Inter-implant distance and buccal bone thickness for a novel implant design: a preclinical study

OBJECTIVES

This study assessed bone height between novel tapered implants at different inter-implant thread peak (TP) distances, and the impact of TP distance from outer buccal bone (BB) on marginal bone levels (MBL).

MATERIALS AND METHODS

Fully tapered implants with 0.5-mm thread depth and TP diameter 1 mm wider than the shoulder diameter were placed in healed ridges of minipigs. On one side, four implants were placed with inter-implant TP distances of 1, 2, or 3 mm corresponding to inter-implant implant shoulder distances of 2, 3, and 4 mm respectively. Three implants were placed on the other side with TP distances to outer BB of > 1 mm, 0.5-1 mm, or < 0.5 mm. After 12 weeks, (a) first bone-to-implant contact (fBIC), total BIC, bone area-to-total area (BATA), and coronal bone height between implants (Bi ½ max) for inter-implant distance, and (b) fBIC, BIC, and perpendicular crest to implant shoulder (pCIS) for BB were evaluated.

RESULTS

No significant differences in bone healing and inter-implant bone height were noted for any of the TP distances. BB resorption was significant when TP distance to outer BB was < 0.5 mm. However, fBIC was lowest with TP to outer BB of 1.75 mm.

CONCLUSIONS

Inter-implant bone height between adjacent implants can be maintained even at an inter-implant TP distance as low as 1 mm. A minimum TP to outer BB distance of 0.75 mm is required for predictable maintenance of MBL.

CLINICAL RELEVANCE

Inter-implant distance and BB thickness are clinically relevant and require preclinical research to clarify concepts.

Referral Compliance Following a Diabetes Screening in a Dental Setting: A Scoping Review

With type 2 diabetes prevalence increasing in Australia, and the condition associated with significant morbidity and mortality, screening for dysglycaemia in the dental setting has been proposed to identify asymptomatic individuals. Screening commences with a risk assessment, and individuals identified at elevated risk for having diabetes are then referred to their medical practitioner for confirmation of their glycemic status. Therefore, for screening to be effective, individuals need to adhere to their oral health professionals’ (OHP) advice and attend their medical follow-ups. This review aims to investigate the literature on referral compliance following a risk assessment in the dental setting and identify barriers and facilitators to screened individuals’ referral compliance. A scoping review of the literature was undertaken, selecting studies of diabetes screening in a dental setting that recorded compliance to referral to follow-up, and explored any barriers and facilitators to adherence. Fourteen studies were selected. The referral compliance varied from 25 % to 90%. Six studies reported barriers and facilitators to attending medical follow-ups. Barriers identified included accessibility, cost, knowledge of the condition, and OHP characteristics.

Risk factors for periodontitis & peri-implantitis

Risk is part of all health professions and generally indicates the chance of getting some form of illness. For dental practitioners this includes periodontitis or peri-implantitis, the focus of this issue. Many risk factors are involved in the development of disease and most likely interact or overlap. Most patients will probably have multiple risk factors, some of which will be the same for both periodontitis and peri-implantitis. The most recent classification of periodontal disease recognises the importance of risk factors and contemporary dental practice requires that clinicians be aware of and manage them. Broadly speaking risk factors can be patient, environment or practitioner related. Patient risk factors would include socio-economic status, smoking, substance use disorders, diabetes, diet and dietary supplements, mental health disorders, old age, poor home dental care or understanding of the need for good home care and use of medications. Environmental modification of the host response through gene function is an emerging risk factor. Lastly, practitioner-related factors in implant dentistry are now known to affect risk. These would include the use of digital technology, but patient related factors such implant location and the body's reaction to an implant itself add to the risk of developing disease. This edition of Periodontology provides an uptodate review of many of these risk factors and their impact summarising current knowledge.

Mental health and periodontal and peri-implant diseases

Mental health disorders, particularly depression and anxiety, affect a significant number of the global population. Several pathophysiological pathways for these disorders have been identified, including the hypothalamic-pituitary-adrenal axis, autonomic nervous system, and the immune system. In addition, life events, environmental factors, and lifestyle affect the onset, progression, and recurrence of mental health disorders. These may all overlap with periodontal and/or peri-implant disease. Mental health disorders are associated with more severe periodontal disease and, in some cases, poorer healing outcomes to nonsurgical periodontal therapy. They can result in behavior modification, such as poor oral hygiene practices, tobacco smoking, and alcohol abuse, which are also risk factors for periodontal disease and, therefore, may have a contributory effect. Stress has immunomodulatory effects regulating immune cell numbers and function, as well as proinflammatory cytokine production. Stress markers such as cortisol and catecholamines may modulate periodontal bacterial growth and the expression of virulence factors. Stress and some mental health disorders are accompanied by a low-grade chronic inflammation that may be involved in their relationship with periodontal disease and vice versa. Although the gut microbiome interacting with the central nervous system (gut-brain axis) is thought to play a significant role in mental illness, less is understood about the role of the oral microbiome. The evidence for mental health disorders on implant outcomes is lacking, but may mainly be through behaviourial changes. Through lack of compliance withoral hygiene and maintenance visits, peri-implant health can be affected. Increased smoking and risk of periodontal disease may also affect implant outcomes. Selective serotonin reuptake inhibitors have been linked with higher implant failure. They have an anabolic effect on bone, reducing turnover, which could account for the increased loss.

Diabetes and Oral Health (DiabOH): The Perspectives of Primary Healthcare Providers in the Management of Diabetes and Periodontitis in China and Comparison with Those in Australia

Diabetes and periodontal disease are highly prevalent conditions around the world with a bilateral causative relationship. Research suggests that interprofessional collaboration can improve care delivery and treatment outcomes. However, there continues to be little interprofessional management of these diseases. DiabOH research aims to develop an interprofessional diabetes and oral health care model for primary health care that would be globally applicable. Community medical practitioners (CMPs), community health nurses (CNs), and dentists in Shanghai were recruited to participate in online quantitative surveys. Response data of 76 CMPs, CNs, and dentists was analysed for descriptive statistics and compared with Australian data. Health professionals in China reported that, while screening for diabetes and periodontitis, increasing patient referral and improving interprofessional collaboration would be feasible, these were not within their scope of practice. Oral health screening was rarely conducted by CMPs or CNs, while dentists were not comfortable discussing diabetes with patients. Most participants believed that better collaboration would benefit patients. Chinese professionals concurred that interprofessional collaboration is vital for the improved management of diabetes and periodontitis. These views were similar in Melbourne, except that Shanghai health professionals held increased confidence in managing patients with diabetes and were more welcoming to increased oral health training.

Knowledge and attitudes towards periodontal health among Australians diagnosed with diabetes

Diabetes and periodontitis are two major diseases affecting the Australian population. Despite the established interrelationship between the diseases, the knowledge of people with diabetes about this interrelationship is limited. This study investigated the knowledge of individuals with diabetes towards periodontal health in Australia. Adults diagnosed with diabetes participated in a survey asking about demographics, medical history, symptoms in the oral cavity, oral hygiene, attendance at the dentist and their knowledge of the interactions between periodontal disease and diabetes. The survey was completed by 113 participants, most of whom thought their diabetes was well controlled. Over half reported bleeding on brushing and one-third reported swollen gums. More than half (53.6%) the respondents were unaware of any complications of diabetes associated with the oral cavity, especially periodontal disease. Most respondents did not talk to their dentist about diabetes (53.6%), yet most wanted to know more about the effects of diabetes on gum health (75.3%). These findings demonstrate that, in this survey, adult Australians diagnosed with diabetes have limited knowledge about how periodontal disease affects them. These individuals, who are at a higher risk of periodontal disease, need to be better informed of the established bidirectional relationship between diabetes and oral health by all health professionals.

Early implant placement in ridge preserved extraction sockets: A pre-clinical in vivo study

OBJECTIVES

The aim was to analyse the outcomes of early implant placement after 6 and 12 weeks of healing in ridge preserved sites in a canine model.

MATERIALS AND METHODS

Implants were placed in second maxillary incisors sites in 9 dogs 6 weeks after grafting of the sockets with 90% deproteinized bovine bone mineral in 10% collagen matrix (DBBMC) and closure with resorbable type I/III porcine collagen matrix (PCM). The implants were randomly assigned to 6 (T6) and 12 (T12) weeks of healing.

RESULTS

The percentage of bone-to-implant contact (%BIC), old bone, new bone and residual DBBMC was similar between T6 and T12. In relation to the implant shoulder (IS), the original bone crest (IS-ROB) was more apical on the buccal than the palatal side. The regenerated bone crest (IS-C) and IS-ROB were similar between groups. However, the distance from IS to first bone-to implant contact (IS-fBIC) was significantly less in T12 compared with T6 (p = .022; Wilcoxon signed-rank test). The bucco-palatal ridge dimensions between T6 and T12 were similar.

CONCLUSIONS

This study confirms that implants can successfully be placed early in ridge preserved maxillary second incisor sites and are osseointegrated by 6 weeks. There were significantly lower IS-fBIC values at 12 weeks than at 6 weeks on the buccal aspect. The original buccal bone crest underwent greater corono-apical resorption than the palatal crest. The %BIC, relative proportions of mineralized tissues and dimensions of the alveolar ridge demonstrated stability between 6 and 12 weeks of healing.

"Say Ahhh": Experience and Views on Halitosis Management in the General Public in Victoria, Australia

Introduction

Halitosis is common and can have a significant impact on quality of life. It is attributed to both intraoral and extraoral causes. Although halitosis treatment depends on the aetiology, little is known about consumers’ perception of halitosis causes and the types of assistance sought. The Say Ahhh Study aimed to explore the interprofessional care for halitosis and improve understanding by the general public. Phase 1 explored the perceptions of health care providers. This article reports the findings of Phase 2, which explored the general public's knowledge of halitosis, its management, and help-seeking behaviour.

Methods

Patients and clients at 2 medical clinics, 3 dental clinics, and 2 pharmacies in Melbourne and rural Victoria were approached and invited to participate in a short semistructured interview. Qualitative data was thematically analysed.

Results

A total of 122 participants (54 males, 66 females, 2 missing) were interviewed. Participants’ past experience with halitosis influences their understanding of the cause. Halitosis was attributed mostly to poor oral hygiene and diet and less commonly to systemic disease. Their perception of the condition's severity influenced whether they seek professional help. Their perceived roles of health professionals and ease of access influenced their choice of health professionals to seek help from.

Conclusion

The Victorian general public is aware of the causes of halitosis and the available treatment options. Choice of treatment and help-seeking behaviour are influenced by experience, perceived severity of the condition, and perceived role of health professionals and their accessibility.

Encode Protocol Versus Conventional Protocol for Single-Implant Restoration: A Prospective 2-Year Follow-Up Randomized Controlled Trial

The Encode protocol for restoring single dental implants simplifies the implant impression technique by using a specially coded transmucosal healing abutment. It allows recording of the implant position without the removal of the healing abutment. This prospective randomized controlled clinical trial compares the 2-year clinical performance of the Encode and the conventional protocols for restoring single implants. A total of 47 implants were randomly allocated for restoration by the Encode (24 implants) and the conventional (23 implants) protocols. The implants were reviewed after 2 years to evaluate patient satisfaction, esthetics, prosthesis cleansability, mucosal health, bleeding on probing (BoP), metallic discoloration, probing pocket depth (PPD), marginal bone level (MBL), and quality of the proximal and occlusal contacts. In addition, all forms of complications were reported. Twenty Encode and 17 conventional implants were reviewed. The 2 protocols were comparable in all variables. A consistent increase of open proximal contacts was detected for the 2 protocols. Two Encode (10.0%) and 4 conventional (21.1%) crowns had screw loosening that was predominantly associated with cross-pins. This had led to the failure of 2 conventional crowns. Three Encode (15.0%) and 2 conventional (11.8%) crowns displayed ceramic chipping. The Encode and the conventional crowns had survival rates of 100.0% and 89.5%, respectively. From the biologic, prosthetic, and esthetic perspectives, the Encode and the conventional protocols provided a comparable clinical outcome over a 2-year duration.

Primary stability and healing outcomes of apically tapered and straight implants placed into fresh extraction sockets. A pre-clinical in vivo study

OBJECTIVES

To compare the stability of apically tapered and straight (non-tapered cylindrical) implants at the time of immediate placement and to histologically evaluate the healing outcomes after 6 weeks.

MATERIALS AND METHODS

The second maxillary incisors were extracted bilaterally in nine dogs. After randomization, apically tapered and straight implants with a 3.3 mm shoulder diameter were inserted into the extraction sockets. The implant stability quotient (ISQ) of the implants was recorded after placement. Peri-implant defects on the buccal aspect were filled with deproteinized bovine bone mineral and covered with resorbable type I/III porcine collagen matrix. After 6 weeks of healing, sections were prepared for histological and morphometric analysis.

RESULTS

All implant sites healed uneventfully. The apically tapered implants had significantly higher ISQ values compared to straight implants at placement (p = .009). The histomorphometric outcomes 6 weeks following implant placement in both experimental groups were similar, except in the apico-palatal region. Apically tapered implants demonstrated significantly less percentage bone-to-implant contact (p = .035) in the apico-palatal region. At both implant types, substantial corono-apical resorption of the buccal bone wall was noted in the coronal 2 mm of the implant.

CONCLUSION

Apically tapered implants had significantly higher ISQ values at immediate placement compared to straight implants. The healing outcomes and remodelling of the buccal bone wall were similar for both implant designs. In the apico-palatal region, there was less %BIC at the implant surface at apically tapered implants compared to straight implants.

The effectiveness of interprofessional education for the management of diabetes and oral health: A systematic review

Diabetes and oral disease are becoming increasingly prevalent in Australia and share a bidirectional relationship. Despite this relationship, collaboration between the medical and dental professions is limited. This study assessed the available evidence of interprofessional educational programs on diabetes and oral health management and their effects on knowledge and confidence of health professionals involved. This review included randomized and non-randomized-controlled trials and before-and-after comparison studies in English with no limits on the year of publication. Electronic databases Medline, EMBASE, Emcare, and CINAHL were systematically searched and studies were critically appraised. Nineteen articles were identified from 411 for full-text screening. Four studies of a quasi-experimental design with a pre- and posttest evaluation were included in the review. Of these, three studies reported positive changes in the participants' knowledge of the roles of other healthcare professionals with improved attitudes toward interprofessional collaboration and communication, and one reported increased confidence of medical and dental professionals when working in an interprofessional team. Interprofessional education should improve health professionals' attitudes and knowledge of the roles of other health professionals in managing diabetes and oral health and their confidence in working together. However, given the limited availability of interprofessional education on diabetes and oral health management, continuous research in this area would improve the evidence base.

The influence of deproteinised bovine bone mineral on dimensional changes in the maxillary second incisor socket

OBJECTIVES

To investigate the dimensional changes following the extraction of maxillary second incisors and to evaluate the influence of deproteinised bovine bone mineral on the healing outcomes.

MATERIALS AND METHODS

The second maxillary incisors in nine dogs were extracted bilaterally in a minimally traumatic manner. Deproteinised bovine bone mineral with collagen (DBBMC) and a collagen matrix (CM) was placed in one socket with the contralateral socket left to heal naturally. After 3 months of healing, the dogs were sacrificed and the pre-maxilla resected. Cone beam computerised tomography scans (CBCTs) were obtained and the specimens prepared for histological preparation and analysis. Surface scans of study models taken pre- and post-extraction were digitally subtracted to analyse volumetric changes.

RESULTS

All dogs healed uneventfully without any complications. No inflammation was seen, and DBBMC was well integrated into a network of mineralised tissues, bone marrow and connective tissue. The horizontal width of the buccal crest was found to be significantly greater in grafted sockets, but the vertical height to be similar. No significant difference was seen in regard to volumetric changes in sockets over 3 months post-extraction.

CONCLUSION

Maxillary second incisor sockets of dogs grafted with DBBMC post-extraction had significantly greater horizontal width at the ridge crest compared with ungrafted sockets. Volumetric analysis revealed no significant difference between grafted and non-grafted sockets, suggesting possible soft tissue thickening post-extraction to counteract osseous resorption.

Group 4 ITI Consensus Report: Risks and biologic complications associated with implant dentistry

OBJECTIVES

The aim of Working Group 4 was to address topics related to biologic risks and complications associated with implant dentistry. Focused questions on (a) diagnosis of peri-implantitis, (b) complications associated with implants in augmented sites, (c) outcomes following treatment of peri-implantitis, and (d) implant therapy in geriatric patients and/or patients with systemic diseases were addressed.

MATERIALS AND METHODS

Four systematic reviews formed the basis for discussion in Group 4. Participants developed statements and recommendations determined by group consensus based on the findings of the systematic reviews. These were then presented and accepted following further discussion and modifications as required by the plenary.

RESULTS

Bleeding on probing (BOP) alone is insufficient for the diagnosis of peri-implantitis. The positive predictive value of BOP alone for the diagnosis of peri-implantitis varies and is dependent on the prevalence of peri-implantitis within the population. For patients with implants in augmented sites, the prevalence of peri-implantitis and implant loss is low over the medium to long term. Peri-implantitis treatment protocols which include individualized supportive care result in high survival of implants after 5 years with about three-quarters of implants still present. Advanced age alone is not a contraindication for implant therapy. Implant placement in patients with cancer receiving high-dose antiresorptive therapy is contraindicated due to the associated high risk for complications.

CONCLUSIONS

Diagnosis of peri-implantitis requires the presence of BOP as well as progressive bone loss. Prevalence of peri-implantitis for implants in augmented sites is low. Peri-implantitis treatment should be followed by individualized supportive care. Implant therapy for geriatric patients is not contraindicated; however, comorbidities and autonomy should be considered.

Periodontal treatment in private dental practice: a case-based survey

BACKGROUND

This study aimed to assess the management and referral patterns of Victorian general dental practitioners based on periodontal diagnosis.

METHODS

Following ethics approval, Victorian general dental practitioners were invited to complete five randomized text-based periodontitis scenario questionnaires. Based on their diagnosis, respondents were asked for their management options and asked to specify who would perform these treatments. Respondents were also asked about referral procedures.

RESULTS

One hundred and thirty-five dentists attempted the survey. Most were in group practice and based in Melbourne. Of the total respondents, 22.5% worked in a practice employing a hygienist. The management of periodontal disease was appropriate, and treatment options increased with severity. As severity increased, patients were more likely to be referred to a periodontist. Periodontal services referred by general dentists to dental hygienists increased with the number of days the hygienists worked within a practice. Over- and underdiagnosis did not markedly affect management. The recommendation of antibiotics, mouthwashes and periodontal surgery varied depending on year and school of graduation.

CONCLUSIONS

The general dentists that completed the survey are managing periodontal conditions appropriately and according to current guidelines.

Retrospective success and survival rates of dental implants placed after a ridge preservation procedure

AIM

Ridge preservation is any procedure that takes place at the time of, or shortly after an extraction, to minimise resorption of the ridge and maximise bone formation within the socket. The aim of this project is to investigate the outcome of implant treatment following ridge preservation and compare it to an ungrafted implant control group.

METHODS AND MATERIALS

Following ethics approval, an electronic and manual search of patient records was conducted, and appropriate cases of implant placement following a ridge preservation procedure were identified. Forty-two patients with 51 implants at ridge-preserved sites were examined by one author (PA) with the following parameters assessed at each implant: pocket probing depth, bleeding on probing, presence/absence of plaque and radiographic bone loss. Clinical and radiographic findings were compared to an ungrafted implant control group and analysed by years in function.

RESULTS

There was a 100% survival rate of implants in ridge-preserved sites. In the majority of cases, ridge preservation was performed in the anterior maxilla with a flap raised and the use of deproteinised bovine bone mineral and collagen membrane materials. The mean time in function was 31 (±24) months with a range of 2-102 months. Differences in the mean PPD, BOP, plaque index and radiographic bone loss were not statistically significant between implants at ridge-preserved or ungrafted sites. The overall success rate was around 58% for ungrafted implants and around 51% for implants in ridge-preserved sites. However, this difference was not statistically significant.

CONCLUSION

In this retrospective study, implant placement at ridge-preserved sites was a predictable procedure that led to very high survival rates and similar success rates to implant placement at ungrafted sites.

Periodontal considerations in older individuals

In the next few years there will be a great increase in the percentage of the population aged over 65. Not only will they have more teeth than previous generations, but also a large number of implants. The increase in age is accompanied by an increase in the prevalence and incidence of periodontal diseases. In addition, there is a decrease in manual dexterity and an increase in co-morbidity and medications affecting the oral cavity. Dental care in aged care facilities can be poor and access to dental professionals difficult. This article discusses these issues.

Periodontal diagnosis in private dental practice: a case-based survey

BACKGROUND

Despite the prevalence of periodontitis in Australia, there are few reports regarding periodontal diagnosis and therapies in the general dental practice setting. This study aimed to assess the degree of diagnostic accuracy in periodontal cases of Victorian general dental practitioners.

METHODS

Following ethics approval, dentists were invited to complete a scenario-based questionnaire on the Australian Dental Association Victorian Branch (ADAVB) website. Five text-based clinical scenarios (from a total of 10) were randomly presented, representing patients with a range of disease levels from periodontal health/gingivitis to severe periodontitis, and respondents were asked what examinations they would usually perform. Based upon the presented results of periodontal and radiographic examinations, a periodontal diagnosis was requested.

RESULTS

One hundred and thirty-five dentists attempted the survey. Most were in group practice and based in Melbourne; 22.5% of respondents worked in a practice employing a hygienist. The clinical parameters most commonly measured to diagnose periodontal disease were pocket depth and mobility. The majority of respondents diagnosed health, gingivitis and mild periodontitis correctly compared to American Academy of Periodontology guidelines. However, moderate periodontitis tended to be diagnosed as severe.

CONCLUSIONS

Dentists in Victoria used appropriate clinical parameters when assessing periodontal disease and were generally accurate in their diagnoses. There is a need for consensus regarding diagnostic definitions.

Comparison of clinical and cone beam computed tomography measurements to diagnose furcation involvement

AIM

This study aimed to determine the degree of discrepancy between clinical measurement of furcation involvement (FI) and cone beam computed tomography image analysis of multirooted teeth.

METHODS

FI measurements obtained from clinical records were compared to CBCT images of the same teeth to determine the degree of discrepancy between CBCT FI grading and clinical FI grading.

RESULTS

Of the hundred and fifty-four sites analysed, 22% of FI measurements from probing and CBCT were in agreement. Fifty-eight percent of clinical FI recordings were overestimated, and 20% were underestimated when compared to CBCT analysis.

CONCLUSION

Clinical recording of FI is both over and underestimated compared to CBCT analysis. This was highest for probing recording grade I furcation involvement where it was highly overestimated. The occurrence of over and under estimation of FI will affect the assignment of prognosis to multirooted teeth, which can influence treatment planning for periodontal therapy and may result in inappropriate treatment.

Ridge dimensional changes following single-tooth extraction in the aesthetic zone

OBJECTIVES

The aims of this study were to investigate the magnitude of the dimensional changes following extraction of a single tooth in the aesthetic zone over a 6- to 8-week healing period and to examine the degree and pattern of resorption of the buccal bone plate during this time frame.

MATERIALS AND METHODS

Twenty subjects who were to have a single tooth in the aesthetic zone extracted and replaced by an implant after a 6-8 week healing period were selected for this study. Hard and soft tissue measurements of the extraction site were obtained pre-extraction and were repeated 6-8 weeks post-extraction at defined points using a key.

RESULTS

After a 6- to 8-week healing period, the total ridge thickness in the crestal midline reduced by 15% of the original value. The buccal plate resorbed in an "inverted V shape". Forty-two percentage of subjects had lost 4 mm or more of buccal bone in the midpoint of the extraction socket.

DISCUSSION

After a 6- to 8-week healing period post-extraction, there were significant reductions in the hard and soft tissue dimensions of the ridge, most notably on the most coronal mid-buccal aspect. All implants placed required simultaneous augmentation as a result.

Preservation of crestal bone by implant design. A comparative study in minipigs

OBJECTIVES

To compare crestal bone modeling at three bone level design implants; Astra Tech Osseospeed(™) Implant (AOI), Straumann(®) Bone Level Implant (SBLI) and NobelReplace(™) Tapered Groovy Implant (NBTI).

MATERIALS AND METHODS

In 12 minipigs one implant of each design was placed on each side of the mandible with submerged healing. The implant platform was placed at the level of the crest (Group 0), and 1 mm above the crest (Group + 1 mm). In addition, one Straumann(®) Tissue Level Implant STLI was placed as a control on each side of the mandible. At 4 weeks, six animals were sacrificed. In the remaining six animals healing abutments were connected until 12 weeks. Clinical, radiographic, and histologic analyses were made. ANOVA and Mann-Whitney U-tests were used to evaluate differences in bone levels between implant designs.

RESULTS

At 4 weeks there was no statistically significant difference in bone changes between implant designs. At 12 weeks implants in Group + 1 mm had minimal bone changes with no differences between implant designs. In Group 0, the AOI and SBLI preserved more crestal bone than NBTI (P < 0.01). Mean distance from the implant platform to the buccal bone was -0.1 ± 0.2 mm for AOI, -0.3 ± 0.3 mm for SBLI, and -1.0 ± 0.3 mm for NBTI. Mean radiographic bone levels from the implant platform were -0.1 ± 0.4 mm for AOI, 0.0 ± 0.3 mm for SBLI and -0.9 ± 0.8 mm for NBTI.

CONCLUSION

Greater bone preservation was observed for the AOI and SBLI compared with the NBTI.

Evidence for a smooth onset of deformation in the neutron-rich Kr isotopes

The neutron-rich nuclei 94,96Kr were studied via projectile Coulomb excitation at the REX-ISOLDE facility at CERN. Level energies of the first excited 2(+) states and their absolute E2 transition strengths to the ground state are determined and discussed in the context of the E(2(1)(+)) and B(E2;2(1)(+)→0(1)(+)) systematics of the krypton chain. Contrary to previously published results no sudden onset of deformation is observed. This experimental result is supported by a new proton-neutron interacting boson model calculation based on the constrained Hartree-Fock-Bogoliubov approach using the microscopic Gogny-D1M energy density functional.

Pattern of cigarette smoking effect on periodontal pocketing and attachment loss: a retrospective study

AIM

The aim of the present retrospective study was to evaluate the local effects of smoking on periodontium and to assess the patterns of periodontitis (pocket depths and attachment loss) in smokers and non-smokers.

METHODS

In this study, records of 126 non-smokers and 51 smokers (≥ 5 cigarettes/day) periodontitis patients were evaluated and probing pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BOP) data were collected from clinical patients records. Patients' data were subject to two sample t-tests to assess the difference between the groups and to analysis of variance using the generalized linear model to seek associations between smoking and site positions, age and clinical parameters.

RESULTS

The difference between CAL of smokers and non-smokers was greatest at the anterior maxillary palatal sites (P = 0.002) and reached 1 mm. When the effect of different site positions as well as smoking as a between subject variable and age as a co-variate on the attachment level measurements were assessed using analysis of variance, significant effects for smoking, jaw (lower versus upper) and anterior-posterior position as well as age were detected. No significant interactions were found between smoking and any of the three position variables.

CONCLUSION

Lack of interaction between smoking and any of the three position variables indicates that the destructive effects of smoking on the periodontal tissues maybe mainly from systemic side-effects and almost independent of the site position within the mouth, although some additional local effects may be present in areas such as anterior palatal sites.

Non-surgical management of periodontal disease

Non-surgical removal of plaque and calculus has been part of the initial phase of the management of patients with gingivitis and periodontitis for decades. It consists of patient motivation and oral hygiene instruction as well as mechanical removal of supra and subgingival plaque deposits. The purpose of this review was to assess recent changes. The article reports on changes in our understanding of plaque as a biofilm, developments in patient plaque control, chemical plaque control and scaling instruments. It also comments on full-mouth disinfection, the use of lasers and host modulation. Modern technology has made removal of microbial deposits by the patient and dental professionals more efficient. However, other advancements need to be used in conjunction with mechanical debridement at this time.

Ridge preservation: does it actually work?

Post-extraction the alveolus undergoes modelling which reduces height and width. This may present a problem for subsequent crown and bridge or implant therapy. Ridge preservation is the use of grafts and/or membranes to try to minimize the loss of the alveolar ridge. Extraction sockets have been filled with autogenous, allogenic and alloplastic materials. Membranes or soft tissue were used to contain the graft. More recently biodegradable sponges and materials coated in growth factors have been tested. Studies have primarily looked at either maintenance of vertical and horizontal dimensions or the healing of the socket and how much of the graft material is incorporated into the newly formed bone. Irrespective of method or materials, there seems to be some maintenance of the alveolus. Bone fill seems to occur in preserved extraction sockets, but in most cases with a high percentage of residual graft particles. In general, there is a lack of evidence to show that ridge preservation aids in correct 3-D implant placement, maintains hard and soft tissue volume over a prolonged period of time or for success and survival of implants placed into ridge preserved sockets. Still the most effective way to maintain ridge volume is to keep the natural tooth.

Examination of 'lipotoxicity' in skeletal muscle of high-fat fed and ob/ob mice

Excess lipid accumulation resulting from an elevated supply of plasma fatty acids is linked to the pathogenesis of the metabolic syndrome and heart disease. The term 'lipotoxicity' was coined to describe how lipid accumulation leads to cellular dysfunction and death in non-adipose tissues including the heart, pancreas and liver. While lipotoxicity has been shown in cultured skeletal muscle cells, the degree of lipotoxicity in vivo and the functional consequences are unresolved. We studied three models of fatty acid overload in male mice: 5 h Intralipid((R)) and heparin infusion, prolonged high fat feeding (HFF) and genetic obesity induced by leptin deficiency (ob/ob mice). Markers of apoptosis, proteolysis and autophagy were assessed as readouts of lipotoxicity. The Intralipid((R)) infusion increased caspase 3 activity in skeletal muscle, demonstrating that enhancing fatty acid flux activates pro-apoptotic pathways. HFF and genetic obesity increased tissue lipid content but did not influence apoptosis. Gene array analysis revealed that HFF reduced the expression of 31 pro-apoptotic genes. Markers of autophagy (LC3beta and beclin-1 expression) were unaffected by HFF and were associated with enhanced Bcl(2) protein expression. Proteolytic activity was similarly unaffected by HFF or in ob/ob mice. Thus, contrary to our previous findings in muscle culture in vitro and in other non-adipose tissues in vivo, lipid overload did not induce apoptosis, autophagy or proteolysis in skeletal muscle. A broad transcriptional suppression of pro-apoptotic proteins may explain this resistance to lipid-induced cell death in skeletal muscle.

Ridge preservation techniques for implant therapy

PURPOSE

The aim of this review was to evaluate the techniques and outcomes of postextraction ridge preservation and the efficacy of these procedures in relation to subsequent implant placement.

MATERIALS AND METHODS

A MEDLINE/PubMed search was conducted and the bibliographies of reviews from 1999 to March 2008 were assessed for appropriate studies. Randomized clinical trials, controlled clinical trials, and prospective/retrospective studies with a minimum of five patients were included.

RESULTS

A total of 135 abstracts were identified, from which 53 full-text articles were further examined, leading to 37 human studies that fulfilled the search criteria. Many different techniques, methodologies, durations, and materials were presented in the publications reviewed, making direct comparison difficult.

CONCLUSIONS

Despite the heterogeneity of the studies, it was concluded that ridge preservation procedures are effective in limiting horizontal and vertical ridge alterations in postextraction sites. There is no evidence to support the superiority of one technique over another. There is also no conclusive evidence that ridge preservation procedures improve the ability to place implants.

Which type of scaling system is best?

DATA SOURCES

Medline and the Cochrane Central register of Controlled Trials were searched for relevant studies.

STUDY SELECTION

Randomised controlled trials and controlled clinical trials conducted in vitro or in vivo on human teeth, which used plaque, bleeding, gingivitis or pocket depth, clinical attachment level, microbiological findings, patient perception and treatment time as outcome measures, were included. Case reports, letters and narrative or historical reviews were excluded and only English-language papers were considered.

DATA EXTRACTION AND SYNTHESIS

The studies included differed in design and outcome so a qualitative summary was presented.

RESULTS

Fifteen studies met the inclusion criteria. The Vector (Dürr Dental, Bietigheim-Bissingen, Germany) ultrasonic scaler (VUS) provided clinical and microbiological periodontal healing results comparable to scaling and root planing and a conventional ultrasonic system in moderately deep pockets.

CONCLUSIONS

The VUS may be used as a gentle root debridement device for supportive periodontal therapy, as an alternative to other conventional ultrasonic systems. The operator should consider, however, the extra time needed for instrumentation.