Effects of the Healing Chambers in Implant Macrogeometry Design in a Low-Density Bone Using Conventional and Undersized Drilling.

BACKGROUND: The ideal installation technique or implant macrogeometry for obtaining an adequate osseointegration in low-density bone tissue follows a challenge in the implantology. AIMS AND OBJECTIVE: The aim of the present study was to evaluate the behavior of three osteotomy techniques and two implant macrogeometries in two low-density polyurethane blocks. The insertion torque (IT), initial stability, pullout resistance, and weight of the residual bone material deposited on the implants were assessed. MATERIALS AND METHODS: A total of 120 implants with two different macrogeometries were used. They were divided into six groups according to the implant macrogeometry and the drilling technique performed (n = 20 implants per group). The implants were installed in polyurethane blocks with pounds per cubic foot (PCF) 10 and PCF 20 densities. The IT, initial stability, pullout resistance, and weight residual bone were measured. RESULTS: Differences were found in the values referring to the macrogeometry of the implants and the type of osteotomy performed. In all groups, the initial stability of the PCF 10 blocks was quite low. The undersized osteotomies significantly increased the values measured in all tests in the PCF 20 density blocks. CONCLUSIONS: In conclusion, even when a modified (undersized) osteotomy technique is used, implants inserted in low-quality bone (type IV) can present problems for osseointegration due their low initial stability and bone resistance. However, the modification in the implant macrogeometry (with healing chambers) presented more quantity of bone on the surface after the pullout test.

Multivariate analysis of the influence of peri-implant clinical parameters and local factors on radiographic bone loss in the posterior maxilla: a retrospective study on 277 dental implants.

OBJECTIVES: The aim of the present study was to investigate whether peri-implant clinical parameters (modified plaque index (mPI), bleeding and/or suppuration on probing (B/SOP)) and local factors (type of prostheses, screw emergence, platform diameter, and abutment angulation) might contribute to the development of additional bone loss and peri-implantitis around dental implants. MATERIALS AND METHODS: Two hundred seventy-seven external hex connection implants placed in the posterior maxilla of 124 patients were retrospectively evaluated. They were divided into two groups: physiologic bone loss < 2 mm (PBL) or additional bone loss ≥ 2 mm (ABL). GEE logistic regression was applied to evaluate the influence of type of prostheses (implant-supported single crown (ISSC), fixed partial denture (ISFPD), and full denture (ISFD)) and clinical parameters (mPI and S/BOP) on bone loss. RESULTS: Among the 277 implants, 159 (57.4%) presented PBL and 118 (42.6%) presented ABL. Within the ABL group, 20.6% implants were diagnosed with peri-implantitis. mPI significantly correlated with the type of prosthesis and the highest value of mPI (index = 3) was observed in ISFD (23.8%). Moreover, peri-implantitis was more frequently associated with ISFD (32.79%) than ISSC and ISFDP (13.79% and 13.48, respectively) CONCLUSIONS: ISFD in the posterior maxilla presented high rates of ABL and showed a higher prevalence of peri-implantitis. None of the local factors seemed to contribute to the development of these conditions. Further investigations are needed to prospectively support the results of the present study. CLINICAL RELEVANCE: Patients rehabilitated with ISFD should be carefully monitored and have more frequent maintenance visits to prevent or control peri-implant bone loss.

Two to six-year disease resolution and marginal bone stability rates of a modified resective-implantoplasty therapy in 32 peri-implantitis cases.

BACKGROUND: Different nonsurgical, antibacterial, surgical, and regenerative approaches to treat peri-implantitis have been proposed, but there is no an actual "gold" standard treatment showing the most favorable results to counteract peri-implantitis effects. PURPOSE: To evaluate radiographically and clinically the disease resolution and peri-implant marginal bone stability rates of peri-implantitis cases treated through a combined resective-implantoplasty therapy in a moderate to long-term period. MATERIALS AND METHODS: Records of patients diagnosed with peri-implantitis and treated through the same protocol applying a combined resective-implantoplasty therapy with minimum 2-year follow-up were screened. Eligible patients were contacted and asked to undergo clinical and radiologic examination. Progressive marginal bone loss, bleeding on probing, suppuration, implant mobility, and implant fracture were considered to establish the disease resolution rate and peri-implant bone stability of the treated implants. RESULTS: Twenty-three patients with 32 treated implants fulfilled the inclusion criteria. Over the 2 to 6-year follow-up, (mean time: 3.4 ± 1.5 years), the disease resolution rate was 83% (patient level) and 87% (implant level). Four implants (13%) were lost or removed due to continuous MBL and osseointegration failure. At follow-up, peri-implant marginal bone remained stable with no further bone loss in 87% of the treated implants. BOP was absent in 89.3% (implant level), suppuration was resolved in all cases, and no pain or implant fracture was reported. CONCLUSION: Implantoplasty treated cases showed high disease resolution rate and peri-implant marginal bone stability. This surgical antibiofilm strategy can counteract peri-implantitis progression providing an adequate environment for implant function and longevity over a moderate to long-term period.

The impact of generic labels on the consumption of and adherence to medication: a randomized controlled trial.

Background: Although generic drugs are pharmacologically equivalent to their brand-name counterparts, prejudices against them remain strong. We assess the extent to which generic (versus brand-name) labels affect patients' consumption of and adherence to medication. Methods: One hundred one patients who received dental implants agreed to participate in a study. In a pre-surgery survey, most patients reported a positive view about generic drugs. After dental surgery, the patients were prescribed a once-daily analgesic regimen (50 mg tramadol hydrochloride) for up to 7 days. All the patients received at no cost the same brand-name medication with either a brand-name label (n = 51) or a generic label (n = 50) and were informed of the retail prices associated with both labels. Telephone follow-up was conducted 24 hours, four days, and seven days after surgery to assess the number of prescribed pills consumed and when their use was discontinued, the number of non-prescribed pills consumed, pain levels throughout the follow-up period, the perceived efficacy of the analgesic, and the willingness to recommend it to a friend. Results: The label manipulation impacted the participants' behaviour and subjective assessments. Discontinuation before the end of the 7-day period was more frequent under the generic (vs. brand-name) label condition. The patients in the generic label group were also more likely to consume non-prescribed pills (non-adherence). Additionally, the patients in the generic label group reported higher levels of pain. Conclusion: Generic labels may negatively affect adherence to treatment even if patients report ex ante positive evaluations of the quality of generics drugs.

Biofilm Analysis of Retrieved Dental Implants after Different Peri-Implantitis Treatments.

The aim of the current study was to analyse the planktonic growth of Streptococcus mutans on the surfaces of three implants retrieved after three different peri-implantitis treatments. Three implants from a male patient with high levels of bone loss were treated by mechanical debridement, chemical decontamination, and implantoplasty. After 4 months of follow-up, the implants were removed. The growth and biofilm formation were measured by spectrophotometry (OD630 nm) and scanning electron microscopy (SEM), after 48 hours of incubation. Results showed an average of Streptococcus mutans planktonic growth over the implants of 0.21 nm (mechanical debridement), 0.16 nm (chemical decontamination), and 0.15 nm (implantoplasty). Data were analysed by ANOVA and Tukey's test (p < 0.05 for chemical decontamination and implantoplasty). Implantoplasty and chemical decontamination showed the lowest levels of planktonic growth, indicating a possible influence of the modification procedures on the titanium surface on the initial biofilm attachment.

Prevalence of Peri-implant Diseases: Analyses of Associated Factors.

UNLABELLED: AIM. Identify the relationship between specific factors (age, sex, smoking, time of prosthesis in function, implant location, and width of peri-implant keratinized mucosa) and peri-implant diseases in patients from the Center of Research and Continuing Education in Implant Dentistry (CEPID) at the Federal University of Santa Catarina (UFSC), Brazil. MATERIALS AND METHODS: A cross-sectional study was conducted in 193 patients that had received 725 external-hexed cylindrical implants supporting functional prosthesis for at least 1 year (range from 1-9 years). Clinical examination included probing depths, bleeding on probing and/or suppuration. Radiographic exam was conducted to measure peri-implant bone levels. RESULTS: There was no statistically significance in the association between prevalence of peri-implant diseases and age, sex, time with prostheses in function and implant location variables independently. There was a statistically significant association between the independent variables of smoking and the width of keratinized peri-implant mucosa less than 2mm, and the presence of peri-implant diseases. When all the categories were evaluated together in relation with the peri-implant diseases, the prostheses in function for 5 years and more had association with presence of both, peri-implant mucositis an peri-implantitis. Peri-implantitis prevalence was higher for males with the prostheses in use for 5 years or more. Peri-implant mucositis was more associated with the participants over 57 years of age, with systemic disease and with the prostheses in function for more than 5 years. CONCLUSIONS: Smoking habits and the width of peri-implant keratinized mucosa as independent variables were associated with the prevalence of peri-implant diseases.

Influence of cantilever length and type of arch antagonist on bone loss in total implant-supported prostheses.

This study selected forty-two implants with full arch implantsupported fixed prostheses (with and without a cantilever) with at least five years' loading. Radiographic measurements were performed using Digimizer software (MedCalc Software, Belgium). Bone loss was measured on the distal side of the implant, from the surface of the platform to the edge of the bone crest, and the extent of the cantilever was measured from the distal surface of the last abutment to the end of the metal structure. Three groups were formed according the length of the cantilever: G1: cantilever ≤ 15 mm; G2: cantilever >15 mm; G3: no cantilever. Types of antagonists were grouped as: RP = removable complete denture; FP = fixed implant-supported prosthesis; ND = natural dentition. Data were analyzed according to the length of the cantilever and type of antagonist using Person's test to analyze normality and Student's t-test with P ≦ 0.05. No statistically significant difference was found between G1 and G2; however, increased bone loss was observed in both cantilever groups (G1 and G2) compared to G3 (P> 0.05). The antagonist showed no significant difference in bone loss ( P ≦ 0.05). Cantilevers showed increases in marginal bone loss. The type of antagonist did not influence bone loss.

Influence of cantilever length and type of arch antagonist on bone loss in total implant-supported prostheses. / Influence of cantilever length and type of arch antagonist on bone loss in total implant-supported prostheses.

This study selected forty-two implants with full arch implantsupported fixed prostheses (with and without a cantilever) with at least five years loading. Radiographic measurements were performed using Digimizer software (MedCalc Software, Belgium). Bone loss was measured on the distal side of the implant, from the surface of the platform to the edge of the bone crest, and the extent of the cantilever was measured from the distal surface of the last abutment to the end of the metal structure. Three groups were formed according the length of the cantilever: G1: cantilever  15 mm; G2: cantilever >15 mm; G3: no cantilever. Types of antagonists were grouped as: RP = removable complete denture; FP = fixed implant-supported prosthesis; ND = natural dentition. Data were analyzed according to the length of the cantilever and type of antagonist using Persons test to analyze normality and Students t-test with P  0.05. No statistically significant difference was found between G1 and G2; however, increased bone loss was observed in both cantilever groups (G1 and G2) compared to G3 (P> 0.05). The antagonist showed no significant difference in bone loss ( P  0.05). Cantilevers showed increases in marginal bone loss. The type of antagonist did not influence bone loss.

Are sectioning and soldering of short-span implant-supported prostheses necessary procedures?

The aim of this study was to evaluate the fit between dental abutments and the metal framework of a 3-unit fixed prosthesis screwed to two implants to determine whether sectioning and soldering of the framework are in fact necessary procedures. The study was based on a model of a metal framework of a 3-unit prosthesis screwed to two implants. A total of 18 metal frameworks were constructed and divided into 3 groups: (1) NS group - each framework was cast in one piece and not sectioned; (2) CS group - the components of each sectioned framework were joined by conventional soldering; and (3) LW group - the components of each sectioned framework were joined by laser welding. The control group consisted of six silver-palladium alloy copings that were not cast together. Two analyses were mperformed: in the first analysis, the framework was screwed only to the first abutment, and in the second analysis, the framework was screwed to both abutments. The prosthetic fit was assessed at a single point using a measuring microscope (Measurescope, Nikon, Japan) and the marginal gap was measured in micrometers. Statistical analysis was performed using analysis of variance (ANOVA), Scheffe's test, Student's t-test, and Mann-Whitney U test. The NS group had larger marginal gaps than the other groups (p<0.01), while the CS and LW groups had a similar degree of misfit with no significant difference between them. The results revealed that, in the case of short-span 3-unit fixed prostheses, the framework should be sectioned and soldered or welded to prevent or reduce marginal gaps between the metal framework and dental abutments.

The use of zygomatic implants for the rehabilitation of atrophic maxillas with 2 different techniques: Stella and Extrasinus.

The zygomatic implant anchorage is a surgical technique that provides a new perspective for patients with severe maxillary atrophy, increasing predictability and reduced cost of treatment, besides being a tool for the hardships of the rehabilitation of such a challenging region. This article describes 2 clinical cases with zygomatic implants with different techniques (Stella and Extrasinus) and both with immediate loading and accompanying clinical radiographic follow-up procedures of 12 and 24 months, respectively.

Clinical and radiographic evaluation of periodontal and peri-implant conditions in patients with implant-supported prosthesis.

The aim of the present study was to clinically and radiographically assess the peri-implant and periodontal conditions in partially edentulous patients with implant-supported fixtures installed, at least, one year prior to the study. 41 patients were examined by a calibrated examiner in relation to the following implant-associated parameters: Modified Plaque Index (mPlI), Modified Bleeding Index (mBI), probing depth (PD), clinical attachment level (CAL) and bleeding on probing of the bottom of the crevice (BOP). Also, the remaining teeth were assessed in terms of Plaque Index (PlI), Gingival Index (GI), PD, CAL and BOP. The peri-implant bone loss was evaluated by means of periapical radiographs. Measurements of pre-operatory and final bone levels allowed an estimation of bone loss associated to teeth and a comparison with bone loss around implants. None of the individuals presented late loss of implants until the examination took place. No statistically significant differences were observed between PlI (0.90+/-0.07) and mPlI (0.82+/-0.13), or between GI (0.11+/-0.02) and mBI (0.10+/-0.02). However, PD, CAL and BOP values were higher in implants than in teeth (Wald Test, p<0.01). Implants presented a mean annual bone loss during the study period of 0.77 mm (SE=0.06). Teeth virtually did not present any bone loss (mean value of 0.36%) whereas implants exhibited a bone loss value of 17.11%. Plaque accumulation and marginal inflammation did not differ between teeth and implants. However, subgingival inflammation was higher in implants than in teeth. The destruction measurements suggest greater losses in implants, as expected because of tissue remodelation.

A newly designed template device for use with the insertion of immediately loaded implants.

This article describes a newly designed surgical template that was used to facilitate dental implant placement. The implants were planned to function by loading them immediately. A case report describing the device and the benefits of its use for a patient with an edentulous mandible is presented. Four implants were placed in the anterior region of the mandible to support an immediately fixed prosthesis. Clinical and radiographic analyses were conducted postoperatively to evaluate bone loss and peri-implant soft-tissue healing. The salutary results demonstrated the positive value of this therapeutic approach and presented the advantages of shorter treatment times, fewer patient visits, lower costs, and elimination of secondary surgical procedures.