Crown Fracture Research Articles

Frequency of Horizontal Crown Fracture in Endodontically Treated Posterior Teeth Restored with Amalgam

Objective: To evaluate the frequency of horizontal crown fracture in endodontically treated posterior teeth restored with amalgam when compared to other restorative materials. Study Design: Cross sectional comparative study. Place and Duration of study: Operative Department, Armed Forces Institute of Dentistry, Rawalpindi Pakistan, from Jan to Dec 2019. Methodology: Patients reporting to Operative Department, Armed Forces Institute of Dentistry, were studied for the frequency of horizontal crown fractured endodontically treated teeth restored with amalgam and other restorative materials. History, clinical examination, mobility and trans-illumination test were used to diagnose horizontal crown fracture. Fracture of one or more cusps of endodontically treated posterior teeth involving enamel and dentin was taken as Horizontal crown fracture. Results: A high percentage of patients with amalgam restoration after endodontic treatment of posterior teeth experienced horizontal crown fracture as compared to composite and glass ionomer cement. Out of 54 patients included in the study, 42(77.8%) patients were having amalgam restorations while 6(11.1%) patients were having composite and other 6(11.1%) were restored with glass ionomer cement material. Conclusion: Patients with endodontically treated posterior teeth restored with amalgam presented with a high percentage of horizontal crown fracture as compared to other restorative materials and there is a need to provide full coverage restoration of endodontically treated tooth as soon as possible to enhance its survival.

TEETH CLIPPED-OUT IN JAVANESSE SLOW LORIS AND ITS PRESERVATION THROUGH ROOT CANAL TREATMENT

Nycticebus javanicus or often called the Javan slow loris is one of Indonesia's endemic primates whose status is now in the critically endangered category because their numbers are decreasing. The illegal trade often causes serious problems for the health and survival of slow lorises in their natural habitat. There is a wrong perception that the teeth of slow lorises are poisonous, which makes illegal traders cut or even pull out the teeth of slow lorises indiscriminately. Slow lorises (Nycticebus spp.) are obligate exudativators that gouge at tree bark with their teeth. In addition to functioning for the process of eating, slow loris teeth also function for defense mechanism and allogrooming. Amputation of dental crowns or crown fractures in slow lorises can be a serious problem. Slow lorises do not survive either slowly in rehabilitation centers due to changes in diet or even faster in their natural habitat when being released. Root canal treatment as an effort that can be taken to maintain the damaged or broken teeth, so as to prevent tooth from infection and maintain the function of slow loris teeth to survive in its natural habitat. The method of root canal treatment involves three fundamental components: root canal shaping, disinfection and obturation. Teeth restoration to be performed after obturation, using composite. Teeth that have been successfully treated provide an opportunity for slow lorises to express their natural behavior as well as in surviving in their natural habitat.

Comparative evaluation of fracture resistance of re-attached teeth using self-adhesive bioactive flowable composite after preconditioning the fractured coronal fragments with different remineralizing agents

One of the common forms of dental injury is anterior crown fractures, which mainly affects the teenagers and young adults. Fractures of the coronal portion of the permanent incisors characterize 18–22% of total traumatic injuries to dental hard tissues; of which 96% of them comprise the maxillary incisors. Uncomplicated fracture of crown is one of the most common types of dental traumatic injury. Dental trauma has an emotional impact on the patient’s overall health and can serious harm to the dentition. The treatment as well as prognosis of the fracture of coronal portion is a major challenge for a dentist because it has to accomplish various parameters like need to obtain an aesthetical result that approaches itself to its natural form and measurement, opaqueness and translucency of the original tooth structure in obtaining a effective restoration. It is suggested that reattachment of the fractured fragment is the best procedure for restoring an uncomplicated fracture of a crown, if a fragment is present. Reattachment of the fractured fragment offers major advantages over the conventional composite restoration. In reattachment, enhanced aesthetics is obtained because enamel’s true shape, colour, intensity, and surface texture are preserved. It re-establishes the major function and produces the favourable emotive and social response from the side of the patient. The reattached fragments are susceptible to further fracture when the restored teeth undergo further trauma. The resistance of the fractured teeth that has been reattached is the subject of the majority of concerns. Preconditioning the fractured fragments with remineralizing agents may aid in hydration. Thus, study will be conducted to evaluate the resistance of the fracture of a tooth that is reattached and pre-treated with remineralizing agents such as sodium fluoride and casein phosphopeptide-amorphous calcium phosphate and further reattached using one of the self-adhesive bioactive composite.

Marginal and Internal Gaps, Surface Roughness and Fracture Resistance of Provisional Crowns Fabricated With 3D Printing and Milling Systems.

To compare the marginal and internal gap, surface roughness, fracture resistance and mode of failure of provisional crowns fabricated with 3D printing and CAD/CAM manufacturing techniques. A maxillary first premolar was prepared for an all-ceramic crown and reproduced in cobalt-chromium metal dies (n=30) following CAD/CAM technology. The die was digitally scanned and exocad software was used to design the missing crown, which was manufactured using a CAM milling machine and two types of 3D printing machines (SLA and DLP) to produce 10 provisional crowns per group. The crowns were cemented to their respective dies and stored in water (24 hours; 37°C) followed by 600 thermal cycles (5°C/55°C) and 100,000 mechanical cycles (at 50N). Marginal and internal gap measurements were carried out using a 3D superimposition technique. Surface roughness (Ra) was determined using a profilometer at 0.5 mm/second cross-head speed. The crowns were loaded to fracture at 0.5 mm/minute cross-head speed. Fracture forces and mode of failure were recorded, and data were analyzed using one-way analysis of variance (ANOVA) and multiple comparisons post hoc tests (p<0.05). The SLA group exhibited higher marginal and internal gaps than both the CAD/CAM and DLP groups (p<0.05). The DLP group showed higher surface roughness than the CAD/CAM and SLA groups (p<0.01). The CAD/CAM and SLA groups showed higher resistance to fracture than the DLP (p<0.05) group. Mode of failure I: Minimal crown fracture or crack, was predominate among DLP and SLA crowns (60%), while the Mode II: Less than half of the crown lost, was predominant among CAD/CAM crowns (60%). Crowns manufactured following CAD/CAM technique have better marginal and internal fit, surface roughness than SLA and DLP crowns. The CAD/CAM and SLA crowns showed higher resistance to fracture than the DLP crowns.

Frequency of Dental Injuries in Patients Reporting to the Armed Forces Institute of Dentistry

Objective: To determine the frequency, cause and type of dental injury in patients reporting to Armed Forces Institute of Dentistry.&#x0D; Study design: Cross-Sectional Survey.&#x0D; Place and Duration of Study: Department of Operative Dentistry Armed Forces Institute of Dentistry, Rawalpindi, Pakistan, from Sep 2021 to Sep 2022.&#x0D; Methodology: A questionnaire was filled out for 357 patients reporting dental injury, including the extent of hard and soft tissue injuries. The cause and place of injury occurred; investigations, the treatment provided by the treating dentists ranging from restoration to root canal, type and duration of splint were also recorded.&#x0D; Results: In the current study, 189(52.9%) out of 357 children got injury due to falls to the playground and other places. Maxillary incisors were mostly affected, and 163(45.7%) children had complicated crown fractures. Rigid splinting was done in 39(70.9%) of root fracture cases, while flexible splinting was done in 162(53.6%) patients with complicated crown fracture cases and 81(26.8%) complicated crown fracture cases. In 72(88.8%) cases of uncomplicated crown fracture, indirect pulp capping was done, and in 67(41.1%) cases of complicated crown fracture, root canal treatment were done. Apexification was done in 28(68.3%) of avulsion cases.&#x0D; Conclusion: Our survey showed that most injuries occurred at school and the roadside. Maxillary incisors are primarily involved with complicated crown fractures, which are effectively managed.Keywords: Avulsion, Complicated crown fracture, Dental injury, Splinting.

Effect of abutment design on fracture resistance of resin-matrix ceramic crowns for dental implant restoration: an in vitro study

BackgroundThe purpose of this study is to investigate the performance and fracture resistance of different resin-matrix ceramic materials for use in implant-supported single crowns with respect to the abutment design (crown thickness: 1 mm, 2 and 3 mm).MethodsForty-eight abutments and crowns were fabricated on implants in the right lower first molar. Two resin-matrix ceramic materials for dental crowns were selected for study: (1) a glass-ceramic in a resin interpenetrating matrix (Vita Enamic, Vita, Germany) and (2) a resin-based composite with nanoparticle ceramic filler (Lava Ultimate, 3 M ESPE, USA). Three types of abutments were designed: 1 mm thick crown + custom titanium abutment, 2 mm thick crown + custom titanium abutment and 3 mm thick crown + prefabricated titanium abutment. The experiment was divided into 6 groups (n = 8) according to the crown materials and abutment designs. After 10,000 thermocycles, fracture resistance was measured using a universal testing machine. The statistical significance of differences between various groups were analysed with ANOVA followed by a post hoc Tukey’s honestly significant difference test. The surfaces of the fractured specimens were examined with scanning electron microscopy (SEM).ResultsTwo-way ANOVA revealed that the abutment design (F = 28.44, P = 1.52 × 10− 8<0.001) and the crown materials (F = 4.37, P = 0.043 < 0.05) had a significant effect on the fracture resistance of implant crown restoration. The Lava Ultimate-2 mm group showed the highest fracture resistance of 2222.74 ± 320.36 N, and the Vita Enamic-3 mm group showed the lowest fracture resistance of 1204.96 ± 130.50 N. Most of the 1 and 2 mm groups had partial crown fractures that could be repaired directly with resin, while the 3 mm group had longitudinal fracture of the crown, and the crowns were detached from the abutments.ConclusionBased on the in vitro data of this study, the fracture resistance of the 2 mm thick resin-matrix ceramic crown design was higher than that of the 1 and 3 mm groups. The 2 mm thick resin-matrix ceramic crown and personalized abutment are an option to replace zirconia for implant crown restoration.

Dental traumatic injuries during the COVID-19 pandemic: A retrospective study

Background: Although dental trauma has been reported at various frequencies worldwide, as far as we know there are few data regarding the frequency of dental trauma during the pandemic period. Purpose: This study aims to retrospectively evaluate the data of pediatric patients who were admitted to the Department of Pedodontics in a university hospital due to dental trauma during the COVID-19 pandemic. Methods: Between April 2020 and December 2020, the clinical records regarding admissions to the Harran University Faculty of Dentistry Pedodontics clinic due to dental trauma were examined. The age and gender of the patient, type of trauma, teeth affected by the trauma, and treatment methods applied after the trauma were recorded. The data obtained were analyzed using the independent sample t-test for intergroup comparisons and Pearson chi-square test for categorical variables with the help of Statistical Package for the Social Sciences version 23.0. Results: The data of 43 patients (27 males and 16 females) aged between 1–13 years (mean age: 9.13±3.20) who were admitted to the clinic with trauma complaints during an eight-month period were evaluated. It was determined that the most common trauma types in the pandemic period were simple crown fracture (25.6%) and subluxation/lateral luxation (23.3%). During the pandemic, 34.9% of all cases were “falling at home”, while “falling at school” was 14.0% (using the Pearson chi-square test). Conclusion: The COVID-19 pandemic period has affected many aspects of social life as well as the number of patients who were admitted for dental trauma and the causes of trauma. Multicenter studies are needed for more accurate results.

Indications for root canal treatment following traumatic dental injuries to permanent teeth.

The dental pulp may respond favourably or unfavourably to traumatic dental injuries. The most serious unfavourable responses are pulp necrosis and infection of the root canal system. These cause apical periodontitis and/or external inflammatory resorption of the tooth. The following injuries require root canal treatment as part of their emergency management-(A) complicated crown fractures (but some may be suitable for conservative pulp treatments, such as pulp capping, partial pulpotomy or pulpotomy), (B) complicated crown-root fractures, (C) supra-crestal coronal third root fractures and (D) injuries where pulp necrosis is predictable or highly likely to occur AND where there has been damage to the root surface and/or periodontal ligament with the aim of preventing external inflammatory resorption. This latter group of injuries are avulsion, intrusion, lateral luxation with a crown fracture, extrusion with a crown fracture (all in fully developed teeth) plus avulsion with a crown fracture and intrusion with a crown fracture (both in incompletely developed teeth). All other injuries should not have root canal treatment commenced as part of the emergency management, but they must be reviewed regularly to monitor the pulp for any adverse changes to its status, particularly pulp necrosis and infection of the root canal system.

Poor oral health predicts cognitive impairment in elders

AbstractBackgroundTooth loss, periodontal disease, dementia, and Alzheimer’s disease share several risk factors in older adults. Several previous studies have reported positive associations between these dental problems and global cognitive defects. However, limited is known about the relationships among multiple dental/periodontal statuses and different cognitive domains.MethodThis six‐year (2011‐2017) cohort study includes 515 older adults (65+). Global cognition was assessed by Montreal cognitive assessment‐Taiwan version (MoCA‐T). For cognitive domains, we used logical memory tests (immediate and delayed theme and free recall) in Wechsler Memory Scale‐Third Edition (WMS‐III) to assess memory. Trail Making Test A and B was used to assess attention and executive function, respectively. Digit span‐forward and backward was used to evaluate attention and working memory/short‐term memory, respectively. Verbal fluency tests were used to assess category/semantic fluency. A Z‐score was calculated for each cognitive domain‐specific test according to baseline mean and standard deviation. Oral health status includes tooth defect (dental caries, tooth wear, cervical abrasion, retained root or crown fracture), periodontal health (disease severity from healthy periodontal status, gingivitis to periodontitis), and arch integrity (no tooth loss nor retained root or crown fracture). Generalized linear mixed models were used to assess the associations above adjust important covariates.ResultAt baseline, periodontitis was associated with poor performance in executive function [Trail Making Test A: b = ‐0.14, 95% confidence interval (CI) = ‐0.27 to ‐0.01]. The association between baseline severity of tooth defect and poor memory decreased (logical memory‐immediate theme recall: b = ‐0.05, 95% CI = ‐0.10 to ‐0.01); similarly finding was found for attention domain (digit span‐forward: b = ‐0.04, 95% CI = ‐0.07 to ‐0.001). At baseline, loss of arch integrity was associated with a better working memory/short‐term memory (digit span‐backward: β = 0.18, 95% CI = 0.01 to 0.36); as follow‐up time increased, this association decreased over six years (β = ‐0.04, 95% CI = ‐0.07 to ‐0.003).ConclusionPeriodontitis, tooth defects, or arch integrity was associated with poor performance of cognitive domains (memory, attention, and executive function) over time. A oral health evaluation may serve as predictors of the preclinical phase of dementia in its upcoming years.

Comparative evaluation of efficacy of physics forcep and conventional forceps for extraction of maxillary molars.

Tooth extraction is one of the most commonly performed procedures in dentistry. It is usually a traumatic procedure often resulting in immediate destruction and loss of alveolar bone and surrounding soft tissues. It is the only dental procedure which was carried out by dentists in the previous centuries and various instruments have evolved for this procedure over time. Atraumatic extraction is one of the essential dental procedures, as atraumatic extraction leads to proper wound healing and appropriate bone healing. Physics forceps have got a new role in extraction technique, that it makes just one contact point with the tooth as a unique benefit. Physics forceps depends on the physics of rotational power, lever and torque much like a bottle top removal. A study was conducted to evaluate the efficacy of physics forceps and conventional forces in the extraction of maxillary molar. Eligible participants were adults aged 18-50 diagnosed with grossly decayed maxillary molars with poor endodontic prognosis and willing to participate in the study. Exclusion criteria were as follows: patients with dilacerate roots; patients with systemic diseases like hypertension, diabetes mellitus, thyroid, tuberculosis, epilepsy seizures, COVID-19 positive; patients' non-acceptance to voluntarily participate in research a refusal to sign the informed consent. Parameters such as a crown fracture or root fracture; buccal bone fracture; time taken for extraction and operator ease on the VAS scale are assessed. Results showed that with the use of physics forces, there was very less incidence of crown fracture and no incidence of buccal bone fracture, whereas with the conventional forceps the result showed that in almost all the time taken for extraction was much more in conventional forcep and the operator ease rating was more with conventional forceps. Hence, oral surgeons as well as general practitioner should adapt the use of physics forceps in routine extractions.

A New Experimental Technique for Complete Extraction of Mandibular First Molar Teeth in Rats.

Intact extraction of the mandibular first molar tooth is an interesting model for studies of alveolar bone healing. The aim of this study was to describe a new experimental technique for extraction of rat mandibular first molar teeth with crown and all 4 roots intact using controlled forces applied to the teeth. One hundred and twenty female Sprague-Dawley rats were used from a center for experimental animal research. Animals underwent general anesthesia and were then placed in a special dental unit (designed by Moghadam) for the extraction of rat teeth. After syndesmotomy, luxation of the tooth began with a tipping movement in the buccal direction with a very low range of motion for 1 s. A tipping movement in the lingual direction was then used to continue luxation. After a maximum of 10 repetitions, the tooth was left alone for 30 s. After 3-4 stages of this cycle, the tooth loosened. To complete the luxation, the same forces were applied in the buccal and lingual directions with larger amplitude for 3 s. After this step, the tooth was loose enough to be easily extracted. The alveolus was then sutured closed. The results showed no hemorrhage or fracture of crowns and mesial or distal roots, and only 8% of the buccal and lingual roots fractured. The technique designed and used in this study was shown to be an effective model for complete molar tooth extraction in the rat. This technique could also be used in the treatment of other rodents.

Causative Factors Associated with Dry Socket; A Retrospective Study Among the Patients Visiting REU Clinics.

Purpose: There are various factors associated with the incidence of dry socket, which includes operator experience, perioperative crown, and root fractures, periodontal disease, posterior teeth, and, interestingly, the use of mental health medications to be significant independent risk factors for the development of alveolar osteitis. This study aims to determine the risk factors associated with dry socket and to compare the prevalence of dry socket on the basis of gender, smoking habit, systemic condition, extraction site and use of antibiotics. &#x0D; Methodology: This is a retrospective study using the patients’ files at Muneseya campus, Riyadh Elm University. A total of 385 patient files were accessed after seeking approval from the hospital director. Information from patients’ files was recorded including gender, operator’s level, habits, medical history and extraction site.&#x0D; Results: According to the findings, the percentage of male participants was 70.9%, whereas the percentage of female participants was 29.1%. The findings indicate that 25.3% of the population suffers from systemic illness, whereas the remaining 74.7% does not have any systematic disease. Dry sockets, which are caused by inflammation of the alveolus bone, are present in upper teeth 40% of the time, whereas lower teeth inflammation affects 60% of individuals with lower teeth.&#x0D; Unique Contribution to Theory, Policy and Practice: In this study significant differences were observed for dry socket prevalence when compared the groups on the basis of smoking, systemic disease and gender.

Is use of CBCT without proper training justified in paediatric dental traumatology? An exploratory study

BackgroundProper skills in radiographic diagnosis are essential for optimal management of dental trauma.AimTo assess diagnostic accuracy obtained by paediatric dentists using Cone Beam Computed Tomography (CBCT) without specific training and to compare this with their performance using intraoral radiographs.MethodsIntraoral and CBCT images of 89 teeth, spread over twenty dental trauma cases were presented in random order to nine paediatric dentists. Diagnostic findings were compared with those of a benchmark reference. Sensitivity and specificity were calculated and compared using paired t-tests.ResultsOverall, observers’ diagnostic performance was rather poor with significantly higher sensitivity when using 2D images (P = 0.017). Performance differed considerably according to the type of pathology. Using either imaging modality, sensitivity for diagnosing apical pathology and root fractures was high while the opposite was seen for inflammatory root resorption, root cracks and subluxations. Statistically significant differences between imaging modalities were seen for root fractures (P = 0.013) and apical pathology (P = 0.001), in favor of 3D, and for crown fractures (P = 0.009) in favor of 2D.ConclusionOverall poor performance of paediatric dentists indicates that additional training in radiographic diagnosis is required. In order to justify the use of CBCT to increase diagnostic performance, proper training of the paediatric dentist is mandatory.

Surgical removal of periapical pathology with root end resection

In children and young adults, traumatic dental injuries (TDIs) to permanent teeth are common. Of all dental injuries, crown fractures and luxations of these teeth are the most frequent. For a successful outcome, accurate diagnosis, treatment planning, and follow-up are critical. This article presents a case report series of surgical management of traumatic injury with periapical lesion with rooth end resection using root end filling materials.

Sports-related dental injuries and oral health status among Malaysian para-athletes: A cross-sectional study.

Athletes with disabilities may be at an even greater risk of orofacial trauma than their counterparts, and the risk may vary depending on the type of sports. This study aimed to assess the incidence of sports-related dental injuries and oral health status among Malaysian para-athletes. A questionnaire survey was conducted to assess self-reported dental injuries and knowledge of their management. An intraoral examination was performed using the decayed, missing, and filled teeth (DMFT) index following the World Health Organization guidelines. A total of 61 para-athletes (men=90.16%, n=55; women=9.84%, n=6) from different sports categories with different disabilities randomly participated in this study. The incidence of self-reported dental injuries was 18.0% (n=11), with the most common injury being crown tooth fracture (72.7%) and lip laceration (63.6%). However, the majority of the athletes (70.5%, n=43) did nothing after experiencing dental trauma, and 82.0% (n=50) were unaware of the immediate management of dental trauma. Based on the intraoral examination, only 9.8% (n=6) of the athletes had perfectly sound teeth. The mean total DMFT index was 3.49±2.371, while the mean DMFT index for decayed, missing, and filled teeth was 1.28±1.293, 0.74±0.705, and 1.48±1.120, respectively. The mean DMFT index for decayed, missing, and filled teeth and total DMFT index significantly differed among the types of disabilities (P<.05) but not between the sexes (P>.05). The most commonly reported injuries among para-athletes are crown tooth fractures and lip lacerations. The total DMFT index among para-athletes is moderate, emphasising the need for improvements.

Research on the cone-beam CT of the fracture morphology and location of a single oblique complicated crown-root fracture of maxillary incisors

Objective: To study the morphological pattern of single oblique complex crown fracture and its relative location to periodontal hard tissues from a three-dimensional perspective by using cone-beam CT, which provides a more intuitive and comprehensive understanding for the pathological features and rules of single oblique complex crown fracture. Methods: Primary cone-beam CT images of 56 maxillary permanent anterior teeth with oblique complex crown root fractures were collected from the Department of Integrated Emergency Dental Care, Capital Medical University School of Stomatology during January 2015 to January 2019. Fracture pattern, fracture angle, fracture depth, fracture width, and the relative location of the fracture line to the crest of the adjacent alveolar ridge were retrospectively analyzed. Independent samples t-test was used to compare the differences in angle, depth and width of fractures between sexes and tooth locations, as well as the pre-and post-fracture crown-to-root ratios between different tooth locations. Then the affected teeth were divided into juvenile group (≤18 years), young group (19-34 years) and middle-aged and elderly group (≥35 years). One-way ANOVA was applied to compare the differences in angle, depth and width of fracture between age groups, and Fisher exact test to compare the differences in fracture pattern of the teeth and the relative position of the fracture line to the crest of the adjacent alveolar ridge. Results: There were 35 males and 21 females in 56 patients, aged (28.2±13.2) years. Among the 56 affected teeth, forty-six were maxillary central incisors and 10 were lateral incisors. According to the patients' age and growing stage, they could be divided into the juvenile group (19 cases), the young group (14 cases), and the middle-aged and elderly group (23 cases). Forty-six (82%) affected teeth had an S-shaped fracture pattern, and ten (18%) had a diagonal pattern, in which the fracture angle of the S-shaped fracture line (47.85°±10.02°) was significantly greater than that of the diagonal line (28.30°±8.07°) (P<0.001). The fracture nadir was flush with or below the top of the alveolar crest in 98% (55/56) of cases. The fracture depth was significantly greater in the juvenile group [(1.75±0.73) mm] than in the young group [(1.21±0.68) mm](P=0.042) and in the middle-aged and elderly group [(1.12±0.90) mm] (P=0.001). The width of fractures among 56 patients was (4.75±1.44) mm, which had no statistically significant differences between different age, sex and tooth location groups (P>0.05). There were no statistically significant differences in the crown-to-root ratios after fracture of maxillary central incisors (1.18±0.13) compared to maxillary lateral incisors (1.14±0.20) (t=1.90, P=0.373). Conclusions: The fracture patterns of single oblique complex crown fracture were mainly S-shaped and oblique alignment; the fracture nadir was mostly located within 2.0 mm below the palatal alveolar crest.

Complex aestheticss treatment of six maxillary anterior teeth with smile design and deep bite correction

Dental trauma mostly damages the maxillary anterior teeth, affecting the individual’s esthetics, functionality, and psychological well-being. Restorative dentistry treatment is required to obtain a natural appearance based on the smile design approach. The aim of this report is to characterize the procedure of complicated cosmetic restoration of the six maxillary anterior teeth, which results in straighter and more beautiful natural-looking smiles. A 32-year-old male patient presented with multiple crown fractures in the anterior maxillary teeth, resulting in an unaesthetics smile. The patient also had a deep bite. A comprehensive aesthetics dental treatment was carried out. The dental treatment plan had to be carefully executed by considering several factors such as dental convexities and contours, re‑establishment of function, and esthetics. Smile design should always be approached as a multi-factor decision-making, which enables the doctor to treat patients using a personalized and interdisciplinary approach.

The effect of Mahogany seeds extract (Swietenia mahagoni) on the quantity of macrophages in the Post-tooth extraction wound healing phase of Wistar Rats (Rattus norvegicus)

Tooth extraction often cause tissue damage and wound. After tooth extraction, the wound healing process becomes a major concern because of many complications and makes patients feel the pain suffered. Lande et al. (2015) showed the prevalence of tooth extraction complications, including crown fracture (31.82%), root fracture (13.6%), dry socket (4%), swelling (2.27%), and bleeding (1.6%). Macrophages are a common inflammatory cell in wounds, and the local macrophage population shifts from pro-inflammatory (M1-like phenotypes) to anti-inflammatory (M2-like phenotypes), indicating to the start of the next healing phase. Various alternative materials can help the healing process of wounds, one of which is mahogany seeds. Flavonoids found in Mahagony seeds can influence cell function by boosting the synthesis of PDGF, VEGF, pro-inflammatory cytokines, activating monocytes, and raising the number of macrophages involved in the wound healing. Proving mahogany seed extract (Swietenia mahagoni) affects the number of macrophages in the wound healing process after extracting Wistar rat (Rattus norvegicus) teeth. 20 Wistar rats were divided into four groups there were one control group (K) performed tooth extraction without any treatment, and three treatment groups (P1, P2, P3) performed tooth extraction and topically induced with three different doses of mahogany seeds extract (50 mg/200g rbw, 100mg/200g rbw, 200mg/200g rbw) in the post-extraction socket. Wistar rats were sacrificed on the 3rd day. Observations were made by reading histologic preparations using Hematoksilin Eosin (HE) 400x light microscope magnification. The quantity of macrophages in each group differed significantly between 4 groups (p = 0.003), namely between K1 and P1 (p = 0.008), P1 and P3 (p = 0.001), P2 and P3 (p = 0.006). Mahogany seeds extract affects the wound healing process, with 50mg/200g rbw as the optimal dose

Histological analysis for pulp mineralisation after severe intrusive luxation of immature molars in rats.

Pulp mineralisation is a survival process that may occur in the pulp of immature teeth following trauma. However, the mechanism of this process remains unclear. The aim of this study was to evaluate the histological manifestations of pulp mineralisation after intrusion in immature molars of rats. Three-week-old male Sprague-Dawley rats were subjected to intrusive luxation of the right maxillary second molar by an impact force from a striking instrument through a metal force transfer rod. The left maxillary second molar of each rat was used as a control. The control and injured maxillae were collected at 3, 7, 10, 14, and 30 days after trauma (n=15 per time group) and evaluated using haematoxylin and eosin staining and immunohistochemistry. Independent two-tailed Student's t-test was used for statistical comparison of the immunoreactive area. Pulp atrophy and mineralisation were observed in 30%-40% of the animals, and no pulp necrosis occurred. Ten days after trauma, pulp mineralisation, with osteoid tissue rather than reparative dentin, formed around the newly vascularised areas in the coronal pulp. CD90-immunoreactive cells were observed in the sub-odontoblastic multicellular layer in control molars, whereas the number of these cells was decreased in the traumatised teeth. CD105 localised in cells around the pulp osteoid tissue of the traumatised teeth, whereas in control teeth, it was only expressed in the vascular endothelial cells of capillaries in the odontoblastic or sub-odontoblastic layers. In specimens with pulp atrophy at 3-10 days after trauma, hypoxia inducible factor expression and CD11b-immunoreactive inflammatory cells increased. Following intrusive luxation of immature teeth without crown fractures in rats, no pulp necrosis occurred. Instead, pulp atrophy and osteogenesis around neovascularisation with activated CD105-immunoreactive cells were observed in the coronal pulp microenvironment characterised by hypoxia and inflammation.

Invitro fracture and fatigue resistance of monolithic zirconia crowns fabricated by stereolithography.

Stereolithography has been used to print zirconia ceramic crowns with acceptable dimensional accuracy and fracture force. However, studies that compared the fatigue resistance of zirconia crowns fabricated by stereolithography are lacking. The purpose of this invitro study was to compare the fracture and fatigue resistance of monolithic zirconia crowns printed by stereolithography apparatus (SLA) and digital light processing (DLP) with those of zirconia crowns milled by computer numerical control (CNC). A total of 120 crowns were fabricated (n=40/material) and underwent 0, 104, 105, or 106 dynamic loading cycles of 30 to 300 N in artificial saliva, followed by a static fracture loading test (n=10). After fracture, 1 crown from each group was selected for fractography analysis by scanning electron microscopy (SEM). Data were statistically analyzed through 2-way ANOVA and post hoc analysis for multiple comparisons (α=.05). The 2-way ANOVA results showed that the mean ±standard deviation force at fracture was the highest for CNC (before fatigue loading: 5154 ±568 N, 104: 5735 ±1231 N, 105: 5523 ±797 N, and 106: 6007 ±1258 N), followed by DLP (before fatigue loading: 3381 ±612 N, 104: 4046 ±1146 N, 105: 2929 ±559 N, and 106: 3223 ±739 N), and the lowest for SLA (before fatigue loading: 2956 ±598 N, 104: 2757 ±421 N, 105: 3326 ±391 N, and 106: 3103 ±246 N) (P<.01). The fracture force of the crowns was not significantly affected by the number of fatigue cycles (P>.05). Fractography analysis showed that the number of arrest lines increased for crowns of all 3 materials. SEM images also showed the steps of SLA and DLP from their layer-by-layer printing and small cracks between layers of SLA after 106 loading cycles. The fracture force of monolithic zirconia crowns milled by CNC was significantly higher than that of zirconia crowns printed by stereolithography. Zirconia crowns printed by SLA and DLP could withstand typical clinical conditions, and their fracture and fatigue resistance exceeded the clinically estimated average occlusal forces.