Dental implants inserted in male versus female patients: a systematic review and meta‐analysis

The aim of this meta‐analysis was to test the null hypothesis of no difference in the failure rates, marginal bone loss (MBL) and post‐operative infection for implants inserted in male or female patients, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in December 2014. Eligibility criteria included clinical human studies, either randomized or not. Ninety‐one publications were included, with a total of 27 203 implants inserted in men (1185 failures), and 25 154 implants inserted in women (1039 failures). The results suggest that the insertion of dental implants in male patients statistically affected the implant failure rates (RR 1·21, 95% CI 1·07–1·37, P = 0·002). Due to the limited number of studies reporting results on MBL, it is difficult to estimate the real effect of the insertion of implants in different sexes on the marginal bone level. Due to lack of satisfactory information, meta‐analysis for the outcome ‘post‐operative infection’ was not performed. The results have to be interpreted with caution due to the presence of several confounding factors in the included studies.     

Mastication and jaw motion of partially edentulous patients are affected by different implant‐based prostheses

The main goal of prosthetic treatment is to restore masticatory function. However, insufficient evidence supports the recommendation of one specific prosthetic intervention for partially edentulous patients. Function after the use of three different prostheses by the same partially edentulous subject. Mastication was assessed in 12 subjects (mean age 62·6 ± 7·8 years) after they had used removable partial dentures (RPDs), implant‐supported partial dentures (IRPDs) and implant‐fixed partial dentures (IFPDs). Masticatory ability (MA) was estimated by visual analogue scale questionnaire, while the mandibular chewing motion was evaluated by kinesiographic device, representing an objective measurement of masticatory function. Data were analysed by repeated‐measures anova followed by Tukey–Kramer (P < 0·05). MA improved after IRPD and IFPD use (P < 0·05). Opening, closing and total cycle time duration were reduced after both IRPD and IFPD use (P < 0·05), irrespectively the implant prosthesis type. IFPDs and IRPDs restore the masticatory function of partially edentulous patients better than RPDs.     

Marginal bone loss of two implant systems with three different superstructure materials: a randomised clinical trial

Marginal bone level is a criterion for implant success. The aetiological factors of bone loss have not been clarified. The aim of this study was to evaluate the influence of implant systems and prosthetic materials on the marginal bone loss. Twenty‐three patients participated; two implant systems and three superstructure materials were used in this study. Twenty‐two of the implants were restored with porcelain fused to base metal alloy (BMA), 25 with porcelain fused to noble metal alloy (NMA) and 20 with zirconium oxide‐based ceramics. Radiographs were taken at baseline and 3, 6 and 12 months after loading. Crestal bone‐level changes were assessed with digital subtraction radiographs. The effects of superstructure materials and implants were evaluated with one‐way anova and independent samples t‐test, respectively (α = 0·05). The mean crestal bone loss was found 0·483 mm in 3 months, 0·622 mm in 6 months and 0·816 mm in 12 months. Prosthetic materials were found to have greater effect (β = 0·575, P = 0·015) on crestal bone loss than implant systems (P > 0·05). The porcelain fused to BMA restorations showed higher crestal bone loss than NMA‐based restorations (P = 0·003) at 3 months, (P = 0·038), at 6 months and (P = 0·00) at 12 months; however, crestal bone loss differences between NMA and zirconia were not significant (P = 0·629) at 3 months, (P = 0·974) at 6 months and (P = 1) at 12 months. Within the limitations of this study, our results revealed that rather than the implant systems, prosthetic materials seemed to have an effective role on crestal bone.     

Effects of the Paced Auditory Serial Addition Task (PASAT) with different rates on autonomic nervous system responses and self‐reported levels of stress

To characterise self‐reported levels of stress and autonomic responses in healthy humans evoked by different rates of the Paced Auditory Serial Addition Task (PASAT). Fifteen participants performed PASATs with different rates (3·6‐, 2·4‐, 1·6‐ or 1·2‐s intervals) and a control task, in random order. Correct responses, self‐reported levels of stress and autonomic responses to the PASATs were estimated. Increased PASAT rates were associated with decreases in correct responses (P < 0·001) and increases in self‐reported levels of stress (P < 0·001). For autonomic responses, significant changes were seen in 10 variables during 2·4‐s PASAT compared with the respective baseline; however, significant differences in relative changes from baseline were found between the 2·4‐s PASAT and control task only for mean RR‐intervals (P < 0·001), systolic and diastolic blood pressure (P = 0·002 and P = 0·006) and cardiac output (P < 0·001). Regarding comparison between the four PASATs, significant differences in the relative changes from baseline were seen between the 3·6‐s PASAT and faster PASATs, for example mean RR‐intervals, high‐frequency power and respiration rate; however, there were no differences between the faster PASATs. The autonomic responses during the PASATs with different rates were quite similar for the faster PASATs (intervals < 2·4 s); however, the slowest 3·6‐s PASAT evoked significantly less self‐reported stress and autonomic arousal compared with the faster PASATs. Standardization of the PASAT rate may be important for studies on autonomic nervous system function and self‐reported measures of stress. Future studies may test more complex interactions between stress, autonomic responses and pain responses.     

Chlorhexidine gel and less difficult surgeries might reduce post‐operative pain,controlling for dry socket,infection and analgesic consumption: a split‐mouth controlled randomised clinical trial

Reports on post‐surgical pain are a few, controversial and flawed (by statistics and analgesic consumption). Besides, it is not known if chlorhexidine can reduce post‐extraction pain adjusting for its effect on prevention of infection and dry socket (DS). We assessed these. A total of 90 impacted mandibular third molars of 45 patients were extracted. Intra‐alveolar 0·2% chlorhexidine gel was applied in a split‐mouth randomised design to one‐half of the sockets. None of the included patients took antibiotics or analgesics afterwards. In the first and third post‐operative days, DS formation and pain levels were recorded. Predictive roles of the risk factors were analysed using fixed‐effects (classic) and multilevel (mixed‐model) multiple linear regressions (α = 0·05, β≤0·1). In the first day, pain levels were 5·56 ± 1·53 and 4·78 ± 1·43 (out of 10), respectively. These reduced to 3·22 ± 1·41 and 2·16 ± 1·40. Pain was more intense on the control sides [both P values = 0·000 (paired t‐test)]. Chlorhexidine had a significant pain‐alleviating effect (P = 0·0001), excluding its effect on DS and infection. More difficult surgeries (P = 0·0201) and dry sockets were more painful (P = 0·0000). Age had a marginally significant negative role (P = 0·0994). Gender and smoking had no significant impact [P ≥ 0·7 (regression)]. The pattern of pain reduction differed between dry sockets and healthy sockets [P = 0·0102 (anova )]. Chlorhexidine can reduce pain, regardless of its infection‐/DS‐preventive effects. Simpler surgeries and sockets not affected by alveolar osteitis are less painful. Smoking and gender less likely affect pain. The role of age was not conclusive and needs future studies.     

Turned versus anodised dental implants: a meta‐analysis

The aim of this meta‐analysis was to test the null hypothesis of no difference in the implant failure rates, marginal bone loss (MBL)and post‐operative infection for patients being rehabilitated by turned versus anodised‐surface implants, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in November 2015. Eligibility criteria included clinical human studies, either randomised or not. Thirty‐eight publications were included. The results suggest a risk ratio of 2·82 (95% CI 1·95–4·06, P < 0·00001) for failure of turned implants, when compared to anodised‐surface implants. Sensitivity analyses showed similar results when only the studies inserting implants in maxillae or mandibles were pooled. There were no statistically significant effects of turned implants on the MBL (mean difference‐MD 0·02, 95%CI ?0·16–0·20; P = 0·82) in comparison to anodised implants. The results of a meta‐regression considering the follow‐up period as a covariate suggested an increase of the MD with the increase in the follow‐up time (MD increase 0·012 mm year^?1), however, without a statistical significance (P = 0·813). Due to lack of satisfactory information, meta‐analysis for the outcome ‘post‐operative infection’ was not performed. The results have to be interpreted with caution due to the presence of several confounding factors in the included studies.     

Effect of waterpipe smoking on peri‐implant health: A systematic review and meta‐analysis

The aim of the present review was to evaluate the effect of waterpipe smoking (WS) on clinical peri‐implant inflammatory parameters compared to non‐smokers (NS) with dental implants. Literature searches were performed using bibliographic databases up to May 2018. Primary outcomes included peri‐implant bone loss (PIBL), while secondary outcomes were probing depth (PD), plaque index, and bleeding on probing. Relative risk (RR) and 95% confidence intervals (CI) for each PIBL and PD were estimated by a random‐effect model. Four retrospective case‐control studies were included in the qualitative and quantitative syntheses. All of the included studies showed statistically‐significantly worse peri‐implant outcomes in WS compared to NS. Considering the effects of WS on peri‐implant parameters, significant heterogeneity for PIBL (Q‐value = 34.21, P < 0.0001, I² = 94.16%) and PD (Q‐value = 51.97, P < 0.0001, I² = 96.15%) was observed between both groups. The overall RR for PIBL (RR = 3.32, 95% CI = 1.01‐3.97, P = 0.001) and PD (RR = 3.40, 95% CI = 1.91‐7.17, P = 0.001) were significant between WS and NS groups. WS has detrimental effect on peri‐implant health. Clinicians should instruct and advise patients about poor prognosis and peri‐implant diseases caused by WS.     

The effect of implant placement in patients with either Kennedy class II and III on oral health‐related quality of life: a prospective clinical trial

There is little evidence of the effect of implants restored with fixed partial dentures on oral health‐related quality of life (OHRQoL) in partially edentulous Kennedy class II and III patients. The aim of this study was to determine the change in OHRQoL in Kennedy classification II and III patients treated with a two‐implant‐supported fixed dental prosthesis (FDP). Kennedy class II and III patients received dental implants and an FDP. Oral health‐related quality of life was measured by administration of the Oral Health Impact Profile‐14 (OHIP‐14NL) questionnaire at intake (T1), 2 weeks after surgery (T2) and after 1 year of loading (T3). The mean OHIP score at T1 was 6·5 ± 1·2, 2·4 ± 1·0 at T2, and 0·9 ± 0·3 at T3. There was a statistically significant difference between T1 and T2 (P = 0·002) and T1 and T3 (P < 0·001) but not between T2 and T3 (P = 0·407). The OHIP score in Kennedy II patients decreased from 4·8 ± 3·2 at T1 to 1·5 ± 2·0 at T2 and 1·1 ± 1·8 at T3, and that in Kennedy III patients decreased from 8·9 ± 9·6 at T1 to 3·6 ± 8·9 at T2 and 0·8 ± 2·2 at T3. There were no statistically significant differences in the reductions in Kennedy II and III patients. Oral health‐related quality of life changed positively in patients treated with implants and an FDP in both groups. There was no change in OHRQoL between the times of implant placement and FDP placement.     

Serum albumin levels and 10‐year tooth loss in a 70‐year‐old population

Serum albumin levels are a practical marker of general health status in the elderly and have been used to determine the severity of underlying diseases and the risk for death. This longitudinal study evaluated the relationship between serum albumin concentrations and tooth loss over 10 years in elderly subjects, after controlling for confounding factors. A sample of 554 dentate subjects among enrolled subjects (n = 600) was involved in this planned longitudinal study with follow‐up examinations after 5 and 10 years. At the 5‐year follow‐up, 373 (67·3%), subjects were available for re‐examination. In addition, 331 (59·7%) were available at the 10‐year follow‐up. Multiple Poisson regression analysis was conducted to evaluate the relationship between the number of missing teeth over 5 or 10 years and serum albumin levels at baseline after adjusting for 10 variables: gender, serum markers levels at baseline, dental status, smoking habits and educational years and oral health behaviour. The number of missing teeth over 5 or 10 years was significantly negatively associated with serum albumin levels at baseline [incidence rate ratios (IRR) = 0·373, P < 0·0001 for 5 years; IRR = 0·570, P < 0·0001 for 10 years]. We conclude that elderly subjects with hypoalbuminemia are at high risk for 5‐ and 10‐year tooth loss.     

Posterior scissors‐bite: masticatory jaw movement and muscle activity

Scissors‐bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case–control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors‐bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors‐bite malocclusion and 18 subjects with normal occlusion in a case–control study. The chewing pattern on the scissors‐bite side significantly differed from that of the non‐scissors‐bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0·01; cycle width, P < 0·01), a longer closing duration (P < 0·05), a slower closing velocity (P < 0·01) and lower activities of both the temporalis (P < 0·05) and the masseter (P < 0·05) muscles on the working side. In 96% of the patients with unilateral posterior scissors‐bite, the preferred chewing side was the non‐scissors‐bite side (P = 0·005). These findings suggest that scissors‐bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors‐bite.     

Maximum bite force following unilateral implant‐supported prosthetic treatment: within‐subject comparison to opposite dentate side

Bite force is a significant component of chewing and masticatory function. The literature lacks studies that compare bite force values of implant‐supported fixed bridges to natural dentition within same subjects. The objective of the study was to assess maximum occlusal bite force (MBF) among patients with an implant‐supported fixed prosthesis and compare it to their opposite dentate side and also to determine the effect of gender, age and Body Mass Index (BMI) on maximum occlusal bite force. Forty patients (20 males and 20 females, mean age = 42·7 ± 9·6 years) with an implant‐supported fixed prosthetic rehabilitation on one side and dentate on the other side were recruited into this study. Participants' MBF were measured bilaterally at the first molar region using a digital hydraulic occlusal force gauge (GM10). The measurements were repeated three times (with 45 s intervals between times) for each side, and the highest value of the bite force (MBF) was recorded for each side. The mean MBF was 577·9 N at the implant‐supported prosthesis side and 595·1 N at the dentate side. The average MBF was higher at the dentulous side (P < 0·05). Maximum occlusal bite force was higher in males and participants with higher weight and height. However, BMI was not significantly related to MBF values. Maximum occlusal bite force values at the dentate side were slightly (3%) but significantly higher than MBF at implant‐supported prosthesis side. Males, taller patients and patients with higher weights had higher MBF values. Body mass index was not significantly related to MBF values.     

Dental implant loss in older versus younger patients: a systematic review and meta‐analysis of prospective studies

The aim of this systematic review was to evaluate implant loss in younger and older patients. An electronic search of four databases (MEDLINE, EMBASE, SCOPUS and the Cochrane Library) was undertaken until May 2016 without time restriction and was supplemented by manual searching. Prospective cohorts were included if they met the following criteria: (i) presence of an exposed group (older subjects) with a minimum age of 60 years; (ii) presence of a control group (younger subjects) with a maximum age of 59 years; and (iii) outcome data considering implant survival or loss. Meta‐analyses were performed to evaluate the impact of ageing on implant failure. Of 4152 potentially eligible articles, four were included in the qualitative analysis and quantitative synthesis. The pooled estimates suggest that the risk of implant loss in older patients is not significantly higher (RR = 0·92; 95% CI 0·43–1·96, P = 0·83) when compared to younger subjects. This systematic review suggests that age is not a limiting factor for dental implant therapy.     

Recognition of patient‐reported impairment in oral aesthetics

The objectives of this study were to investigate the degree of effective recognition by professionals of patient‐estimated oral aesthetic impairment and the most reliable aspects in such recognition. Participants consisted of 95 patients with partial dentition in need of prosthodontic replacements. The oral aesthetics was professionally evaluated using the Prosthetic Esthetic Index (PEI), compiling 13 aesthetic aspects and an overall evaluation. The patient‐reported impairment was evaluated using the Oral Health Impact Profile Aesthetic (OHIP‐Aes) and the Oral Esthetic Scale (OES). Background variables were as follows: gender, age, work situation, education level, marital status, number and location of teeth, wearing a removable dental prosthesis (RDP) and smile line. A significant correlation was found between the overall professional evaluation and the OHIP‐Aes score (R = 0·43, P < 0·05), the OES score (R = 0·46, P < 0·05) and the overall patient evaluation (0·35, P < 0·05). Correlations of the 13 specific aspects of the PEI with the patient‐reported evaluations were generally small to moderate: the aspect ‘discoloration of the teeth’ showed the highest correlation. The multivariate analyses showed that up to 57% of the patient‐reported impairment could be explained by the professionally evaluated oral aesthetic in combination with background variables. Discoloration of the teeth was the greatest explanatory variable, but also dental arch symmetry, and position and colour of the teeth were significant aspects. A high percentage of the patient‐reported aesthetic impairment can be recognised by the professionals. The most reliable aspect is discoloration of the teeth, but also dental arch symmetry, and the position and colour of the teeth are important for recognising the aesthetic impairment.     

Free amino acids in stimulated and unstimulated whole saliva: advantages or disadvantages

This study determines the mean concentrations of free amino acids in stimulated and unstimulated whole saliva in healthy young adults. Standardised salivary amino acids as a substitute for their counterpart in blood, searched for the source of free amino acids in saliva, the probable correlation between particular amino acids with caries experience. Stimulated and unstimulated whole saliva were collected by the draining method in 31 dental students. Saliva was purified, and amino acids were separated by high‐performance liquid chromatography. DMFT scores were recorded, and the relation of amino acids to caries experience was explored by generalised linear model. Almost all amino acids had higher concentration in unstimulated whole saliva than in stimulated saliva. The normal range of amino acids (95% CI) and their natural logarithm were defined. There was a significant relationship between caries experience and threonine (P < 0·008), citrulline (P < 0·023) and ornithine (P < 0·001) as a detrimental factor, whereas serin (P < 0·026), glutamine (P < 0·015) and phenylalanine (P < 0·014) had an inhibiting effect on caries. However, in comparison, salivary flow rate (P < 0·013) was a more preventive factor than amino acids. Amino acids in saliva contribute as a marker, instead of their counterpart in blood. Unstimulated saliva had higher concentration of amino acids. Amino acids have different impact on caries and may be one of underlying risk factors for caries experience.     

Gastric emptying rate in subjects with malocclusion examined by [13C] breath test

Masticatory function is significantly lower in individuals with malocclusion than in those with normal occlusion. Although several studies suggest that masticatory function influences gastrointestinal digestive function, the relationship between malocclusion and gastrointestinal symptoms has not been studied extensively. We hypothesised that insufficient masticatory function would increase the functional burden of the stomach and have some influence on the gastrointestinal system. The purpose of this study was to investigate masticatory function and gastric emptying rate in subjects with malocclusion. Eleven healthy dentate female volunteers and eleven female patients with maloc‐clusion underwent a ¹³C‐acetate breath test with a liquid meal. Maximum ¹³CO₂ exhalation time (T_max) was compared statistically between both groups. Masticatory function was assessed by colour‐changeable chewing gum. In addition, the frequency scale for the symptoms of gastroeso‐phageal reflux disease (FSSG) and questionnaires on food intake were given to both groups. The mean T_max of the malocclusion group was significantly longer than that of the normal occlusion group (P = 0·007). Masticatory performance, measured by colour‐changeable gum and questionnaires, was significantly lower in the malocclusion group than in the normal occlusion group (P = 0·023, P = 0·003). There was no significant difference in the FSSG results between the two groups (P = 0·262). This study suggested that there was a correlation between malocclusion and gastric emptying function in women.     

Effect of implant‐supported prosthesis on the bite force and masticatory efficiency in subjects with shortened dental arches

The aim of the study was to assess changes in bite force and masticatory efficiency in shortened dental arch (SDA) subjects rehabilitated with implant‐supported restoration for 1st molar. Ten SDA subjects with bilaterally missing mandibular molars (experimental group) were recruited. In each subject, one tapered threaded implant was placed bilaterally in 1st mandibular molar region and restored. Masticatory efficiency was evaluated objectively by measuring the released dye from chewed raw carrots, with a ‘spectrophotometer’ at 530 nm preoperatively and at 3 months after restoration. Bite force was evaluated using ‘bite force measuring appliance’ preoperatively, at 6 weeks and at 3 months after restoration. Ten completely dentate‐matched subjects (in terms of age, sex, height and weight) acted as control. The results revealed that as compared with the control group, the experimental group showed significantly less (P < 0·05) mean maximum bite force at pre‐restoration and at 6 weeks after restoration. Although at 3 months the mean maximum bite force value was less than the control group but the mean difference was statistically insignificant. The mean difference of masticatory efficiency between control and experimental group was statistically significant (P < 0·05) before restoration, but was statistically insignificant at 3 months after restoration. Thus it was concluded that after the restoration of mandibular arch with implant‐supported prosthesis, both bite force and masticatory efficiency of all SDA subjects increased and were comparable to that of matched completely dentate subjects after 3 months.     

Long‐term subjective tongue function after partial glossectomy

There have been limited studies of subjective tongue function over long‐term follow‐up in spite of swallowing and articulation disorders are common complications of glossectomy. To assess long‐term subjective swallowing and articulation function after partial glossectomy. A total of 63 patients with the mobile tongue cancer who underwent partial glossectomy without reconstruction were interviewed to score their swallowing and articulation function on a 100‐point scale. The relation of this subjective scoring to the perioperative data was subjected to multivariate analysis. The mean patient age was 53·4 (19–81) years, and the mean follow‐up duration was 78·9 (14–277) months. Mean swallowing and articulation function score was 87·7 ± 6·1 and 88·6 ± 5·4. Age, follow‐up duration, T stage and resection volume were significantly correlated with swallowing function (P = 0·026, 0·029, 0·016, 0·002, respectively); follow‐up duration was correlated with articulation function (P = 0·039). Patients who undergo partial glossectomy without reconstruction generally demonstrate good function on long‐term follow‐up. Subjective dysfunction was correlated with larger resection volume, older age and shorter follow‐up duration.     

Improvement in patients with a TMD‐pain report. A 6‐month follow‐up study

Even though chronic TMD pain tends to persist in most patients, some chronic patients show improvement. It is largely unknown which factors contribute to the improvement of chronic pain. The aim of this study is to investigate which factors, from a biopsychosocial perspective, help to predict improvement in patients with a report of TMD pain. Methods: Subjects with a report of TMD pain were recruited in seven TMD clinics. They received a baseline questionnaire which included a wide range of possible predictors for improvement. After 6 months they received a follow‐up questionnaire which included a measure to determine which participants were ‘improved’ or ‘not improved’. To study which predictive variables were associated with improvement, multiple regression models were built. Results: From the 129 patients who responded to the baseline questionnaire, 100 patients also filled in the follow‐up questionnaire (85% women, mean age (years) ± s.d. = 46·0 ± 13·8). Fifty percentage of these subjects had improved at the 6‐month follow‐up. Pain duration was the strongest (negative) predictor for 6‐month improvement (P = 0·009). Also the number of care providers (P = 0·017) and the degree of hindrance on function (P = 0·045) helped to predict improvement. Conclusions: The duration of the TMD‐pain complaint, the number of care practitioners attended and the degree of hindrance on function (negatively) helped to predict 6‐month improvement. No evidence is found to support the role of psychological or social factors on the improvement in patients with a report of TMD pain.