THE EFFECT OF LOCAL AND SYSTEMIC FACTORS ON DENTAL IMPLANT FAILURE - ANALYSIS OF 670 PATIENTS WITH 1260 IMPLANTS.

The etiopathogenesis of dental implant failure is multifactorial and may include numerous local and systemic factors, however, studies including both local and systemic factors are still lacking. Therefore, the aim of this study was to evaluate whether periodontal disease, oral hygiene index, i.e. bleeding on probing (BOP), full mouth plaque index (FMPI), smoking, systemic diseases, as well as implant characteristics (length and diameter) affect failure of implant-prosthodontic therapy. Data on 670 patients were retrieved in whom 1260 dental implants had been placed and followed-up for at least five to ten years. Categorical data were analyzed by the χ2-test, whereas Mann-Whitney test was used for continuous variables (age, BOP and FMPI). The values of p<0.05 were considered significant. The effect of local and systemic factors on the success of implant-prosthodontic therapy was assessed by multiple logistic regression analysis. Forty-five (6.7%) patients had systemic diseases, of which diabetes mellitus was most common, followed by atherosclerosis, diabetes and atherosclerosis, diabetes mellitus type 1, lymphoma, and hepatitis C. One-third (33.4%) of the patients were smokers. Periodontal disease was present in 170 patients, while 500 patients were without periodontal disease. Nine implants were lost during the period of five years. There were no differences regarding the type of implant or type of connection to the prosthetic suprastructure. However, most of these patients had a periodontal disease. There were no significant differences in dental implant failure rates between smokers and non-smokers or between patients with and without systemic diseases. Furthermore, the results of this study showed that implant type (straight vs. tapered) and type of connection with prosthodontic appliance (cemented or screw retained) did not affect BOP and FMPI. In smokers, significant improvement of BOP and FMPI was noticed. Initially, smokers had a significantly worse BOP (0.0037) when compared to non-smokers; however, there were no differences regarding FMPI (p=0.4218) between the two groups. In patients with periodontal disease, improvement of BOP and FMPI was seen at 5-year follow-up and no significant differences were found when compared to patients without periodontal disease. There were no significant differences in BOP and FMPI between patients with and without diabetes at 5-year follow-up. Atherosclerosis had a significant negative effect on BOP, but not on FMPI at 5-year follow-up. It is concluded that periodontal disease had a significant impact on the implant-prosthodontic therapy.

Surgical treatment of excessive gingival display using lip repositioning technique and laser gingivectomy as an alternative to orthognathic surgery.

Excessive gingival display (EGD) is a condition in which an overexposure of the maxillary gingiva (>3 mm) is present during smiling. The proper diagnosis and determination of its etiology are essential for the selection of the right treatment modality. Different techniques have been used in cases of hyperactive upper lip: botulinum toxin injections, lip elongations with rhinoplasties, lip muscle detachments, myotomies, and lip repositions. This report presents a case of a young woman with an EGD larger than 10 mm during smiling caused by altered passive eruption, vertical maxillary excess, and a hyperactive upper lip that was treated with a modified lip repositioning technique and laser gingivectomy because she strongly refused orthognathic surgical treatment. A novel addition to the technique is proposed, a reversible trial accomplished just by applying sutures on the borders of the future split-thickness flap, marked using diode laser, before starting the flap incision.

Jaw injuries of independence victims from the 1991 War in Croatia.

In the aetiology of maxillofacial injuries, car accidents, violence, sports injuries and lately war injuries are frequently mentioned. The purpose of this study was to exhibit and analyse types of jaw injuries on bodies exhumed from massive and individual graves located in regions temporarily occupied during the War in Croatia that lasted from 1991 to 1995. The sample was the post-mortal documentation of the orofacial region (set of teeth, photographs, radiographic images) of 1068 victims exhumed from massive grave sites in Croatia. The jaw traumatism was analysed on the whole sample as well as on individual graves, whilst the analysis of trauma frequency was performed separately. Descriptive statistics were computed and the value of P < .05 was accepted as statistically significant. Results of this study showed that out of 1068 examined corpses, 332 had midface and lower face fractures, which was 31.1% of the total number. Lower face fractures were more frequent with 28.1%. Age related frequency analysis showed a significant dependency. There were 34.6% of fractures in the under 30 age group, 34.2% in those aged 30-60, while 21.3% of fractures were noted in the over 60 age group. Female bodies had the lowest number of jaw fractures regardless of the osteoporotic changes. The results of this study suggest that younger and middle aged persons were molested more. Jaw fractures suggest ante-mortal molestation. In females, the more likely fracture causes were the falls of the bodies into the graves or body to body hits.

Evaluation of sentinel node biopsy in oral carcinomas.

It is still a matter of debate whether sentinel node biopsy might replace neck dissection in patients with clinically negative neck lymph nodes who suffer from oral squamous cell carcinoma. In 30 patients (26 male, 4 female, average age 59.4 years) with oral squamous cell carcinoma we performed ultrasound guided punction of the lymph nodes which were lymphoscintigraphically seen together with histopatological analysis of the dissected node. Sentinel lymph node was seen in 93% cases. By use of lymphoscintigraphy sentinel node was verified in 23 patients. Ultrasound guided punction showed presence of regional disease in 10% of cases, whereas sentinel biopsy revealed 23 of the converted necks. Histopathological findings were positive in 33% of our patients. The results of this study revealed that sentinel biopsy did not reveal 27% of the patients with positive neck histopathology. In conclusion, sentinel node biopsy should be performed in selective cases as in some localizations it is easier to perform neck dissection in comparison to the sentinel node biopsy.

Pink Esthetic Score Around Single-Tooth Implant Crowns After Socket-Shield Technique: A Prospective Cohort Study.

Esthetics is important for any dental implant but crucial for implants in the anterior region. Restorations in this region are demanding, and the goal of re-establishing an attractive smile without revealing differences from the natural teeth is difficult to achieve. The aim of this study was to examine the clinical success of the socket-shield technique regarding soft tissue stability and overall esthetic outcome. Pink esthetic scores (PESs) were collected at two time points (T1: 6 months; T2: 6 years) by three different specialists. This prospective cohort clinical study involved 30 patients (7 women and 23 men) with a mean age of 42.3 years. There were no significant differences in PES values assessed by the oral surgeon and prosthodontist (P > .05) at either of the assigned time points. The periodontist found differences in PES values between T1 and T2 (P < .05), but they were modest in value. Analyses of each individual variable at given time intervals revealed significant differences in the shape of the distal papillae (χ2 = 6.182; P < .05) and soft tissue margin level (χ2 = 6.507; P < .05). The final results suggest that the socket-shield technique is promising for implant placement in the esthetic zone.

Salivary analytes in patients with oral squamous cell carcinoma.

Literature data indicates that measurement of certain salivary constituents might serve as a useful diagnostic/prognostic tool in the patients with oral squamous cell carcinoma (OSCC). In 24 patients with OSCC (60 +/- 2.5 yrs) and in 24 controls (24 +/- 3.7 yrs) we have determined levels of salivary magnesium, calcium, copper, chloride, phosphate, potassium, sodium, total proteins and amylase. Sodium, potassium and chloride were determined by indirect potentiometry whereas copper, magnesium and phosphate were determined by atomic absorption spectrophotometry. Total proteins were determined by pyrogalol colorimetric method. Amylase levels were determined by continued colorimetric method. Statistical analysis was performed by use of chi2 test and Spearman's correlation test. The results of this study indicate that the concentrations of sodium and chloride were significantly elevated in patients with OSCC when compared to the controls. However, level of total protein was significantly decreased when compared to the healthy controls. Furthermore, there was a negative correlation between alcohol consumption and total protein concentration in patients with oral carcinoma. We might conclude that in patients with OSCC increased salivary sodium and chloride might reflect their overall dehydration status due to alcohol consumption rather than consequence of OSCC itself.

Evaluation of Antimicrobial Efficacy and Permeability of Various Sealing Materials at the Implant-Abutment Interface-A Pilot In Vitro Study.

The microenvironment of the oral cavity is altered when an implant, a biocompatible foreign body, is inserted into the mouth. Bacteria settle in the tissues in and around the implant due to the passage of microorganisms through the microgap at the connection of the implant and prosthetic abutment. To prevent colonization of the implant by microorganisms, one idea is to use sealing and antimicrobial materials to decontaminate the implant-abutment interface and close the microgap. The purpose of this study is to evaluate the antimicrobial efficacy and permeability of different types of sealing materials at the implant-abutment interface, under static conditions. Three different sealing material (GapSeal gel, Oxysafe gel and Flow.sil) were used for sealing the implant-abutment interfaces in 60 titanium dental implants, which were first contaminated with a solution containing Staphylococcus aureus and Candida albicans for 14 days under an aerobic condition. Results showed that a complete seal against bacterial infection was not formed at the implant-abutment interface, while for fungal infections, only GapSeal material helped to prevent microleakage. Findings of this in vitro study reported that application of sealing material before abutment connection may reduce peri-implant bacterial and fungal population compared with the interface without sealing material.

Assessing health-related quality of life outcomes after the surgical removal of a mandibular third molar.

This study was designed to assess the impact of the surgical removal of a mandibular third molar on health-related quality of life (HRQoL) in the postoperative period. Data was obtained from 101 patients who had undergone 105 surgical procedures. Only one mandibular third molar was removed per visit. The inclusion criterion for surgical procedures was creating a mucoperiosteal flap either with or without osteotomy. Surgical details were noted in a pre-made questionnaire. A self-administered health-related quality of life questionnaire, designed for assessment of the patient's perception of recovery for pain, lifestyle and oral function, was given to all patients. Patients evaluated postoperative pain and other sequelae on a scale ranging from 0 (none) to 3 (severe). Follow-up visits were scheduled on the third and the seventh postoperative day, when wound healing was clinically evaluated and noted. At the review appointment, one week later, patients had their sutures removed and returned a completed follow-up questionnaire. Patients were contacted 14 days after surgery for the purpose of gathering additional data pertaining to their recovery. The mean score for pain had a peak value on day one (1.8), and showed an exponential decrease (1.2 on day three, 0.5 on day seven, 0.1 on day 14). All the other postoperative sequelae showed the same tendency to decrease exponentially. The type of operative procedure and tooth position showed significant impact on postoperative recovery. The surgical removal of a mandibular third molar causes severe deterioration in a patient's quality of life during the first 3 days postoperatively. The quality of life can be expected to return to a preoperative level by the end of the first postoperative week.

Comparison of Er:YAG and Er,Cr:YSGG Laser in the Treatment of Oral Leukoplakia Lesions Refractory to the Local Retinoid Therapy.

Objective: The aim of this study was to compare the efficacy of Er:YAG and Er,Cr:YSGG laser in the treatment of oral leukoplakia refractory to conventional retinoid therapy. Materials and methods: The study sample consisted of 54 patients (16 men and 38 women) who were histopathologically diagnosed with oral leukoplakia that was refractory to conventional retinoid therapy. Patients were randomly allocated into two groups according to the type of the laser used for treatment of oral leukoplakia: Group 1. Er:YAG laser; Group 2. Er,Cr:YSGG laser. Patients were recalled at 6 months and 1 year after treatment to evaluate possible recurrence and assess the patients' postoperative quality of life. Results: After initial ablation, the degree of residual lesion was significantly greater in the Er:YAG laser group (74.1%), compared with the Er,Cr:YSGG group (18.5%) (p = 0.0001). Six months and 1 year after the second ablation, there was no lesion recurrence in either laser group. Fourteen days after the initial ablation, the visual analog scale (VAS) pain rating and the total oral health impact profile score fell significantly in both groups (p < 0.0001). However, in the Er,Cr:YSGG laser group, the average value of the VAS rating was significantly lower than in the Er:YAG laser group (p = 0.039). Conclusions: The Er:YAG and Er,Cr:YSGG lasers showed similar efficacy in the treatment of oral leukoplakia and resulted in full postoperative recovery without recurrence after 1 year of follow-up.

Idiopathic Exposed Bone Lesions of the Jaw.

INTRODUCTION: Osteonecrosis of the jaw is defined as exposed bone in the oral cavity that does not heal longer than eight weeks after identification. The two most common predisposing factors for osteonecrosis of the jaw are medication-related and radiotherapy. Rarely, exposed bone in the maxillofacial region can occur due to other causes and represents a clinical and therapeutic challenge for the dentist because there is no universally accepted treatment protocol. CASE PRESENTATION: We report a case of a patient with two idiopathic lesions of exposed bone which have healed after systemic antibiotic therapy, seven weeks after the first examination. CONCLUSION: Exposed bone lesions of the jaw are a rare entity and are poorly documented in the literature. It is necessary to exclude possible local or systemic contributing factors. Surgical and conservative therapy (antibiotics) are the treatment of choice.

Densitometric analysis of dental implant placement between flapless technique and the two-stage technique--a pilot study.

Flapless technique is a surgical approach of implant placement without raising a mucoperiosteal flap. Such approach has many advantages: shorter surgical treatment, minimal bleeding, postoperative discomfort for the patient is reduced; possibility of immediate loading of the inserted implant, faster procedure of implant placement and by that less time is needed for the complete implant-prosthetic restoration. Purpose of this pilot study was radiographic assessment of flapless technique and determination of its clinical values in comparison with two-stage dental implant technique through computerized densitometric analysis. The sample consisted of 10 patients with missing teeth in the premolar region in the upper jaw. An implant was placed in that position. In the first group of 5 patients the implants were inserted with the flapless technique, and in the other group of 5 patients implant insertion was done with a two-stage technique. All inserted implants were loaded with metal-ceramic crowns 3 months after placement. The patients were followed for 18 months through clinical follow-ups and radiovisiographical (RVG) images made after 3, 12 and 18 months. After comparing the average densities, the results showed similar decrease of density in both groups, conventional two-stage technique showed 3.24 and flapless technique 1.23. It can be concluded that flapless technique in everyday clinical usage has the same result as the two-stage dental implant technique.

Implant stability comparison of immediate and delayed maxillary implant placement by use of resonance frequency analysis--a clinical study.

The purpose of this study was to objectively evaluate the stability of dental implants by use of resonance frequency analysis (RFA). In this study, 60 Nobel Replace Tapered Groovy implants were placed in the premolar region of the maxilla in 60 patients. Thirty implants were placed immediately after tooth extraction and 30 implants were placed in healed bone sites. Implant stability quotient (ISQ) was obtained by use of the Osstell Mentor device and was recorded at the time of implant placement (T1) and 20 weeks after placement, at the time of implant loading (T2). All implants were not functionally loaded during the follow up period. Data were analyzed using simple linear regression. No implant failures were reported in the 6-month follow up period. The mean ISQvalue for immediate implant placement was 61.43 at T1 and 66.23 at T2. The implants placed in healed bone showed higher ISQvalues compared to the immediately placed implants (mean ISQvalue was 64.17 at T1 and 68.83 at T2). Differences in the mean ISQ values were statistically significant (p < 0.001). After the completed period of osseointegration, the mean ISQ value was 4.8 for immediately placed implants compared to 4.67 for implants placed in delayed sites.

Odontogenic sinus tract to the neck skin: a case report.

We describe a 22-year-old woman with neck skin sinus tract that developed as a consequence of dental infection. The patient was treated twice in an inappropriate way with recurrence of the sinus tract. We opted for an extraction of the tooth. This case illustrates the need for cooperative diagnostic referrals between physicians and dentists.

Periodontal conditions in individuals with Down's syndrome.

Periodontal disease in Down's syndrome (DS) population seems to be a more common and serious problem than caries. The aim of this study was to assess the state of periodontal structures in patients with DS. The Community Periodontal Index of Treatment Needs was used for periodontal status assessment in 71 DS subjects aged 9-34 years. A control group consisted of 71 age- and sex-matched healthy individuals. Both groups were divided into three age groups: 9-15 (n = 24); 16-25 (n = 32); and 26-34 (n = 15) years. The results showed a similar percentage of subjects with bleeding and calculus. The intact periodontium was significantly higher in control than in DS (16.9% vs. none; p < 0.01). Deep pockets were more frequent in DS group than in the control group (14.1% vs. 1.4%; p < 0.01). The mean number of sextants with healthy tissue was lower, and of those with bleeding, calculus and shallow pockets significantly higher in DS patients than in controls (p < 0.01), so all DS subjects required some periodontal treatment (p < 0.01). It can be concluded that the severity of periodontal disease and the treatment needs seem to be significantly greater in DS than in healthy subjects.

Morphological and ultrastructural comparative analysis of bone tissue after Er:YAG laser and surgical drill osteotomy.

OBJECTIVE: The purpose of this study was to analyze morphological, chemical, and crystallographic changes of bone tissue after osteotomy performed with an erbium:yttrium-aluminium-garnet (Er:YAG) laser and a low speed pilot drill. MATERIALS AND METHODS: Bone blocks were prepared from porcine ribs, and on each block, two tunnel preparations were performed using the Er:YAG laser (pulse energy: 1000 mJ, pulse duration: 300 µs, pulse repetition rate: 20 Hz) or the low-speed surgical pilot drill. The morphological changes of the cortical and the spongious surface of the tunnel preparations were analyzed under the field emission scanning electron microscopy (FE-SEM) at low and high resolution. The distribution and the level of chemical elements in the treated surfaces were evaluated by qualitative and semiquantitative energy dispersive x-ray analysis (SEM-EDX). Diffraction x-ray analysis was used to detect any differences and thermally induced modifications of hydroxyapatite crystals. RESULTS: FE-SEM revealed sharp edges of the Er:YAG preparations, with empty intertrabecular spaces and no signs of carbonization. In the drill group, the surface of the preparations was smooth, completely covered with smear layer and microcracks, and with hairy-like irregularities on the edges. SEM-EDX analysis did not reveal any differences in the number of specific chemical elements between the laser and the drill group. There were no thermally induced modifications of hydroxyapatite crystal structure in the bone tissue in either group. CONCLUSIONS: The Er:YAG laser ablation did not cause any chemical or crystallographic changes of the bone tissue. Compared with the drill, Er:YAG laser created well-defined edges of the preparations, and cortical bone had no smear layer.

Properties of axially loaded implant-abutment assemblies using digital holographic interferometry analysis.

OBJECTIVE: The aim of this study was to (i) obtain the force-related interferometric patterns of loaded dental implant-abutment assemblies differing in diameter and brand using digital holographic interferometry (DHI) and (ii) determine the influence of implant diameter on the extent of load-induced implant deformation by quantifying and comparing the obtained interferometric data. METHODS: Experiments included five implant brands (Ankylos, Astra Tech, blueSKY, MIS and Straumann), each represented by a narrow and a wide diameter implant connected to a corresponding abutment. A quasi-Fourier setup with a 25mW helium-neon laser was used for interferometric measurements in the cervical 5mm of the implants. Holograms were recorded in two conditions per measurement: a 10N preloaded and a measuring-force loaded assembly, resulting with an interferogram. This procedure was repeated throughout the whole process of incremental axial loading, from 20N to 120N. Each measurement series was repeated three times for each assembly, with complete dismantling of the implant-loading device in between. Additional software analyses calculated deformation data. Deformations were presented as mean values±standard deviations. Statistical analysis was performed using linear mixed effects modeling in R's lme4 package. RESULTS: Implants exhibited linear deformation patterns. The wide diameter group had lower mean deformation values than the narrow diameter group. The diameter significantly affected the deformation throughout loading sessions. SIGNIFICANCE: This study gained in vitro implant performance data, compared the deformations in implant bodies and numerically stated the biomechanical benefits of wider diameter implants.

The influence of psychological state on oral lichen planus.

Oral lichen planus (OLP) is a T-cell mediated disease directed to a still unknown antigen, which may affect oral mucosa. The aim of this study was to determine whether differences in anxiety, depression and stress could be seen in patients with OLP in acute stage and in remission, as well as in comparison with healthy control subjects. The study included 50 OLP patients aged 22-79 (mean age 61.04) years and 50 control subjects who had healthy oral mucosa aged 38-80 (mean age 58.70) years. Patients with OLP filled out the State-Trait Anxiety Inventory for Adults and Beck Depression Inventory II test in acute stage and in remission. Control subjects also filled out the same tests. On detailed medical history, study subjects were asked about the possible stressors, which might have happened in the previous year. Statistical analysis was performed by use of descriptive statistics and t-test. There were no differences in the level of anxiety, depression and stress between the two stages of OLP disease (acute vs. remission period). Patients with OLP were significantly more anxious, depressed and stressed in both OLP stages as compared with healthy controls. It might be that psychological disturbances precede OLP development rather than worsening the disease process itself.

The prevalence of human papillomavirus 16 and Epstein-Barr virus in patients with oral squamous cell carcinoma.

It has been suggested that certain viruses such as human papillomaviruses (HPV) and Epstein-Barr virus (EBV) might have a role in oral squamous cell carcinoma (OSCC). However, results of the published studies are controversial and are dependent on the geographic distribution and methods of sampling and sample analysis. The aim of this study was to determine the prevalence of HPV 16 and EBV in OSCC patients. In 24 patients with OSCC (mean age 59.6 +/- 8.8) and 30 controls (mean age 49.1 +/- 8.3), 5 mL of blood was collected to determine the prevalence of EBV by serologic methods. In addition, swabs were obtained to analyze the presence of HPV 16 and EBV by use of polymerase chain reaction. Statistical analysis was performed by use of Mann-Whitney test, chi2-test and Spearman correlation test. The results of this study showed that there were no significant differences between OSCC patients and control subjects according to the presence of EBV or HPV 16. Therefore, it can be concluded that the role of the aforementioned viruses is less likely in our population of OSCC patients.