76.8% ± 8.3% for the loaded sites and 74.1% ± 10.5% for the unloaded sites. The percentages of new and old bone densities were 69.0% ± 8.3% and 7.8% ± 3.9% at the loaded sites, and 65.9% ± 10.3% and 8.2% ± 4.5% at the unloaded sites, respectively. No statistically significant differences were disclosed. CONCLUSION: Applying a delayed load to implants supporting single crowns did not yield statistically significant differences, and only a tendency of higher osseointegration and bone density was observed at loaded sites compared with the unloaded sites.

Healing at the Interface Between Autologous Block Bone Grafts and Recipient Sites Using n-Butyl-2-Cyanoacrylate Adhesive as Fixation: Histomorphometric Study in Rabbits.

The aim of the present split-mouth (split-plot) study was to describe the sequential healing in the interface between autologous bone grafts and recipient parent bone, fixed using an n-butyl-2-cyanoacrylate adhesive with or without an additional titanium fixation screw. Bone grafts were collected from the calvaria and fixed to the lateral aspect of the mandible in 24 rabbits. The cortical layers of the recipient sites were perforated, and the grafts were randomly fixed using an n-butyl-2-cyanocrylate adhesive, either alone or in conjunction with a 1.5 mm × 6.0 mm titanium fixation screw. The animals were sacrificed after 3, 7, 20, and 40 days, and histomorphometric evaluations of the interface between graft and parent bone were performed. Only 2 of 6 grafts in each group were partially incorporated to the parent bone after 40 days of healing. The remaining grafts were separated from the parent bone by adhesive and connective tissue. It was concluded that the use of n-butyl-2-cyanoacrylate as fixation of an autologous bone graft to the lateral aspect of the mandible was able to maintain the fixation over time but did not incorporate the graft to the recipient sites. Use of fixation screws did not improve the healing.

Sequential morphometric evaluation at UnicCa® and DCD® implant surfaces. An experimental study in the dog.

AIM: To study tissue components adjacent to implants with nanotechnologically modified surfaces at different periods of healing. MATERIAL & METHODS: In 12 beagle dogs, two different implant systems with different surface configurations were randomly installed in the edentulous premolar regions of the mandible. One surface was first acid-etched and subsequently, nanotechnologically modified with calcium ions (UnicCa® ), while the other was first sandblasted and acid-etched, and then additionally treated with a nanometer calcium phosphate deposition (discrete crystalline deposition; DCD® ). The implants were fully submerged; surgeries and sacrifices were planned to harvest biopsies after 1, 2, 4 and 8 weeks of healing (n = 6 per period). A morphometric evaluation of percentages of new and old bone, bone debris/particles and clot, new soft tissues (provisional matrix and immature marrow), mature bone marrow and vessels was performed in the spongiosa compartment adjacent to the implant surface up to a distance of about 0.4 mm from the surface. RESULTS: After 2 weeks of healing, the soft tissues were represented by 41.0% at the UnicCa® and 37.9% at the DCD® surfaces, in both cases mainly being composed of provisional matrix. These percentages decreased over time, being composed of greater amounts of immature bone marrow, and disappeared after 8 weeks. New bone increased progressively between 1 and 8 weeks of healing from 9.7 ± 6.3% to 70.0 ± 8.4% and from 8.2 ± 3.5% to 67.0 ± 6.1% at the UnicCa® and DCD® surfaces, respectively. Pristine bone was progressively resorbed. CONCLUSIONS: Throughout the periods of healing observed, the formation of a provisional matrix followed by the formation of new bone and marrow was revealed in a similar fashion as for other modified surface configurations.

Morphometric evaluation of the early stages of healing at cortical and marrow compartments at titanium implants: an experimental study in the dog.

OBJECTIVE: To study the early sequential stages of tissue composition in the cortical and marrow compartments of the alveolar bone crest at implants with a moderately rough surface. MATERIALS AND METHODS: Three month after tooth extraction in 12 Labrador dogs, full-thickness flaps were elevated in the edentulous region of the right side of the mandible and one implant was installed. The flaps were sutured to allow a fully submerged healing. The timing of the installations in the left side of the mandible and of sacrifices were scheduled in such a way to obtained biopsies representing the healing after 5, 10, 20, and 30 days. Ground sections (n = 6 per each healing period) were prepared, and the percentages of osteoid/new bone, old bone, new soft tissues (provisional matrix and primitive marrow), mature bone marrow, vessels, and other tissues (bone debris/particles and clot) were evaluated laterally to the implant surface up to a distance of about 0.4 mm from it. RESULTS: Osteoid/new bone was found after 5 days at percentages of 10.8 ± 4.3% at the marrow and 0.6 ± 0.6% at the cortical compartments. After 30 days, these percentages increased up to 56.4 ± 4.0% and 23.3 ± 6.1%, respectively. Old parent bone was resorbed between 5 and 30 days from 28.7 ± 10.9% to 14.9 ± 3.4% at the marrow (~48% of resorption) and from 81.2 ± 9.4% to 67.6 ± 5.6% at the cortical (~17% of resorption) compartments. All differences were statistically significant. CONCLUSION: Bone apposition to an implant surface followed a significantly different pattern in the compact and the marrow compartments around the implants. While in the compact compartments, bone apposition had to develop through the BMUs following resorption, it developed in very dense layers through an early apposition in the marrow compartments.