Radiographic marginal bone level evaluation around two different tissue-level implant systems: a one-year prospective study.

BACKGROUND: Marginal bone loss, is a frequently reported variable in the evaluation of dental implants. The primary objective of this study was to evaluate radiographic marginal bone level changes around the two different tissue-level implant systems placed adjacently in the posterior maxilla or mandible. The influence of implant macro-geometry and vertical soft tissue thickness on marginal bone loss were also evaluated. METHODS: Seven patients were included in the study and a total of 18 implants were analyzed. Each patient received two different implants placed adjacently in the maxilla or the mandible. The implants used in our study were either Straumann® SP cylindrical implants or JD Octa® tapered implants. During the surgery, vertical soft-tissue thickness was measured with a periodontal probe placed on the top of the bony crest and in the center of the future implant site. Healing abutments were then seated. Three months following implant placement, impressions were taken, and screw-retained metal ceramic prostheses were delivered. Standardized intraoral radiographs were taken immediately after implant placement and one year following implant loading in order to assess marginal bone level changes. RESULTS: Results showed a mean marginal bone loss of 0.55±0.5 mm for Straumann® SP implants and 0.39±0.49 mm for JD Octa® implants after one year of loading and the difference was not statistically significant between the two systems. A statistically significant correlation was found between soft tissue thickness and marginal bone loss; in sites with thin mucosal tissues (≤2 mm), there was significantly greater bone loss compared to sites with thick, soft tissues (> 2 mm) in both implants. CONCLUSIONS: Radiographic marginal bone loss was not statistically different between the two implant systems at the one-year examination period. Moreover, vertical soft tissue thickness influenced marginal bone loss regardless of the implant system used.

Cytotoxicity of V-Prep Versus Phosphoric Acid Etchant on Oral Gingival Fibroblasts.

The most used etchant in dental daily practice is the phosphoric acid (P.A.; 37%). However, acid etchants can induce necrosis on the oral mucosa and cause the ulceration of periodontal tissue when a rubber dam is not used. V-prep is a new practical alternative, and it has satisfactory results. It is used as a preparation before the application of a resin-modified glass ionomer composite (RMGIC) to bond the orthodontic brackets. The aim of this study was to investigate the effect of the V-prep on oral gingival fibroblasts cells by comparing the cell damage and cell viability after the use of V-prep and a conventional phosphoric acid etchant with different application times and concentrations. Therefore, Gingival fibroblasts passage 6 (GFP6) was grown and treated with an acid etchant and V-prep at three different concentrations (1:1, 1:2 and 1:10) for two different application durations (30 s and 1 min). The morphological changes, cell death and cell viability were assessed. Pyknosis, karyolysis, nucleus reversible and irreversible damages and membrane destruction were observed for both of the etchants at the higher concentrations and longer application durations. Mann-Whitney U-tests were used for the statistical analyses. The application of the V-prep for 30 s showed better values than the acid etchant did in the cell damage analysis and cell viability analysis (p = 0.03). V-prep at a 1:10 concentration applied for a 30 s duration can preserve the viability of gingival fibroblasts cells up to 100%. The toxicity of V-prep is equal or lower than the toxicity of the acid etchant that is commonly used in dentistry. Thus, the V-prep can be used with precautions intra-orally, and it should be applied on the enamel as a gel for 30 s only before it is rinsed and removed.

Response of dental pulp capped with calcium-silicate based material, calcium hydroxide and adhesive resin in rabbit teeth

Direct pulp capping induces a local inflammatory process. Several biomaterials have been used for this procedure. The aim of this study was to compare the dentinal bridge thickness using three different pulp capping biomaterials with the conventional technique (high speed diamond bur) or Er-Yag laser, 1 month after pulp effraction. Materials and Methods: Forty two Class V cavities were prepared on the buccal surface of 4 maxillary incisors and 2 mandibular incisors of New Zealand rabbits. Specimens were divided into 6 treatment groups. Teeth were treated with: In Group 1: Er-Yag laser and Biodentine® (Septodont), in Group 2: Er: Yag laser and calcium hydroxide (Dycal® Dentsply), in Group 3: Er: Yag laser and adhesive system (Prime& Bond® NT Dentsply), in Group 4: high speed diamond bur and Biodentine® (Septodont), in Group 5: high speed diamond bur and calcium hydroxide (Dycal® Dentsply), and in Group 6: high speed diamond bur and adhesive system (Prime& Bond® NT Dentsply). The preparation was done with copious irrigation. The animals were sacrificed at 30 days and the teeth were extracted and prepared for histological analysis. Results: In the group of « laser Er-Yag ¼, iatrogenic pulpal wounds treated with Biodentine® were covered with a thick hard tissue barrier after 1 month. The difference was not significant with the groups of Dycal® used with Er: Yag laser and high speed diamond bur. Prime& Bond® NT Dentsply specimens showed a thin dentinal bridge layer. Conclusion: At 1 month, Er-Yag laser proved to be useful with Biodentine® for direct pulp capping procedures

Implant Placement With Graftless Sinus Floor Elevation via the Lateral Approach: A Case Series With 4 Years Post-Loading Radiographical Outcomes and Implant Survival Rate.

ABSTRACT: The purpose of the present study was to evaluate the radiographical outcomes, survival rate, and amount of bone formation around implants placed during graftless lateral sinus lift approach (GLSLA). Five patients (6 sinus augmentations) were consecutively treated with GLSLA. After Schneiderian membrane elevation and implant insertion, only blood clot was left to fill the new sinus compartment. After 4 months of healing, implants were functionally loaded. in all cases, samples were taken for biopsy at the time of second-stage surgery. The radiographical marginal bone variations and apical bone gain were assessed using cone beam- computed tomography taken 4 months after the surgery (at crown insertion) and after 4 years of loading. A total of 14 implants were placed in a mean initial residual bone height of 3.1 mm (range 1.64 mm). No failure was recorded, and all the implants were successfully loaded yielding a 100% survival rate. Vital bone formation was 33% according to the histomorphometry data. Four years after loading the mean radiographic bone remodeling was 1.3 mm. The mean ridge height was 7.6 mm and the mean apical bone gain amounted for 3.8mm. Within the limitations of this study, the placement of dental implants in conjunction with GLSLA seems to be feasible and accompanied by high implant survival rate.

Appraisal of Schoolchildren's Feelings and Attitudes towards Dentists and Their Potential Impact on Oral Health.

AIM: To assess schoolchildren's feelings and attitudes towards dentists and their potential impact on oral health. MATERIALS AND METHODS: 7902 schoolchildren (12 and 15 years old) attending public and private schools completed a questionnaire that assessed their feeling and attitude toward dentists. DMFT and CPI indices were used to assess dental caries and periodontal diseases respectively according to the World Health Organization method and criteria. RESULTS: 79.7% of all schoolchildren who participated in this study had been to the dentist. 24.7% reported that they are afraid of dental visits, pain being the main reason for this disturbing feeling (88, 2%). Of the children, 81.4% preferred a female dentist; 82.3% preferred a dentist with a colored coat and 80.3% favored a renovated dental facility. 91.1% of the children are irritated by the noises in the dental clinic. The mean DMFT and CPI scores were significantly higher in patients with dental fear, and in patients who never had a dental visit. CONCLUSION: Meeting patient's perceptions and preferences regarding their dentist may help to reduce the potential dental anxiety and thus ensure the delivery of a high-quality dental treatment leading to better oral health status. CLINICAL RELEVANCE: Patient perception about dentists is affected by a series of factors related to the dentist, the patient, and the dental clinic. Patients who experience the worst perceptions of dental professional tend not to seek dental care, which leads to a bad oral health status, hence the importance of further studies in this area to improve such perceptions, and promote attitudinal changes toward positive health-seeking behavior.

Alveolar Ridge Preservation on Maxillary Molars Using Solvent Dehydrated Bone Allograft and d-PTFE Membrane: A CBCT and Histologic Human Pilot Study.

The purpose of this study was to evaluate vertical and horizontal alveolar resorption after the extraction of eight single maxillary molars using solvent-dehydrated bone allograft (Puros) covered with a nonresorbable membrane for ridge preservation. At implant placement 4 months later, ridge dimensions were measured clinically and radiographically and compared to baseline, and a histologic analysis was performed. The mean buccal height decreased by 1.51 mm at midpoint, 0.88 mm mesially, and 1.16 mm distally. The implants were placed without additional ridge augmentation, and six of eight required an internal sinus elevation. Within the limits of this study, this technique succeeded in preserving the alveolar bone.

Prevalence and Etiological Factors of Dental Trauma among 12- and 15-Year-Old Schoolchildren of Lebanon: A National Study.

BACKGROUND: Traumatic dental injuries represent nearly 5% of children and adolescents' injuries leading to serious medical and psychological issues. This current study aims to evaluate the prevalence of dental trauma and its potential association with different predisposing factors among 12-and 15-year-old schoolchildren in Lebanon. MATERIALS AND METHODS: 7902 schoolchildren, 3806 male and 4096 female aged 12 years (n = 3985) and 15 years (n = 3917), were recruited by a stratified multistaged randomized cluster sampling method from public and private schools and were clinically examined in a national cross-sectional study. WHO criteria were used to assess anterior permanent teeth; the nature of trauma, the tooth involved, the size of the incisal overjet, and the type of the lip coverage were furthermore assessed. Data regarding age, sex, and causes of TDI were recorded through a structured questionnaire. RESULTS: The prevalence of dental trauma to anterior teeth was 10.9%. Maxillary central incisors (83.7%) were commonly affected. The most common type of injury was enamel fracture (68.3%), falls being the main reason (52.5%). Increased overjet (OR = 2.32, p = 0.034), deficient lip coverage (OR = 5.73, p = 0.019), and gender (OR = 5.36, p ≤ 0.001) were significant predisposing factors for dental trauma. CONCLUSION: This research highlighted many predisposing factors for dental trauma that affect commonly the anterior teeth. Based on these results, the implementation of strategic preventive measurements targeting especially the identified risk groups remains crucial.

Implant placement with sinus floor elevation via the lateral approach using only absorbable collagen sponge: 12-month post-loading radiographical outcomes and implant survival rate.

PURPOSE: The purpose of the present study was to evaluate the radiographical outcomes and survival rate of implants placed during graftless lateral sinus lift approach (GLSLA) using an absorbable collagen sponge. MATERIALS AND METHODS: Fourteen patients (14 sinus augmentations) were consecutively treated with GLSLA. After Schneiderian membrane elevation and implant insertion, only collagen sponges were used to fill the new sinus compartment. After 4 months of healing, implants were functionally loaded. The radiographical marginal bone variation and apical bone gain were assessed on periapical radiographs taken 4 months after the surgery (at crown insertion) and at 12 months post-loading. RESULTS: A total of 41 implants were placed in a mean initial residual bone height of 3.5 mm (range 1.6-6.7 mm). No failure was recorded and all the implants were successfully loaded with fixed prosthesis. Twelve months post-loading the mean radiographic bone remodeling was 2.22 mm. The mean ridge height was 8.4 mm and the mean apical bone gain amounted for 4.4 mm. CONCLUSIONS: Within the limitations of this study, the placement of dental implants in conjunction with GLSLA using only a collagen sponge to fill the sinus compartment seems to be feasible and accompanied by a high implant survival rate. Further studies on a large population and with a longer follow-up are warranted to drawn definitive conclusions.

Prevalence of Interproximal Contact Loss Between Implant-Supported Fixed Prostheses and Adjacent Teeth and Its impact on Marginal Bone Loss: A Retrospective Study.

PURPOSE: To investigate the prevalence of interproximal contact loss between implant-supported fixed prostheses and adjacent teeth and its impact on marginal bone loss and to identify potential risk factors. MATERIALS AND METHODS: Patients who received implant-supported fixed prostheses at Saint-Joseph University between the years 2011 and 2017 and met the inclusion/exclusion criteria were eligible to participate in this retrospective study. Interproximal contacts were evaluated with a 70-µm dental floss and confirmed visually and by periapical radiographs. Contact was considered open if the floss passed without resistance. Plaque Index and bleeding on probing were assessed, and radiographic bone loss around implants was measured at recall. RESULTS: Eighty-three patients (183 interproximal contact points) were evaluated. Interproximal contact loss between implant-supported fixed prostheses and adjacent teeth occurred in 32.8%; among mesial contact points, 42.1% had interproximal contact loss, whereas 14.5% had interproximal contact loss on the distal side. In interproximal contact loss sites, a mean marginal bone loss of 0.73 mm was noted; the difference was statistically significant compared with marginal bone loss at sites with interproximal contact (P = .017). Age, sex, smoking status, periodontal status, implant sites, and the type of restoration were not significantly associated with interproximal contact loss or marginal bone loss. Sites with interproximal contact loss were 2.24 times more likely to present bleeding on probing than others. CONCLUSION: Interproximal contact loss occurred in 32.8% of implant-supported fixed prostheses, and a positive relationship between interproximal contact loss and marginal bone loss was found, which suggests that interproximal contact loss should be included as a prosthetic implant complication. Future research aiming at identifying the causative factor for interproximal contact loss is necessary.

Guided bone regeneration in calvarial critical size bony defect using a double-layer resorbable collagen membrane covering a xenograft: a histological and histomorphometric study in rats.

PURPOSE: The aim of the present study was to evaluate histologically and histomorphometrically the bone regeneration in critical size calvarial defects in rats grafted with either a deproteinized bovine bone mineral (DBBM) alone or in combination with a single or double layer of native bilayer collagen membrane (NBCM). The secondary objective was to evaluate histologically and histomorphometrically the residual DBBM in these defects. MATERIAL AND METHODS: Thirty-two Wistar rats were divided into two groups: a control group of 16 rats with two critical size calvarial defects (CSD) of 5 mm performed each on either side of the median sagittal suture, where the frontal defect remained without any filling (negative control), while the occipital defect (positive control) was filled with DBBM; and then a test group of 16 rats, with two CSD filled with DBBM and covered by either a single (SM) or a double layer (DM) of NBCM. The animals were sacrificed at 4 and 8 weeks. RESULTS: At 1 month, the histological and histomorphometric analysis showed new bone formation (NBF) in the defects that received only DBBM, DBBM+DM, and DBBM+SM (11.5, 17.3, and 22.7%, respectively), while the negative control defects showed only 0.4% of new bone formation. At 2 months, the histological and histomorphometric analysis showed NBF in the defects that received only DBBM, DBBM+DM, and DBBM+SM (16.8, 24.5, and 37%, respectively), while the negative control defects showed only 0.9% of new bone formation. The residual xenogeneic material (RXM) was higher in defects covered by SM (30.2% at 1 month and 25.3% at 2 months) or DM (32.5% at 1 month and 28.5% at 2 months) compared with defects that were not covered by membranes (15.3% at 1 month and 9.4% at 2 months). CONCLUSIONS: This study demonstrated that GBR with a xenogeneic material in rat calvarial (CSD) of 5 mm requires the application of resorbable collagen membranes in either single or double layer, and a single layer alone is sufficient to promote this regeneration.

Bone formation with deproteinized bovine bone mineral or biphasic calcium phosphate in the presence of autologous platelet lysate: comparative investigation in rabbit.

Bone substitutes alone or supplemented with platelet-derived concentrates are widely used to promote bone regeneration but their potency remains controversial. The aim of this study was, therefore, to compare the regenerative potential of preparations containing autologous platelet lysate (APL) and particles of either deproteinized bovine bone mineral (DBBM) or biphasic calcium phosphate (BCP), two bone substitutes with different resorption patterns. Rabbit APL was prepared by freeze-thawing a platelet suspension. Critical-size defects in rabbit femoral condyle were filled with DBBM or DBBM+APL and BCP or BCP+APL. Rabbits were sacrificed after six weeks and newly formed bone and residual implanted material were evaluated using nondemineralized histology and histomorphometry. New bone was observed around particles of all fillers tested. In the defects filled with BCP, the newly formed bone area was greater (70%; P < 0.001) while the residual material area was lower (60%; P < 0.001) than that observed in those filled with DBBM. New bone and residual material area of defects filled with either APL+DBBM or APL+BCP were similar to those observed in those filled with the material alone. In summary, osteoconductivity and resorption of BCP were greater than those of DBBM, while APL associated with either DBBM or BCP did not have an additional benefit.