Knowledge and attitude of dental students regarding etiology, diagnosis, and treatment of peri-implantitis.

OBJECTIVE: The objective of this study was to assess the level of knowledge and attitude of dental students about the etiology, diagnosis, and management of peri-implantitis. METHODS: An online cross-sectional study that targeted senior undergraduate dental students at the College of Dentistry was conducted. A closed-ended survey consisting of 28 questions was designed. Three sections were created: 1) participants' characteristics; 2) Knowledge of peri-implantitis etiology, risk factors, diagnosis, and complications; 3) The use of antibiotics in peri-implantitis, diagnosis, and treatment methods. SPSS version 22 (IBM Corp.) was used for data analysis. Counts and percentages were calculated for correct answers in each section. RESULTS: A total of 267 dental students responded to the questionnaire. The majority of the participants (81.6%) were knowledgeable about peri-implantitis being an inflammatory reaction, and a lesser percentage (77.9%) knew that bacterial plaque is an etiologic factor for peri-implant diseases. 82.0% of the participants identified smoking as a risk factor, followed by periodontitis (80.5%). Regarding implant complications, 57.3% of the participants considered implant mobility as a definitive indication for implant removal. More than half of the participants reported using crater-like bone defects surrounding implants to diagnose peri-implantitis. The most commonly used antibiotic was amoxicillin (34.1%), followed by amoxicillin combined with metronidazole (26.9%). CONCLUSION: Most participants had a basic understanding of the etiology and risk factors of peri-implantitis. On the other hand, more courses addressing peri-implantitis diagnosis are needed.

Impact of Harvesting Method and Donor Age on the Behavior of Human Osteoblast-Like Cells.

Autogenous particulate bone grafts are being utilized in oral implantology for minor grafting procedures. This study aimed to investigate the influence of the bone-harvesting technique, donor age, and donor site on proliferation and differentiation of human primary osteoblast-like cells in the cell culture. Autogenous bone particles (20 samples) were harvested from the maxilla and mandible during surgery using two different protocols, and two types of particulate bone grafts were collected: bone chips and bone sludge. Bone samples were cultured in growth medium and, after 2 to 3 weeks, the cells that grew from bone grafts were cultured in the normal and osteogenic medium for 0, 4, 7, and 20 days. DNA, alkaline-phosphatase (ALP), calcium-content measurements, and Alizarin red/toluidine blue staining were performed. Data were analyzed by repeated-measures analysis of variance with Bonferroni test. The level of statistical significance was set at 5% (P < .05). Total DNA, ALP, and calcium content were significantly higher for the bone chip samples compared to the bone sludge samples. Total DNA and ALP content were significantly higher for the patients in age group 1 (≤ 60 years) compared to age group 2 (> 60 years) and was significantly higher for mandibular samples than maxillary samples on day 20. However, the calcium measurement showed no significant difference concerning donor age and donor site. Data analysis revealed that harvesting technique (bone chips vs bone sludge), donor age (≤ 60 years vs > 60 years), and donor site (maxilla vs mandible) influenced the osteogenic potential of the collected particulate bone graft. The bone chips were superior in terms of osteogenic efficacy and should be considered a suitable option for particulate bone graft collection.

Alveolar Bone Loss in Diabetic Patients: A Case-Control Study.

OBJECTIVES: Based on literature, very few case-control studies have been executed to confirm the relationship between diabetes mellitus and the severity of mean alveolar bone loss. Therefore, the aim was to assess the differences in mean alveolar bone loss among diabetic (type 2) and nondiabetic patients in the Saudi population. MATERIALS AND METHODS: Nine-hundred eighty-two patient records were seen in this retrospective study. Patient demographic data and medical records were examined. The mean alveolar bone loss was measured in posterior teeth by calculating the distance from the base of cementoenamel junction to the alveolar crest using the bitewing radiographs. SPSS 20.0 was used for data analysis. An unpaired t-test was utilized to analyze the mean alveolar bone loss across multiple variables. p-Value less than or equal to 0.05 was contemplated as significant. RESULTS: The overall mean alveolar bone loss for all 124 patients was 2.83 ± 1.13 mm. Diabetic patients had greater mean alveolar bone loss measured in millimeters than nondiabetic patients (3.07 ± 1.14mm vs. 2.59 ± 1.08mm, respectively), and the difference was significant (p = 0.018). In terms of the severity of mean alveolar bone loss, diabetic patients experience statistically higher mean alveolar bone loss as compared with nondiabetic patients. CONCLUSION: In our study population, the overall mean alveolar bone loss prevalence was greater in diabetes patients than in nondiabetic individuals. According to the severity of bone loss, the distribution of moderate and severe periodontitis was higher in diabetic patients. To enhance patients' quality of life, the awareness and education among patients regarding the association among diabetes mellitus and oral health, particularly periodontal disease, should be promoted.

Prevalence of periodontitis based on retrospective radiographic evaluation at dental hospital in Eastern Province of Saudi Arabia: A retrospective study.

Objectives: The contemporary information on the prevalence of periodontitis and associated risk factors is deficient in the Kingdom of Saudi Arabia. Our aim was to measure the prevalence of periodontitis and associated risk factors among the Saudi population in the Eastern Province of Saudi Arabia who visited the University Dental Hospital. Methods: In this retrospective study, the demographic data and medical and dental records of 700 subjects were examined. Bitewing radiographs were analyzed to measure the alveolar bone loss in posterior teeth by measuring the distance between the cementoenamel junction and the crest of the alveolar bone. A chi-square test was performed to compare the severity of periodontitis. A comparison of multivariate mean bone loss was performed using a t-test. Logistic regression analysis was used to evaluate the predictors of periodontitis. A P-value equal to or under 0.05 reflected statistical significance. Results: Among 700 cases, the patients' mean age was 35.6 ± 12.1; 52.6 % were male and 47.4 % were female. Overall periodontitis prevalence was 52.1 %. The distribution of mild, moderate, and severe periodontitis prevalence was 36.1 %, 14.1 %, and 1.8 %, respectively. The severity of periodontitis was statistically similar between males and females (p = 0.148); however, significantly more Saudi than non-Saudi patients had moderate periodontitis. Higher proportions of severe periodontitis were seen in the age group of over 50-years-old (p < 0.001) and in patients with poor oral hygiene (p < 0.001), diabetes mellitus (p < 0.005), and hypertension (p < 0.002). Six total predictors of periodontitis were depicted, i.e., age > 50 years (OR = 3.73), poor OH status (OR = 2.24), BOP (OR = 3.35), presence of plaque (OR = 2.61), diabetes mellitus (OR = 3.19), and hypertension (OR = 3.62). Conclusion: The primary factors associated with the prevalence of periodontitis were age, nationality, diabetes, hypertension, BOP, plaque, and OH status. However, no association was observed between gender or cardiovascular disease and the prevalence of periodontitis in the studied population.

The Relationship between Unilateral Palatal Maxillary Canine Impaction and the Morphology of the Maxilla: A CBCT Study in Eastern Province of Saudi Arabia.

OBJECTIVE: This study aimed to examine the correlation between the morphology of the maxilla and unilateral palatally impacted maxillary canine (PIMC) among the Saudi population in the Eastern Province of Saudi Arabia. MATERIALS AND METHODS: In this retrospective study, 36 patients' records [(17 PIMC, 8 male, 9 female, mean age 16.75 ± 2.12 years) (19 control; 9 male,10 female, mean age: 17.16 ± 2.12 years)] were included from a teaching dental hospital. On cone-beam computed tomographic images, measurements of maxillary arch length (MAL), palatal vault depth (PVD), intermolar width, sum of widths of 4 maxillary incisors, available arch space (AAS), palatal maxillary width (PMW) in the molar and premolar regions, nasal cavity width (NCW), maxillary arch shape (MAS) (arch length/intermolar width x 100), and palatal vault shape (PVS) (the PVD/intermolar width x100) were performed. Data were analyzed by SPSS-20.0. p-value less than or equal to 0.05 reflected statistical significance. RESULTS: This study's findings depicted that AAS (p = 0.012), PVD (p = 0.028), and PMW in the molar and premolar regions at the level of the alveolar crest (p = 0.002 and p = 0.034) and mid-root (p = 0.004 and p = 0.022) were significantly higher in the control compared to the PIMC group. PVS showed a significant difference between the PIMC and control groups (p = 0.037). However, regarding MAS, no significant difference was observed (p = 0.707). CONCLUSION: MAS was narrower in PIMC compared to the control group. The control group had a deeper palatal vault and greater AAS compared to the PIMC group. However, no significant difference was observed between groups regarding tooth size or NCW.

Effect of dexamethasone on the growth and differentiation of osteoblast-like cells derived from the human alveolar bone.

Objectives: This study aimed to investigate the effect of dexamethasone on the growth and differentiation of osteoblast-like cells derived from the human alveolar bone. Methods: Bone particles were collected from patients during implant-site preparation. The samples were cultured in a growth medium, and the cells that propagated after two-three weeks were cultured in three types of culture media: group 1, normal medium; group 2, osteogenic medium without dexamethasone; and group 3, osteogenic medium with dexamethasone-for zero, four, seven, and 20 days. DNA and alkaline phosphatase (ALP) measurements and alizarin red/toluidine blue staining were performed. Results: DNA levels were significantly higher in group 2 than in group 1 on day 7 (p < 0.001) and in group 3 on days 4, 7, and 20 (p < 0.041, p < 0.006, and p < 0.001, respectively). Further, total ALP levels were significantly higher in group 3 than in groups 1 on day 20 (p < 0.023). A greater amount of matrix mineralisation was observed in group 3 than in groups 1 and 2. Conclusions: Human alveolar bone cells exhibit improved osteogenic efficacy in terms of osteogenic differentiation when cultured in the presence of dexamethasone. The cell number (total DNA content) decreased in the presence of dexamethasone; however, an increased differentiation of osteoblast-like cells was observed.

Attitudes and satisfaction of dental faculty toward calibration: A cross-sectional study.

OBJECTIVE: To evaluate attitudes and satisfaction of faculty members about calibration efforts in the undergraduate dental program at Imam Abdulrahman Bin Faisal University, Saudi Arabia. METHODS: The cross-sectional study included faculty members (n = 75) who participated in calibration exercises for effective assessments in preclinical and clinical courses. The previously validated questionnaire was utilized. The questionnaire was composed of four sections: demographics, faculty members' attitude, quality of calibration efforts, and faculty satisfaction. The satisfaction score of faculty members was calculated and compared with their demographic data. Descriptive statistics included means, standard deviations, frequencies, and proportions. The data were analyzed using an independent sample t-test and one-way analysis of variance. RESULTS: The response rate was 92% (n = 69). Note that 97% participants agreed that faculty calibration was an important aspect of dental education and 88.10% were willing to attend calibration exercises even if not required by their institution. Most participants (82.1%) agreed students were more satisfied with their clinical education when faculty members were calibrated. In this study, the perception of 85.1% of the participants was that calibration efforts reduced faculty variations. Most participants (73.10%) were satisfied with the quality of faculty calibration exercises in the college. The mean satisfaction score of the sample was 13.21 ± 3.65, which was significantly higher among faculty members with a doctoral degree (13.88 ± 3.64) than those with a master's degree (12.08 ± 3.46) (p = 0.048). The study showed no significant relationship of gender, age, status, and year of experience with faculty's satisfaction with calibration efforts. CONCLUSION: Most faculty members recognized the importance of faculty calibration in dental education and were satisfied with the quality of calibration efforts. Satisfaction with calibration efforts was significantly related to the high education of faculty members.

Radiographic comparisons of crestal bone levels around implants placed with low-speed drilling and standard drilling protocols: Preliminary results.

BACKGROUND: The present study aimed to investigate the mean crestal bone loss (CBL) by placing implants using two different drilling-protocols, i.e., standard drilling with saline irrigation and low-speed drilling without saline irrigation. MATERIAL AND METHODS: The patients were enrolled in the present study from a university teaching institute. Patients who fulfilled the inclusion criteria were randomly placed in two study groups: 1) control group: Standard drilling with saline irrigation and 2) test group: low-speed drilling without saline irrigation. The radiographic mean crestal bone loss (CBL) was evaluated at 3 months of follow-up before implant loading. Data analysis was performed using SPSS 20.0 (IBM product, Chicago, USA) and a p-value ≤ 0.05 was considered statistically significant. RESULTS: Sixteen patients (10 males and 6 females) participated in the study. Thirty Camlog®-screw-line implants were placed (15 implants per study group). After 3 months of follow-up, the means CBL of implants placed with standard drilling and low-speed drilling protocols were 1.01 ± 0.49 mm and 0.74 ± 0.62 mm, respectively. No statistically significant difference could be recorded between two groups (p = 0.206). CONCLUSIONS: Dental implants placed with low-speed drilling without saline irrigation exhibited a similar CBL to implants installed with the standard drilling protocol. However, further randomised clinical trials are recommended to obtain stronger evidence and a better understanding of the effect of the low-speed drilling protocol without saline irrigation on mean CBL and long-term implant survival.

A Prospective Randomized Clinical Trial on Radiographic Crestal Bone Loss Around Dental Implants Placed Using Two Different Drilling Protocols: 12-Month Follow-up.

PURPOSE: There is a substantial need to perform studies to evaluate crestal bone loss (CBL) and implant success when using a newly introduced low-speed drilling protocol. Therefore, this study aimed to evaluate the mean CBL and implant success rate by placing implants utilizing two drilling protocols, ie, standard and low-speed drilling protocols. MATERIALS AND METHODS: A randomized controlled clinical trial was carried out in patients who required dental implants to restore their esthetics and function. The patients were recruited from a university hospital (Academic Centre for Dentistry Amsterdam [ACTA], the Netherlands). Based on the inclusion criteria, patients were randomized to two study groups: (1) control group, standard drilling protocol; and (2) test group, low-speed drilling protocol without saline irrigation. The mean CBL and the implant success rate were evaluated after 12 months of implant placement. RESULTS: Twenty-three patients (15 men and 8 women with a mean age of 57.5 ± 10.7 years) contributed to the study. Forty Camlog screw-line implants were placed (20 implants per study group). After 12 months of implant placement, the mean CBL of implants placed with the standard protocol and the low-speed protocol was 0.206 ± 0.251 mm and 0.196 ± 0.178 mm, respectively. No statistically significant difference could be recorded among both groups (P = .885). Concerning implants placed in the maxilla, the standard drilling group and low-speed drilling group showed a mean CBL of 0.252 ± 0.175 mm and 0.251 ± 0.175 mm, respectively, compared with 0.173 ± 0.210 mm and 0.141 ± 0.172 mm in the mandible, with no significant difference. The success rate of dental implants at 12 months was 95% in the control group and 90% in the test group. CONCLUSION: Within the limitations of this study, it can be concluded that implants placed with the low-speed drilling protocol without saline irrigation exhibited a similar CBL compared with implants placed with the standard drilling protocol. However, a higher success rate was recorded especially in type 1-quality bone for the control group compared with the test group. Further randomized clinical trials with greater sample sizes and extended follow-up times should be performed to obtain stronger evidence and a better understanding of the influence of drilling speed on mean CBL and long-term implant success.

Combined effect of undersized surgical technique and axial compression on the primary implant stability and host bone architecture.

AIM: The aim of this study was to investigate the combined effect of the lateral-compression of host-bone (undersized-osteotomy-preparation) and axial-compression of host-bone (not drilling the full length of the implant) on the primary-implant-stability and the host-bone-architecture. MATERIALS AND METHODS: In this experimental-study, 44 dental implants (diameter-4.2 mm; length-10 mm; Dyna®) were installed in the femoral-condyles of four cadaver-goats using four different surgical approaches (11 implant/surgical approach; n = 11). Approach-1: Standard preparation according to the manufacturer's guidelines. The bone-cavity was prepared up to 10 mm in depth and 4 mm in diameter. Approach-2: Preparation up to 8 mm in depth and 4 mm in diameter. Approach-3: Preparation up to 10 mm in depth. Approach-4: The bone-cavity was prepared up to 8 mm in depth and 3.6 mm in diameter. Insertion torque (n = 11), removal torque (n = 7) and % bone-implant contact (n = 4) measurements were recorded. Bone architecture was assessed by micro-computer tomography and histological analysis (n = 4). RESULTS: For approaches 2, 3, and 4 (P < .05), insertion-torque values were significantly higher as compared to approach 1. Regarding the bone-implant-contact percentage (%BIC), approach 3 and 4 were significantly higher compared to approach 1 and 2 (P<.05). For approach 2, the %bone volume (%BV) was significantly higher as compared to approach 1 (P<.05) for the most the inner zone of host bone in proximity of the implant. CONCLUSION: Lateral and axial compression improved the primary-implant-stability and therefore this new surgical-technique should be considered as an alternative approach especially for placing implants in low-density bone. Nevertheless, additional in vivo studies should be performed.

Knowledge, Attitudes, and Clinical Practices of Dental Professionals during COVID-19 Pandemic in Pakistan.

OBJECTIVE: The aim of this study is to assess knowledge, attitudes, and clinical practices of dental professionals regarding the prevention and control of coronavirus disease 2019 (COVID-19) in Pakistan. MATERIALS AND METHODS: General dentists and dental specialists working in public and private dental practices, hospitals, and academic institutions participated in this cross-sectional study. A pilot-tested questionnaire was sent to dental professionals through an online link in Pakistan and data collection was completed in April-May 2020. The knowledge score was calculated from 22 variables about the COVID-19. RESULTS: The study included data of 343 dental professionals with 47.2% of males and 52.8% of females. The mean knowledge score was 16.78 ± 2.25, and it significantly differed between general dentists (16.55 ± 2.36) and dental specialists (17.15 ± 2.04) (p = 0.020), and those with up to 10 years of experience (16.58 ± 2.28) and those with more than 10 years of experience (17.05 ± 2.2) (p = 0.026). Only 15.5% of the participants were comfortable in treating patients during the COVID-19 pandemic. A workshop/seminar on the COVID-19 was attended by 23% of the participants. In multivariate analysis, being comfortable in treating patients (odds ratio = 3.31, 95% confidence interval = 1.63, 6.73) was associated with the attendance of workshop/seminar on COVID-19. CONCLUSIONS: Dental professionals had adequate knowledge about COVID-19, but a few of them were comfortable in treating patients during the pandemic. A minority of dental professionals attended a workshop/seminar on the COVID-19. Continuous education activities should be provided to dental professionals to enhance their role in the prevention of COVID-19 spread and promotion of oral health.

Assessing Knowledge, Attitude and Practices for Oral Squamous Cell Carcinoma among Health Care Professionals in Princess Nourah University, Riyadh, KSA.

BACKGROUND: Oral Squamous Cell Carcinoma (OSCC) is a growing public health problem affecting 2.2 million of the world's population per year and the rates are increasing annually. The disease is usually diagnosed in later stages, and carries high morbidity and mortality rates worldwide. Proper awareness among health care professionals (HCP) is the most significant factor for ensuring early diagnosis and treatment. They should have thorough knowledge to identify all suspicious lesions or otherwise to seek specialist opinion when unsure. The present study aimed to assess the knowledge, attitude, and practices (KAPs) of OSCC among dental and medical undergraduate students along with general practitioners and specialists of both disciplines. MATERIALS AND METHODS: The present cross-sectional study was conducted at Princess Nourah Bint Abdulrahman University and its affiliated hospital. A total of 332 participants filled a close-ended online questionnaire. Responses to the questionnaire were analyzed using descriptive and analytical statistics. RESULTS: Of the 450 health care professionals approached, 332 filled the questionnaire with a response rate of 73.77.%. It was observed that the mean knowledge index was higher among dental participants (10.96 ± 1.85). The attitude index was higher at medical side (6.89 ± 1.11), and the practice index was also higher among the dental participants (4.95 ± 0.91). Most of the health care professionals had knowledge regarding risk factors associated with OSCC. HCPs indicated their lack of training as the main barrier for conducting a comprehensive examination for OSCC. Interestingly, the vast majority of HCPs expressed their interest to have further educational and training sessions regarding this malignancy. CONCLUSION: The study puts forward, the need for intensive training and workshops for awareness and improvement of the abilities of the HCPs, (including dental and medical undergraduate students along with practitioners and specialists) to diagnose OSCC.

Comparison of Proliferation and Differentiation of Human Osteoblast-like Cells Harvested During Implant Osteotomy Preparation Using Two Different Drilling Protocols.

PURPOSE: Autogenous bone grafts are considered a "gold standard." The success of autografts mainly depends on their ability to promote an osteogenic response. The aim of this study was to collect autogenous bone during implant osteotomy preparation using two different drilling protocols and to evaluate and compare the proliferation and differentiation ability of the collected bone particles. MATERIALS AND METHODS: Autogenous bone particles were harvested from 20 patients during implant osteotomy preparation using two different drilling protocols: (1) standard drilling protocol with saline irrigation (according to the manufacturer's recommendation) and (2) low-speed drilling protocol without saline irrigation (speed < 200 rpm). Bone samples collected were cultured in growth medium, and after 2 to 3 weeks, cells that grew out from bone grafts were cultured in the normal medium as well as in osteogenic medium for days 0, 4, 7, and 20. Scanning electron microscopy, alizarin red/toluidine blue staining, DNA, ALP, and calcium content measurements were performed. Repeated measures analysis of variance (ANOVA) with Bonferroni's test was employed to analyze the data of this study. RESULTS: The total DNA content was significantly higher for the low-speed drilling samples compared with the standard drilling on day 4 (P < .05), day 7 (P < .01), and day 20 (P < .001) in the normal medium and on day 7 (P < .01) and day 20 (P < .01) in the osteogenic medium. Besides, calcium measurements and mineralized matrix formation observed with alizarin red/toluidine blue staining were significantly higher for the low-speed drilling group compared with the standard drilling group. CONCLUSION: Osteogenic efficacy (differentiation and proliferation) of autogenous bone particles collected using low-speed drilling was superior compared with standard drilling samples.

Evaluation of primary and secondary stability of titanium implants using different surgical techniques.

OBJECTIVE: To investigate the influence of different surgical techniques on the primary and secondary implant stability using trabecular bone of goats as an implantation model. MATERIAL AND METHODS: In the iliac crest of eight goats, 48 cylindrical-screw-type implants with a diameter of 4.2 mm (Dyna(®) ; Bergen op Zoom, the Netherlands) were installed, using three different surgical techniques: (i) 5% undersized, using a final drill diameter of 4 mm; (ii) 15% undersized, using a final drill diameter of 3.6 mm; and (iii) 25% undersized, using a final drill diameter of 3.2 mm. Peak insertion torque values were measured by a Digital(®) (MARK-10 Corporation, New York, NY, USA) torque gauge instrument during placement. At 3 weeks after implantation, removal torque was measured. Histomorphometrically, the peri-implant bone volume was measured in three zones; the inner zone (0-500 µm), the middle zone (500-1000 µm) and the outer zone (1000-1500 µm). RESULTS: Evaluation of the obtained data demonstrated no statistically significant difference between different surgical techniques regarding removal torque values. With respect to the percentage peri-implant bone volume (%BV), also no significant difference could be observed between all three applied surgical techniques for both the inner, middle and outer zone. However, irrespective of the surgical technique, it was noticed that the %BV was significantly higher for the inner zone as compared to middle and outer zone (P < 0.05) around the implant. CONCLUSION: At 3 weeks after implant installation, independent of the used undersized surgical technique, the %BV in the inner zone (0-500 µm) peri-implant area was improved due to both condensation of the surrounding bone as also the translocation of host bone particles along the implant surface. Surprisingly, no mechanical beneficial effect of the 25% undersized surgical technique could be observed as compared to the 5% or 15% undersized surgical technique to improve primary or secondary implant stability.

Translocation of autogenous bone particles to improve peri-implant osteogenesis.

During the placement of titanium implants into bone, particles are loosened and translocated as a result of the inherent roughness of the surface. Such bone particles have been shown to play a significant role in new bone formation. Therefore, the aim of the present study was to establish a new regenerative procedure, which can be implemented immediately during surgery, to provide implants with additional autogenous bone particles. Thereafter, we investigated the effect of such 'bone-coated' implants on the healing response. In our model, dental screw-type implants were placed in the iliac crests of goats, following three approaches: (a) implants were placed, then removed while retaining bone debris on the surface, and subsequently placed into freshly prepared holes; (b) new implants were installed in the donor sites from group 1; and (c) control implants were inserted according to the standard protocol. After 3 weeks, microcomputed tomography and histomorphometerical analyses on bone-implant contact (BIC) and bone area (BA) were performed. The results showed that the retained bone debris in group 1 was viable bone-like tissue when cultured in vitro. In vivo histological results showed a significantly higher BIC for the 'bone-coated' (43.42 ± 11.29%) compared to the control (28.15 ± 11.86%) implants. Also, adjacent to the implants a significantly higher BA was found for 'bone-coated' implants (39.51 ± 11.17%) compared to the controls (31.92 ± 10.25%). Notably, no detrimental effects were noticed for the 'donor-site' positions. In conclusion, the transported autogenous bone particles accelerated peri-implant osteogenesis. Clinical studies are needed to evaluate the potential of this procedure in clinical practice.

The influence of surface roughness on the displacement of osteogenic bone particles during placement of titanium screw-type implants.

BACKGROUND: Previously, we demonstrated that bone debris, which is translocated during dental implant placement, has osteogenic potential. Therefore, it was hypothesized that implant surface roughness can influence the amount of translocated bone debris/particles and thereby the osteogenic response. MATERIAL AND METHODS: Small titanium implants were left turned (smooth) or blasted and acid etched. The implants were placed in fresh cadaver bone. After explantation, the implants were incubated in a culture medium containing ß-glycerophosphate and dexamethasone up to 24 days. Subsequently, histology, scanning electron microscopy (SEM), DNA analysis, and calcium (Ca) content measurements were performed. RESULTS: For both types of implant during implant placement, bone particles were translocated because of inherent roughness of the implant. SEM and histology confirmed the presence of a bone-like tissue on the surface of both types of implants, as also confirmed by DNA and Ca measurements. However, the significantly higher roughness of the etched implants accounted for more bone debris and accordingly elevated osteogenic response. Control samples, which had not been placed into bone, did not show mineralization in the same medium. CONCLUSION: The present study, for the first time, demonstrated that implant surface roughness can increase the amount of the translocated bone particles and thereby also have a beneficial effect on the osteogenic response of these bone particles. It is hypothesized that these bone fragments behave like miniature auto-grafts and thereby play a significant role to enhance peri-implant osteogenesis. Optimization of surface topography should be evaluated to take advantage of this additional effect of surface roughness.

Biological limits of the undersized surgical technique: a study in goats.

OBJECTIVE: The purpose of the present study was to investigate the influence of different implant placement techniques on the early bone healing response in an animal model. MATERIAL AND METHODS: In the present study, 24 cylindrical-screw-type implants with a diameter of 4.2 mm (Dyna®) were installed, using three different surgical techniques; (1) 5% undersized, using a final drill diameter of 4 mm; (2) 15% undersized, using a final drill diameter of 3.6 mm; and (3) 25% undersized, using a final drill diameter of 3.2 mm. After 3 weeks of implantation period, the peri-implant bone response was histologically evaluated and the percentage of bone-implant contact (%BIC) calculated. RESULTS: New bone formation was more pronounced for implants placed with the 5% undersized or 15% undersized technique, as compared with implants installed with the 25% undersized technique. Histomorphometrical data corroborates these findings as the %BIC was significantly higher for implants inserted with the 5% undersized (47.7 ± 11.1) or 15% undersized protocol (47.5 ± 9.5) as compared with implants inserted with the 25% undersized technique (32.1 ± 9.7). No significant difference in %BIC could be observed between the 5% undersized and 15% undersized installed implants. CONCLUSION: Within the limitation of the present study, it was concluded that excessive compression of the host bone, when a discrepancy between implant and final drill diameter more than 15%, can result in an inferior tissue response in the early stage of healing. To compare research results in the future, it is advised to specify the term "undersized" by mentioning the real reduction in diameter.

Influence of surgical technique and surface roughness on the primary stability of an implant in artificial bone with different cortical thickness: a laboratory study.

OBJECTIVE: The aim of this biomechanical study was to assess the interrelated effect of both surface roughness and surgical technique on the primary stability of dental implants. MATERIAL AND METHODS: For the experiment, 160 screw-designed implants (Biocomp), with either a machined or an etched surface topography, were inserted into polyurethane foam blocks (Sawbones). As an equivalent of trabecular bone, a density of 0.48 g/cm(3) was chosen. To mimic the cortical layer, on top of these blocks short-fibre-filled epoxy sheets were attached with a thickness varying from 0 to 2.5 mm. The implant sites were prepared using either a press-fit or an undersized technique. To measure the primary stability of the implant, both the insertion and the removal torques were scored. RESULTS: Independent of the surgical technique used, both implant types showed an increased insertion and removal torque values with increasing cortical thickness, although >2 mm cortical layer no further increase in insertion torque was observed. In the models with only trabecular bone (without cortical layer) and with a 1 mm cortical layer, both implant types showed a statistically higher insertion and removal torque values for undersized compared with the press-fit technique. In addition, etched implants showed a statistically higher insertion and removal torque mean values compared with machined implants. In the models with 2 and 2.5 mm cortical layers, with respect to the insertion torque values, no effect of either implantation technique or implant surface topography could be observed. CONCLUSION: The placement of etched implants in synthetic bone models using an undersized preparation technique resulted in enhanced primary implant stability. A correlation was found between the primary stability and the cortical thickness. However, at or above a cortical thickness of 2 mm, the effect of both an undersized surgical approach, as also the presence of a roughened (etched) implant surface, had no extra effect. Besides the mechanical aspects, the biological effect of undersized drilling, i.e. the bone response on the extra insertion torque forces should also be elucidated. Therefore, additional in vivo studies are needed.

Influence of the surgical technique and surface roughness on the primary stability of an implant in artificial bone with a density equivalent to maxillary bone: a laboratory study.

OBJECTIVE: The aim of this biomechanical study was to assess the effect of surgical technique and surface roughness on primary implant stability in low-density bone. MATERIAL AND METHODS: Eighty screw-shaped (Biocomp) implants with machined or etched surface topography were inserted into a low-density bone equivalent. Solid rigid polyurethane blocks (Sawbones) with two different bone densities (group A=0.32 g/cm(3); group B=0.48 g/cm(3)) were used that are very similar to the density of the maxilla. The implant sites were prepared either by a press-fit or by an undersized technique. Peak insertion and removal torques were measured using a Digital torque gauge instrument. RESULTS: Independent of the surgical technique used, both implant types showed an increased mean insertion and removal torque value with increasing bone density. Insertion and removal torque values were 54.3+/-5.3 and 43.5+/-6.5 N cm for group A and 89.3+/-7.6 and 55+/-9.1 for group B, respectively. For group A and B, both implant types showed statistically higher insertion and removal torque mean values for the undersized compared with the press-fit technique (P<0.01). In addition, etched implants showed statistically higher insertion and removal torque mean values compared with machined implants (P<0.01). CONCLUSION: The placement of etched implants in synthetic bone models using an undersized preparation technique resulted in enhanced primary implant stability; further, a correlation was found between primary stability and bone density of the synthetic bone, implying that in case of an implant site with low bone density, by changing the surgical technique and choosing an implant with an optimal surface roughness, the primary stability can be enhanced significantly.